NSTA Story of Sci Einstein

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The Story of ScienceCLASSROOM COMPANIONE i n s t e i n A d d s a N e w D i m e n s i o n

J U L I A N A T E X L E Y

Arlington, Virginia

T E A C H E R E D I T I O N

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Resources for Integration and Implementation ..............................................................iv

A Note From Joy Hakim ...................................................................................................vii

11: A Boy With Something on His Mind .................................................................................1

12: Time on Replay .................................................................................................................... 4

13: Electrifying Thoughts and Magnetic Reasoning .............................................................. 7

14: The M. and M.’s of Science ............................................................................................... 10

15: Invisible Bits of Electricity .................................................................................................. 12

16: Smaller Than Atoms? Subatomic? Is This a Joke? ........................................................... 15

17: Nobel Marie ........................................................................................................................ 17

18: Mysterious Rays .................................................................................................................. 19

19: Making Waves ....................................................................................................................22

10: Five Papers ..........................................................................................................................25

11: Seeing the (Photon) Light .................................................................................................28

12: Molecules Move .................................................................................................................30

13: Getting the Picture Right ..................................................................................................32

14: Getting Atom .....................................................................................................................35

15: Still Shooting Alpha Particles ...........................................................................................38

16: Bohr Taking Quantum Leaps ..........................................................................................40

17: An American Tracks Photons; a Frenchman Nails Matter ...........................................43

18: What’s Uncertain? Everything, Says Heisenberg ...........................................................45

19: A Cat, Quarks, and Other Quantum Critters ...............................................................47

20: Smashing Atoms ................................................................................................................50

21: Chemistry, Charisma, and Peace .....................................................................................52

22: Energy Equals Mass Times the Square of the Speed of Light or E=mc2 .......................55

23: On the Way to War (a List of Happenings) ....................................................................57

24: The Fission Vision ............................................................................................................59

table of contentsT E A C H E R E D I T I O N

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25: Presidential Power ..............................................................................................................63

26: Manhattan on a Mesa .......................................................................................................65

27: Quantum Electrodynamics? Surely You’re Joking .........................................................68

28: Those Relatives: Galileo and Albert ................................................................................70

29: Relativity: It’s About Time ...............................................................................................72

30: An Event? To a Physicist It’s Not a Party .........................................................................74

31: Timely Dimensions ...........................................................................................................76

32: A Man in a Red Hat .........................................................................................................78

33: The Paradox of the Twins .................................................................................................80

34: Relative Gravity ..................................................................................................................82

35: Warps in Spacetime ..........................................................................................................84

36: Does It Change? Or Is It Changeless? .............................................................................87

37: Expanding Times ..............................................................................................................89

38: An Expanding Universe ...................................................................................................92

39: A Luminous Indian ..........................................................................................................94

40: Explosive? And How! ........................................................................................................96

41: Singular Black Holes .........................................................................................................99

42: Gravity Waves? ..................................................................................................................102

43: A Singular BANG With a Background .........................................................................104

44: Inflation? This Chapter Is Not About Economics! .......................................................107

45: Entanglement? Locality? Are We Talking Science? ........................................................ 110

46: Super Stars ......................................................................................................................... 112

47: A Surprising Information-Age Universe .........................................................................116

48: Is Anyone Out There? .......................................................................................................118

49: This Is the Last Chapter, but It’s Not the End ..............................................................120

References .........................................................................................................................122

table of contentsT E A C H E R E D I T I O N

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In 1996, the National Science Education Standards (NSES) made a bold and impassioned plea for scientific literacy, or “the knowledge and understanding of scientific concepts and processes required for personal decision making, participation in civic and cultural affairs, and economic productivity” (NRC 1996, p. 22). Moving away from the idea that science is for the elite, the authors of NSES defined the content, skills, and attitudes that were necessary for every citizen. Under this umbrella they included language arts skills, which were almost exclusively associated with the idea of “literacy” before the Standards expanded its definition.

In the years since the publication of NSES, the inclusion of language arts literacy skills into science and across the curriculum has been heavily emphasized. There has also been an effort to assess student achievement in informational reading, often using selections from textbooks as prompts. While research reaffirms the value of reading about science, quality science literature remains a rare find. Despite the best efforts of teachers, reading about modern physics has seldom been fun or motivating—not until the publication of Joy Hakim’s series The Story of Science.

Einstein Adds a New Dimension, Hakim’s third volume, is unique in both its content and its value as an outstanding science trade book. Enjoyable reading about modern physics may seem like an oxymoron—until you open to the first page. Reviewers have called Hakim’s prose some of the most exciting and accurate in the field. This great expository writing can become the foundation of an integrated program that infuses the knowledge, skills, and attitudes of scientific literacy across the curriculum.

With inspiration from the real scientists in the story, as well as their creative biographer Hakim, you can show your students the future. Please consider the ideas that follow simply as clues that can help you expand the potential of Einstein Adds a New Dimension in your school program.

Using Einstein Adds a New Dimension in the ClassroomThe Story of Science series is first and foremost good literature—trade books that are designed to spark the curiosity of students. Both the biographies of scientists and the descriptions of their experiments are meant to light fires in young minds. So the first recommendation for the use of Einstein Adds a New Dimension is read and enjoy!

The books represent fascinating informational reading. The format and text elements lend themselves to the teaching of informational reading skills in 7th- through 12th-grade language arts courses. However, the content of The Story of Science is, of course, science—that is, not just a body of facts but a process and way of knowing. So the reading must be inextricably linked to exploration and inquiry. Whether the books are used as the skeleton of a program or as support, they must be accompanied by hands-on exploration.

Resources for Integration and Implementation

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There are also mathematics and social studies links everywhere in these books, with tempting invitations to follow them to new adventures. Those unique features have made The Story of Science volumes very popular with schools that have developed integrated multisubject blocks, as well as with homeschool communities, where the boundaries between subjects are not as sharply defined as in traditional school programs.

The level of content and the minimal mathematics that are woven into Einstein Adds a New Dimension connect most easily to an integrated physical science program in grades 7 through 10, but the content in modern physics is every bit as rich as that found in most textbooks written for students in grades 11 through 13.

Both the Teacher and Student editions of this guide correspond chapter by chapter to Einstein Adds a New Dimension and offer1

• classroom demonstrations and activities that engage students in inquiry-based science lessons;

• original quotes2 from well-known scientists that help students explore concepts in greater depth by connecting big scientific ideas to scientists’ individual experiences;

• lists of important science terms that also can be used to explore concepts in greater depth; • links to web resources that encourage active learning and help explain content;• links to informational sites, where students can pursue independent research and elaborate

on their understandings; and • writing prompts through which to evaluate students’ understanding.

In addition, the Teacher Edition also provides

• short synopses of each chapter;• teaching tips for clarifying misconceptions and encouraging further inquiry; • answers to the activity questions; and• resources for further reading to expand background knowledge (or, perhaps, to recommend

to precocious students).

The guide for teachers provides selected examples of the type of innovative ideas and activities from which professionals might develop a program that meets the needs of their particular students. Activities were selected for ease of implementation and are limited to those that involve a minimum of expensive equipment. In addition, wherever possible, mathematics, geography, and history notes are included so that the text can easily be integrated into subject areas other than science. Many of the activities are interchangeable since this story of science moves back and forth through time, space, and the physical universe. How education professionals add these “new dimensions” to their school’s curriculum will ultimately depend on the unique characteristics of their learning communities.

1 In these components, we have referenced the “5 E” model for an inquiry-based lesson developed in 2006 by the Biological Sciences Curricu-lum Study. See the report “The BSCS 5E Instructional Model: Origins, Effectiveness, and Applications.”

2 Many of the translations of these passages have been taken from Stephen Hawking’s collection On the Shoulders of Giants (2003).


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National Science Education StandardsEinstein Adds a New Dimension provides a great path to language arts literacy in the context of science. It’s important to recognize that this cluster of skills is only one component of science literacy. The text also interweaves content from a variety of areas defined by the NSES. While many teachers will use this book successfully as part of a middle school program, most will find the book and the program built around it to contribute to achievement of these 9th- through 12th-grade standards:

Area Standard

A. Science as Inquiry (p. 143)Abilities necessary to do scientifi c inquiryUnderstandings about scientifi c inquiry

B. Physical Science (p. 176)

Structure of atomsStructure and properties of matterMotions and forcesConservation of energy and increase in disorderInteractions of energy and matter

D. Earth and Space Science (p. 187)

Energy in the Earth systemOrigin and evolution of the universe

E. Science and Technology (p. 190)

Abilities of technological designUnderstandings about science and technology

F. Science in Personal and Social Perspectives (p. 193)

Science and technology in local, national, and global challenges

G. History and Nature of Science (p. 200)

Science as a human endeavorNature of scientifi c knowledgeHistorical perspectives

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The teacher was young, intense, and very bright. I had just given a talk, and she stayed to continue the conversation, telling me about a science lesson she had taught a few months earlier. She had led her students from experimentation, to discussion, to written analysis and, at the time, thought it was the best teaching she had ever done. So six weeks later, when her students were given a standardized test, she knew they would all get the correct answer to the question that dealt with the material she had taught on that inspired day. As it happened, not one student got it right. And when she spoke to some of them about the material, they hardly remembered her wonderful lesson.

She was baffled and asked if I had an explanation for her. She wondered, How do we make science stick? How do we take those terrific hands-on activities and help students turn them into concepts that they will hold in their minds?

The quick answer is not easily. Finding ways to help form retentive, thinking minds is a central educational challenge, especially today when knowledge, and the ability to find and use it, is key to success in almost every field of endeavor. Science, perhaps more than any other subject, seems to offer unique opportunities for mental stretching, and yet it’s a subject that misses much of the school population. Why isn’t contemporary science permeating curricula? Why are so many of our school graduates “scientifically illiterate”? How can adults with prestigious diplomas in languages, literature, or law consider themselves educated if they are without a basic understanding of modern physics or chemistry? Does it matter? Is broad scientific literacy really important?

Yes. We live in what is probably the greatest scientific era ever. The 20th century was a golden age for physics; we’re in the midst of a golden age of cosmology; biophysics is coming on fast. Anyone without basic knowledge of those sciences is missing the intellectual underpinnings of our time. And yet that describes much of our population.

But aren’t today’s sciences very difficult? Aren’t they only understandable to an intellectual elite? No question, the mathematical specifics of quantum theory and relativity (the two great physical science concepts of the modern era) are beyond many of us. But the overarching ideas are not.

Do these sciences impact our everyday world? You bet. We wouldn’t have TV, computers, or cell phones if we hadn’t delved into the quantum world. We wouldn’t have GPS or space travel without general relativity. As to cosmology, it now takes us back—with stunning specifics—almost to the moment of creation. Recently we learned, with measured precision, the direction the universe is heading. The search for alien life, once the domain of science fiction, is now mainstream. School science is boring? Maybe we’ve been leaving out the good stuff.

In Einstein Adds a New Dimension you’ll struggle with some astonishing concepts. Much of modern science is counterintuitive. It doesn’t seem to make sense. That makes it challenging, and also—to use an appropriate cliché—mind-blowing. Science is a critical-thinking subject. It’s an analytical-reading


a note from joy hakim

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a nOTE fROM jOY hAKIM

subject. It’s a stretch-your-mind subject, and we’ve been missing its potential. There are political implications: Leadership in science translates into world leadership. Science is now too important to be left just to scientists.

So what do we do? We consider science as a reading and thinking subject—without eliminating the traditional experiment-based approach. How can we possibly add anything else to the curriculum? We don’t. We do some rethinking of the literary arts (and maybe social studies, too). Today’s dominant literary form is narrative nonfiction. And some of the most creative nonfiction is coming from science writers. We’re proposing that you consider science as both a reading subject and a doing subject.

Then science becomes a several-bangs-for-your-buck endeavor. Link activities to a narrative and you will teach subject matter as you hone reading and thinking skills. There’s an important bonus: Educational psychologists tell us that students are likely to remember facts woven into a story. Our experience tells us that reading comprehension scores go up with vocabulary-rich narrative nonfiction. It’s the classic approach to teaching.

From Homer to McGuffey’s readers, stories are the way that cultures have traditionally passed on their most important ideas. In recent times, we’ve gotten away from storytelling. The very word story has been given a negative connotation—“Don’t tell me a story, tell me the truth.” But the best stories are true. And we all know that truth is stranger than fiction.

Why did Dutch police set out after Daniel Fahrenheit when he wanted to build a thermometer? What happened when Niels Bohr tried to climb up a bank building in Copenhagen? What famous American physicist was a prankster skilled at cracking safes? Science is boring? No way. Einstein Adds a New Dimension takes the scientific adventure into the 21st century (it began in ancient Greece in Aristotle Leads the Way and journeyed into the world of classical physics with Newton at the Center).

Schools talk a lot about multidisciplinary learning, and The Story of Science books are intended to help make it possible. Ideally, science, language arts, history, and math teachers will use the books in a joint exploration. However, if no team is available and you’re on your own with the books, just put on multiple hats. Science is an arena in which everyone can become an explorer.

You don’t feel secure with the material covered? So much the better. You won’t be tempted to lecture. Create an environment in which you and your students learn together. Let them become the experts. They’ll love taking that role. These books were written with the hope that you and your students would question, research, discuss, and write—thus honing essential information-age skills.

Science is an unending search for answers; the best scientists are those who learn to pose challenging questions. This teachers guide and accompanying student pages will ease you and your students into the process. We expect you to embark together on an adventure for your minds. Hardly anything is as intellectually satisfying as today’s science.

Intro.


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The young Albert Einstein was often distracted in school

by his active curiosity. His teachers often saw this creativity

as laziness. He was fascinated by mathematics, music, and

especially the laws that guided the physical phenomena

around him. He tried to imagine “riding on a beam of light,”

a challenge that would eventually result in the development

of the Special Theory of Relativity when he was only 26.

a boy with something on

his mind

Teaching TipIn this introductory chapter, it is important for students to identify with Einstein as a person in order to find the qualities of a scientist in themselves. Ask students: “Does Einstein remind you of yourself? If so, how? Is there anything Einstein did that seems like something you might do?”

Exploring the UnseenScientific literacy means “that a person can ask…questions derived from curiosity about everyday experiences” (NRC 1996, 22). A study of Einstein’s world can begin by questioning what may have been taken for granted. First ask students to brainstorm: “What forms of radiation or unseen forces are in the room?” Begin a chart like the one below, in which students track evidence for unseen waves. Students shouldn’t have difficulty with the first few entries, but filling in the entire chart may require additional reading and research. Collate class responses. Continue to fill in this chart as you and your class read further in the book. (Sample answers are provided in bold.)

Radiation Instrument What Stops It?

Visible light Eyes Anything opaque

Ultraviolet UV-sensitive materials Anything opaque, some

chemicals with SPV ratings

Infrared Thermometer

IR goggles

Insulators

Radio Any radio receiver Very thick concrete walls

Microwaves Some cell tower

communications

Relatively thin walls of

microwave ovens

1



a boy with something on his mind1

Next, students can explore the unseen world of radiation using a traditional AM radio with a rotating (analog) dial. AM radio waves are longer than FM waves, so reception can be affected by electromagnetic radiation, including solar flares and terrestrial storms. AM waves bounce off the D layer of the ionosphere, which is lower at night. With students, cover the AM radio dial with a round, white sticker to avoid possible confusion (the AM frequencies are different from the range and limits they are recording), and then identify an area near the bottom of the AM range where no distinct channels exist. Have students check this range every day at the same time for the presence of static. A simple sound meter can be used to quantify the volume. Students may want to compare the range of AM signals at night or correlate results to sunspots.

VocabularyDynamo• Electromagnetic radiation•

Online Learning ToolsElectric Force Fields www.colorado.edu/physics/2000/waves_particles/wavpart3.htmlThe Electromagnetic Spectrum http://science.hq.nasa.gov/kids/imagers/ems/waves3.htmlTuning a Radio Receiver http://micro.magnet.fsu.edu/electromag/java/radio

For Further InvestigationNASA AM Radio Ionosphere Station http://lasp.colorado.edu/education/space_weather/files/middle/AMRadio.pdfNASA IMAGE Education Center http://image.gsfc.nasa.gov/poetry/activities.htmlRadio Waves: FM vs. AM www.teachersdomain.org/resources/phy03/sci/phys/energy/amfm/index.htmlSpace Weather (Graphing Sunspot Data) www.solarstorms.org/Strends.html

Photo courtesy of the author.


a boy with something on his mind1


Extended ReadingDelano, M. F. 2005. Genius: A photobiography of Albert Einstein. Washington, DC: National Geographic.

Evaluation The student page presents the following scenario as a tool for assessing student understanding of radiation:

“In school, Einstein was fascinated with statistics, a branch of mathematics about analyzing data” (Hakim 2007, p. 7). Some astronomers believe that there is a correlation between sunspot frequencies and global temperatures. Look at this National Oceanic and Atmospheric Administration graph. Then write a short news article describing both what you see and the limitations of what you can infer.

Source: Rodney Viereck, NOAA Space Environment

Center, NOAA Research, “The Sun-Climate Connection

(Did Sunspots Sink the Titanic?)” www.research.noaa.gov/

spotlite/archive/spot_sunclimate.html.

When evaluating the student news articles, make sure students included factual information (paraphrasing the data), inferences (interpreting the data), and limitations (what scientists do not know about the data).


time on replay

The reader sprints through hundreds of years of science,

considering how ideas form the foundation for more

ideas. The timeline begins with a revolutionary attitude

change—the idea that an experiment could provide new

understanding, even if it contradicted traditional wisdom.

This change wasn’t easy and often caused the experimenter

to get into trouble with society’s traditionalists.

2T E A C H E R E D I T I O N

Teaching TipsBegin a classroom timeline with photos of key scientists mentioned in each chapter (images are almost always available online in a format that can be enlarged). Encourage students to identify world events unrelated to science that occurred during the lives of key researchers. This chapter discusses compasses. Have students follow a compass trail to a “treasure” on the schoolyard. Many students who have grown up in the age of GPS have never used a compass.

Table Tricks and TalkStudents can complete the following experiment at home. Students begin by using a hole punch to make tiny punches of newsprint or other nonglazed paper (salt and pepper can also be used in place of the paper). Next, students rub a plastic straw on their heads, and then bring the straw near the paper punches (or salt and pepper). Students are asked to describe what happens in words and drawings (a sample description is provided in bold.) When the straw is brought near the paper, the charge on the straw induces a charge on the paper. The force of the charge is greater than the force of gravity, so the paper “jumps” to meet the straw. If the paper touches the straw, they share the charge. The paper dot may then induce a charge in the next dot of paper by repelling similar charges. Students are then asked to explain to family members what is happening without using words or concepts unfamiliar to people in 1905. For example, the phenomenon they observe, static electricity, would have been familiar to Pieter van Musschenbroek or Benjamin Franklin. But van Musschenbroek or Franklin could not have supported their explanations by any discussion of electrons because electrons had not been discovered yet. (A sample student explanation is provided in bold.) A charge from hair changes the charge on the paper. Like charges repel one another; opposite charges attract.

In Their Own WordsThis chapter discusses Nicolaus Copernicus’s (1473–1543) amazing statement that Earth orbits the Sun. Read aloud the following excerpt in which the Danish astronomer claims that the Sun, Moon, and the planets obey the same laws of physics as Earth:

The apparent irregular movement of the planets and their variable distances from the Earth—which cannot be understood as occurring in circles homocentric with the Earth—


time on replay2


make it clear that the Earth is not the centre of their circular movements. Therefore, since there are many centres, it is not foolhardy to doubt whether the centre of gravity of the Earth rather than some other is the centre of the world. I myself think that gravity or heaviness is nothing except a certain natural appetency implanted in the parts by

the divine providence of the universal Artisan, in order that they should unite with one another in their oneness and wholeness and come together in the form of a globe. It is believable that this affect is present in the sun, the moon, and other bright planets and that through its efficacy they remain in the spherical figure in which they are visible, though they nevertheless accomplish their circular movements in many different ways.

—Copernicus,On the Revolution of Heavenly Spheres

Although students may struggle with this excerpt, they will be able to infer meaning even if they don’t understand every word.

VocabularyAtomic mass• Element• Compound• Microgravity•

Online Learning ToolsAncient Observatories: Chaco Canyon www.exploratorium.edu/chacoForce and Work Applet http://lectureonline.cl.msu.edu/~mmp/kap5/work/work.htmMagnetism www.edumedia-sciences.com/m198_l2-magnetism.htmlScience, Civilization, and Society www.es.flinders.edu.au/~mattom/science+society/index.html

For Further InvestigationCool Experiments With Magnets http://my.execpc.com/~rhoadley/magindex.htm

Extended ReadingBen Franklin’s Lightning Bells http://sln.fi.edu/franklin/bells.htmlThe Fat Boys (TIME, September 3, 1979) www.time.com/time/magazine/article/0,9171,948608,00.html



TIME ON REPLAY2

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of magnetism:

Dartmouth archaeologist Vincent H. Malmström found 4,000-year-old statues in Central America with a very unusual property. A compass needle is sharply attracted to their navels! The pre-Olmec people seem to have discovered magnetism some 1,500 years before the earliest evidence of Chinese compasses. Other archaeologists have found Olmec statues of frogs and turtles with magnetic snouts dating from about 3500 BC. What can be hypothesized about their function?

Students’ responses should demonstrate an understanding of magnetism as a property of certain metals. Possible hypotheses include the following: (1) The statues may have been used to create/magnetize compasses, and (2) the Olmecs might have considered magnetism a religious phenomenon.

Photo taken by Hajor, July 2001. Released

under cc.by.sa and/or GFDL.


From Volta to Tesla, scientists looked for connections

between electricity and magnetism. Scientists made great

leaps of understanding in the 19th century but also arrived

at a few experimental dead ends—from ether to Edison’s

work with direct current. 3Electrifying

Thoughts and Magnetic

ReasoningT E A C H E R E D I T I O N

Teaching TipsMany young students hold misconceptions about electricity. They have special difficulty distinguishing between voltaic and current electricity. Remind students that a “battery” is actually a series of cells. The “In Their Own Words”quote from Isaac Newton (see p. 8) is worth repeating in later discussions. When students know more about relativity, ask one student to act as Newton and repeat his basic assumptions. This may help students contrast their own physical experiences with the truths in Einstein’s universe. After students have speculated on the “Evaluation” challenge below, you might share with them that President Theodore Roosevelt sent the first message around the world in 1903. It took nine minutes.

A Pile of Money Most students have the raw materials in their pockets to replicate Alessandro Volta’s electricity experiment. Before class begins, however, you will have to add 15 g of salt to 200 ml of vinegar. Divide students into groups and ask each group to collect six pennies and six nickels. Give each group 10 ml of the solution in a labeled plastic container. Each group will also need safety goggles, one sheet of paper towel, and forceps. You will also need two 30 cm pieces of insulated wire and at least one voltmeter. Have each group cut their paper towels into 3 cm squares. Each group then places a nickel on the table. Next, they soak one of the squares of paper towel in the saltwater solution and place it on top of the nickel. Then they add a penny on top of the paper towel, put another saltwater-soaked square of paper towel on top of that, and add another nickel. Students continue alternating the paper towels and coins until all the coins are used. You can then test the pile by touching one wire from the voltmeter to the top (penny) and one to the bottom (nickel). After the experiment, ask students the following questions (answers in bold):

1. What kind of current is generated? Direct current

Once a base value is obtained for the “battery,” encourage students to investigate further:

2. Does the current increase if more coins are used? Yes. More coins, more current.



Electrifying Thoughts and Magnetic Reasoning3

3. What if more salt is added? There is a limit to the increase affected by salt.

The results of these experiments should ideally be shown in graphs.

In Their Own WordsIsaac Newton (1642–1727) was renowned for proposing seemingly immutable laws for the motion of everything in the universe. In his world, everything stayed in place without the action of an unbalanced force. Read the following excerpt, and then ask students, “Could Newton have imagined Einstein’s relativity?”

Absolute time, in astronomy, is distinguished from relative, by the equation or correction of the vulgar time. For the natural days are truly unequal…It may be that there is no such thing as an equable motion whereby time may be accurately measured. All motions may be acceler-

ated and retarded, but the true, or equal progress of absolute time is liable to no change. The duration or perseverance of the existence of things is liable to no change…As the order of the

parts of time is immutable, so also is the order of the parts of space. Suppose those parts to be moved out of their places…all things are placed in time as to order of succession; and in space as to order of situation. It is from their essence or nature that they are places; and that the pri-mary places of things should be moveable is absurd. These are therefore the absolute places…

—Isaac Newton, Principia

VocabularyAmpere• Battery• Charge• Current• Volt•

Online Learning ToolsApplet: Induction www.lon-capa.org/~mmp/applist/induct/faraday.htmThe Battery: Using Chemistry to Make Energy www.ieee-virtual-museum.org/collection/tech.php?id=2345793

For Further InvestigationFruity Electricity www.miamisci.org/af/sln/frankenstein/fruity.html

Extended ReadingDeMauro, L., ed. 2005. Thomas Edison: A brilliant inventor. New York: HarperCollins.Ancestors of E=mc2

www.pbs.org/wgbh/nova/einstein/ancestors.html


Electrifying Thoughts and Magnetic Reasoning3


EvaluationThe student page includes the following scenario as a tool for assessing students’ under-stand ing of the power of electricity and its impact on long-distance communication: “When Samuel Morse (1791–1872) sent an electric current from Washington, D.C., to Baltimore in 1844, it turned a magnet on and off” (Hakim 2007, p. 26). That was the first telegram. How did long-distance communication change the world? Imagine you are a senior citizen in 1870. Write a letter to your grandchild explaining, “When I was young, it took weeks to send important information across the country.” Then give examples.

In their letters and examples, students should make reference to specific items of technology in appropriate time sequence (for example, telegraph and telephone) and to the types of communication the average person uses.


Michelson and Morley tried unsuccessfully for nearly 20

years to measure the speed of light in ether. In the end their

failed experiment caused physicists to question: “If ether

doesn’t exist at all, how does light travel?”4The M. and M. ’s of Science


Teaching TipMany teachers use the analogy of a river to describe the “ether” that Michelson and Morley tried to establish. A swimmer might be analogous to the light, trying to swim straight across but being pulled downstream. After students have discussed the effect the stream would have on the swimmer, ask them: “What if there was no effect? Would that prove there was no water?”

Does “Close” Count?Explain to students that in 1676 Olaf Roemer was the first to measure the speed of light. He knew that when Earth was at the point of its orbit that was closest to Jupiter, it took 42 hours for one of its moons to orbit the giant planet. But when Earth was at the opposite side of the Sun, it took 1,300 seconds longer for one of the moons to orbit Jupiter. Roemer thought Earth was then 3 × 108 km farther away, and he calculated the speed of light by dividing the distance by the delay. Roemer’s measuring instruments weren’t all that good, though. The actual delay time is 980 seconds, and the actual distance is 1.47 × 108 km. Ask students the following questions (answers in bold):

1. What was Roemer’s answer? Roemer’s calculation was 2.3 × 105 km/s. 2. What was the percentage of Roemer’s error? Correcting for instrumentation

errors, the answer is 10 × 105 km/s. He was off by 23%.

VocabularyAnode• Cathode• Ether•

Earth

Earth

Jupiter Jupiter


the m. and m. ’s of science4

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Online Learning ToolsMichelson-Morley Experiment http://galileo.phys.virginia.edu/classes/109N/more_stuff/flashlets/mmexpt6.htmMichelson-Morley Experiment, 3D Animation http://movingscience.de/en/projects/physics/michelson_morley_experiment.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the importance of experimentation:

Some of the most famous experiments have had no results. When that happens, it’s often hard to explain their value. Imagine you are Michelson writing a letter to one of his original sponsors, Alexander Graham Bell. Explain why the funding he offered was worth the expense even though your experiment seems to have failed.

In their explanations students should demonstrate an understanding that experiments begin with hypotheses, and that either confirming or refuting a hypothesis is an appropriate result of an experiment.


J. J. Thomson discovered the electron—the tiny, negatively

charged particle of an atom—using a device that is now

part of most traditional television sets. The observations

he made form the basis for most of the technology we use

today.5

Invisible Bits of

ElectricityT E A C H E R E D I T I O N

Teaching TipsUnless students have experienced severe storms, they may never have had to live without electricity. Begin this section by asking students to make a list of everything they do in a day that requires power. Safety tip: Under no circumstances should students ever open televisions or monitors to observe cathode ray tubes. These tubes can maintain strong charges long after they are unplugged.

Making Inferences About Unseen MassesIn this activity, students use very simple materials, envelopes and index cards, to model the methods that Robert Millikan used to determine the charge of the electron. Before students enter the classroom, prepare a collection of 100 envelopes: Put 3 index cards in each of 15 envelopes, 6 index cards in each of 20 envelopes, 9 cards in 15 envelopes, 12 cards in 13 envelopes, 15 cards in 12 envelopes, 18 cards in 15 envelopes, and 21 cards in 10 envelopes. Working as a team, students measure the masses of the filled envelopes to the nearest 0.1 g. They enter all the measurements into a spreadsheet program, sort the data by mass, and create a bar graph with groups of similar mass on the x axis and masses in grams on the y axis (see sample).

MA

SS

25

20

15

10

5

01 2 3 4 5 6 7

GROUPS

To get the most from this modeling activity, students must be guided to think about and discover the idea that the masses in the envelope are discrete units. Thinking about the mass ratio of the unseen materials in the envelopes will be new to students; make sure they take their time and discuss carefully.


invisible bits of electricity5


Ask students the following questions (answers in bold):

1. What evidence could be used to determine the mass of the envelope itself? In the example above, the contents are grouped in increments of 3 g, so the envelope probably weighs 2 g.

2. Draw a horizontal line across the graph showing the mass of the envelope. Subtracting that mass, create a hypothesis about the mass of the contents. (Line at 2 g) Because all have a base of 2 g, all groups occur in further increments of 3 g.

VocabularyElectron• Proton• Neutron• X-ray•

Online Learning ToolsApplet: Electron Orbit http://lectureonline.cl.msu.edu/~mmp/applist/coulomb/orbit.htmBohr’s Theory of the Hydrogen Atom www.walter-fendt.de/ph14e/bohrh.htmMillikan’s Oil-Drop Experiment http://physics.nad.ru/Physics/English/mill_tmp.htmMillikan Oil-Drop Experiment (simulation) www.xplora.org/ww/en/pub/xplora/news/latestnews/xplora_wins_grant_for_web_expe.htmMore on Millikan’s Oil Drop Experiment (Quicktime Movie) http://chemistry.umeche.maine.edu/~amar/Millikan.html

For Further InvestigationCharge and Carry: Exploratorium Snacks www.exploratorium.edu/snacks/charge_carry/index.htmlA Laboratory Exercise in Fundamental Units http://ed.fnal.gov/samplers/hsphys/activities/millikantchr.html“Static Electricity” Page www.Eskimo.com/~billb/emotor/statelec.html

Extended ReadingGlasser, R. E. 1970. Mass analogy for Millikan’s oil drop experiment. The Science Teacher

37 (4): 82.

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of assumptions:



Invisible Bits of Electricity5

You are teaching a class in which you describe your experiment on protons and electrons. A student challenges you: How do you know that the unseen “units” you’ve identified in your massing are single particles (discrete units) and not combinations of particles? Can you defend your assumptions? Write two “If…, then…” statements that describe experiments or consequences. For example, if the units of mass that were measured are single particles, then…

In their explanations, students should note that if the units are single particles, there will never be any envelopes that show intermediate mass. If the units are combinations, a very few envelopes might be found with intermediate mass (or using more power, you might be able to crack open the envelopes).

Intro.



J. J. Thomson has a lot of convincing to do! His fellow

physicists can’t see electrons, and can’t even imagine

the electrons’ behavior. “Even Thomson has a hard time

accepting the results of his experiments” (Hakim 2007, p. 51).

So he must use statistics to support his discovery of

electrons.

Smaller than Atoms?

Subatomic? Is This a Joke?

Teaching TipsWhile Piaget would have asserted that middle school students are able to reason about things they can’t actually see or touch, today we know that many students don’t reach this level of logical reasoning until high school (if ever). Therefore, make as many concrete and authentic (personal) analogies in this introduction to atomic structure as possible. Review potential and kinetic energy on the playground slide. Explain to students that potential energy exists at the top of the slide and kinetic energy is released as one goes down the slide. Students may also have examples of kinetic energy in their drivers’ education materials. The “Powers of 10” link listed under “Online Learning Tools” does not include subatomic levels; other examples later in this guide will expand this experience.

Seeing the UnseeableWhile we can’t see electrons, we move them around a lot and see the effects of their motion all the time. Ask students to conduct the following three experiments at home, and in class the next day ask, “Can you explain what’s common among these demonstrations?”

Ask students to carefully turn on • the burner of their electric range at home, with adult supervision, then stand back and watch the color of the burner change as it gets hot. Tell them to let it cool and watch the color again.Instruct students to put some nylon and polyester clothing in their dryers at home on • a dry evening (tell them not to use fabric softener). After 10 minutes, have them turn the lights off and pull out the clothes. Ask them to observe what happens when they pull the clothing apart.Tell students to chew some Wint-O-Green Life Savers in a dark room. Tell them to chew • the Life Savers with their mouths open and observe the candy in a mirror as they chew.

Photon

Excited State

Ground State

Source: NASA/Goddard Space Flight Center, “NASA’s Imagine the

Universe! Understanding the Atom.” http://imagine.gsfc.nasa.gov/

docs/science/how_l2/atom.html.


Smaller than Atoms? Subatomic? Is This a Joke?6

A sample student observation: All of these experiments involve the movement of electrons to different energy levels due to the addition of photons (discrete amounts) of energy. Adding energy to the iron of a burner increases the energy of the electrons; “static electricity” involves free electrons. The energy of electrons is raised by chemical or physical energy, causing them to emit light: sodium vapor lamps, neon signs, flames, sparks, lightning, incandescence of heated metals.

VocabularyKinetic energy• Potential energy•

Online Learning ToolsPowers of 10 www.powersof10.comSecret Worlds: The Universe Within http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10

Extended Reading3 Experiments, 1 Big Idea www.aip.org/history/electron/jj1897.htm EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the importance of analogies:

Analogies about size are helpful for the imagination. Begin an imaginary story by writing: “If I were 1/10th my size, I could…”; “If I were 1/100th my size, I could…”; “If I were 1/1,000th my size, I could…”

In their explanations, students should include an accurate sense of ratios and proportions. The “Powers of 10” website is a great resource for students who may need inspiration.


Intro.



Marya Sklodowska (Marie Curie) grew up in Poland. There,

her chances of achieving her academic dreams seemed

dim. But her persistence and the help of her family made

it possible for her to get degrees in both physics and

mathematics. 7 Nobel Marie


17

Teaching TipsIf students have had their own x-rays (especially of broken bones), ask them in advance to share them with the class as an anticipatory activity. When sharing Marie Curie’s speculations about rays in space with students, discuss how other scientists might have responded to her suggestion. Safety note: In older textbooks, you may find activities using old-fashioned ozalid (drafting) paper. The development process for this paper is considered too dangerous for classrooms today.

Through and ThroughIt’s possible to model the sorts of photos that Roentgen and Becquerel saw with photosensitive paper, which is available for purchase from various sources including www.kindredlearning.com, www.acornnaturalists.com, and www.stevespanglerscience.com. You can even use old-fashioned red construction paper for this experiment. Students begin by cutting six exact copies of a “snowflake” pattern from plain white paper. For the first part of the demonstration, each student lays one of his or her snowflake cutouts on a square of photosensitive (or red construction) paper and places it in direct sunlight. For photosensitive paper, allow just a few minutes for fading to occur; for construction paper, allow a day. After the necessary time has elapsed, ask students to remove their snowflakes and then describe the amount of fading on the paper. Next, students build some “shielding” out of layers of blue cellophane. Students start this part of the experiment by placing each of their six identical snowflakes on a piece of photosensitive paper. They leave one paper unshielded, put one square of blue cellophane on the second paper, put two squares on the third, put three squares on the fourth, and so on. Ask students, “What thickness of cellophane is effective?” Answers will vary depending on the type of cellophane used. Often about six sheets produces a filter effect that students will perceive as effectively opaque. Remind students that this experiment uses ultraviolet light waves, which are not the same wavelength as x-rays. Ask students to refer back to the chart they began for the activity in Chapter 1.

In Their Own WordsIn 1898, Marie Curie (1867–1934) reported that she was able to get photographic images from the radiation emitted from many materials. Tell students that Curie wondered whether the entire universe was filled with these rays. Read the following Marie Curie



Nobel Marie7

quote aloud to students, then ask, “Why did she believe that science is beautiful?”

I am among those who think that science has great beauty. A scientist in his laborato-ry is not only a technician: he is also a child placed before natural phenomena which impress him like a fairy tale. —Marie Curie, 1933 “Future of Culture” Conference

VocabularyPhotography• Radium• Uranium wave•

Online Learning ToolChain Reaction: Mouse Trap Model www.physics.umd.edu/lecdem/services/demos/demosp4/p4-62.htm

For Further InvestigationX-ray Spectra www.exploratorium.edu/spectra_from_space/xray_activity.html

Extended ReadingJerome, K. B. 2006. Atomic universe: The quest to discover radioactivity. Washington, DC:

National Geographic.Krull, K. 2007. Giants of science: Marie Curie. New York: Viking.McClafferty, C. K. 2006. Something out of nothing: Marie Curie and radium. New York: Farrar,

Straus, and Giroux. Steel, P. 2006. Marie Curie: The woman who changed the course of science. Washington, DC:

National Geographic.

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of gender equality:

Marya Sklodowska (Marie Curie) was not allowed to enter the university in Poland because she was a female. Imagine you had to write her letter of application. Tell the provost of the university why you believe that every student should have an equal opportunity to study there.

In their letters, students should make reference to specific skills that would make prospective students likely to succeed and offer evidence that applicants from all genders, ethnicities, and socioeconomic backgrounds might have these skills.

Intro.



The Curies’ quest to isolate the elements polonium and

radium was a historical triumph over difficulties and

adversity. Like most scientific triumphs, these discoveries

were not ends, but beginnings. The radiation that they

studied provided the first clues that smaller particles existed;

the hunt was on for a better model of the atom.

8 MysteriousRays


Teaching TipThe idea of risk (especially from radiation) is often quite difficult for teenagers to internalize. Movies and other media may have created some misconceptions. Take class time to discuss the very real and ultimately fatal exposures to radiation experienced by Marie Curie and Rosalind Franklin.

Using StatisticsWe are exposed to natural sources of radiation every day. These sources range from very short gamma γ rays to long radio waves. Below are data from Princeton University with estimates of our average exposure to various sources of radiation.

Radiation Source

Average Annual Whole Body Dose

(millirem/year)

Cosmic rays 29

Radioactive rocks 29

Radon (in some basements and rocky building sites) 200

Isotopes (K-40, C-14, etc.) in the air (mostly made in the upper atmosphere) 40

One dental x-ray per year 10

One chest x-ray per year 8

Cross-country round-trip by air 5

Consumer products (like home smoke detectors) 11

Source: Data adapted from Princeton University, ”Open Source Radiation Safety Training Module 2: Background

Radiation & Other Sources of Exposure.” http://web.princeton.edu/sites/ehs/osradtraining/backgroundradiation/

background.htm.

Present these data to your students and ask them to develop a bar graph of the various sources of radiation.



Mysterious Rays8

Adding to the Radiation TableNow that students have learned about additional sources of radiation, ask them to add to the table of unseen radiation they began in Chapter 1. (Possible answers are in bold.)



Ultraviolet UV-sensitive materials Anything opaque, some

chemicals with SPV ratings


IR goggles

Insulators



communications

Relatively thin walls of

microwave

α Particles Radiation meter, some fi lms Paper

β particles Radiation meter, some fi lms Water

γ radiation Radiation meter, some fi lms Heavy shielding (concrete)

X-rays Radiation meter, some fi lms Metal (lead) shielding

Vocabularyα• particlesβ• particlesγ• radiation

Online Learning ToolsApplet: Decay http://lectureonline.cl.msu.edu/~mmp/applist/decay/decay.htmApplet: Nuclear Isotope Half-Lifes http://lectureonline.cl.msu.edu/~mmp/kap30/Nuclear/nuc.htmX-rays www.colorado.edu/physics/2000/xray


Mysterious Rays8


Extended Readingα, β, γ Penetration and Shielding www.fas.harvard.edu/~scidemos/QuantumRelativity/PenetrationandShielding/

PenetrationandShielding.htmlBoehm, J. 2006. Atomic universe: The quest to discover radioactivity. Washington, DC:

National Geographic.Open Source Radiation Safety Training http://web.princeton.edu/sites/ehs/osradtraining/backgroundradiation/background.htm

EvaluationThe student page includes the following scenario, derived from the same Princeton University website as the table above, as a tool for assessing students’ understanding of radiation and the dangers of smoking:

The average person receives approximately 340 millirem a year of radiation exposure. Smoking adds about 280 millirem of radiation a year to normal exposure. According to data from Princeton University, we increase our risk of cancer by about 0.05% for every 1,000 millirem of exposure. (Of course, everyone is different. Some people have a greater capacity to repair genetic damage from radiation than others.) Develop a short public service announcement describing the dangers of this radiation. (Remember, the radiation is only one smoking-related cause of cancer. Tars and benzene in cigarette smoke can also lead to cancer.)

In their public service announcements, students should include quantitative data to support the warnings they provide, including reasonable assessments of risk.


Max Planck imagined things that couldn’t really exist, like

“blackbodies” that absorbed all the radiation that hit them,

and violins that could play only whole notes. In the end, he

imagined a form of energy that acted like both a wave and

a particle—light.9 Making Waves


Teaching TipsTo introduce the concept of waves in a general way, have students model waves physically as they begin to use the term. In a large, open area, such as the cafeteria or courtyard, model transverse waves with a long rope or clothesline. Tie one end firmly to a piece of furniture or a pole. Stretch the rope or clothesline until it sags in the middle, about halfway to the ground. Gently move your hand up and down with enough energy to form one standing wave (an S shape) on the line. Now add more energy to the up and down motion of your hand until you create two crests (or two troughs) between the fixed end and your hand. Ask students to use their hands to point out the distance between two peaks or troughs (the wavelength) and to count the number of waves per unit time (the frequency). Explain to students that they will explore waves like this as they study light, radio, and microwaves in later chapters. Then, using a coil-spring toy, illustrate transverse waves, such as sound, for comparison. This activity is also appropriate for Chapter 11.

Students see satellite photos on weather reports, but they may not realize the differences in wavelength that these images can represent. One way to begin this lesson is to give students yellow “sunglasses,” which are often used for archery or sports shooting to reduce glare. Ask students to describe how the world is different with one wavelength filtered out.

Transverse Wave

Longitudinal WaveParticle Movement

Direction of Energy Transport

Direction of Energy Transport

Particle Movement


Making Waves9


Satellite EyesSatellites use cameras that can sense radiation to monitor Earth’s environment and human activities. Show students the following image from the National Oceanic and Atmospheric Administration:


1. What wavelengths of the electromagnetic spectrum are being sensed? (As a hint, tell students to look at the patterns in the area of the ocean nearest you.) This graph shows heat in Celsius degrees.

2. What can this tell us about Earth? While the equatorial areas are warmer, the currents change the flow of water significantly.

VocabularyFrequency• Quantum• Wavelength•

Online Learning ToolsAn Example of Doppler Effect www.walter-fendt.de/ph14e/dopplereff.htmAnimation Collection: Wave Motion http://physics.usask.ca/~hirose/ep225/anim.htm

Source: NOAA Satellite and Information Service, National Environmental Satellite, Data, and Information Services

(NESDIS). www.osdpd.noaa.gov/PSB/EPS/SST/data/FS_km5000.gif.


Making waves9

Electromagnetic Waves www.colorado.edu/physics/2000/waves_particles/index.htmlNASA Lunar Prospector http://lunar.arc.nasa.gov/education/activities/active22a.htmRipple (Simulation of Reflection, Refraction, and Interference) www.physicslab.co.uk/ripple.htmTransverse and Longitudinal Waves www.control.co.kr/java1/wave%20Trans/WaveTrans.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the concept of waves: Imagine you witnessed a train robbery that took place in complete darkness. The police ask, “How did you know if the train was coming toward you or going away from you?” Write down how you would answer. If you need a hint, observe the animation of the Doppler effect at www.walter-fendt.de/ph14e/dopplereff.htm.

In their written explanations, students should demonstrate an understanding of how the sound of the train changes depending on whether the sound emitter is approaching or withdrawing.


Intro.



During his amazing “miracle year,” Einstein published five

papers, with topics ranging from the motion of atoms

and electrons to the nature of the universe. These papers

would eventually change the world of physics and our

understanding of the world.10 Five Papers


Teaching TipsThe electroscope in the demonstration below can also be made using a peanut butter jar. If available, gold foil from a craft store works better than aluminum for the demonstration. Although gold foil is more expensive, it is also a great visual aid for the lessons on Rutherford’s experiment in Chapter 13. As students read Einstein’s “In Their Own Words” quote (see p. 26), display the applet simulation at http://micro.magnet.fsu.edu/electromag/java/faraday2, or allow students to experiment on their own with simple materials.

At the Threshold of GreatnessTo observe the photoelectric effect, students first build an electroscope using a bottle that has been carefully cleaned (a Snapple or Frappuccino bottle works best). Next, students cut two 1 cm × 6 cm strips of aluminum or gold foil. Students then hook the strips to a large paper clip they’ve opened, by making a small punch hole about 0.5 cm from the end, so that the strips hang straight down. Students fill the mouth of the jar with plumber’s putty, holding the paper clip exactly in the middle so that about 2 cm of the clip sticks out of the top. Students insert a small hollow coffee stirrer through the top, ensuring that the putty is firmly in place. Students test the electroscope with a piece of tape, sticking the tape to a smooth table surface, ripping it off, then bringing it near the top of the paper clip. Ask students to observe what happens when they bring the tape near the top of the paper clip (answer in bold). The leaves separate, because they accumulate similar charges. Students then discharge the electroscope by touching the top of the clip with their finger. They repeat the charge and discharge routine a few times, until they are sure everything is in place. After doing this, students can seal the top of the bottle with rubber cement and let it dry. Ask students, “What other ways can the electroscope be charged?” (Sample answer in bold.) Anything that generates electricity, such as rubbing wool with a comb.




five papers10

In Their Own WordsAsk students to read the following excerpt from the first of Albert Einstein’s (1879–1955) “miracle year” papers, “On the Electrodynamics of Moving Bodies,” where he explains the photoelectric effect. Einstein begins with simple examples, which can be replicated in any classroom or online with the simulation at http://micro.magnet.fsu.edu/electromag/java/faraday2. Sixteen years after his paper, Einstein earned a Nobel Prize.

Take, for example, the reciprocal electrodynamic action of a magnet and a conductor. The observable phenomenon here depends only on the relative motion of a conductor

and the magnet…in which either the one or the other of these bodies is in motion.…If the magnet is in motion and the conductor at rest, there arises in the neighbourhood of the magnet an electric field with a certain definite energy.…But if the magnet is stationary

and the conductor in motion, no electric field arises.…Examples of this sort…suggest…the same laws of electrodynamics and optics will be valid for all frames of reference.

—Albert Einstein, “On the Electrodynamics of Moving Bodies”

VocabularyAmplitude• Conductor• Magnet• Photoelectric effect• Threshold frequency•

Online Learning ToolsApplet: Photo Effect www.lon-capa.org/~mmp/kap28/PhotoEffect/photo.htmBuild Your Own Electroscope www.chicos.caltech.edu/classroom/escope/escope.htmlEinstein http://movingscience.de/en/projects/physics/einstein.htmlFaraday’s Magnetic Field Induction Experiment http://micro.magnet.fsu.edu/electromag/java/faraday2

Extended ReadingEinstein’s Big Idea www.pbs.org/wgbh/nova/einsteinHawking, S., ed. 2004. The illustrated On the Shoulders of Giants: The great works of physics and

astronomy. Philadelphia: Running Press.On Truth & Reality: The Famous Michelson & Morley Experiment www.spaceandmotion.com/Physics-Michelson-Morley.htm


Five Papers10


EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the process for evaluating new inventions: A patent clerk examines descriptions of new inventions. The written applications must be clear and concise and must distinguish one invention from all others like it. Practice writing a description of an invention—a mousetrap, or something else you invent yourself. Convince a careful patent officer that your idea is unique. In their written descriptions, students should include specific descriptions that are unique and quantitative. The descriptions should be understandable to another reader.


Einstein’s paper topics ranged from the very small (a study

of Brownian motion) to the very large (the nature of the

universe). Perhaps the most difficult of his discoveries for the

scientific community to accept was the idea that light exists

as both particles and waves—an idea that combined the

two previously competing theories of Newton and English

physicist Thomas Young.

11Seeing the

(Photon) Light


Teaching TipIf you have not done the wave activity suggested in Chapter 9 (or even if you have), begin students’ introduction to a wave by having them do “the wave”—the same “wave” that spectators do in crowded stadiums. Then ask students to think about the analogy as they read about light.

Polarized LightThis demonstration can also be done by using two pairs of polarized sunglasses (at right angles). Not all inexpensive glasses that are labeled polarized are made properly, so try them out before class to make sure they are polarized. Provide each student with two sheets of polarized filter (a fine plastic into which thin lines have been etched). Students hold a single filter up to a window or other light source and rotate it 90°. Then they overlap the filters and rotate only one filter through 360°. Ask students to observe the light that is transmitted. Next, students use an instrument that can measure light intensity (a computer-interfaced or camera light meter) to develop a graph of the intensity of light when the difference between the two filter papers is 0°, 45°, 90°, 135°, and 180°, respectively. Ask students to describe what they observe (sample description in bold). The wavelengths of sunlight vary, so only a fraction of the total sunlight can pass through a polarized filter. When the “slits” in the polarized filters are parallel, all the light vibrating in the same plane can pass. But as the filters are rotated, less light can pass; when the slits are perpendicular, no light can pass. This demonstrates the wave nature of light.

VocabularyPhoton• Polarized•

Online Learning ToolsPolarizing Filter www.colorado.edu/physics/2000/applets/polarized.htmlPolarization of Light http://micro.magnet.fsu.edu/primer/java/polarizedlight/filters/index.html


seeing the (photon) light11


EvaluationsThe student page includes two scenarios as tools for assessing students’ understanding of the relationship between wavelength and visible light.

Lord Rayleigh (see p. 96 of Einstein Adds a New Dimension) explained why the sky was blue. But there are times when the sky is green (just before a tornado) or even red. How can you explain the painting The Scream, by Edvard Munch? (Hint: Look at the date it was painted, 1893, and research what earthshaking events happened in the previous decade.)

In their research students should learn that after the eruption of Mt. Krakatau in Indonesia, dust made skies red all over Europe and Asia. Munch’s paintings (an entire series) were related to the sky after that eruption.

Today a red sunset in the Atlantic Ocean is often caused by a distant Saharan dust storm. When the Saharan Air Layer (SAL) is full of dust, there are dense winds aloft out of the Eastern Atlantic. Discuss how this is related to the verse “Red sky at night, sailor’s delight.”

In their discussion, students should answer that the SAL causes tropical storms to fall apart before they become hurricanes. The verse “Red sky at night, sailor’s delight” may be related to the idea that weather from the east was better for sailors who crossed the Atlantic than strong winds from the west.


In his “miracle year,” Einstein solved old problems and

proposed new ones that physicists had never thought to

ask. One of the simplest problems he solved—the random

motion of molecules—turned out to be one of the most

elegant and most cited.12 Molecules

MoveT E A C H E R E D I T I O N

Teaching TipDespite their (self-perceived) sophistication, middle school students still learn best with concrete and kinesthetic experiences. Try copying the “dance” of the molecules on page 102 of Einstein Adds a New Dimension and ask students to replicate it on the school yard under conditions of low energy and high energy.

Smoke and MirrorsTo demonstrate Brownian motion—the phenomenon that inspired one of Einstein’s papers—give students a microscope, a slide and coverslip, a plastic coffee stirrer, some water, an eyedropper, and a drop of India ink. Students place a tiny drop of India ink on a microscope slide and add a drop of clear, cool water. Students then stir the two drops together a bit, cover the drops gently, and look at the mixture through the microscope. (Instruct students to sit very still and not to bump the table.) Ask students to describe how the tiny bits of black (carbon) move around. (Sample description is in bold.) The random movement is what is termed Brownian motion. The particles are not the size of molecules, but they are light enough to be bounced by the movement of molecules. Also ask students to draw a sketch of what they observe. Next, tell students to let their drops get a little warmer. (Most microscopes have a light or a mirror, so that will happen anyway!) Ask students, “How does the movement change?” More energy results in more molecular—and hence more Brownian—motion. Instruct students to use another color pencil to show the change in their sketches. Remind them that the bits of carbon they see are much larger than molecules but are very, very light. Their movement is caused by the movement of molecules of water around them that bump and jostle them.

In Their Own WordsAlbert Einstein puzzled over the motion of molecules—called Brownian. Read the following excerpt aloud:

In this paper it will be shown that according to the molecular-kinetic theory of heat, bodies of microscopically-visible size suspended in a liquid will perform movements of such magnitude that they can be easily observed in a microscope, on account of the

molecular motions of heat. It is possible that movements…are identical with the so-called


molecules move12


“Brownian molecular motion”; however, the information available to me regarding the latter is so lacking in precision, that I can form no judgment in that matter.

If the movement discussed here can actually be observed…we must assume that the suspended particles perform an irregular movement—even if a slow one—in the liquid. —Albert Einstein, “On the Movement of Small Particles Suspended in a Stationary

Liquid Demanded by the Molecular-Kinetic Theory of Heat”

Ask students, “Why was Einstein so hesitant to actually claim that he had the explanation to Brown’s puzzle?”

VocabularyBrownian motion•

Online Learning ToolsBrownian Molecular Motion I, 2D/3D Animation, Drawings: Laurent Taudin, Paris http://movingscience.de/en/projects/physics/brownian_molecular_motion_i.htmlBrownian Motion www.control.co.kr/java1/idealgas/brownian.htmlBrownian Motion (Applet) www.aip.org/history/einstein/brownian.htm

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of Brownian motion:

If Albert Einstein could have written a letter to Robert Brown, how would he have explained the observations?

In their explanations, students should describe their observations as well as the particle movement that caused the observations.


Niels Bohr had to imagine something he could never

hope to see. In the end, he struck gold—both literally and

scientifically—in his modeling.13Getting

the Picture Right


Teaching TipsNeither the plum pudding nor the cookie is really a good analogy for the structure of an atom. Students should realize that each successive analogy proposed by scientists was a little bit better, but that no analogy will ever be perfect. Safety tip: Do not allow students to eat in the science lab.

Cookies, Chemistry, and ConversationWhen trying to figure out what the inside of an atom looks like, J. J. Thomson got inspiration from plum pudding. Here’s another tasty analogy that students can make at home (remind students again that they cannot eat in the science lab). When students are done making the recipe at home, tell them to think about how matter changes and how models are useful for visualizing what we cannot see. Instruct students to bake cookies using the following recipe (Nestle 2003, p. 7):

2 ¼ cups all-purpose flour 1 teaspoon baking soda 1 teaspoon salt 1 cup (2 sticks) butter or margarine, softened ¾ cup granulated sugar ¾ cup packed brown sugar 1 teaspoon vanilla extract 2 large eggs 2 cups (12-ounce package) semi-sweet chocolate morsels 1 cup chopped nuts

Preheat oven to 375°F. Combine flour, baking soda, and salt in small bowl. Beat butter, granulated sugar, brown sugar, and vanilla extract in large mixing bowl until creamy. Add eggs, one at a time, beating well after each addition. Gradually beat in flour mixture. Stir in morsels and nuts. Drop by rounded tablespoons onto ungreased baking sheets. The original recipe recommends baking for 9 to 11 minutes (or until “golden brown”), letting cookies cool on baking sheets for 2 minutes, then removing to wire racks to cool completely. However, you should instruct students to bake a bit longer, until cookies are nearly crispy.


getting the picture right13


With a toothpick, students test and describe the consistency of the cookie matrix and the chocolate chip. They then put the cookie in the microwave for 20 seconds, check out the consistency of the materials again, and fill out the chart below (answers in bold):

Ingredient Can you see it in

the cookie?

Consistency

when cool

Consistency

when reheated

Has a chemical

change

occurred?

Eggs No Firm Firm Yes

Butter No Firm Soft No

Nuts Yes Firm Firm No

Chocolate chips Yes Firm Soft No


1. When you bake, how do you know which changes are physical and which are chemical? In general, those changes that are easily reversed are physical changes. In this example, that includes changes in the consistency of oils and chocolate.

2. How would you explain the cookie analogy to J. J. Thomson and Niels Bohr: “This cookie is like an atom because…, but it is not like an atom because…”? (Students may want to review Thomson’s image of an atom on p. 52 of Einstein Adds a New Dimension for comparison.) The cookie is more like Thomson’s model; Bohr realized that the nucleus and electrons were quite small by comparison. The chips are far larger than the proportional size of electrons; while their position is relatively random, actual electrons can only be found in specific energy levels (shells).

VocabularyRadioactive decay•

Online Learning ToolBohr Atom www.lon-capa.org/~mmp/kap29/Bohr/app.htm

EvaluationThe student page includes the following scenarios as a tool for assessing students’ understanding of atoms and electrons:

How small is an electron? That’s a question that can’t really be answered, since an electron acts more like a wave than a particle. But it’s sometimes useful to think of the electron as a particle about 10–15 m. A carbon atom is about 10–13 m in diameter. Use an analogy: If an electron were the size of a baseball, the entire carbon atom would be about the size of… (See the cathedral analogy on p. 111 of Einstein Adds a New Dimension for hints.)


Getting the Picture Right13

In their analogies, students should demonstrate an understanding of the relative sizes of atoms and electrons. For example, Earth’s orbit would be 1 × 1015 times the size of a baseball.

Research: How many carbon atoms would be found in a 1-carat diamond?

Students should answer that a carat is 0.2 g and a mole of carbon is 12 g. There are 10,036,666,666,666,666,666,666 atoms in a 1-carat diamond.


Intro.



Rutherford and Bohr were a great team and made “quantum

leaps” in understanding the structure of the atom. The two

scientists learned to understand the rules by which electrons

occupy energy levels or shells.14 Getting Atom


Teaching TipHere’s one way to introduce students to the type of thinking involved in the creation of the first periodic table. Think of a way to classify your students that is not sensitive or embarrassing (such as by school club affiliation or hair color). Before students enter the classroom, organize the desks in groups and place names on the desks according to the groups you have predetermined. Challenge students to figure out what criteria you used to group them. (This can be repeated for several days if necessary.)

Missing PiecesThis activity can be completed while students examine pages 122–123 of Einstein Adds a New Dimension or at other times in the term. Given 19th-century knowledge, there are several possible answers to the questions asked in the activity. This activity can be limited to a brief “what if” discussion or extended using the database available at the NASA Genesis website, http://genesismission.jpl.nasa.gov. If time permits, students can write notes about each element’s properties on large note cards. Arrange the cards on the bulletin board as Mendeleyev would have done, and then gradually move them to their modern positions based on properties.

GroupPeriod

1

I II III IV V VI VII VIII

H=1

2 Li=7 Be=9.4 B=11 C=12 N=14 O=16 F=19

3 NA=23 Mg=24 Al=27.3 Si=28 P=31 S=32 Cl=35.5

4 K=39 Ca=40 Ti=48 V=51 Cr=52 Mn=55 Fe=56, Co=59, Ni=59

5 Cu=63 Zn=65 AS=75 Se=78 Br=80

6 Rb=85 Sr=87 ?Yt=88 Zr=90 Nb=94 Mo=96 Ru=104, Rh=104, Pd=106

7 Ag=108 Cd=112 In=113 Sn=118 Sb=122 Te=125 J=127

8 Cs=133 Ba=137 ?Di=138 ?Ce=140

9

10 ?Er=178 ?La=180 TA=182 W=184 Os=195, IR=197, Pt=198

11 Au=199 Hg=200 TI=204 Pb=207 Bi=208

12 Th=231 U=240


getting atom14

Students begin this activity by looking at Mendeleyev’s first periodic table in 1869. Mendeleyev made many educated guesses based on his observations of chemical properties. (The tools he would have used are shown on p. 119 of Einstein Adds a New Dimension.) Students compare Mendeleyev’s periodic table to the modern table online or on page 123 to find the answers to the following questions (answers in bold):

1. Copper, silver, and gold are in Mendeleyev’s Group I but are in modern Group II (coinage metals). What characteristics might have prompted the first placement? They donate electrons in reactions, but Li, Na, and K are far more reactive than coinage metals.

2. Based on 19th-century knowledge, what element might have fit in Group III of Mendeleyev’s table under boron and aluminum? Gallium, a liquid metal at room temperature that expands as it solidifies, would have fit in Group III.

3. What element might have fit in Group VII of Mendeleyev’s table under bromine? Iodine, another very active halogen, which like chlorine and bromine is an irritating gas at room temperature. (Note: Manganese wouldn’t be there.)

VocabularyAngular momentum• Energy level• Shell•

Online Learning ToolsInside the Human Brain www.nia.nih.gov/Alzheimers/Publications/

UnravelingTheMystery/Part1/InsideBrain.htmPeriodic Table of the Elements http://periodic.lanl.gov/default.htmWebelements www.webelements.com

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of isotopes:

Today we use isotopes of elements for vital studies. Since the 1990s, the positron emission tomography (PET) scan has been used to diagnose the functioning of important body systems. This image shows a series of PET scans of the human brain. The patient was injected with radioactive sugar and scanned for the places where it was metabolized.


Source: National Institutes of Health, National

Institute on Drug Abuse. www.nida.nih.gov/NIDA_

notes/NNvol21N2/brains.gif.


Getting Atom14


You be the radiologist: Compare the series to a brain diagram, and describe what parts of the brain are most active in each process.

In their descriptions, students might, for example, associate speaking or reading language with the parietal lobe.


Source: Electromagnetic spectrum image from Virtual Hawaii,

Hawaii Space Great Consortium, UH Hanoa, “How Are Satellite

Images Different From Photographs?” http://landsat.gsfc.nasa.

gov/education/compositor.

What we see is largely due to the action of the very outer

layers of atoms—and that’s pretty random, as we know. 15Still Shooting

Alpha Particles


Teaching Tip Satellite images are difficult for students to conceptualize; use group discussions for the following activity so that students won’t be too intimidated to speak up.

Seeing More With SatellitesIn the activity for Chapter 9, students may have puzzled over the satellite image of Earth’s oceans. The satellite cameras that took that photo were sensitive to electromagnetic waves in the infrared (heat) range. Have students look on page 126 of Einstein Adds a New Dimension at the photos of Mars’s ice cap taken with specialized cameras. Discuss the various wavelengths of the electromagnetic spectrum and how each might be useful. Next, have students look at these photos of Hawaii and see if they can infer what sorts of wavelengths are being sensed (answers in bold). Which band shows foliage most clearly? Band 2 looks at greens. Why might this be true? While it’s not universally true, many plants reflect green light.

VocabularyIsotope•

Online Learning ToolsApplet: Spectrum http://lectureonline.cl.msu.edu/~mmp/applist/

Spectrum/s.htmHow Are Satellite Images Different From Photographs? http://landsat.gsfc.nasa.gov/education/compositor

Band Wavelength1. 0.45–0.52 μm2. 0.52–0.60 μm3. 0.63–0.69 μm4. 0.76–0.90 μm

5. 1.55–1.75 μm6. 10.40–12.50 μm7. 2.08–2.35 μm


still shooting alpha particles15


EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the wavelengths of the electromagnetic spectrum:

Research the NASA website above for the applications for which each of these bands are useful. Then write a short letter to your congressional representative supporting continued funding of Landsat research. In their letters, students should include specific examples of questions that could be answered by Landsat observations. Check for a relationship between at least one band (range of wavelengths) and an Earth feature.


When Einstein went for walks with his dog and his baby son,

he would often jot equations down on scraps of paper and

tuck them into the pram. The baby probably saw the world

in light and color, the dog in scents, but Einstein saw the

world in mathematical equations.16

Bohr Taking Quantum

LeapsT E A C H E R E D I T I O N

Teaching Tips Students often make physical models of the natural world, but the idea of creating a mathematical model may seem strange to them, though mathematical models are the most common method used in science today. One analogy that may be familiar to students is the “model” that a gambler uses: The chances of a certain team winning depends on a number of factors. Each gambler weighs the factors in a unique way, and only experimentation (experience) determines which model is most accurate. There are many additional ideas and activities for students in Gilbert and Ireton’s Understanding Models in Earth and Space Science (see“Extended Reading”).

Modeling the Real WorldThis modeling exercise can be adapted depending on the grade level of the students. If students have not yet studied algebra, they can choose word descriptions; if they have algebra skills, they can experiment with functions. More advanced students can do curve fitting with Excel or scientific calculators. (Note: Air pressure varies greatly, and the curve is actually not linear at high altitudes. These values are approximate.) Present the following scenario to students: Imagine you are traveling up through the atmosphere in a hot air balloon, and you have a barometer and altimeter. Imagine measuring the air pressure as you rise. Here are the data you collect (see graph).

Ask students to choose the expression that matches the data best (answers in bold):

Air pressure increases just as much as altitude • increases. Air pressure decreases as altitude increases. • Air pressure doubles as altitude decreases. • Air pressure is always half of the altitude.•

Now ask students the following questions (answers in bold):

Altit

ude

Air Pressure8000

7000

6000

5000

4000

3000

2000

1000

0

Air PressurePressure Millibars

0 500 1000 1500


Bohr Taking Quantum Leaps16


1. What will the air pressure be if the balloon rises to 8,000 feet? Approximately 390 millibars (Note: The slope changes above 4,000 feet so curve fitting is less than accurate.)

2. Scientists often use equations to describe data like these. Which of these equations would come closest to predicting the air pressures at altitudes below 4,000 feet? Pressure = (11,000 – altitude)/11• • Pressure = (11,000 – altitude) × 11 Pressure = 11,000• / altitude Pressure = 11,000 + altitude•

In Their Own WordsRead aloud the following paradox from Zeno (495–430 BC):

Listen to the following argument: Achilles runs 10 times as fast as a tortoise, neverthe-less he can never catch the tortoise. For, suppose that they start in a race where the tortoise is 100 meters ahead of Achilles; then when Achilles has run the 100 meters to the place where the tortoise was, the tortoise has proceeded 10 meters, having run

one-tenth as fast. Now, Achilles has to run another 10 meters to catch up with the tor-toise, but on arriving at the end of that run, he finds that the tortoise is still 1 meter ahead of him; running another meter, he finds the tortoise 10 centimeters ahead, and so on, ad infinitum. Therefore, at any moment the tortoise is always ahead of Achilles

and Achilles can never catch up with the tortoise. —Zeno

Ask students, “Could you draw a graph that would represent the tortoise and Achilles?”

VocabularyModel•

Online Learning ToolApplet: Decay www.lon-capa.org/~mmp/applist/decay/decay.htm

Extended ReadingGilbert, S. W., and S. W. Ireton. 2003. Understanding models in Earth and space science.

Arlington, VA: National Science Teachers Association.

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of half-lives and dating techniques:



Bohr Taking Quantum Leaps16

Scientific dating often involves measurement of radioactive carbon isotopes in a sample. On page 135 of your text, you learned that the half-life of the isotope is 5,730 years. By about 50,000 years, the amount of isotope left in a sample is normally so small that it is difficult to get accurate measurements. The graph below is a model of the decay of a different isotope, radioactive potassium. (It’s often found in zircon crystals in igneous rocks.) It decays to argon, with a half-life of 1,251 million years. Imagine you are writing a proposal for a new research project. What kind of scientific question would be better answered with K-Ar dating than carbon-14 dating? Why would your results be more accurate with one method versus the other?

In their proposals, students should demonstrate an understanding that answering questions about Earth events of more than 1 billion years ago (for example, the appearance of the earliest forms of life) requires K-Ar dating.

Amou

nt o

f Par

ent N

uclid

e Re

mai

ning

Number of Half-Lives(Each half-life is equivalent to 1251 million years)

0

1/1

1/2

1/4

1/81/16

1 2

Sample containing ½ of original amount of parent material is 1,251 million years old.

2,502 million years

3,753 million years

5,004 million years

3 4 5

Original 40KDaughter Nuclides

40Ar-------- = 1 40K

40Ar-------- = 3 40K 40Ar-------- = 7 40K 40Ar-------- = 15 40K

Adapted from “Dr. Nicholas Short’s Remote Sensing Tutorial, Section 2: Geological Applications I: Stratigraphy and

Structure,” NASA/Goddard Space Flight Center. http://rst.gsfc.nasa.gov/Sect2/K-Adeclay.jpg.

Intro.


When x-rays hit atoms, the electrons in their outer shells

sometimes splatter, like mud does when it is hit by water

from a hose. The result of x-rays hitting atoms is not a mess

but an amazing image that physicists can interpret. The

patterns hold clues to structures we can’t see clearly.17An American

Tracks Photons; a Frenchman Nails Matter


Teaching TipWhen describing the first views of the internal structure of crystals, it is no exaggeration to describe them as works of art. The order that William and Lawrence Bragg found in metal crystals inspired not just researchers but those who appreciated the beauty of this unseen universe.

Crossing BordersScience can reveal structures that are as beautiful as any artist might imagine. Have students research the crystal structure of any metal, like the actinide oxide pictured here, the zinc sulfide on page 145 of Einstein Adds a New Dimension, or any other metal crystal. (Ideas can be found on the Crystal Lattice Gallery website below.) Students can build a work of art using the crystal structure as a subunit.

VocabularyX-ray crystallography•

Online Learning ToolsBragg’s Law and Diffraction: How Waves Reveal the Atomic Structure of Crystals www.eserc.stonybrook.edu/ProjectJava/BraggCrystal Lattice Gallery www.uncp.edu/home/mcclurem/lattice/lattice.html

Extended ReadingThe Structures of Life http://publications.nigms.nih.gov/structlife/chapter2.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ appreciation of scientists’ essential questions regarding light during Compton’s time:

© Copyright 2006 Los Alamos National Security, LLC. All

Rights Reserved. http://lanl.gov/source/orgs/nmt/nmtdo/

AQarchive/04summer/xray.html.



An American Tracks Photons; a Frenchman Nails Matter17

Louis-Victor de Broglie’s military responsibility was sending telegraphs. In the days when this was the only form of communication, messages had to be brief. (People paid by the word so they were concise, similar to today’s instant messaging or text messaging.) Write a telegram message in less than 20 words describing Arthur Compton’s discoveries.

In their telegram messages, students should include, in succinct language, evidence that light sometimes acts as a particle.

18What’s Uncertain?

Everything, Says

HeisenbergT E A C H E R E D I T I O N

Intro.


Intro.


The closer physicists got to the quantum world, the more

puzzling it became. It seemed impossible to measure the

same particle or phenomenon twice. Einstein struggled

against randomness, and he insisted that God was not

“playing dice.” But researchers must learn to accept

uncertainty.

Teaching TipPiaget suggests that many adolescents have trouble with the concept of proportionality, which extends to mathematical uncertainty. Do not assume that students have a good understanding of ratios.

Playing Dice for Real Prizes Can reliable predictions be made about random events? Ask each member of the class to toss a penny 10 times. Then, make a frequency graph, grouping students by how many heads they got. (A sample for 30 students is shown.) Add up the total number of heads and remember that number. Next, repeat the experiment but have students toss a penny 100 times each. Graph the frequency once again. Then compare the percentage of heads in each trial.

After the experiment, ask students the following questions (answers in bold):

1. Did the ratio come closer to 50/50 as the number of trials increased? Why or why not? In any random event, the larger the number of trials the more likely the result is to be characteristic of the entire system. Note: Coins are not symmetrical and almost never result in perfect ratios.

2. What does this say about observations about random events? There is an optimal number of observations. (Students may note that pollsters and other behavioral scientists calculate the most efficient number of samples to take.)

Num

ber o

f Stu

dent

s

Number of Heads

Ratios of Heads10

5

1 2 3 4 5 6 7 8 9

Num

ber o

f Stu

dent

s

Trials

Percent of Heads60

40

201 2



What’s Uncertain? Everything, Says Heisenberg18

Have students divide the coins into new coins (less than 10 years old) and old coins. Then calculate the percentage of heads in each group.

3. Are coin tosses really random? Does it make a difference if the coin is old or new? Why or why not? The way in which a coin wears with use can affect its mechanics when it is tossed.

4. What other factors might affect the phenomena that we think of as random, like coin tosses? The process of minting coins does not create a symmetrical object, so the coins do not flip consistently.

VocabularyMechanics• Randomness• Uncertainty•

Online Learning ToolUnderstanding Uncertainty http://school.discoveryeducation.com/lessonplans/programs/understanding-uncertainty

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of randomness:

When pollsters want to know information about an issue, they try to choose a small sample of random people who would represent the entire population. Think of a controversial question in your community. Then think of three locations that you might go to do opinion polls. Two of the locations should be nonrandom: They should be places where the people would mostly agree on one side or another about the issue. The third place should be the location where you think the opinions would be random. Write a short newspaper article about the opinions you think you’d find on this issue in these locations.

Provide the following example to students to further explain the assignment: Suppose an investor wanted to start a new radio station in town and wanted to know the favorite music in the community. If the survey were taken at a youth center, in front of a theater where a teen movie was being shown, or at a store where there was a sale on video games, the results might be skewed in one way. If it were taken in front of the senior center or a place that offered discounts for AARP members, the result might be different. The population in a large mall or at a subway stop might be relatively random. In their newspaper articles, students should include a method for getting random responses.

Intro.


Erwin Schrödinger imagined the uncertainties he could

not see, using the analogy of a cat in a box. We use other

analogies to think of atoms and molecules—some more

accurate than others.19A Cat, Quarks,

and Other Quantum Critters


Teaching TipsUse the section “Up and Atom” (pp. 166–169 in Einstein Adds a New Dimension) to take a break from the historical approach and review some of the basic concepts that might confuse students. The first chapters of Einstein Adds a New Dimension review how scientists have studied the energy between atoms and molecules (Brownian motion, entropy of various states of matter), the energy that holds molecules together (bond energy), and the energy that keeps electrons around their nuclei. Chapter 20 represents an important transition, as scientists break the nucleus apart to release a totally new type of energy. This is a good time to review the basics of atomic theory, even if students have studied this material in earlier years. As students watch salts go into solution, ask them to discuss and record the differences between these forces. In Chapter 6 an animation on the “Powers of 10” was presented. In this chapter “A Question of Scale: Quarks to Quasars” (see website in “Online Learning Tools” on p. 48) expands the range of size into the subatomic world. This is a great time to compare the two websites.

Entropy, Energy, and EinsteinSome of the most common “chemical experiments” that we do every day can illustrate key concepts in chemistry. The following experiment challenges students to reconsider one of the most basic ideas of physics—entropy. While physicists express entropy in long paragraphs and mathematical equations, everyone knows the idea: Nothing gets more organized unless you put energy into it. Remind students to keep this in mind as they try this experiment. Students take a foam plastic cup and fill it with 50 ml of water at 20°C and slowly stir in 10 g of NaCl. Then they measure the change in temperature.


1. What do you observe? The temperature slowly goes down.

Encourage students to think about the molecular structure of the salt as they try to formulate an explanation for what is happening. The ions (Na+ and Cl–) are pulled apart. That takes energy. But the ions are also slightly attracted to the polar water molecules. That frees energy.



A Cat, Quarks, and Other Quantum Critters19

2. Which process is stronger as salt dissolves? Is the solution more or less organized than the original solid and liquid? The separation of ions uses more energy than the attraction between the ions and the water frees.

Direct students to the website “Energy Exchange Associated With Dissolving Salts in the Water” listed below and ask them to try the same experiment with a variety of salts, keeping the temperature the same.

3. Do they all react in the same way? If not, can you categorize the reactions? Heats of solution vary because the strengths of the ionic bonds broken as the salt ionizes are different. For example, NaCl = +1.02 kcal/mole, while CuSO4 (solid) = –16.20 kcal/mole. CO2 = –4.6 kcal/mole.

Students then try the same experiment at a warmer temperature.

4. Can you get more salt into the water before it begins to sink because no more can dissolve? Students compare other salts using the applet in “Energy Exchange Associated With Dissolving Salts in the Water.” In general, the warmer the water, the more a solid can dissolve.

Finally, encourage students to think about the situation where a gas is dissolved in a liquid (for example, the oxygen that’s dissolved in tap water).

5. When the water gets warmer, can it hold more or less oxygen? Can you explain the difference in terms of entropy? Solids get less organized as they dissolve, but gases get more organized. So in general, as the solute (water) warms, it can hold less of a gas.

VocabularyEntropy• Solution•

Online Learning ToolsA Question of Scale: Quarks to Quasars www.wordwizz.com/pwrsof10.htmEnergy Exchange Associated With Dissolving Salts in the Water www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/thermochem/

heat_soln.html

For Further InvestigationThermodynamics Laboratory www.saskschools.ca/curr_content/chem30_05/1_energy/labs/heat_solution.htm


A Cat, Quarks, and Other Quantum Critters19


EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the energy in substances:

Salt is a great way to melt sidewalk ice but it kills plants. Can you propose an alternative that would work as well? Explain why you think it would work.

In their explanations, students should include an example of either an exothermic reaction or a solution process that would lower the freezing point of water.


From Cambridge, England, to Cambridge, Massachusetts,

the race is on to smash the atom. A machine is built to

accelerate protons and reveal the nucleus’s secrets.20 Smashing Atoms


Teaching TipsThis chapter represents a major leap, not only in science but in student understanding. For many students subatomic particles may seem counterintuitive. In addition, the size of the subatomic particles will be difficult for students to imagine. Physical models are especially appropriate for this transition. Keep the models for continued reference as students explain new ideas in the next dozen chapters. The structure of the Fermi Laboratory accelerators will be referenced in a number of future chapters. The Fermilab games from the Fermilabyrinth (Warp Speed Game) website below are used in Chapter 27 but are appropriate here as well. The work of Leo Szilard, especially the Manhattan Project, is also referenced in later chapters. His political activities are also important in this story.

Falling ApartIn this activity, students build models of the Standard Model of particle physics. Half of the class builds a model like the one pictured here using dice that have been relabeled with stickers. The other half of the class builds their models from plastic foam balls that are sold in craft stores. (Note: Although this open-inquiry exercise challenges students to explain a model they themselves create, it does not require explicit instructions. However, before students assemble their plastic foam–ball atoms, they must cut their neutrons and restick them with tiny Velcro dots. They also need to color code the particles with markers and use tiny bits of clay to hold the entire nucleus together.) Have students explain their version of the model to a partner who has built another model, and encourage students to think about the advantages of both versions.

Elementary Particles

electron neutrino muon neutrino tau neutrino Z boson

electron muon tau W boson

up charm top photon

down strange bottom gluon

Quar

ksLe

pton

s Forc

e Ca

rrier

s

Three Generations of MatterI II III


SMASHING ATOMS20


VocabularyAccelerator• Gluon• Neutrino• Quark• Standard Model of particle physics•

Online Learning ToolsApplet: Quarks www.lon-capa.org/~mmp/applist/q/q.htmFermilabyrinth (Warp Speed Game) http://ed.fnal.gov/projects/labyrinth/games/index1.htmlParticle Physics, Quarks, and All That http://home.fnal.gov/~carrigan/Pillars/Quarks.htm

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of subatomic particles:

Szilard’s model wasn’t physical; it was mathematical. Imagine you are writing the cover sheet that he might have placed on the paper as he offered it to his doctoral adviser. Explain why you think the revolutionary approach should be considered instead of traditional models.

Although student responses will vary, it’s important for students to emphasize that a mathematical model must be consistent with observations and be able to predict future phenomena.


Linus Pauling didn’t just know about chemistry; he

understood chemicals. His understanding of bonding

enabled leaps of progress in his field as well as in medicine

and genetics.21Chemistry, Charisma, and Peace


Teaching TipsExploring crystals is a good anticipatory activity for this chapter. Students do not need a great deal of experience to visualize the internal structure of a crystal. For the activity below, use kosher salt and only small, labeled quantities of alum. Safety tip: Avoid mineral samples that could contain asbestos or heavy metals, and wash hands after handling. If snowflakes aren’t available for this activity (from the inside of a traditional freezer), pictures can suffice. When students reach the limits of their imaginations, introduce the x-ray diffraction concepts from Chapter 17. If your facilities permit, isolating a spiraled mass of students’ own DNA is relatively straightforward; directions can be found in many biology lab manuals.

Can You See With a Crystal?Even with the best of today’s technology, it is impossible to see molecules directly. But we can often see properties of very well-ordered materials, like crystals, that give us clues to how their molecules are arranged. For this activity, students look at each of the crystals listed in the table below with a hand lens or stereo microscope, draw what they see, and fill in the table (answers are in bold.). Then students use their imaginations to develop a hypothesis about how the molecules are arranged and show it in another drawing. Finally, students use the internet (see “Online Learning Tools”) to discover what chemists know about how the molecules are arranged.

Crystal External Structure Hypothesis:

Molecular Structure

Your Research

Salt Cubic

Snowfl ake Snowfl akes (six-sided);

ice forms rhomboids

Quartz Hexagonal

Alum Tetrahedral


chemistry, charisma, and peace21


Show students the image provided here and describe how the angles of the hydrogens contribute to six-sided snowflakes. NASA’s “The Chemistry and Thermodynamics of Ice Cream” activity (see “For Further Investiga-tion”) provides a good resource and also explains the phenomena:

The hydrogen atoms are attracted to each other and form hexagonal rings in all directions. As ice crystals or snowflakes grow, they expand by attaching new water molecules to each other. Looking at them with a hand lens or microscope tells us about how they join together. The angles are always the same so the designs always have six sides. Whether ice crystals or snowflakes, observing the shape under “atomic microscopes” reveals a shape that is always hexagonal.

VocabularyIonic bond• Covalent bond•

Online Learning ToolsAutomatical Pattern Making www.asahi-net.or.jp/~SI4K-NKMR/inpaku/p400e.htmInteractive Example: 2D Crystal Builder www.mineralogie.uni-wuerzburg.de/crystal/teaching/ispace_a.htmlStructure of Solids www.chm.davidson.edu/ChemistryApplets/index.html#StructureOfSolids

For Further InvestigationThe Chemistry and Thermodynamics of Ice Cream http://deepimpact.jpl.nasa.gov/educ/IceCream04.htmlCrystal Growth and Buoyancy-Driven Convection Currents http://quest.nasa.gov/space/teachers/microgravity/11grow.htmlMob Rules (An Experiment on Crystals Aboard the International Space Station) www.nasa.gov/vision/space/workinginspace/16jun_colloids_prt.htm

Extended ReadingPasachoff, N. E. 2004. Linus Pauling: Advancing science, advocating peace. Berkeley Heights,

NJ: Enslow.

Source: “The Chemistry and Thermodynamics of

Ice Cream,” created for the Deep Impact Mission,

A NASA Discovery Mission, by Maura Rountree-

Brown and Art Hammon. http://deepimpact.jpl.

nasa.gov/educ/IceCream04.html.



Chemistry, Charisma, and Peace21

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of crystal structure:

One of the most famous x-ray diffraction photos was the one taken of the DNA molecule by Rosalind Franklin, pictured here. Today most people are familiar with the arrangement of the molecules in DNA. Can you explain the connection between the molecule and the image? What was Franklin seeing?

In their written explanations, students should answer that Franklin saw the center of the spiraled helix. Students should also explain that the atoms reflected x-rays.

Source: Talking Glossary of Genetics, National

Human Genome Research Institute, National

Institutes of Health. www.genome.gov/Pages/

Hyperion/DIR/VIP/Glossary/Illustration/Images/

dna.gif.

Intro.


Einstein’s short equation revolutionized how we see the

universe.

22

Energy Equals Mass Times the Square

of the Speed of Light or E=mc2


55

Teaching TipResearchers tell us that unless students have time to examine the paradigms that they bring to class, it is almost impossible for them to learn new ideas and construct new understandings. That is certainly the case for the idea of conservation of matter and energy. Until this point, it may have been a phrase that students heard, read, or memorized. Before this text or any lesson, students need to re-examine what they already know.

Conservation ConundrumBefore students think about that equal sign in Einstein’s equation, encourage them to reconsider the idea of conservation of mass and energy in normal chemical reactions. For the following activity, students will need a water bottle filled with 30 ml of water; an Alka-Seltzer tablet; and a small, round balloon. Alka-Seltzer is made of sodium bicarbonate and citric acid. In water, the tablets react to form sodium citrate. Students first must carefully mass each component and fill in the chart below.

Material Mass in Grams

Balloon

Alka-Seltzer

Bottle + water

Total

Then students stretch the mouth of the balloon a bit to make it more flexible. After that, students break the Alka-Seltzer tablet over a bit of paper and put the entire tablet into the water. Students immediately put the balloon over the bottle, watch the reaction, and then feel the bottle. After students put the balloon over the bottle and watch the reaction, ask them the following questions (answers in bold).

1. Does the bottle get warmer or cooler? Why? Cooler. The reaction is endothermic.



Energy Equals Mass Times the Square of the Speed of Light or E=mc222

When the reaction is done, students estimate how much volume has been added using the formula for the volume of a sphere: V=4/3πr3. (Answers will vary depending on the size of the balloon.) Students then mass the total.

2. How close is the mass to the original? Very slight differences can result from the escape of gas through the walls of the balloon.

3. Has energy gone in or come out of the system? Gone in 4. Where did that energy come from? From air, hands, or table

VocabularyConservation of energy• Conservation of mass•

Online Learning ToolsApplet: Ideal Gas www.lon-capa.org/~mmp/applist/pvt/pvt.htmConservation http://library.thinkquest.org/3042/conservation.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of nuclear energy:

Einstein wondered why the energy contained in every gram of material went unnoticed for so long. Many natural phenomena are misunderstood, and people tend to believe “old wives’ tales” or assumptions without really examining them. Think of something you know about science that many people don’t believe or understand. Think of a short YouTube video that you could make to explain it to an uninformed person.

In their examples, students should include a specific misunderstanding and a specific observation that could be used to illustrate a concept. Many times, these observations take the form of “discrepant events.”

Intro.



The path to war can be traced around the world and

through almost every walk of life.23On the Way to War

(a List of Happenings)


Teaching TipThis is the ideal chapter for interdisciplinary teams. Below you’ll find two different methods for both organizing and reviewing content.

Mapping the PlayersThe student edition contains a blank version of the map below. For this activity, students outline the Axis powers and Allied forces in World War II, and mark the sites where each phase of the war began.

VocabularyDigital computer•

Answer key: Axis powers Allied forces All ied forces that joined after Pearl Harbor neutral countries



On the Way to War (a List of Happenings)23

For Further InvestigationThe Manhattan Project: An Interactive History www.cfo.doe.gov/me70/manhattan/index.htmManhattan Project www2.scholastic.com/browse/article.jsp?id=5203The Perilous Flight: America’s World War II in Color www.pbs.org/perilousfight

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of World War II, especially its catalysts:

Draw a fishbone diagram (you may use the example as a guide) to show the events that led to the war.

Intro.



Leo Szilard was the contrarian, constantly posing questions

that seemed unanswerable. Enrico Fermi was the hard worker,

spending endless hours resolving his students’ questions. As

Adolf Hitler built support for his Nazi agenda, these scientists

built on the work of Frédéric and Irène Joliot-Curie, Lise Meitner

(who was also fighting gender bias in the scientific world),

and others. Ultimately, the physicists found a self-sustaining

process of nuclear fission that would change the world.

24 The Fission Vision


Teaching TipsAlthough they may have heard the term many times, students often have difficulty conceptualizing the process of nuclear fission. The kinesthetic simulation below, as well as the two suggested applets, are worthwhile activities for clarifying the process of nuclear fission. Ask students to respond to what they model and observe in discussions and journal entries. Another point of confusion is the source of fission energy—the nucleus rather than the electron shells. Remind students that before fission became a reality, even physicists were skeptical that bombarding a nucleus with neutrons could create significant energy. Labeled drawings can help clarify this concept.

Fission SimulationStudents can model nuclear fission in an open space. In the following simulation, students represent uranium atoms, either U-235 (which is fissile) or U-238 (which is nonfissile), while the teacher represents the neutron. Students draw roles at random, based on predetermined ratios. For the first simulation, 25% of students should draw fissile. Once roles have been assigned, students stand in a matrix formation, leaving 1 m between one another. (Discuss this arrangement with students as they move to their positions: The rigid structure may remind them of atoms in a crystal.) Make sure students understand the directions for their roles. The neutron (teacher) walks into the formation in a straight line and touches the first atom (student) he or she encounters. If the atom is nonfissile, nothing happens. The neutron continues on the same straight path and touches another atom at random. When a fissile atom is touched, that student silently counts, “One tomato, two tomato, three tomato,” then shouts, “Bang,” and quickly (but gently) tags all the other students within arm’s reach. If one of the atoms touched is nonfissile, it remains still, but if it is fissile, it repeats the count and then tags surrounding atoms. Capture and play back the simulation via audio or video recorder. The class can count the number of “bangs” that occur until the process stops. In the second round, students draw new roles. This time designate 50% of them fissile; in the third round designate 75% fissile. Students should track the number of generations of reactions (“bangs”) for each percentage of fissile atoms using the chart on page 60:



the fission vision24

% Fissionable

# of Generations

of Reactions

25

50

75

While discussing the data, students can compare the various ratios they have modeled and answer the following questions (answers in bold):

1. What percentage of fissile atoms produced the longest/strongest chain reaction?75%

2. Why? The chain reaction is longer because the likelihood of finding a fissile atom is higher.

You may also want to extend the discussion to incorporate current events. News stories often cite the role of governments in enriching uranium. Lead your class into a discussion of the high ratio of fissile to nonfissile isotopes necessary for the chain reaction to be perpetuated.

3. On the news you often hear the term enriched uranium. Why do scientists enrich uranium before fission can occur? The higher the percentage of fissionable material, the stronger the reaction.

Encourage students to look carefully at the diagram on page 217 of Einstein Adds a New Dimension. Note that when the first neutron hits the uranium-235, two neutrons are released in addition to the original one. In the next reaction, potentially nine neutrons are released. Have students complete the table showing the reaction number and number of free neutrons (see p. 61) and answer the following questions:

4. How many reactions are required to release at least 1 million free neutrons? 13 5. Graph the number of free neutrons in each reaction. What is the shape? The result

is a curve in the shape of a J. 6. If each reaction takes about 10–7 second, how long will this process take? 13 × 10–7

seconds 7. In fission reactors, rods are sometimes used to slow reactions. If a rod absorbed

one of every three released neutrons, how would the shape of the graph change? It would slope later but have the same J shape.




Reaction # Free Neutrons

1 3

2

3

4

5

6

7

•

•

•

n > 1 million

VocabularyFission• Fusion•

Online Learning ToolsChain Reaction: Mouse Trap Model www.physics.umd.edu/lecdem/services/demos/demosp4/p4-62.htmNuclear Fission www.lon-capa.org/~mmp/applist/chain/chain.htm

For Further InvestigationEinstein’s Big Idea: Messing With Mass www.pbs.org/wgbh/nova/teachers/activities/3213_einstein_03.htmlNuclear Science in Society: Student Fission Activity http://old-www.ansto.gov.au/edu/pdf/stu_act1_9.pdf

Extended ReadingSullivan, E. 2007. The ultimate weapon. New York: Holiday House.

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of nuclear fission:




Physicists love to do rough, “back of the napkin” estimates. These are often called Fermi Questions after Enrico Fermi. Here’s a Fermi Question for you: Look at the chart below. It shows the energy needed to get from Earth to the dwarf planet Pluto, at the edge of our solar system, if we were to harness the energy of a fission reaction. Compare that to the energy available in gasoline. If we could somehow create a gasoline-powered rocket, how much fuel would we need to get to Pluto? How much mass would that represent?

Answers are in bold.

Fuel

Mass (g) per

Molecule or

Reaction

Energy Released

per Molecule/

Reaction (eV)

# of Reactants/

Reactions

Needed to Get

to Pluto

Total Mass of

Fuel Needed

Fission 4 x 10-23 2 x 107 3.5 x 1024 680

Gasoline 1.9 x 10-22 66 1.2 × 1031 2.3 × 109

Source: Adapted from NOVA, “A Trip to Pluto.” www.pbs.org/wgbh/nova/teachers/activities/3213_einstein_05.html, where

complete answers, explanations, and extensions can be found.

Intro.



At Princeton, Einstein found security, friends, and inspiration.

He also became an inspiration for many who considered

him the university’s resident genius. But in many ways he

was still the young man imagining a ride on a light beam.

Everything fascinated him.25Presidential

PowerT E A C H E R E D I T I O N

Teaching TipsThis is a long chapter in which social relationships are interwoven with vital scientific ideas. Encourage students to find the key science ideas, while at the same time discussing the ways in which scientists interact. As students grapple with the heavy significance of heavy water, do not hesitate to take a side trip to explore how the yo-yo works. Einstein did. The “Evaluation” section implies that a good scientist must be able to communicate his or her ideas. But there is an opposing view. Once, when asked by a reporter to explain his ideas in simple terms, Richard Feynman said that if he could, it would not have merited the Nobel Prize! Students might argue that scientists must be able to communicate, but many find it difficult.

The Manhattan Team For this activity, students use a concept map to describe the contributions of the scientists in this chapter. Students should add as many circles as they like to the diagram for scientists they would like to investigate. Ask students: “How are social relationships among scientists important for the development of ideas?” Although answers will vary, students should realize that there are different styles of learning and thinking, and that informal conversations are as important as formal publications in presenting ideas. An example of a student concept map is offered here:

Fermi

Szilard

Feynman

Fission

Teller

Oppenheimer



Presidential Power25

VocabularyDeuterium• Heavy water•

Online Learning ToolsHow We Know What We Know (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxYo-Yo Animation www.rotatingobjects.com/animation4d.html

For Further InvestigationThe Physics of a Yo-Yo http://clackhi.nclack.k12.or.us/Physics/projects/Final%20Project-2005/2-FinalProject/

yoyo/physics%20of%20yoyo.htm

Extended ReadingHow Yo-Yos Work www.howstuffworks.com/yo-yo.htm

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the role of curiosity in scientific study:

What are the key characteristics of a scientist? One trait is curiosity. Einstein wondered about light, the universe, and yo-yos. Study a yo-yo or go to the Yo-Yo Animation website above to complete the activity.

Put the loop on your finger. Why does the yo-yo move down?

Predict how far the yo-yo will move back up the string.

Then let the yo-yo fall without moving your hand. Was your prediction correct?

Repeat the motion. Does the yo-yo move the same amount up the string each time?

Write a paragraph explaining the motion of a yo-yo. (Use velocity and momentum in your explanation if you can.) Illustrate your paragraph with a picture.

In their paragraphs and illustrations, students should reflect an understanding that gravity and elasticity are opposing forces in the operation of the yo-yo.

Intro.



Szilard warned the world to be ready, while Bohr was spirited

from Scandinavia to England. Across the ocean, the world’s

best scientists struggled to make amazing progress in record

time. Isolated in New Mexico, great minds worked together

to create a massive weapon...hoping that devastating

destruction would ultimately achieve peace.

26 Manhattan on a Mesa


Teaching TipsThe story of the Manhattan Project can work on at least three levels for students. The basic progress of the nuclear science and control of fission continues. However, there is also the story of how scientists of different backgrounds, talents, and methods interacted and how they handled ethical and political issues. The role-play in the activity below can emphasize any of these levels, depending on students’ maturity and the time you wish to allocate to research. It is important to show students the human side of these scientists. For example, Oppenheimer was interested in ancient language, Teller in music, and Feynman in magic tricks. The movie Fat Man and Little Boy is an outstanding reenactment of the personal and psychological dynamics of the Manhattan Project (this movie is good for older students). If you show the movie, emphasize one sentence at the start of it: “You have all these great minds dancing to different tunes…” The movie also highlights the ongoing argument between Robert Oppenheimer and General Groves about the value of free and open discussion, as well as the significant political discussion about whether a demonstration of the bomb should be made on an uninhabited Japanese island rather than in the city of Hiroshima. (There were only two bombs.) Note: One mature scene with sexual overtones makes this movie PG-13. The study of this area of history can be extended and enriched with classic literature. For example, students can read and interpret parts of R.U.R. (Rossum’s Universal Robots) by Karel Čapek, a play written about how robotic entities caused great destruction for humans. After students read the play, ask the following questions:

1. Who were these robots and what did they have to say to the world during the 1920s?

2. How do the philosophies and actions of the robots mirror and compare to the scientists at work on the Manhattan Project?

Debate Beneath the MesaFor reasons of security, the scientists of Los Alamos were strictly isolated as they worked on the Manhattan Project. Imagine the conversations they might have had. For this activity, students take on the role of any of the scientists represented in the concept map developed for Chapter 25. Students research the scientists’ backgrounds and skills and then imagine a conversation about the nature of matter and energy from each of their perspectives.



Manhattan on a Mesa26

For example, suppose Oppenheimer (expert in Sanskrit) had told his colleagues: “The founder of the Vaisheshik Darshan school of Hindu philosophy was Acharya Kanad. He described atoms in the 9th century BC. He classified all objects in creation into nine elements—earth, water, light, wind, ether, time, space, mind, and soul—and said: ‘Every object of creation is made of atoms, which in turn connect with each other to form molecules.’” How would the other scientists respond to Oppenheimer’s statement? Students create a short, imaginary conversation among the Los Alamos scientists to illustrate how the scientists’ approaches might have differed.

Online Learning ToolEinstein’s Big Idea: The Power of Tiny Things www.pbs.org/wgbh/nova/einstein/tiny.html

Extended ReadingCapek, K. 1921/2004. R.U.R. (Rossum’s universal robots). Repr., translated by Claudia

Novack-Jones, New York: Penguin.

Video ValuePaul Newman, Dwight Schultz, Bonnie Bedelia, and John Cusack. 1989. Fat Man and

Little Boy. DVD. Directed by Roland Joffé. Hollywood, CA: Paramount Pictures.

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the importance of scientific study:

Below is an excerpt from a poem that Richard Feynman wrote as part of his “The Value of Science” address to the autumn meeting of the National Academy of Sciences, in 1955:

Deep in the seaAll molecules repeat

The patterns of anotherTill complex new ones are formed.They make others like themselves

And a new dance starts.Growing in size and complexity

Living thingsMasses of atomsDNA, protein

Dancing a pattern ever more intricateOut of the cradleOnto dry land

Here it is


Manhattan on a Mesa26


StandingAtoms with consciousness

Matter with curiosity.Stands at the sea, wondering: I

A universe of atomsAn atom in the universe.

Write your own poem about humans from the perspective of quantum physics. In their poems students should include at least one accurate science fact and creative observations regarding the consequence of that fact.


For both Einstein and Feynman, the universe was

an interconnected place, where nothing was really

separate from anything else. But there are aspects of

quantum theory that don’t work in a relativistic world.

Quantum electrodynamics marries quantum theory with

electrodynamics and relativity.27Quantum

Electrodynamics? Surely You’re

JokingT E A C H E R E D I T I O N

Teaching TipsThe principles of quantum electrodynamics challenge graduate students and are elusive to anyone below that level. But your students can learn a lot about how particle physics works from debating ideas about how light and matter interact, or how the time and space paths of subatomic particles relate to their functions. You can draw parallels between the 1948 Copenhagen conference (at which Feynman was one of the youngest participants) and the 1911 Solvay Conference (at which Einstein was the youngest presenter). Students will enjoy discussing the relationship between younger and older students of any field.

Life’s a Game—and a Dance!Most people think scientists conduct “controlled experiments” all day. But that’s not how particle physicists work at all. After students have read “Adventures in Particle Research” on page 259 of Einstein Adds a New Dimension, direct them to the Fermilabyrinth website to play “games” that simulate how particle physicists work. Encourage students to visualize elementary particles by dancing with the quarks at the “QuarkDance.org” website. Say, “I like to polka, do you?” After students have enjoyed the quark dance, encourage them to visit “The Particle Adventure” website to help them answer the following questions (answers in bold). Encourage students to be as specific as they can in their answers.

1. What does fundamental mean? “Fundamental” particles, or building blocks, cannot be broken down into smaller pieces.

2. What particles are fundamental? Scientists currently believe quarks (which make up protons and neutrons) and leptons (of which electrons are an example) to be fundamental particles.

3. What forces are fundamental? Scientists talk about strong and weak nuclear forces, electromagnetism, and gravitation.

4. Where do these forces act? They act everywhere in the universe. 5. Which fundamental force is the strongest? Although it depends on the distance,

the strong nuclear force has the greatest potential. 6. Which is the weakest? The weak nuclear force 7. Does this surprise you? Why or why not?


Quantum Electrodynamics? Surely You’re Joking27


8. How many quarks are there? What are their names? There are six kinds of quarks: up, down, strange, charm, top, bottom.

9. Do quarks pair up? How? For each quark there is an antiquark; when they meet, they annihilate one another.

10. What is meant by “color charge”? Color charge really has nothing to do with color. It is a way that physicists describe the kind of a quark or gluon and how it behaves.

VocabularyElectrodynamics• Fundamental particle• Quantum mechanics•

Online Learning ToolsAnimations for Breaking Spacetime Symmetries http://physics.indiana.edu/~kostelec/mov.html#5Fermilabyrinth http://ed.fnal.gov/projects/labyrinth/games/index1.htmlHow We Know What We Know (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxQuarkDance.Org http://pdg.lbl.gov/quarkdanceThe Particle Adventure http://particleadventure.orgTiny Machines—The Feynman Lecture on Nanotechnology www.photosynthesis.com/flash/tiny-machines/video.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the types and variety of skills that may be valuable in science:

Write a “Want Ad” for a job for a particle physicist. List the qualifications, the rewards, and the challenges.

Although answers will vary, students should realize that a high level of education (including strong preparation in mathematics and physics) would be required, as well as the abilities to be organized and to work well with teams. The job requires great patience and accuracy, and the salary will be lower than that of other professions requiring similar levels of education, such as a doctor, lawyer, and engineer.


Galileo understood the basics of relativity; he realized that

perspectives could be different depending on your position

and your movement. Einstein took Galileo’s ideas one giant

leap forward.28Those Relatives:

Galileo and Albert


Teaching TipsThe next three chapters challenge student preconceptions with selected applications of special relativity. Therefore, this is a great time to repeat basic concepts, reinforcing them with the website listed on page 71 under “Online Learning Tools.” As an alternative to the “frame of reference” activity below, try playing a simple melody on a piano transposed in two or three different keys. Ask students, “What is the same? What is different?” As an example, students may find that no matter what the key, the ratio between the third and fourth step in a scale is always half of the ratio between the fourth and fifth. A scale is “relative.”

Perspective—It’s All RelativeThis simple activity is a good way to begin a discussion on “frame of reference.” Students begin by identifying a tree on the school property within sight of the bleachers. Before they know their assignment, divide students into teams of three. Place one student from each group under the tree, one as far as possible from the tree, and another on the top of the bleachers (make sure students are careful on the bleachers). Depending on your campus, other sites may be appropriate. Once situated, ask each student to draw the same tree on the same size paper from their individual perspectives. Back in the classroom, students compare the different “frames of reference” of each member of their group. Ask students the following questions (answers in bold):

1. How does the picture vary from the different perspectives? The drawings vary in size and position relative to backgrounds, as well as lighting and the students’ personal views.

2. How does frame of reference determine what information you receive? The perspective, distance, background, and preconceptions affect what you see.

In Their Own WordsAsk students to think of real-world examples of the idea discussed in Galileo Galilei’s (1564–1642) relativity hypothesis:

Any two observers moving at constant speed and direction with respect to one another will obtain the same results for all mechanical experiments. —Galileo Galilei


Those Relatives: Galileo and Albert28


VocabularySpeed• Velocity• Acceleration•

Online Learning ToolsAnimations for Breaking Spacetime Symmetries http://physics.indiana.edu/~kostelec/mov.html#5EinsteinLight: Relativity in Brief. Module 1: Galileo www.phys.unsw.edu.au/einsteinlightEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.htmlWelcome to the Space-Time Lab www.its.caltech.edu/~phys1/java/phys1/Einstein/Einstein.html

For Further InvestigationGalileo’s Spacetime: Introducing the Principle of Relativity (includes Galilean Map Reading 201) http://physics.syr.edu/courses/modules/LIGHTCONE/galilean.html

Extended ReadingAncestors of E=mc2

www.pbs.org/wgbh/nova/einstein/ancestors.htmlRelativity Tutorial http://aether.lbl.gov/www/classes/p139/RelativityTutorial.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of frame of reference:

Witnesses to a crime often have totally different views of what occurred. Imagine you are a prosecutor and explain to a jury how “frame of reference” matters. In their explanations, students should include an example of how two different observers might have two different perspectives.


Einstein admitted that he stood on the shoulders of giants

like Newton, but he wasn’t afraid to challenge Newton’s

most basic assumptions. Newton wrote about an absolute

space that was “immovable.” In Einstein’s world, everything

moved.29

Relativity: It ’s About

TimeT E A C H E R E D I T I O N

Teaching TipAsk students to think of a time when they were very bored and minutes seemed to tick by slowly. Then ask students to think of another example when time seemed to pass quickly. Ask students: “What was the difference in the two events? Can the circumstance make time seem relative?” This activity will help students open their minds to the idea of relativity.

Flash! Bang!On Earth, light is almost instantaneous. Most students will know about the “scout trick” of watching for a flash of lightning and then counting the seconds until a crack of thunder is heard. Sound travels at an average of 1,125 ft./sec., though the actual speed depends on temperature, humidity, and other factors. The distance to the storm cloud can be determined by multiplying the delay (in seconds) by 1,125. Make the same experiment more precise by having students use two computer-interfaced probes, one for light and one for sound. After experimenting with the computer-interfaced probes, discuss whether light moves instantaneously and ask students the following questions (answers in bold).

1. Why does this method work? Because the speed of sound is significantly lower than the speed of light, which seems to us to be almost instantaneous

2. Does light move instantaneously? No, it is simply faster than we can count or measure without specialized tools.

3. How does the medium affect its speed? The speed is different in different media. 4. How does the medium affect its wavelength? Change in speed is different for

different wavelengths, so a mixture of colors (“white light”) is separated as it moves from air to water, crystal, or oil.

5. Can you think of simple examples that illustrate this? Spectra in prisms, oil slicks, rainbows


Relativity: It ’s about time29


VocabularyGravitation• Speed of light• Speed of sound• Thought experiment•

Online Learning ToolsEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.htmlLightning Distance Calculator www.csgnetwork.com/lightningdistcalc.htmlWelcome to the Space-Time Lab www.its.caltech.edu/~phys1/java/phys1/Einstein/Einstein.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of rotation, revolution, and galactic movements:

It’s a common insult to say, “You think the world revolves around you!” But, in fact, nearly everyone in Newton’s time believed Earth was the center of the universe. Imagine you are debating an Aristotelian traditionalist in Newton’s time. Explain all the ways in which you are moving every second of every day. (Review “Hold on to Your Hat” on p. 29 of Einstein Adds a New Dimension.)

Although answers will vary, students should demonstrate understanding of the revolution of Earth, the orbit of the planet around the Sun, the movement of the solar system in the Milky Way, and the movement of the galaxy in the universe.


To a physicist, an event is an occurrence at a single point

in space and time. With this understanding, students can

reexamine the events studied by particle physicists in

accelerators such as Fermilab.

Teaching TipsThe exercise below on map projections is an analogy for non-Euclidean geometrical projections. The analogy is not exact, but it is a good, concrete example from which students can extend discussions. As students compare the distortions involved in virtually all flat representations of a round globe, they should think about the compromises that models must make. In the student materials for Chapter 43, students will be asked why the universe is represented as an oval. The answer is that it seems to represent the least distortion. But in Chapter 44, students will discover that the newest data support a flat universe. Remind students that for scientists from many different countries—like those in the Manhattan Project—the only common language was mathematics. New mathematics must precede new ideas. Do not assume that because students have completed several “thought experiments” in previous chapters, their preconceptions have disappeared. The exercise below in non-Euclidean mathematics is a way to emphasize that math is a tool of science.

It’s All in How You Look at ItNewton could never have explained his ideas without inventing calculus. Modern physicists rely on many other forms of mathematics, including non-Euclidean geometry (see “Math Matters” on p. 282 of Einstein Adds a New Dimension). To stress the importance of mathematics, students compare flat maps to a globe. Students take a look at the maps below. The one on the left is a Hammer-Aitoff projection, and the one on the right is a Mercator projection. Students compare the proportions of sizes of the United States at the 30th and 60th parallels (N). Have students use a bit of yarn to compare the proportions of various continents on the flat projections and on the globe.

800

600

400

200

00

900 600 6003001200 120015001800 00300 900

200

400

600


30An Event?

To a Physicist It ’sNot a Party


An Event? To a Physicist It ’s Not a Party30



1. Which is closest to the actual proportions of a (round) globe? While the Hammer-Aitoff projection is better, neither is accurate.

2. How does the shape of the surface affect the accuracy of a map? (Students may realize that “accuracy” isn’t a very valuable term, since each map has different values.) Only a globe is accurate.

3. Is there one single correct way to draw a spherical Earth on a flat piece of paper? No.

4. Imagine that two airplanes want to fly parallel courses along different lines of latitude from east to west on Earth. Would they fly straight lines? No. The shortest distance is often different, and may loop northward.

5. How could non-Euclidean geometry like that described on page 283 help us analyze such maps? Since the surface is not flat, the lines may not be parallel in the traditional sense.

VocabularyEuclidean• Geometry• Non-Euclidean•

Online Learning ToolsEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.htmlHow We Know What We Know (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxThe Light Cone: Events and Spacetime http://physics.syr.edu/courses/modules/LIGHTCONE/events.html

For Further InvestigationGeometry in Space http://universe.sonoma.edu/activities/geometry.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the various perspectives that can be shown by maps:

Write an advertisement for three kinds of maps, two flat projections and a globe. Describe why each is good for a specific purpose.

In their advertisements, students should promote the advantages and address the distortions inherent in each different type of map.


As the text returns to young Einstein, who struggled to

support his family by working in the patent office, the reader

returns to imagining spacetime. 31 Timely Dimensions


Teaching TipsAsk students to use language carefully as they discuss and draw the thought experiment below. What do they mean by moving? By two events being simultaneous? Students will return to a similar thought experiment as an assessment in the next chapter. Encourage students to read about NASA’s current research, which only partially verifies Einstein’s theories, at http://imagine.gsfc.nasa.gov/docs/features/topics.

Daydreaming Away Time and SpaceEinstein famously liked to participate in thought experiments. For this activity, students examine one such experiment:

A train is pulling away from a station platform. A passenger stands at the center of the moving train, and an observer stands on the platform next to the tracks. Lightning strikes both ends of the train, in a way that seems simultaneous to the person on the platform. How does the lightning appear to the person on the train?

Students draw the scenario and write a trial explanation. Have students show their drawings and explanations to other students. Here is a sample student explanation: This thought experiment challenges the idea of simultaneity. From Einstein’s standpoint (the realization he came to), there is no arbitrary rule that says that the passenger is moving and the person on the platform is standing still. They are moving relative to one another. But the lightning at the front of the train is moving toward the passenger, while it is stationary from the perspective of the person on the platform.

VocabularyDimension• Simultaneity• Spacetime•


timely dimensions31


Online Learning ToolsAtomic Clocks in Space http://physics.indiana.edu/~kostelec/mov.html#5Chasing a Beam of Light: Einstein’s Most Famous Thought Experiment www.pitt.edu/~jdnorton/Goodies/Chasing_the_light/index.html

EvaluationThe student page includes the following scenario as a tool for exploring what aspects of scientific study best capture the attention of other scientists:

A very important part of scientific work is attending conferences and meetings. Imagine the program of the Solvay Conference of 1911. Einstein was the youngest participant, but he was selected to give the “grand finale” speech. Write what might have been in the program describing what the older scientists were about to hear. Answers will vary. However, students should realize that by 1911 Einstein’s ideas were intensely interesting to, if not fully accepted by, other scientists. He fascinated others in the scientific community.


To understand motion, Einstein abandoned his under-

standing of measurements. Neither size nor mass was

constant…only time. In his mind, Einstein rode a train, then

a rocket. He found that the rocket on which his mind rode

got shorter and more massive as it accelerated.32 A Man in

a Red HatT E A C H E R E D I T I O N

Teaching TipThe “Evaluation” section is a variation on the thought experiment that was introduced in the previous chapter. This time, instead of watching lightning, both the passenger on the train and the observer on the platform are juggling. Repeating the scenario helps assess student comprehension.

Tracking AccelerationFor this activity, students are urged to think like the scientists who built a linear accelerator in the 1930s, scientists who attempted to find and measure the tiniest particles in the universe. A tiny particle is made to go faster and faster by electromagnetic forces accelerated almost to the speed of light. Students draw and explain what happens to that particle (answers in bold).

As the particle accelerates it gets more massive. Ask students, “Why is Einstein’s theory absolutely necessary for these scientists?” The original particle is so small that instruments would have difficulty tracking it, but under relativistic “rules” it becomes more massive.

In Their Own WordsAs shown in the following quote, Einstein speculated on his own education:

The ordinary adult never gives a thought to space-time problems…I, on the contrary, developed so slowly that I did not begin to wonder about space and time until I was an adult. I then delved more deeply into the problem than any other adult or child

would have done. —Einstein, to Nobel laureate James Franck


a man in a red hat32


Online Learning ToolEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.html

Extended ReadingA Pop Quiz for Einstein http://science.nasa.gov/headlines/y2000/ast24may_1m.htmEinstein’s Big Idea: Einstein Quotes www.pbs.org/wgbh/nova/einstein/wisdom.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of spacetime:

Remember the train in Einstein’s thought experiment? Now, instead of watching lightning, both the passenger on the train and the observer on the platform are juggling. Explain the movement of the balls.

One student answer might be, “To the passengers, the balls move up and down; to the observers on the platform, the balls move backward as the train moves forward.”


The paradox of the twins is probably Einstein’s most

famous—and least understood—thought experiment. 33The Paradox

of the Twins


Teaching Tips Students can research the twin paradox on their own because it is well known and understandable; many internet sources provide descriptions. Compare student expla-nations in the following “Time Travelers” activity to the diagrams of Einstein’s “rocket” on page 294 of Ein-stein Adds a New Dimension to link and integrate content.

Time TravelersFor this activity, students tell the story of the twin paradox as Einstein might have told it. Students write captions for each panel. Remind students to comment on the clock.

In Their Own WordsRead this quote from Einstein aloud to students and ask: “What charac ter istic of Einstein’s personality is common among scientists today?”

The important thing is not to stop questioning. Curiosity has its own reason for exist-ing. One cannot help but be in awe when he contemplates the mysteries of eternity,

of life, of the marvelous structure of reality. It is enough if one tries merely to compre-hend a little of this mystery every day. —Einstein, Life magazine, May 2, 1955


the paradox of the twins33


VocabularyInertia• Paradox•

Online Learning ToolEinstein’s Big Idea: Time Traveler www.pbs.org/wgbh/nova/einstein/hotsciencetwin

Extended ReadingThe Twin Paradox: Is the Symmetry of Time Dilation Paradoxical? www.phys.unsw.edu.au/einsteinlight/jw/module4_twin_paradox.htmTime Is of the Essence in Special Relativity. www.science.doe.gov/Sub/Newsroom/News_Releases/DOE-SC/2005/THE_TWIN PARADOX.htmWas Einstein Wrong About Space Travel? http://science.nasa.gov/headlines/y2006/22mar_telomeres.htm

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the twin paradox:

Has Einstein’s twin paradox been proved? Think about the experiments done at accelerators like Fermilab. (If you’ve forgotten them, review pp. 170 and 173 in Einstein Adds a New Dimension.) Write a letter to a skeptic explaining why you think Einstein’s theories have been supported.

Although answers might vary, students should note the importance of increased mass with increased speed.


There are many myths about Isaac Newton. One involves

that apple, which never did hit him on the head. Einstein

thought that Newton’s Law of Universal Gravitation may

have been a bit mythical as well.34 Relative Gravity


Teaching TipsBefore students think about gravitation and how it supports Einstein’s vision of space-time, they need to review what they already know about gravity. Before watching the video of toys in space (see “Online Learning Tools,” p. 83), allow students to play with toys that are similar to what were sent into space and then hypothesize about what happens to the toys in space. Carefully distinguish between microgravity and “weightlessness,” which doesn’t exist for all practical purposes. The resources below list NSTA’s Science Objects on traditional (Newtonian) mechanics to help students review these concepts.

Toys in SpaceGravitation is a law that is consistent throughout the universe. That’s why it’s so interesting to study gravitation on Earth. Students begin this activity by becoming familiar with how the following toys work in normal (Earth) gravity.

Next, students write a hypothesis about how the toys would work in microgravity—not zero gravity, but the much lower gravity of the space shuttle. Although hypotheses will vary, students should realize that gravity will be far less. For a ball-in-cup toy, the ball will not “fall” into the cup; for a race car on

Inertia

Gravity

Car’s Motion


relative gravity34


a track, there will be very little friction of tires on the track. Then students watch the videos on the NASA websites listed below to learn more about how the toys work in microgravity. For each toy, students should compare their hypothesis to their observations. Answers may vary, but students should have a clear hypothesis related to the role of gravitation on the function of the toy. For example, to catch a ball the player must be able to predict its “fall.” It wouldn’t fall in microgravity. The friction of tires (which is dependent on gravity) keeps tires on the track pictured on page 82. If the car was in microgravity, the car’s inertia would send it off the track.

Vocabulary• Microgravity

Online Learning ToolsForce and Motion (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxLiftoff to Learning: Toys in Space 2 http://quest.nasa.gov/space/teachers/liftoff/toys.html

EvaluationThe student page includes the following scenarios as tools for assessing students’ understanding of gravitation:

Einstein used the image of a free-falling elevator as a thought experiment. (Don’t worry, modern elevators don’t free-fall.) Write a few paragraphs of a horror story, describing a person falling in an old-fashioned elevator.

In their answers, students should point out that an old-fashioned elevator would not have the safety features of a modern conveyance. Therefore, the passenger and the carriage would fall at the same rate.

Or pretend you are a guidance counselor. You have a student who doesn’t want to take academic courses like math or physics, because he or she wants to be a NASCAR driver. Convince the student that you need physics to drive a race car.

In their answers, students should mention concepts such as friction, acceleration, and dynamics.


Einstein imagined local areas in which laws like inertia ruled

as patches in a universal quilt, stitched to a background that

acted like a rubber sheet. He challenged the rest of the world

to imagine it too.35 Warps in Spacetime


Teaching TipsWhen doing the following activity, remind students again of the values and limitations of modeling. Make sure that the piece of rubber for this activity is quite flexible. It can also be used in an activity for Chapter 40 if it is not transparent.

Warped ImagesFor this activity, students build a model of how mass can warp spacetime. Students take a very pliable piece of rubber and mark parallel lines on it when it is flat. Then students place massive objects (stones or large ball bearings to modify the model) on the rubber. (Cling wrap may be used in lieu of rubber.) For an example of what the model should look like, students may want to refer to the image on p. 313 of Einstein Adds a New Dimension.

Source: NASA/HONEYWELL MAX-Q DIGITAL GROUP/DANA BERRY, NASA/Goddard

Space Flight Center. www.gsfc.nasa.gov/gsfc/spacesci/structure/spinningbh/spinninghpix.

htm.


warps in spacetime35


After students make the model, ask them the following questions (answers in bold):

1. What does the rubber represent? Spacetime 2. What does the stone or ball bearing represent? A great mass—star or planet—or

singularity 3. How does the nature of “parallel” change? In a classical universe, parallel lines

never meet. But that’s not true in non-Euclidean geometry. 4. How does the heavy object move when the rubber is flat on a table? An object at

rest remains at rest; an object in motion remains in motion. 5. What law of traditional physics would this represent? Inertia 6. How does the model change in Einstein’s universe, when space is allowed to flex?

Mass curves spacetime 7. What modification of the laws of physics does this represent? Relativity

VocabularyEclipse•

Online Learning ToolsEvents and Space-Time http://physics.syr.edu/courses/modules/LIGHTCONE/events.htmlFluid Dynamics to Study Stars www.nsf.gov/news/mmg/mmg_disp.cfm?med_id=57213One Universe: At Home in the Cosmos: Gravity and Light www.nap.edu/html/oneuniverse/linked_motion_40-41.htmlRelativity of Simultaneity www.control.co.kr/java1/masong/relativity.html

For Further InvestigationPaper “Embedding Diagram Models” of Black Holes www.sff.net/people/Geoffrey.Landis/blackhole_models/paper_blackholes.html

Extended ReadingDelano, M. F. 2005. Genius: A photobiography of Albert Einstein. Washington, DC: National

Geographic. 1919 Eclipse and General Relativity www.simonsingh.net/1919_Eclipse.htmlEinstein’s Big Idea www.pbs.org/wgbh/nova/einstein



Warps in Spacetime35

Evaluation The student page includes the following scenario as a tool for assessing students’ understanding of the relationship between light and gravitation:

To demonstrate his ideas, Einstein predicted the bending of light in an eclipse in 1919. His predictions were not exactly correct, but once he realized his error, a new understanding of his theories resulted. Describe a mistake you’ve made that resulted in better understanding.

In their descriptions, each student should describe a specific mistake, use scientific language to explain why it was a mistake, and explain the improved understanding he or she achieved as a result.

Intro.



What we see is what we get…not only on Earth, but in the

universe. Our ability to predict what will happen at incredible

distances begins right here at home.36Does it Change?

Or Is It Changeless?


Teaching TipsThis chapter provides another familiar example of gravity, which helps reinforce the concept for students. In a literal and figurative sense, it is worthwhile to spiral the curriculum and the concepts. You can use the NSTA Science Objects listed below to review with students traditional Newtonian mechanics at any point in the course.

Relying on PhysicsIn the familiar patch of the universe that we inhabit, we rely on the constant laws of physics. To illustrate this, take your class outside to the playground and tell students to swing as high as they can (while taking safety precautions). When you return to the classroom, ask students to formulate and diagram explanations for why they don’t fall off the swing. In their explanations, students should use force arrows to show inertia, centripetal force, and gravity. Students can also explore the physics of a roller coaster by watching a video of a roller coaster or using the interactive website “Amusement Park Physics: Roller Coaster” (see “Online Learning Tools,” p. 88). Again, have students carefully describe the laws of physics that keep them from falling out of the roller coaster. Students should once again use force arrows to show inertia, centripetal force, and gravity. Students can also think about a roller coaster on Saturn’s moon Titan. Ask students: “How would the roller coaster act? How do you know?” (Answer in bold.) Mass and inertia remain the same, but gravitation changes due to the mass of the Moon.

In Their Own WordsHave students read the following quote from Archytas of Tarentum (428–350 BC):

Mathematicians seem to me to have excellent discernment, and it is not at all strange that they should think correctly about the particulars that are; for inasmuch as they can discern excellently about the physics of the universe, they are also likely to have excellent perspective on the particulars that are. Indeed, they have transmitted to us

a keen discernment about the velocities of the stars and their risings and settings, and about geometry, arithmetic, astronomy, and, not least of all, music. These seem to be sister sciences, for they concern themselves with the first two related forms of being

[number and magnitude]. —Archytas



Does it Change? Or Is It Changeless?36

Ask students to review Archytas’s speculations on the infinity of the universe (Hakim 2007, p. 323), and then pose these questions: “How advanced was Archytas? What did his spear demonstrate?”

VocabularyInfinite•

Online Learning ToolsAmusement Park Physics: Roller Coaster www.learner.org/interactives/parkphysics/coaster.htmlForce and Motion (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

Extended ReadingArchytas of Tarentum www-history.mcs.st-and.ac.uk/Biographies/Archytas.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of how the laws of physics can be used to interpret our observations:

Some shapes have edges; some don’t. Some are real; some are imaginary. Look at this one carefully. Can it exist? Why or why not?

Students should answer that a Mobius strip is an optical illusion and cannot exist.

Intro.



37 Expanding Times


Teaching TipsBegin this lesson by reviewing the Doppler effect (with real-world experiences or by going back to the suggested sources found in Chapter 9). If there is a train crossing near your school, have students listen (at a safe distance) to the train horn. If your classroom is equipped with appropriate safety equipment, it is possible to show students the various colors of very small (<0.5 g) samples of various salts (calcium chloride, copper chloride, potassium chloride, sodium chloride) in a Bunsen burner. Safety notes: Eye protection is needed; do not bring stock bottles near fire or flame.

By the Light of Ancient Stars Starlight can be investigated in a number of ways. For this activity, students compare luminosities using a standard bathroom light bar. Put a variety of 25- to 60-watt lightbulbs in the bar. (Watch the limit on the device and be careful of hot bulbs.) Students loosen all but one at a time to make measurements. Students use a photo light meter or computer-interfaced light probe to measure the illumination from each bulb as distance increases. They then graph the data. Next, students ask a partner to tighten a bulb at random and then measure the luminosity at a specific point. Ask students the following questions (answers in bold):

1. Can you predict which bulb it is from one measurement? Not if distance is unknown; you would need two measurements or would need to know the distance to the star.

2. How would you get data on distance to the star? Parallax provides one way to compare distances.

Students then use a handheld spectroscope to compare the light given off by standard incandescent bulbs with that of new fluorescent energy-saving bulbs.

3. What is the difference? The light from incandescent bulbs is normally concentrated in the yellow wavelengths.

Dutch astronomer Willem de Sitter and Belgian Priest

Georges Lemaître began to speculate about, and offer

mathematical evidence of, an expanding universe. Einstein

disagreed with their theories, and his efforts to disprove

them even resulted in an antigravitational force hypothesis.

However, in 1926 American astronomer Edwin Hubble

discovered that our Milky Way galaxy is just one of many

galaxies—all of which are moving away from one another.



Expanding Times37

Students then draw, color, and identify the wavelengths of the spectra of light on the form provided (p. 23 of Einstein Adds a New Dimension can be used as a reference).

Ask students the following questions:

4. What are the longest wavelengths? Red 5. The shortest? Violet 6. What is the meaning of the prefix “infra” in infrared? Below 7. What is the meaning of “ultra” in ultraviolet? Higher (frequency, rather than

wavelength) 8. Think back to the familiar Doppler effect; what change occurs when a train passes?

The wavelength of the train’s sound gets longer as it moves away. 9. If the wavelengths of these colors get longer, toward what (visible) color do they

move? The wavelengths are stretched, shifting to the red. 10. Look at page 127 in Einstein Adds a New Dimension. Imagine you are observing the

spectrum of hydrogen from a star that is moving away. How would it change? The wavelengths would shift toward red.

In Their Own WordsRead this quote from Georges Lemaître (1894–1966) to students, and ask them to imagine the first second of this universe. What existed? What laws governed it?

The expansion of the universe is a matter of astronomical FACTS interpreted by the theory of relativity, with the help of assumptions as to the homogeneity of space, without which any theory seems to be impossible. I shall not discuss the legitimacy of this inter-pretation, as I do not know any definite objection made against it and this is not the place; and it is not necessary to give a new popular version of the leading principles of

the theory of relativity. I shall rather try to show that the universe MUST be expanding, or rather that the most necessary processes of evolution are contradictory to the view that

space is and has always been static. —Georges Lemaître, The Primeval Atom

VocabularyCosmological constant• Lambda• Redshift•

Online Learning ToolsAmazing Space http://amazing-space.stsci.edu


expanding times37


Intute: Redshift www.intute.ac.uk/sciences/spaceguide/redshift.htmlThe Sun as a Star (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

For Further InvestigationDetermining Redshift in a Receding Star www.pbs.org/deepspace/classroom/activity2.html

Extended ReadingA Day Without Yesterday www.catholiceducation.org/articles/science/sc0022.htmlThe Expanding Universe www.aip.org/history/cosmology/ideas/expanding.htm

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of redshift:

Astrophysicists have two basic scientific methods, observation and inference. It’s not enough just to “see” and measure the universe. They must also understand it, interpreting the data and making inferences. Look at the following chart and think about what aspects of theoretical cosmology the observations in the first column imply or prove.

Observations/Measurements Interpretations/Inferences

The light emitted from almost all galaxies shows redshift.

The farther away a galaxy is, the greater the redshift.

For every kiloparsec of distance of a galaxy, the speed at which the galaxy is moving increases by 50 to 100 km/s.

In the most empty areas of deep space, there is still some heat (temperature).

Source: Adapted from Ceres: The Expanding Universe, http://btc.montana.edu/ceres/html/Universe/uni1.html.

In their interpretations and inferences, students should demonstrate an understanding that radiation moves through empty space and that the wavelengths of radiation from objects moving away from our galaxy increase (redshift).


Einstein could imagine a relativistic universe and Hubble

could see it. This chapter melds theory and practice, joining

together two completely different scientific methods.38An

Expanding Universe


Teaching TipsThe web search activity suggested in the “Evaluation” section (p. 93) can be used either as an assessment or an independent project. Tell students to focus on websites that end in “.gov,” which will eliminate some of the spurious sources. For a kinesthetic model, borrow a pitching machine and place it on a rolling cart. Set the speed of the pitches, and ask a student who is a good catcher (in appropriate protective gear) to catch the balls. Then move the machine slowly away from the catcher. Ask students: “How does the reaction time change? What happens as the pitcher moves slowly away?” Refer to the “Long = Red, Short = Blue” sidebar on page 335 of Einstein Adds a New Dimension for further explanation of this activity.

Stretching Your Mind and the UniverseProvide noninflated small balloons for your students and ask them to draw several galaxies on the balloons with indelible markers. Have students measure the difference between five pairs of galaxies on the balloon and then blow up the balloon. Ask students to measure the distance again once the balloon is inflated and explain to a partner how the demonstration illustrates Lemaître’s theory. Students should enter their measurements in the table on page 93.

Source: “Dr. Nicholas Short’s Remote Sensing Tutorial, Section 20: Astronomy and Cosmology:

The Description, Origin, and Development of the Universe,” NASA/Goddard Space Flight Center.

http://rst.gsfc.nasa.gov/Sect20/A1a.html.


an expanding universe38


Galaxies Distance Before Infl ation Distance After Infl ation

Students should explain that the redshift and other evidence suggests an expanding universe; all galaxies are moving away from each other.

VocabularyGalaxy• Universe•

Online Learning ToolsAmazing Space http://amazing-space.stsci.eduExpanding Universe Animation http://bccp.lbl.gov/Images/990404b.gifThe Universe Beyond Our Solar System (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

For Further InvestigationThe Expanding Universe http://btc.montana.edu/ceres/html/Universe/uni1.html

Extended ReadingNASA Science: Astrophysics http://science.hq.nasa.gov/universe/science/expanding.htmlThe Hubble Space Telescope http://hubble.nasa.gov

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the expanding universe:

Using a search engine such as Google, look for images that illustrate an expanding universe using public domain sources (primarily websites that end in “.gov”). Create a PowerPoint presentation of five slides that demonstrate the concept.

In their PowerPoint presentations, students should include examples of galactic objects that vary in their distance from Earth.


Subrahmanyan Chandrasekhar described the aging of

seemingly ageless bodies. He applied quantum mechanics

to observations and developed a new understanding of

what is inside a star. 39 A Luminous Indian


Teaching Tip Most solar system models that students build are inaccurate, because when students achieve a realistic scale for the planets, they can’t achieve a realistic scale for the distance between the planets (their model wouldn’t fit in the classroom). That scale problem is true of the galaxy project below, as well. The disk of the Milky Way galaxy is about 100,000 light-years in diameter and about 1,000 light-years thick. If the Milky Way were reduced to the size of a basketball, the next galaxy would be about 50 m away.

Sky ArtUsing the images at http://spaceplace.nasa.gov/en/educators/teachers_star_images.shtml or any other images from NASA’s web sources, students create a mobile of galaxies. Before they begin, students determine a standard scale that everyone in the class will use for the actual galaxies. When the mobiles are done, students use the same scale to estimate how far apart the galaxies would actually have to be to represent their true distance from one another in the universe. Finally, students write an explanation of their scales and a disclaimer for the parts of the model (scale between galaxies and movement) that they cannot achieve in the classroom. One example: Earth’s orbit is about 3 × 105 km in diameter; the distance to the nearest star, Alpha Centauri, is about 4.2 × 1013 km, or more than 10,000,000 times as far.

Source: NASA Goddard Space Flight Center. http://imagine.gsfc.nasa.gov/

Images/basic/xray/supernova_cycle.gif.


a luminous indian39


VocabularyNeutron star• Red giant• White dwarf•

Online Learning ToolsBirth, Life, and Death of Stars (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxImages for the Classroom: Stars, Galaxies, and Nebulae http://spaceplace.nasa.gov/en/educators/teachers_star_images.shtmlAstronomy Picture of the Day: Kepler’s Supernova Remnant in X-rays http://antwrp.gsfc.nasa.gov/apod/ap070116.html

Extended ReadingImagine the Universe http://imagine.gsfc.nasa.gov/index.htmlMeasuring a White Dwarf Star www.nasa.gov/multimedia/imagegallery/image_feature_468.htmlUniverse Resource Reel http://learners.gsfc.nasa.gov/mediaviewer/UniversePromo

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of data sampling and relative size of the galaxy:

In Chapter 48 you’ll speculate whether there is life on other planets around other stars. Before you get there, take a survey of people by asking, “Do you believe there is life on other planets?” When you analyze this data, divide the respondents by age and by how much background they have in astronomy. As a class, create a question or two for determining whether people have a realistic idea of how far away stars are. Keep track of all answers for each respondent.

In their data reporting, students should include appropriate analysis, including averages for each subgroup that they have surveyed.


Students may have noted the name Arthur Eddington below

the image of the 1919 eclipse in the materials for Chapter 35.

In Chapter 40, Eddington’s observations become part of an

“explosive” debate among astronomers.40 Explosive? And How!


Teaching Tips Students may have already used images of neutron stars or other astronomical phenomena during the web-search or mobile-building activities in the previous two chapters. If not, they should now conduct some internet research on stars. Then, after students have read Chapter 40 of Einstein Adds a New Dimension, ask them to refer back to their research material to find information on the new phenomena, neutron stars and supernovas, they have just read about. When discussing redshift, remind students that the change in frequency is apparent because the observer and the source are moving away from one another. Return to Einstein’s thought experiment of the juggler on the train for a more easily understood example. Chandrasekhar’s contributions provide another opportunity for classes to review the international nature of science. In previous chapters there have been references to little-known contributions from Mesoamerica, China, and other areas that are seldom covered in textbooks. The quote on ancient Hindu ideas of atomic research used for the role-play in Chapter 26 might begin a discussion of Indian science. If students are interested in learning about international contributions to science, take time to allow independent research. A web search of the nationalities of Nobel Prize winners is also valuable.

Going, Going, Gone…For this activity, students should refer to a diagram of the electromagnetic spectrum (see p. 23 of Einstein Adds a New Dimension). The Chandra probe measures x-rays. Have students add x-rays to the diagram they made for Chapter 37. Ask students the following questions (answers in bold):

1. How would the redshift phenomenon affect x-rays? There is an apparent change in frequency of all wavelengths to an observer moving away from the source.

Students can demonstrate the effect of a black hole on light near it using the back side of the same flexible rubber that was used in the Chapter 35 activity. Have students draw a spectrum of visible light with indelible markers.

2. What do the colors represent? Wavelengths 3. What color of visible light has the longest wavelength? Red 4. The shortest? Violet


explosive? and How!40


5. Tell students to stretch the rubber. What does the stretching represent? Redshift 6. How do the colors change? All wavelengths extend. 7. Ask students to imagine they are observing the light from a luminous body that

is being drawn into a black hole. What effects do you expect to see? Because the luminous body has mass, it accelerates as it nears the black hole, and the light it emits will apparently redshift.

In Their Own WordsTycho Brahe (1546–1601) described a supernova he didn’t actually see and didn’t really understand. No one else would either until the 20th century. Still, Brahe knew what he didn’t know:

Now it is quite clear to me that there are no solid spheres in the heavens, and those that have been devised by the authors to save the appearances, exist only in the imagi-nation…I conclude, therefore, that this star is not some kind of comet or a fiery me-

teor...but that it is a star shining in the firmament itself one that has never previously been seen before our time, in any age since the beginning of the world. —Tycho Brahe

Many years later, Stephen Hawking described what you might see if you could “ride” a spaceship as it follows a star into a black hole:

Everything that happens on the surface of the star would be spread out over an infinite period of time…the time interval between the arrival of successive crests and troughs of any light from the star would get successively longer…the frequency of the

light from the star would get lower…The light would appear redder and redder. —Stephen Hawking, A Briefer History of Time

Source: Gravitational Astrophysics Laboratory, Astrophysics Laboratory,

Astrophysics Science Division, NASA/Goddard Space Flight Center. www.

universe.nasa.gov/gravity/research.html.



Explosive? And How!40

VocabularyPulsar• Quasar• Supernova•

Online Learning ToolsBirth, Life, and Death of Stars (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxCosmicopia http://helios.gsfc.nasa.gov/cosmic.htmlNeutron Star Animation http://universe.nasa.gov/press/images/neutronNeutron Star Collision http://svs.gsfc.nasa.gov/vis/a000000/a000500/a000560The Universe Beyond Our Solar System (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

Extended ReadingBankston, J. 2005. Stephen Hawking: Breaking the boundaries of time and space. Berkeley Heights,

NJ: Enslow.Hawking, S., and L. Mlodinow. 2005. A briefer history of time. New York: Bantam Books.Star Life Cycle http://aspire.cosmic-ray.org/labs/star_life/starlife_main.htmlThe Life Cycles of Stars http://imagine.gsfc.nasa.gov/docs/teachers/lifecycles/LC_main_p1.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the life cycle of a star:

William Blake’s “The Tyger”—which begins, “Tyger, tyger, burning bright/In the forests of the night”—offers a literary perspective on a natural phenomenon. Read his poem, and use it as inspiration for a poem of your own that describes another natural phenomenon, the explosive life cycle of a star. Record your verses on a podcast. In their poems, students should include a specific physical phenomenon and some evidence of their own creativity.


Teaching TipAn expanded version of the activity below is available from NASA at http://heasarc.gsfc.nasa.gov/docs/xte/outreach/HEG/bhm/black_hole_mass.html.

Modeling a Black Hole For this activity, students will need 10 screw eyes, masking tape, measuring tape, a large clear plastic cup, four sturdy paper plates, and a ball of yarn.

Students begin by tracing the circumference of the rim of the plastic cup on the center of each of the plates. Next, students cut out the circles they’ve drawn and make a small hole in the bottom of the cup with a screw. Students pile the four plates on top of one another and put the cup (rim up) in the holes they’ve created. (If the plates don’t fit tightly, they can use a bit of masking tape to make a tight fit.) Next, students lightly draw a spiral from the edge of the cup to the rim of the plates. Then, they place the screw eyes in the plates following the spiral line and use masking tape to cover the points of the screws where they come through. They thread the yarn through the screw eyes (outside first), around the spiral, and end in the hole in the bottom of the cup. Make sure students leave the ball attached. The ball represents a companion star and the cup represents a black hole. The string is the accretion disk. The bottom of the cup is the event horizon. Tell students to slowly pull the yarn through the bottom of the cup.

The death of a star can be slow or violent, and throughout

the 20th century, Robert Oppenheimer, Hartland Snyder, and

John Archibald Wheeler made strides toward understanding

the role a violent star death plays in the creation of a

phenomenon we now know as “black holes.” However, it is

not until late in the century that Stephen Hawking, whose

mind seems to have been sharpened by his body’s struggle

with Lou Gehrig’s disease (ALS), proposes the theory of black

holes as dynamos that can radiate energy.

41 Singular Black Holes


Source: “High Energy Groove X-ray Binary,” NASA/Goddard

Space Flight Center. http://heasarc.gsfc.nasa.gov/docs/xte/

outreach/HEG/bhm/black_hole_mass.html.


singular black holes41



1. What happens to the mass of the companion star over time? It is converted to energy as it enters the black hole.

Allow students time to explore with the model.

2. How is the model like a black hole? The mass of the companion star is reduced as it enters the black hole.

3. What part might represent the singularity? The bottom of the cup

In Their Own WordsRead the following quote aloud and then discuss with your students how Hawking’s idea of a theory differs from that of the average person:

Any physical theory is always provisional, in the sense that it is only a hypothesis: You can never prove it. No matter how many times the results of experiments agree with

some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observa-tion that disagrees with the predictions of the theory....Each time new experiments are observed to agree with the predictions, the theory survives, and our confidence in it is increased; but if ever a new observation is found to disagree, we have to abandon or

modify the theory. —Stephen Hawking, A Brief History of Time

VocabularyBlack hole• Singularity•

Online Learning ToolsMatter Surfs on Ripples of Space Time Around Black Hole www.nasa.gov/centers/goddard/universe/blackhole_surfing.htmlFalling Into a Black Hole http://casa.colorado.edu/~ajsh/schw.shtml

Extended ReadingBankston, J. 2005. Stephen Hawking: Breaking the boundaries of time and space. Berkeley

Heights, NJ: Enslow.

Evaluation The student page includes the following scenario as a tool for assessing students’ understanding of the warping of spacetime:


singular black holes41


How is the illustration in the previous chapter (or the one on p. 357 of Einstein Adds a New Dimension) like the model you just made? How is it different? You may wish to consult the image from Chapter 40 of your materials as a reference.

In their answers, students will probably note the physical shape but not the relationship between time or redshift. There is no analogy for redshift or changes in light or energy in the model.


Teaching TipsFor most students, the interactions described on pages 378–379 may be new and may contradict very firmly held preconceptions about atoms and molecules. Models, conversation, and explorations are necessary for students to construct new information. The gravitational tutorial on pages 380–381 of Einstein Adds a New Dimension can be reviewed at any point in the second half of the course and is especially relevant to connect Chapter 35 to Chapter 42.

InteractionsFor this activity, students list at least two examples of each interaction (answers in bold).

Interaction Illustration Examples

Strong Carried by mesons, holds the nucleus together

Holds quarks and gluons

together

Forms protons and neutrons

Electromagnetism Carried by photons Light

X-rays

Weak Radioactivity and nuclear fusion

Beta decay

Radioactivity

Gravity Curves spacetime Orbit of planets

Event horizon in black holes

VocabularyForce• Interaction• Strong (Interaction)• Electromagnetic (Interaction)• Weak (Interaction)• Gravity (Interaction)•

A modern version of the Michelson-Morley experiment

tracks gravitational waves.42 Gravity Waves?



Online Learning ToolAtoms—The Inside Story: The Standard Model http://resources.schoolscience.co.uk/PPARC/16plus/partich6pg2.html

Extended ReadingHistoric Supernovae www.mpa-garching.mpg.de/HIGHLIGHT/2000/highlight0005_e.html Evaluation The student page includes the following scenario as a tool for assessing students’ understanding of supernovas:

There have been a number of supernovas mentioned throughout history. Pictured is part of a record from China in 14th century BC. Research the evidence that this was a supernova. Without using information that would have been out of time or place, write a news article that describes what the discovery of a supernova might mean. In their news articles, students should include what people might have seen and how their observations might have been interpreted.


gravity waves?42

Source: www.mpa-garching.mpg.de/

HIGHLIGHT/2000/highlight0005_e.

html.


Teaching TipsThe models that students built for Chapter 20 should be reused in this chapter as visual aids. If students used plastic foam balls to illustrate subatomic particles, they may want to further subdivide them to illustrate baryons. Begin by reminding students of the experiment they did to support the very first chapter of this book—tuning a radio. (If you still have the radio, bring it out again.) Compare the design of the Bell Labs experiments that are described in this chapter to that of the Michelson-Morley experiment on page 31 of Einstein Adds a New Dimension. Ask students to imagine the frustration of Penzias and Wilson at Bell Labs, tuning and tuning, and still finding background static. What could it mean? Finally, remind students of the various representations of the globe that they compared in the Chapter 30 activities. No single representation or model was accurate; all had advantages and disadvantages. That’s true of the representation of the universe in this section as well. The coloring exercise below encourages students to make very careful observations of the digitally produced map of the cosmic microwave background (CMB). Ask students to discuss the value of enhancing imaging with “false” digital coloration. Emphasize the sidebar on page 391 of Einstein Adds a New Dimension, which explains the theory of why dark matter is cold.

Out of (Supposedly) Nothing—Heat!In this activity, students develop a map that defines the relative temperatures in Kelvin of areas of the universe. (The image provided on p. 105 shows a temperature range of ± 200 microKelvin.) Instruct your students to develop a map of the universe. First have them establish a color code by putting the image into a drawing program such as Paint and selecting four different color areas. (Remind students that they are arbitrarily dividing a continuous spectrum of radiation frequencies into categories.) Tell students to outline the color areas with the drawing (pen) tool in the program. Then they should use the sampling (eyedropper) tool to match their color selections and create a key. Finally, send students to http://aether.lbl.gov/www/projects/cobe to read about the COBE program. Ask them to write explanations for their color keys and descriptions of what the COBE project achieves. Students should realize that these temperatures are very low and that the variations across the universe are no greater than a fifth of a degree. In their descriptions, they should note that these temperatures reflect radiation remaining from the big bang.

History took on new meaning when physicists such as

George Gamow began to describe the world’s beginning.

Did it start with a whimper—or a bang? 43A Singular

BANG with a Background


105Copyright © 2008 NSTA. All rights reserved. For more information, go to www.nsta.org/permissions.105

Ask students to explain what the model tells us about the universe (answers in bold).

1. Why is the image an oval? It represents the least distortion of the data. Students will note in their research of the WMAP and BOOMERANG projects in the next chapter that the data imply a flat universe.

2. The average temperature of almost all of the universe is about 2.725°K, but the operative word is about. What do the slight variations in temperature imply? The matter in the universe is not uniform.

3. Why is there an inverse relationship between temperature and density? In theory, dark matter is cold because the expansion of the universe cools it. Condensation, which releases energy, occurred so long ago that the energy it released has dissipated (see p. 391 of Einstein Adds a New Dimension).

4. What is the advantage of enhancing the data collected by instruments with “false” digital coloration? The coloration is not only a way to emphasize differences, but reflects the imposition of theory on the data. The physicists’ model is reflected in the coloration.

Vocabulary

Baryon• Big bang• Cosmic microwave background (CMB)•


A Singular BANG with a Background43

Source: Wilkinson Microwave Anisotropy Probe, NASA/Goddard Space Flight Center. http://wmap.

gsfc.nasa.gov/media/030653/index.html.



A Singular BANG with a Background43

Online Learning ToolsCOBE Satellite Launch Movie http://lambda.gsfc.nasa.gov/product/cobe/c_edresources.cfmCosmic Background Explorer http://lambda.gsfc.nasa.gov/product/cobe

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of scientific methods, especially their use in attempts to refute null hypotheses:

Einstein Adds a New Dimension includes many examples of experiments that didn’t work the way they were intended but that provided amazing insights nevertheless. Recall the Michelson-Morley experiment. How was it similar to the work of Penzias and Wilson? How was it different?

Although student answers will vary, in both cases the scientists collected data that defied current theory and forced scientists to rethink their assumptions.


Teaching TipsReinforce the idea that energy can be neither created nor destroyed. Then help students understand that energy of positive and negative forms can be created in equal amounts because matter can be converted to energy, and vice versa, in nuclear reactions. You may wish to refer back to the discussion of quarks and antiquarks on page 174 of Einstein Adds a New Dimension as students grapple with this idea.

Pure Science—Pure TheoryNASA has developed a number of important experiments to investigate the beginning of the universe. The purpose of this activity is for students to investigate each of these projects online and fill in the chart below (sample answers are provided in bold).

Project Instrument Purpose

COBE (Cosmic Background Explorer)

DIRBE This project measured

infrared absolute sky

brightness in the wavelength

range 1.25 to 240 microns

to carry out a search for the

cosmic infrared background

(CIB).

DMR This project looked for tiny

variations in the intensity

of the cosmic microwave

background (CMB) over the

sky to show how matter and

energy were distributed.

FIRAS This project has

demonstrated that the CMB

spectrum is that of a nearly

perfect blackbody with a

temperature of 2.725 +/-

0.002 K. This observation

matches the predictions of

the hot big bang theory.

The big bang is an exciting and attractive theory. But it is still

unproved. Today’s scientists go beyond static to measure

the siren songs of distant dark matter.44T E A C H E R E D I T I O N

Inflation? This Chapter Is NOT About

Economics!


Inflation? This Chapter Is NOT About Economics!44


BOOMERANG (Balloon Observations of Millimetric Extragalactic Radiation and Geophysics [over the South Pole])

Balloon The most prevalent

temperature fl uctuations

were about three-quarters

of a degree across, the value

predicted for a fl at universe.

WMAP (Wilkinson Microwave Anisotropy Probe)

Probe This project was designed

to determine the geometry,

content, and evolution of the

universe via a 13 arcminute

resolution full-sky map of

the temperature anisotropy

of the cosmic microwave

background radiation. It

verifi ed observations of a fl at

universe.

IRAS (Infrared Astronomical Satellite)

A liquid helium–cooled 0.6 m Ritchey-Chrétien telescope

This project conducted an

all-sky survey at wavelengths

ranging from 8 to 120

microns in four broadband

photometric channels

centered at 12, 25, 60, and

100 microns.

SWAS (Submillimeter Wave Astronomy Satellite)

Elliptical off-axis Cassegrain telescope

This project measured the

amounts of water, molecular

oxygen, carbon monoxide,

and atomic carbon in

interstellar clouds.

Relikt ExperimentDicke-type modulation radiometer

This experiment was

desisgned to investigate the

anisotropy of the cosmic

background radiation at 37

GHz.

VocabularyHorizon distance• Inflationary universe•

Online Learning ToolsLAMBDA—Legacy Archive for Microwave Background Data http://lambda.gsfc.nasa.govOrigin and Evolution of the Universe (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx


Inflation? This Chapter Is NOT About Economics!44


EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of how scientists must sometimes fight common wisdom:

Paul Steinhardt and João Magueijo have produced alternative theories that may resolve some of the difficult contradictions in the big bang theory. Can you think of another scientist who boldly offered an unpopular variation of commonly accepted theory? How should such scientists be received by “the establishment”?

Although student answers will vary, two good examples are Alfred Wegener and Charles Darwin.


While moving from the classical universe to the quantum

universe, even Einstein’s imagination occasionally came up

short. He never achieved “unified field theory.” Will we?45Entanglement?

Locality? Are We Talking

Science?

Teaching TipUse the animations on the websites listed on page 111 to illustrate the content of Chapter 45 in Einstein Adds a New Dimension.

Here and There Much of what we imagine about “outer space” comes from books, movies, or television shows. Ask students, “Could teleportation really exist? Could humans really reach another galaxy?” Individuals seldom use their scientific background knowledge when they watch television or a movie. For this activity, students will analyze fictional scenes from a scientific perspective. Students begin by considering a “transporter,” which involves changing matter to energy and back again. To get a sense of how practical a transporter is, students might do a Fermi Question (a “back of the napkin” estimate). Students answer the following questions (answers in bold):

1. What is the mass of your body? 2. Using Einstein’s equation E=mc2, how much energy would be produced if the mass

was all changed to energy? Students’ estimates may vary widely, from Chapter 26 they might estimate 2 × 107 electron volts per molecule.

3. How does this compare with the energy emitted by the Sun? Do you believe it’s practical? It’s impractical to think the mass of your body would all change to energy.

Tell students to choose another “impossible” scene from a familiar science-fiction movie. (They may even find a clip of the scene on YouTube.) Students can then research the views of a professional scientist as to whether the scene could actually take place in the future. Ask students to describe or show the scene to the class and discuss whether they think the scene is possible from a scientific perspective.



entanglement? Locality? are we talking science?45

1 1 1Copyright © 2008 NSTA. All rights reserved. For more information, go to www.nsta.org/permissions.

VocabularyString theory• Unified field theory•

Online Learning ToolsSpin-Precession Effects http://physics.indiana.edu/~kostelec/mov.html#2String Theory: A Multihistory http://superstringtheory.com/theatre/stringmovie.html

Extended ReadingQuantum Teleportation www.research.ibm.com/quantuminfo/teleportation

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of information science:

Develop a code that depends on the orientation of letters. Send a coded message to a friend, along with information on how to decipher the code.

In their coded messages, students should create an organized system that can be understood and deciphered by another student.


Dark energy is a concept that may answer unsolved

questions and provide hints about the fate of the universe.

But no one knows exactly what dark energy is or how much

there is. Will the universe continue to expand or begin to

contract? 46Super Stars


Teaching TipsBegin the lesson by asking students to look at the eight-layer model of a star on the student page. Ask them to speculate about which areas are hotter, where fusion is occurring, and how the star might change over its life cycle. If time permits, the Dark Energy website from NASA (see Extended Reading) gives specific directions for building a physical model of the core of a star from a ball bearing and clay. It is also possible to model the interaction between dark matter and dark energy kinesthetically, with three groups of students. Have one group of students stand in the center of a large, open, grassy space. They represent matter. A second group of students makes a large circle around them, representing the edge of the universe; each attaches him- or herself to a student in the center with yarn. The students in the center gently pull the others toward

them. Meanwhile, a third group of students who represent dark energy and who are also attached to the students in group 2 with yarn, gently pushes outward on the edges. Ask students to analyze: What’s the balance?

Inside a StarThe following activity has been modified from an activity found online at http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/activity-fusion.html. Hand out large index cards with elements writ ten on them. You will need to make the

Source: “NASA’s Imagine the Universe! Fusion Reactions,” NASA/Goddard Space Flight

Center. http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/activity-fusion.

html.


super stars46


following index cards in advance. If your class does not have a strong background in chemistry, limit the exercise to those isotopes and particles highlighted in bold.

• 4 hydrogen-1 (1H)• 13 helium-4 (4He)• 4 carbon-12 (12C)• 1 magnesium-24 (24Mg)• 4 oxygen-16 (16O)• 1 sulphur-32 (32S)• 1 neon-20 (20Ne),• 1 silicon-28 (28Si)• 2 nickel-56 (56Ni)• 2 cobalt-56 (56Co) • 2 iron-56 (56Fe)• 2 iron-57 (57Fe) • 2 iron-58 (58Fe) • 1 iron-59 (59Fe) • 3 neutrons (n) • 4 positrons (e+) • 2 neutrinos

At the front of the room, have a separate set of color-coded cards that indicate arrows and energy. Encourage students to use a periodic table and the internet to research how helium, carbon, magnesium, oxygen, sulphur, neon, nickel, cobalt, and four different isotopes of iron could be formed in the fusion reactions inside a star. Students should note that energy is released in the formation of helium, carbon, magnesium, oxygen, sulfur, neon, and nickel, but it is required to form cobalt and iron. Have students join with other students to form equations that might happen inside a star. When students have decided on the right combinations, have them display their equations in a visible area of the room and prepare to explain them. Students should come up with the following equations:

4 (1H) ------> 4He + 2 e+ + 2 neutrinos + energy 3 (4He) ------> 12C + energy 12C + 12C ------> 24Mg + energy 12C + 4He ------> 16O + energy 16O + 16O ------> 32S + energy 16O + 4He -----> 20Ne +energy 28Si + 7(4He) ------> 56Ni + energy 56Ni ------> 56Co + e+ 56Co ------> 56Fe + e+ 56Fe + n ------> 57Fe 57Fe + n ------> 58Fe 58Fe + n ------> 59Fe



Super Stars46

Finally, enlarge or project the diagram of a red giant star pictured here and ask students to review where in the star and at what point in a star’s life cycle these reactions would occur. If a protostar has enough mass, fusion of hydrogen to helium begins. When the core of such a star eventually collapses, the temperature can increase enough to fuse helium into larger atoms. Virtually all of the reactions shown on page 113 occur in red giant stars. It is important to relate the diagram to the appropriate stage in the “Life Cycle of a Massive Star” (p. 94) to emphasize the differences in fusion in various stages.

Continue VisualizingRemember the ongoing chart of radiation that students created at the beginning of this book? Ask students to add sources of radiation they’ve discovered since then.



Ultraviolet UV-sensitive materials Anything opaque, some chemicals

with SPV ratings


IR goggles

Insulators



communications

Relatively thin walls of microwave

ovens

α Particles Radiation meter, some fi lms Paper

β particles Radiation meter, some fi lms Water

γ radiation Radiation meter, some fi lms Heavy shielding (concrete)

X-rays Radiation meter, some fi lms Metal shielding (lead)


super stars46


VocabularyDark energy• Dark matter•

Online Learning ToolsLAMBDA—Legacy Archive for Microwave Background Data http://lambda.gsfc.nasa.govThe Sun as a Star (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

For Further InvestigationFusion Reactions http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/activity-fusion.htmlX-ray Spectroscopy and the Chemistry of Supernova Remnants http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/spectra_cover.html

Extended ReadingDark Energy http://imagine.gsfc.nasa.gov/docs/science/mysteries_l1/dark_energy.htmlRubber Band Invoked to Explain Dark Energy www.space.com/scienceastronomy/acceleron_darkenergy_040727.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the relationship between art and science:

Read Robert Frost’s poem “Fire and Ice,” which can be found online. Find images of objects from the farthest reaches of space from NASA to illustrate the poem. Use the Picasa program (free from Google) to coordinate an oral reading with your images.

In their oral readings, students should include both scientific facts and creative interpretations.


Information theory has wide applications in many areas of

science—in and out of physics.47A Surprising

Information-Age Universe


Teaching TipStudents today take the abilities of computerized devices for granted. Students have as much difficulty thinking about how computer chips work as most teachers have remembering how to use a slide rule. Begin the following activity with a review of how to count in binary, which students probably learned in elementary school.

Play a Google GameExplain to students that when you were a child you studied Boolean logic but you found it frustrating and wondered why you had to learn it. Then explain that Boolean logic is used every day. Tell students to go to Google or another search engine and type in one common science term. Have students record how many hits they get. Then have them search another term and record the number of hits.

Term Number of Hits

AND

OR

Next, tell them to conduct an “Advanced Search.” Ask students: “What’s the difference between ‘At least one of the words’ (or) and ‘Both of the words’ (and)?” Then ask students to find examples of 10 different astronomical objects in the sources that they’ve studied. Have students develop four different examples of Boolean searches. Examples include “Milky Way and Star,” “Rocky and Planet,” or “Planet or Asteroid.” Partners can share examples.

VocabularyInformation theory•


a surprising information-age universe47


Extended ReadingClaude Shannon www.nyu.edu/pages/linguistics/courses/v610003/shan.html

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of information science:

Much of an organism’s DNA doesn’t make much sense to biologists; it doesn’t contain a “genetic code.” But information scientists (mostly electrical engineers) say the patterns are predictable. What else could the “nonsense DNA” be telling the cell? Imagine you are the head of a team of physicists investigating mysterious DNA. Write a memo to the human resources department of your institution and explain why the biologist should work in partnership with an information scientist.

Students should answer that the “extra” DNA appears to be responsible for controls to determine which genes will be expressed. In their memos, students should demonstrate an understanding that there are different methods used by different scientific disciplines.


The idea of alien encounters is fascinating, but hard to

reconcile with our understanding of the size and power of

the quantum universe.48 Is Anyone Out There?


Teaching TipThe remoteness of space will be hard to imagine for students who have grown up with images of aliens. This is a good chapter to challenge students. Ask them: “How do you know aliens exist? What facts do you have to support your opinions?”

The SearchIn 1961, Cornell astronomer Frank Drake developed the Drake equation (p. 442 of Einstein Adds a New Dimension), which estimated the number of civilizations in our galaxy. Since that time, a number of Earthlike planets have been discovered. Ask students, “Does that mean that intelligent life is much more likely?” In Chapter 39, students designed a survey that measured whether people have realistic ideas of the vastness of space and whether people believe that humans will encounter intelligent life anywhere else in the universe. Students also recorded the age of their respondents. Now it’s time to disaggregate the data. First, students will have to determine parameters for dividing their respondents into those with “good” backgrounds and those without. This will, of course, be arbitrary but it’s a great discussion to have. Students will have to decide whether people who have good ideas about the size of the universe are more or less likely to believe in intelligent aliens. They’ll also have to see if age makes any difference. Ask students to develop a rubric to divide respondents into those who have a good sense of distance and those who don’t. Here is a sample rubric:

Respondents Age Background Knowledge

Believe in life on other planets Over 30 Good

Under 30 Poor

Don’t think there’s life on other planets

Over 30 Good

Under 30 Poor

Finally, ask students to write a summary of their results.


is anyone out there?48


For Further InvestigationSETI and the Search for New Homes in Space www.pbs.org/deepspace/classroom/activity8.html

Extended ReadingWhat Is the Drake Equation? www.setileague.org/general/drake.htm

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding that the basic laws of physics apply throughout the universe; these laws might be used to communicate:

Look at the image pictured here. It’s the message that was placed on the Voyager space probe many decades ago. Write an essay explaining what it says about us and the assumptions that we make about other life-forms. Then design your own plaque for a future space probe.

In their plaques, students should include symbols that would be understood without human interpretation. Because we assume that the laws of physics are consistent throughout the universe, the images of atoms and solar systems in the plate should be understandable.


This Is the Last Chapter,

but It ’s Not the End


What Rutherford, Cockcroft, and Walton began—smashing

atoms—required a great input of energy. Now scientists

search for the self-sustaining process that will release energy

and change the world.

Teaching TipsRole-play activities are usually very interesting to students. The type of activity below allows students to take opposing views without risking their personal beliefs or reputations. Give each student a large note card with a role on one side, and allow them to prepare notes for their presentation on the other. Teachers sometimes have a difficult time grading these activities. Before you begin, consider developing a rubric like this one with the cooperation of the class:

Trait Never (0) Sometimes (1) Mostly (2) Always (3)

Preparation

Communication

Incorporating facts

Consistency

Taxing for Theoretical ResearchPresent students with the following imaginary scenario: Congress is discussing a future budget allocation for basic research. Physicists have proposed expensive new probes and a totally new space telescope program. Students then assume the roles they were assigned on their note cards. They can write a few notes about their role on one side of the note card to help them make a five-minute presentation to an imaginary Senate hearing. Remind students to be prepared, incorporate facts, and make sure their arguments are consistent. Examples may include:

Role Responsibilities Position

Meteorologist This person studies global warming, including the effects of pollution and sunspots.

The results of research will have side benefi ts for all other studies of this planet.

Social worker This person knows rebuilding communities always requires more money than is available.

More budget money should be available for immediate needs.

Science teacher This person has studied astronomy and has sent students to space camp.

We can never tell how valuable astronomy research might be, and it is worth a signifi cant expenditure.


this is the last chapter, but it ’s not the end49


Other roles might include owners of companies that need rare metals, owners of telecommunications satellites, developers of drugs or other products that might be produced in space, oceanographers, climatologists, or small-business owners.

Online Learning ToolsContemporary Physics Education Project www.cpepweb.orgPhysics 2000 www.colorado.edu/physics/2000/index.pl

EvaluationThe student page includes the following scenario as a tool for assessing students’ understanding of the relationship between basic and applied research:

Write a letter to the editor of your local paper in the year 2020. More funding for basic research has been approved since the year 2010, and now the legislature must approve it again. Begin your letter with the following prompt: “In 2010 the United States approved a significant appropriation for basic research on the nature of our universe. In the years since, we’ve discovered…We should continue this program because we can discover…in the future.” Use your imagination to fill in the blanks.

In their letters, students should include at least one discovery that might be expected in the next 15 years and at least one that might be expected years later.


ReferencesBiological Sciences Curriculum Study (BSCS). 2006. The BSCS 5E Instructional Model:

Origins, effectiveness, and applications. Colorado Spring, CO: BSCS.

Hakim, J. 2007. The story of science: Einstein adds a new dimension. Washington, DC: Smithsonian Books.

Hawking, S. 2003. On the shoulders of giants. Philadelphia: Running Press.

National Research Council (NRC). 1996. National science education standards. Washington, DC: National Academy Press.

Nestle. 2003. Classic recipes. Lincolnwood, IL: Publications International.


References

Copyright © 2008 NSTA. All rights reserved. For more information, go to www.nsta.org/permissions.

The Story of ScienceCLASSROOM COMPANIONE i n s t e i n A d d s a N e w D i m e n s i o n

J U L I A N A T E X L E Y

Arlington, Virginia

S T U D E N T E D I T I O N

i iCopyright © 2008 NSTA. All rights reserved. For more information, go to www.nsta.org/permissions.

11: A Boy With Something on His Mind .................................................................................1

12: Time on Replay .................................................................................................................... 3

13: Electrifying Thoughts and Magnetic Reasoning ..............................................................5

14: The M. and M.’s of Science ................................................................................................ 7

15: Invisible Bits of Electricity ...................................................................................................8

16: Smaller Than Atoms? Subatomic? Is This a Joke? ........................................................... 10

17: Nobel Marie ..........................................................................................................................11

18: Mysterious Rays .................................................................................................................. 12

19: Making Waves ..................................................................................................................... 14

10: Five Papers ........................................................................................................................... 16

11: Seeing the (Photon) Light .................................................................................................. 18

12: Molecules Move .................................................................................................................. 19

13: Getting the Picture Right ...................................................................................................21

14: Getting Atom .....................................................................................................................23

15: Still Shooting Alpha Particles ...........................................................................................25

16: Bohr Taking Quantum Leaps ..........................................................................................26

17: An American Tracks Photons; a Frenchman Nails Matter ...........................................28

18: What’s Uncertain? Everything, Says Heisenberg ...........................................................29

19: A Cat, Quarks, and Other Quantum Critters ................................................................31

20: Smashing Atoms ................................................................................................................33

21: Chemistry, Charisma, and Peace .....................................................................................34

22: Energy Equals Mass Times the Square of the Speed of Light or E=mc2 .......................35

23: On the Way to War (a List of Happenings) ....................................................................37

24: The Fission Vision ............................................................................................................38

25: Presidential Power ............................................................................................................... 41

table of contentsS T U D E N T E D I T I O N

i i iCopyright © 2008 NSTA. All rights reserved. For more information, go to www.nsta.org/permissions.

26: Manhattan on a Mesa .......................................................................................................43

27: Quantum Electrodynamics? Surely You’re Joking .........................................................44

28: Those Relatives: Galileo and Albert ................................................................................47

29: Relativity: It’s About Time ................................................................................................48

30: An Event? To a Physicist It’s Not a Party .........................................................................50

31: Timely Dimensions ...........................................................................................................52

32: A Man in a Red Hat .........................................................................................................53

33: The Paradox of the Twins .................................................................................................54

34: Relative Gravity ..................................................................................................................55

35: Warps in Spacetime ..........................................................................................................56

36: Does It Change? Or Is It Changeless? .............................................................................58

37: Expanding Times ..............................................................................................................59

38: An Expanding Universe ...................................................................................................62

39: A Luminous Indian ..........................................................................................................64

40: Explosive? And How! ........................................................................................................65

41: Singular Black Holes .........................................................................................................67

42: Gravity Waves? ...................................................................................................................69

43: A Singular BANG With a Background ..........................................................................70

44: Inflation? This Chapter Is Not About Economics! ........................................................72

45: Entanglement? Locality? Are We Talking Science? ........................................................73

46: Super Stars .........................................................................................................................75

47: A Surprising Information-Age Universe .........................................................................77

48: Is Anyone Out There? .......................................................................................................78

49: This Is the Last Chapter, but It’s Not the End ...............................................................79

References ..........................................................................................................................80



A Boy With Something on His Mind1


Exploring the UnseenEinstein could imagine what he couldn’t see. Can you? Take time to think about what forms of radiation or unseen forces are in the room around you. Fill in the chart below as best as you can. Keep this chart in your notebook to complete as you read further in the book and continue your exploration of Einstein’s world.


Next, explore the unseen world of radiation using a traditional AM radio with a rotating (analog) dial. AM radio waves are longer than FM waves, so reception can be affected by electromagnetic radiation, including solar flares and terrestrial storms. AM waves bounce off the D layer of the ionosphere, which is lower at night. With help from your teacher, cover the AM radio dial with a round, white sticker, and then identify an area near the bottom of the AM range where no distinct channels exist. Check this range every day at the same time for the presence of static. A simple sound meter can be used to quantify the volume. You may also want to compare the range of AM signals at night or correlate results to sunspots.

1S T U D E N T E D I T I O N

A Boy With Something on His Mind



VocabularyDynamo• Electromagnetic radiation•

Online Learning ToolsElectric Force Fields www.colorado.edu/physics/2000/waves_particles/wavpart3.htmlThe Electromagnetic Spectrum http://science.hq.nasa.gov/kids/imagers/ems/waves3.htmlTuning a Radio Receiver http://micro.magnet.fsu.edu/electromag/java/radio/

For Further InvestigationNASA AM Radio Ionosphere Station http://lasp.colorado.edu/education/space_weather/files/middle/AMRadio.pdfNASA IMAGE Education Center http://image.gsfc.nasa.gov/poetry/activities.htmlRadio Waves: FM vs. AM www.teachersdomain.org/resources/phy03/sci/phys/energy/amfm/index.htmlSpace Weather (Graphing Sunspot Data) www.solarstorms.org/Strends.html

Evaluation“In school, Einstein was fascinated with statistics, a branch of mathematics about analyzing data” (Hakim 2007, p. 7). Some astronomers believe that there is a correlation between sunspot frequencies and global temperatures. Look at this National Oceanic and Atmospheric Administration graph. Then write a short news article describing both what you see and the limitations of what you can infer.

Source: Rodney Viereck, NOAA Space Environment

Center, NOAA Research, “The Sun-Climate Connection

(Did Sunspots Sink the Titanic?)” www.research.noaa.gov/

spotlite/archive/spot_sunclimate.html.

2



Time on Replay

Table Tricks and TalkHere’s an experiment for home. Using a hole punch, make tiny punches of newsprint or other nonglazed paper (salt and pepper can also be used in place of the paper). Rub a plastic straw on your head, and then bring it near the paper punches (or salt and pepper).

Describe what happens in words and drawings:

__________________________________________________________________________

__________________________________________________________________________

Explain to your family members what is happening, but don’t use any words or concepts that would not have been familiar to people in 1905.

__________________________________________________________________________

__________________________________________________________________________

VocabularyAtomic mass• Element• Compound• Microgravity•


time on replay


2S T U D E N T E D I T I O N

Online Learning ToolsAncient Observatories: Chaco Canyon www.exploratorium.edu/chacoForce and Work Applet http://lectureonline.cl.msu.edu/~mmp/kap5/work/work.htmMagnetism www.edumedia-sciences.com/m198_l2-magnetism.htmlScience, Civilization, and Society www.es.flinders.edu.au/~mattom/science+society/index.html

For Further InvestigationCool Experiments With Magnets http://my.execpc.com/~rhoadley/magindex.htm

EvaluationDartmouth archaeologist Vincent H. Malmström found 4,000-year-old statues in Central America with a very unusual property. A compass needle is sharply attracted to their navels! The pre-Olmec people seem to have discovered magnetism some 1,500 years before the earliest evidence of Chinese compasses. Other archaeologists have found Olmec statues of frogs and turtles with magnetic snouts dating from about 3500 BC. What can be hypothesized about their function?

Photo taken by Hajor, July 2001. Released

under cc.by.sa and/or GFDL.

3



Electrifying Thoughts and Magnetic Reasoning

A Pile of MoneyYou probably have the raw materials in your pocket to replicate Alessandro Volta’s electricity experiment. To begin, your class will be divided into groups. Each group needs to collect six pennies and six nickels. Your teacher will give your group 10 ml of a salt/vinegar solution in a labeled container, safety goggles, a sheet of paper towel, and forceps. Cut the paper towel into 3 cm squares. Place a nickel on the table. Wearing goggles and using the forceps, soak one of the paper towel squares in the saltwater solution and place it on top of the nickel. Add a penny on top of the paper towel, put another saltwater-soaked square of paper towel on top of that, and add another nickel. Continue alternating the coins and paper towels until all the coins are used. The pile will then be tested by your teacher who will touch one wire from the voltmeter to the top (penny) and one to the bottom (nickel). After the experiment, answer the following questions:

1. What kind of current is generated?

________________________________________________________________________

Once a base value is obtained for the “battery,” investigate further.

2. Does the current increase if more coins are used?

________________________________________________________________________

3. What if more salt is added?

________________________________________________________________________

Graph the number of coins and voltage:


Electrifying Thoughts and Magnetic Reasoning


3

VocabularyAmpere• Battery• Charge• Current• Volt•

Online Learning ToolsApplet: Induction www.lon-capa.org/~mmp/applist/induct/faraday.htmThe Battery: Using Chemistry to Make Energy www.ieee-virtual-museum.org/collection/tech.php?id=2345793

For Further InvestigationFruity Electricity www.miamisci.org/af/sln/frankenstein/fruity.html

Evaulation“When Samuel Morse (1791–1872) sent an electric current from Washington, D.C., to Baltimore in 1844, it turned a magnet on and off” (Hakim 2007, p. 26). That was the first telegram. How did long-distance communication change the world? Imagine you are a senior citizen in 1870. Write a letter to your grandchild explaining, “When I was young, it took weeks to send important information across the country.” Then give examples.

4



The M. and M. ’s of Science

Earth

Earth

Jupiter Jupiter

Does “Close” Count?In 1676 Olaf Roemer was the first to measure the speed of light. He knew that when Earth was at the point of its orbit that was closest to Jupiter, it took 42 hours for one of its moons to orbit the giant planet. But when Earth was at the opposite side of the Sun, it took 1,300 seconds longer for one of the moons to orbit Jupiter. Roemer thought Earth was then 3 × 108 km farther away, and he calculated the speed of light by dividing the distance by the delay. Roemer’s measuring instruments weren’t all that good, though. The actual delay time is 980 seconds, and the actual distance is 1.47 × 108 km.

1. What was Roemer’s answer?

______________________________________________________

2. What was the percentage of Roemer’s error?

______________________________________________________

VocabularyAnode• Cathode• Ether•

Online Learning ToolsMichelson-Morley Experiment http://galileo.phys.virginia.edu/classes/109N/more_stuff/flashlets/mmexpt6.htmMichelson-Morley Experiment, 3D Animation http://movingscience.de/en/projects/physics/michelson_morley_experiment.html

EvaluationSome of the most famous experiments have had no results. When that happens, it’s often hard to explain their value. Imagine you are Michelson writing a letter to one of his original sponsors, Alexander Graham Bell. Explain why the funding he provided was worth the expense even though your experiment seems to have failed.

5



Invisible Bits of ElectricityM

AS

S

25

20

15

10

5

01 2 3 4 5 6 7

GROUPS

Making Inferences About Unseen MassesIt’s possible to model the methods that Robert Millikan used to determine the charge of the electrons. Begin by obtaining a collection of 100 envelopes that your teacher has prepared. Working as a team, measure the mass of all the filled envelopes to 0.1 g and enter all the masses in a spreadsheet program. Sort by mass and create a bar graph with groups on the x axis and masses on the y axis.

1. What evidence could be used to determine the mass of the envelope itself?

________________________________________________________________________

2. Draw a horizontal line across the graph showing the mass of the envelope. Subtracting that mass, create a hypothesis about the mass of the contents.

________________________________________________________________________

VocabularyElectron• Proton• Neutron• X-ray•

Online Learning ToolsApplet: Electron Orbit http://lectureonline.cl.msu.edu/~mmp/applist/coulomb/orbit.htmBohr’s Theory of the Hydrogen Atom www.walter-fendt.de/ph14e/bohrh.htmMillikan’s Oil-Drop Experiment http://physics.nad.ru/Physics/English/mill_tmp.htm


Invisible Bits of Electricity


5

Millikan Oil-Drop Experiment (simulation) www.xplora.org/ww/en/pub/xplora/news/latestnews/xplora_wins_grant_for_web_expe.htmMore on Millikan’s Oil Drop Experiment (Quicktime Movie) http://chemistry.umeche.maine.edu/~amar/Millikan.html

For Further InvestigationCharge and Carry: Exploratorium Snacks www.exploratorium.edu/snacks/charge_carry/index.htmlA Laboratory Exercise in Fundamental Units http://ed.fnal.gov/samplers/hsphys/activities/millikantchr.html“Static Electricity” Page www.Eskimo.com/~billb/emotor/statelec.html

EvaluationYou are teaching a class in which you describe your experiment on protons and electrons. A student challenges you: How do you know that the unseen “units” you’ve identified in your massing are single particles (discrete units) and not combinations of particles? Can you defend your asumptions? Write two “If… , then…” statements that describe experiments or consequences. For example, if the units of mass that were measured are single particles, then…

6



Smaller than Atoms? Subatomic? Is This a Joke?

Photon

Excited State

Ground State

Seeing the UnseeableCan you explain what’s common among these demonstrations?

With an adult, carefully turn on the burner of • your electric range at home. Stand back and watch the color of the burner change as it gets hot. Then let it cool, and watch the color again. On a dry evening, put some nylon and polyester • clothing in the dryer at home. (Don’t use fabric softener.) After 10 minutes, turn the lights off and pull out the clothes. Observe what happens when you pull the clothes apart.In a dark room, chew some Wint-o-Green Life • Savers with your mouth open. Observe the candy in a mirror as you chew.

Write down what these demonstrations have in common:

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

VocabularyKinetic energy• Potential energy•

Online Learning ToolsPowers of 10 www.powersof10.comSecret Worlds: The Universe Within http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10

EvaluationAnalogies about size are helpful for the imagination. Begin an imaginary story by writing: “If I were 1/10th my size, I could…”; “If I were 1/100th my size, I could…”; “If I were 1/1,000th my size, I could…”

7



Nobel Marie

Through and ThroughCut six exact copies of a “snowflake” pattern from plain white paper. For the first experiment, lay one of the cutouts on a square of photosensitive paper (you may also use red construction paper) and place it in direct sunlight. After a few minutes (or a day if using construction paper), remove your snowflake and then describe the amount of fading on the paper.

__________________________________________________________________________

__________________________________________________________________________

Next, build some “shielding” from layers of blue cellophane. Place each of the six identical snowflakes on a piece of photosensitive paper. Leave one unshielded, put one square of blue cellophane on the second, put two squares on the third, put three squares on the fourth, and so on.

What thickness of cellophane is effective?

__________________________________________________________________________

__________________________________________________________________________

VocabularyPhotography• Radium• Uranium wave•

Online Learning ToolChain Reaction: Mouse Trap Model www.physics.umd.edu/lecdem/services/demos/demosp4/p4-62.htm

For Further InvestigationX-ray Spectra www.exploratorium.edu/spectra_from_space/xray_activity.html

EvaluationMarya Sklodowska (Marie Curie) was not allowed to enter the university in Poland because she was a female. Imagine you had to write her letter of application. Tell the provost of the university why you believe that every student should have an equal opportunity to study there.

8



Mysterious Rays

Using StatisticsWe are exposed to natural sources of radiation every day. These sources range from very short gamma rays to long radio waves. Below are data from Princeton University with estimates of our average exposure to various sources of radiation.

Radiation Source

Average Annual Whole

Body Dose (millirem/year)

Cosmic rays 29

Radioactive rocks 29

Radon (in some basements and rocky building sites) 200

Isotopes (K-40, C-14, etc.) in the air (mostly made in the upper atmosphere) 40

One dental x-ray per year 10

One chest x-ray per year 8

Cross-country round-trip by air 5

Consumer products (like home smoke detectors) 11

Source: Data adapted from Princeton University. “Open Source Radiation Safety Training Module 2: Background Radiation & Other

Sources of Exposure. ” http://web.princeton.edu/sites/ehs/osradtraining/backgroundradiation/background.htm

Adding to the Radiation TableNow that you have learned about additional sources of radiation, add to the table of unseen radiation you began in Chapter 1.

Vocabularyα• particlesβ• particlesγ• radiation

Online Learning ToolsApplet: Decay http://lectureonline.cl.msu.edu/~mmp/applist/decay/decay.htmApplet: Nuclear Isotope Half-Lifes http://lectureonline.cl.msu.edu/~mmp/kap30/Nuclear/nuc.htmX-rays www.colorado.edu/physics/2000/xray

EvaluationThe average person receives approximately 340 millirem a year of radiation exposure. Smoking adds about 280 millirem of radiation a year to normal exposure. According to data from Princeton University, we increase our risk of cancer by about 0.05% for every 1,000 millirem of exposure. (Of


Mysterious Rays


8

course, everyone is different. Some people have a greater capacity to repair genetic damage from radiation than others.) Develop a short public service announcement describing the dangers of this radiation. (Remember, the radiation is only one smoking-related cause of cancer. Tars and benzene in cigarette smoke can also lead to cancer.)

9



Making Waves

Source: NOAA Satellite and Information Service, National Environmental Satellite, Data, and Information Services

(NESDIS). www.osdpd.noaa.gov/PSB/EPS/SST/data/FS_km5000.gif.

Satellite EyesSatellites use cameras that can sense radiation to monitor Earth’s environment and human activities. Look at the following image from the National Oceanic and Atmospheric Administration:

1. What wavelengths of the electromagnetic spectrum are being sensed? (Hint: Look at the patterns in the area of the ocean nearest you.)

________________________________________________________________________

________________________________________________________________________

2. What can this tell us about Earth?

________________________________________________________________________

________________________________________________________________________

VocabularyFrequency• Quantum• Wavelength•


Making waves


9

Online Learning ToolsAn Example of Doppler Effect www.walter-fendt.de/ph14e/dopplereff.htm Animation Collection: Wave Motion http://physics.usask.ca/~hirose/ep225/anim.htmElectromagnetic Waves www.colorado.edu/physics/2000/waves_particles/index.htmlNASA Lunar Prospector http://lunar.arc.nasa.gov/education/activities/active22a.htmRipple (Simulation of Reflection, Refraction, and Interference) www.physicslab.co.uk/ripple.htmTransverse and Longitudinal Waves www.control.co.kr/java1/wave%20Trans/WaveTrans.html

EvaluationImagine you witnessed a train robbery that took place in complete darkness. The police ask, “How did you know if the train was coming toward you or going away from you?” Write down how you would answer. If you need a hint, observe the animation of the Doppler effect at www.walter-fendt.de/ph14e/dopplereff.htm.

10



Five Papers


At the Threshold of GreatnessTo observe the photoelectric effect, first build an electroscope using a bottle that has been carefully cleaned (a Snapple or Frappuccino bottle works best). Cut two 1 cm × 6 cm strips of aluminum or gold foil. Hook the strips to a large paper clip you have opened, by making a small punch hole about 0.5 cm from the end, so that the strips hang straight down. Fill the mouth of the jar with plumber’s putty, holding the paper clip exactly in the middle so that about 2 cm of the clip sticks out of the top. Insert a small hollow coffee stirrer through the top, ensuring that the putty is firmly in place. Test the electroscope with a piece of tape, sticking the tape to a smooth table surface, ripping it off, then bringing it near the top of the paper clip.

What happens when you bring the tape near the top of the paper clip?

_______________________________________________________

_______________________________________________________

Discharge the electroscope by touching the top of the clip with your finger. Repeat the charge and discharge routine a few times, until you are sure everything is in place. After doing this, seal the top of the bottle with rubber cement and let it dry.

What other ways can the electroscope be charged?

__________________________________________________________________________

__________________________________________________________________________

VocabularyAmplitude• Conductor• Magnet• Photoelectric effect• Threshold frequency•

Online Learning ToolsApplet: Photo Effect www.lon-capa.org/~mmp/kap28/PhotoEffect/photo.htmBuild Your Own Electroscope www.chicos.caltech.edu/classroom/escope/escope.html


five papers


10

Einstein http://movingscience.de/en/projects/physics/einstein.htmlFaraday’s Magnetic Field Induction Experiment http://micro.magnet.fsu.edu/electromag/java/faraday2

EvaluationA patent clerk examines descriptions of new inventions. The written applications must be clear and concise and and must distinguish one invention from all others like it. Practice writing a description of an invention—a mousetrap, or something else you invent yourself. Convince a careful patent officer that your idea is unique.

11



Seeing the (Photon) Light

Polarized LightYour teacher will give you two sheets of polarized filter (a fine plastic into which thin lines have been etched). Hold a single filter up to a window or other light source and rotate it 90°. Then overlap the filters and rotate only one filter through 360°. Observe the light that’s transmitted. Next, use an instrument that can measure light intensity (a computer-interfaced or camera light meter) to develop a graph of the intensity of light when the difference between the two filter papers is 0°, 45°, 90°, 135°, 180°, respectively. Describe what you observe.

__________________________________________________________________________

__________________________________________________________________________

__________________________________________________________________________

VocabularyPhoton• Polarized•

Online Learning ToolsPolarizing Filter www.colorado.edu/physics/2000/applets/polarized.htmlPolarization of Light http://micro.magnet.fsu.edu/primer/java/polarizedlight/

filters/index.html

EvaluationsLord Rayleigh (see p. 96 of Einstein Adds a New Dimension) explained why the sky was blue. But there are times when the sky is green (just before a tornado) or even red. How can you explain the painting The Scream, by Edvard Munch? (Hint: Look at the date it was painted, 1893, and research what earthshaking events happened in the previous decade.)

Today a red sunset in the Atlantic Ocean is often caused by a distant Saharan dust storm. When the Saharan Air Layer (SAL) is full of dust, there are dense winds aloft out of the Eastern Atlantic. Discuss how this is related to the verse “Red sky at night, sailor’s delight.”

12



Molecules Move

Smoke and MirrorsTo demonstrate Brownian motion —the phenomenon that inspired one of Einstein’s papers—start with a microscope, a slide and coverslip, a plastic coffee stirrer, some water, an eyedropper, and a drop of India ink. Place a tiny drop of India ink on a microscope slide and add a drop of clear, cool water. Then stir the two drops together a bit, cover the drops gently, and look at the mixture through the microscope. (Make sure you sit very still and do not bump the table.)

Describe how the tiny bits of black (carbon) move around.

__________________________________________________________________________

__________________________________________________________________________

Draw a sketch of what you observe (use the diagram on p. 102 of the book as a guide).

Let your drops get a little warmer. (Most microscopes have a light or a mirror, so that will happen anyway.) How does the movement change?

__________________________________________________________________________

__________________________________________________________________________

Use another color of pencil to show the change in the same space above. Remember, the bits of carbon that you see are much larger than molecules but are very, very light. Their movement is caused by the movement of molecules of water around them that bump and jostle them.

VocabularyBrownian motion•


MOLECULES MOVE


12

Online Learning ToolsBrownian Molecular Motion I, 2D/3D Animation, Drawings: Laurent Taudin, Paris http://movingscience.de/en/projects/physics/brownian_molecular_motion_i.htmlBrownian Motion www.control.co.kr/java1/idealgas/brownian.htmlBrownian Motion (Applet) www.aip.org/history/einstein/brownian.htm

EvaluationIf Albert Einstein could have written a letter to Robert Brown, how would he have explained the observations?

13



Getting the Picture Right

Cookies, Chemistry, and ConversationWhen trying to figure out what the inside of an atom looks like, J. J. Thomson got inspiration from plum pudding. Here’s another tasty analogy that you can make at home (do not eat in the science lab). When you are done making the recipe at home, think about how matter changes and how models are useful for visualizing what we cannot see.

2 ¼ cups all-purpose flour 1 teaspoon baking soda 1 teaspoon salt 1 cup (2 sticks) butter or margarine, softened ¾ cup granulated sugar ¾ cup packed brown sugar 1 teaspoon vanilla extract 2 large eggs 2 cups (12-ounce package) semi-sweet chocolate morsels 1 cup chopped nuts

Preheat oven to 375°F. Combine flour, baking soda, and salt in small bowl. Beat butter, granulated sugar, brown sugar, and vanilla extract in large mixing bowl until creamy. Add eggs, one at a time, beating well after each addition. Gradually beat in flour mixture. Stir in morsels and nuts. Drop by rounded tablespoons onto ungreased baking sheets (Nestle 2003, p. 7). The original recipe recommends baking for 9 to 11 minutes (or until “golden brown”), letting cookies cool on baking sheets for 2 minutes, then removing to wire racks to cool completely. However, you should bake a bit longer, until cookies are nearly crispy, before letting them cool. With a toothpick, test and describe the consistency of the cookie matrix and the chocolate chip. Put the cookie in the microwave for 20 seconds. Check out the consistency of the materials again and fill out the chart below:

Ingredient

Can you see it

in the cookie?

Consistency

when cool

Consistency when

reheated

Has a chemical change

occurred?

Egg

Butter

Nuts

Chocolate chips


Getting the Picture Right


13

1. When you bake, how do you know which changes are physical and which are chemical?

________________________________________________________________________

________________________________________________________________________

2. How would you explain the cookie analogy to J. J. Thomson and Niels Bohr: “This cookie is like an atom because…, but it is not like an atom because…”? (You may want to review Thomson’s image of an atom on p. 52 of Einstein Adds a New Dimension for comparison.)

________________________________________________________________________

________________________________________________________________________

VocabularyRadioactive decay•

Online Learning ToolBohr Atom www.lon-capa.org/~mmp/kap29/Bohr/app.htm

EvaluationHow small is an electron? That’s a question that can’t really be answered, since an electron acts more like a wave than a particle. But it’s sometimes useful to think of the electron as a particle about 10–15 m. A carbon atom is about 10–13 m in diameter. Use an analogy: If an electron were the size of a baseball, the entire carbon atom would be about the size of…. (See the cathedral analogy on p. 111 of Einstein Adds a New Dimension for hints.) Research: How many carbon atoms would be found in a 1-carat diamond?

Missing PiecesBegin this activity by looking at Mendeleyev’s first periodic table from 1869. Mendeleyev made many educated guesses based on his observations of chemical properties. (The tools he would have used are shown on p. 119 of Einstein Adds a New Dimension.) Compare Mendeleyev’s periodic table to the modern table online or on page 123 of the book to find the answers to the following questions:

1. Copper, silver, and gold are in Mendeleyev’s Group I but are in modern Group II (coinage metals). What characteristics might have prompted the first placement?

________________________________________________________________________

________________________________________________________________________

2. Based on 19th-century knowledge, what element might have fit in Group III of Mendeleyev’s table under boron and aluminum?

________________________________________________________________________

________________________________________________________________________

3. What element might have fit in Group VII of Mendeleyev’s table under bromine?

________________________________________________________________________

________________________________________________________________________

14



Getting Atom

Group

Period1

I II III IV V VI VII VIII

H=1

2 Li=7 Be=9.4 B=11 C=12 N=14 O=16 F=19

3 NA=23 Mg=24 Al=27.3 Si=28 P=31 S=32 Cl=35.5

4 K=39 Ca=40 Ti=48 V=51 Cr=52 Mn=55 Fe=56, Co=59, Ni=59

5 Cu=63 Zn=65 AS=75 Se=78 Br=80

6Rb=85 Sr=87 ?Yt=88 Zr=90 Nb=94 Mo=96

Ru=104, Rh=104, Pd=106

7 Ag=108 Cd=112 In=113 Sn=118 Sb=122 Te=125 J=127

8 Cs=133 Ba=137 ?Di=138 ?Ce=140

9

10 ?Er=178 ?La=180 TA=182 W=184 Os=195, IR=197, Pt=198

11 Au=199 Hg=200 TI=204 Pb=207 Bi=208

12 Th=231 U=240



14

Source: National Institutes of Health, National

Institute on Drug Abuse. www.nida.nih.gov/NIDA_

notes/NNvol21N2/brains.gif.

VocabularyAngular momentum• Energy level• Shell•

Online Learning ToolsInside the Human Brain www.nia.nih.gov/Alzheimers/Publications/UnravelingTheMystery/Part1/InsideBrain.htmPeriodic Table of the Elements http://periodic.lanl.gov/default.htmWebelements www.webelements.com

EvaluationToday we use isotopes of elements for vital studies. Since the 1990s, the positron emission tomography (PET) scan has been used to diagnose the functioning of important body systems. This image shows a series of PET scans of the human brain. The patient was injected with radioactive sugar and scanned for the places where it was metabolized. You be the radiologist: Compare the series to a brain diagram, and describe what parts of the brain are most active in each process.

Getting Atom

15



Still Shooting Alpha Particles

Seeing More With SatellitesIn the materials for Chapter 9, you may have puzzled over a satellite image of Earth’s oceans. The satellite cameras that took that photo were sensitive to electromagnetic waves in the infrared (heat) range. Take a look at these images and see if you can infer what sorts of wavelengths are being sensed.

Which band shows foliage most clearly?

__________________________________________________________________________

Why might this be true?

________________________________

________________________________

VocabularyIsotope•

Online Learning ToolsApplet: Spectrum http://lectureonline.cl.msu.edu/~mmp/

applist/Spectrum/s.htmHow Are Satellite Images Different From Photographs? http://landsat.gsfc.nasa.gov/education/

compositor

EvaluationResearch the NASA website above for the applications for which each of these bands are useful. Then write a short letter to your congressional representative supporting continued funding of Landsat research.

Source: Electromagnetic spectrum image from Virtual Hawaii,

Hawaii Space Great Consortium, UH Hanoa, “How Are Satellite

Images Different From Photographs?” http://landsat.gsfc.nasa.

gov/education/compositor.

1. 0.45–0.52 μm2. 0.52–0.60 μm3. 0.63–0.69 μm4. 0.76–0.90 μm

5. 1.55–1.75 μm6. 10.40–12.50 μm7. 2.08–2.35 μm

16



Bohr Taking Quantum Leaps

Altit

ude

Air Pressure8000

7000

6000

5000

4000

3000

2000

1000

0

Air PressurePressure Millibars

0 500 1000 1500

Modeling the Real WorldImagine you are traveling up through the atmosphere in a hot-air balloon, and you have a barometer and an altimeter. Imagine measuring the air pressure as you rise. Here are the data you collect (see graph). Choose the expression that matches the data best:

Air pressure increases just as much as altitude increases. • Air pressure decreases as altitude increases.• Air pressure doubles as altitude decreases. • Air pressure is always half of the altitude.•

Now answer the following questions:

1. What will the air pressure be if the balloon rises to 8,000 feet?

________________________________________________________________________

________________________________________________________________________

2. Scientists often use equations to describe data like these. Which of these equations would come closest to predicting the air pressures at altitudes below 4,000 feet?

• Pressure = (11,000 – altitude)/11• Pressure = (11,000 – altitude) × 11• Pressure = 11,000/altitude• Pressure = 11,000 + altitude


Bohr Taking Quantum Leaps


16

VocabularyModel•

Online Learning ToolApplet: Decay www.lon-capa.org/~mmp/applist/decay/decay.htm

EvaluationScientific dating often involves measurement of radioactive carbon isotopes in a sample. On page 135 of your text, you learned that the half-life of the isotope is 5,730 years. By about 50,000 years, the amount of isotope left in a sample is normally so small that it is difficult to get accurate measurements. The graph below is a model of the decay of a different isotope, radioactive potassium. (It’s often found in zircon crystals in igneous rocks.) It decays to argon, with a half-life of 1,251 million years. Imagine you are writing a proposal for a new research project. What kind of scientific question would be better answered with K-Ar dating than carbon-14 dating? Why would your results be more accurate with one method versus the other?

Amou

nt o

f Par

ent N

uclid

e Re

mai

ning

Number of Half-Lives(Each half-life is equivalent to 1251 million years)

0

1/1

1/2

1/4

1/81/16

1 2

Sample containing ½ of original amount of parent material is 1,251 million years old.

2,502 million years

3,753 million years

5,004 million years

3 4 5

Original 40KDaughter Nuclides

40Ar-------- = 1 40K

40Ar-------- = 3 40K 40Ar-------- = 7 40K 40Ar-------- = 15 40K

Adapted from “Dr. Nicholas Short’s Remote Sensing Tutorial, Section 2: Geological Applications I: Stratigraphy and

Structure,” NASA/Goddard Space Flight Center. http://rst.gsfc.nasa.gov/Sect2/K-Adecay.jpg.

17



An American Tracks Photons; a Frenchman Nails Matter

Crossing BordersScience can reveal structures that are as beautiful as any artist might imagine. Research the crystal structure of any metal, like the actinide oxide pictured here, the zinc sulfide on page 145 of Einstein Adds a New Dimension, or any other metal crystal. (Ideas can be found on the Crystal Lattice Gallery website below.) Build a work of art using the crystal structure as a subunit.

VocabularyX-ray crystallography•

Online Learning ToolsBragg’s Law and Diffraction: How Waves Reveal the Atomic Structure of Crystals www.eserc.stonybrook.edu/ProjectJava/BraggCrystal Lattice Gallery www.uncp.edu/home/mcclurem/lattice/lattice.html

EvaluationLouis-Victor de Broglie’s military responsibility was sending telegraphs. In the days when this was the only form of communication, messages had to be brief. (People paid by the word so they were concise, similar to today’s instant messaging or text messaging.) Write a telegram message in less than 20 words describing Arthur Compton’s discoveries.

© Copyright 2006 Los Alamos National Security, LLC. All Rights Reserved. http://lanl.gov/

source/orgs/nmt/nmtdo/AQarchive/04summer/xray.html.

Num

ber o

f Stu

dent

s

Number of Heads

Ratios of Heads10

5

1 2 3 4 5 6 7 8 9

18



What’s Uncertain? Everything, Says Heisenberg

Num

ber o

f Stu

dent

s

Trials

Percent of Heads60

40

201 2

Playing Dice for Real Prizes Can reliable predictions be made about random events? Toss a penny 10 times. All of the students in your class will do the same and, together with your teacher, will make a frequency graph, grouping students by how many heads they got. (A sample graph for 30 students is shown.) Add up the total number of heads and remember that number. Now toss a penny 100 times (everyone in your class should do the same). Again with your teacher, graph the frequency. Compare the percentage of heads in each trial.


What’s Uncertain? Everything, Says Heisenberg


18

Answer the following questions:

1. Did the ratio come closer to 50/50 as the number of trials increased? Why or why not?

________________________________________________________________________

2. What does this say about observations about random events?

________________________________________________________________________

3. Divide the coins into new coins (less than 10 years old) and old coins. Then calculate the percentage of heads in each group. Are coin tosses really random? Does it make a difference if the coin is old or new? Why or why not?

________________________________________________________________________

4. What other factors might affect the phenomena that we think of as random, like coin tosses?

________________________________________________________________________

VocabularyMechanics• Randomness• Uncertainty•

Online Learning ToolUnderstanding Uncertainty http://school.discoveryeducation.com/lessonplans/programs/understanding-uncertainty

EvaluationWhen pollsters want to know information about an issue, they try to choose a small sample of random people who would represent the entire population. Think of a controversial question in your community. Then think of three locations that you might go to do opinion polls. Two of the locations should be nonrandom: They should be places where the people would mostly agree on one side or another about the issue. The third place should be the location where you think the opinions would be random. Write a short newspaper article about the opinions you think you’d find on this issue in these locations.

19



A Cat, Quarks, and Other Quantum Critters

Entropy, Energy, and EinsteinSome of the most common “chemical experiments” illustrate key concepts in chemistry. The following experiment challenges you to reconsider one of the most basic ideas of physics—entropy. While physicists express entropy in long paragraphs and mathematical equations, everyone knows the idea: Nothing gets more organized unless you put energy into it. Keep this in mind as you try this experiment. Take a foam plastic cup and fill it with 50 ml of water at 20°C and slowly stir in 10 g of NaCl. Then measure the change in temperature.

1. What do you observe?

________________________________________________________________________

Think about the molecular structure of the salt as you try to formulate an explanation for what is happening. The ions (Na+ and Cl–) are pulled apart. That takes energy. But the ions are also slightly attracted to the polar water molecules. That frees energy.

2. Which process is stronger as salt dissolves? Is the solution more or less organized than the original solid and liquid?

________________________________________________________________________

________________________________________________________________________

Go to the website “Energy Exchange Associated With Dissolving Salts in the Water” listed on page 32 and try the same experiment with a variety of salts, keeping the temperature the same.

3. Do they all react in the same way? If not, can you categorize the reactions?

________________________________________________________________________

Try the same experiment at a warmer temperature.

4. Can you get more salt into the water before it begins to sink because no more can dissolve? Compare other salts using the website in “Energy Exchange Associated With Dissolving Salts in the Water.”

________________________________________________________________________

________________________________________________________________________


A Cat, Quarks, and Other Quantum Critters


19

Think about the situation where a gas is dissolved in a liquid (for example, the oxygen that’s dissolved in tap water).

5. When the water gets warmer, can it hold more or less oxygen? Can you explain the difference in terms of entropy?

________________________________________________________________________

VocabularyEntropy• Solution•

Online Learning ToolsA Question of Scale: Quarks to Quasars www.wordwizz.com/pwrsof10.htmEnergy Exchange Associated With Dissolving Salts in the Water www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/flashfiles/thermochem/heat_soln.html

For Further InvestigationThermodynamics Laboratory www.saskschools.ca/curr_content/chem30_05/1_energy/labs/heat_solution.htm

EvaluationSalt is a great way to melt sidewalk ice but it kills plants. Can you propose an alternative that would work as well? Explain why you think it would work.

20



Smashing Atoms

Elementary Particles

electron neutrino muon neutrino tau neutrino Z boson

electron muon tau W boson

up charm top photon

down strange bottom gluon

Quar

ksLe

pton

s Forc

e Ca

rrier

s

Three Generations of MatterI II III

Falling ApartThis activity involves building models of the Standard Model of particle physics. Half of the class builds a model like the one pictured here, using dice relabeled with stickers. The other half of the class builds models from plastic foam balls. Before you assemble your plastic foam–ball atoms, you must cut your neutrons and restick them with tiny Velcro dots. You also need to color code the particles with markers and use tiny bits of clay to hold the entire nucleus together. Partner with a classmate who has built the other type of model. Explain your different models to each other and think about the advantages of both versions.

VocabularyAccelerator• Gluon• Neutrino• Quark• Standard Model of particle physics•

Online Learning ToolsApplet: Quarks www.lon-capa.org/~mmp/applist/q/q.htmFermilabyrinth (Warp Speed Game) http://ed.fnal.gov/projects/labyrinth/games/index1.htmlParticle Physics, Quarks, and All That http://home.fnal.gov/~carrigan/Pillars/Quarks.htm

EvaluationSzilard’s model wasn’t physical; it was mathematical. Imagine you are writing the cover sheet that he might have placed on the paper as he offered it to his doctoral adviser. Explain why you think the revolutionary approach should be considered instead of traditional models.

Can You See With a Crystal?Even with the best of today’s technology, it is impossible to see molecules directly. But we can often see properties of very well-ordered materials, like crystals, that give us clues to how their molecules are arranged. For this activity, look at each of the crystals listed in the table below with a hand lens or stereo microscope, draw a sketch of what you see, and fill in the table below. Use your imagination to develop a hypothesis about how the molecules are arranged, and show it in another drawing. Finally, use the internet (see “Online Learning Tools”) to discover what chemists know about how the molecules are arranged.

Crystal External Structure

Hypothesis:

Molecular Structure Your Research

Salt

Snowfl ake

Quartz

Alum

VocabularyIonic bond• Covalent bond•

Online Learning ToolsAutomatical Pattern Making www.asahi-net.or.jp/~SI4K-NKMR/inpaku/p400e.htmInteractive Example: 2D Crystal Builder www.mineralogie.uni-wuerzburg.de/crystal/teaching/ispace_a.htmlStructure of Solids w w w. ch m . d av i d s o n . e d u / C h e m i s t r y A p p l e t s / i n d e x .

html#StructureOfSolids

EvaluationOne of the most famous x-ray diffraction photos was the one taken of the DNA molecule by Rosalind Franklin, pictured here. Today most people are familiar with the arrangement of the molecules in DNA. Can you explain the connection between the molecule and the image? What was Franklin seeing?

21



Chemistry, Charisma, and Peace

34


Source: Talking Glossary of Genetics,

National Human Genome Research

Institute, National Institutes of Health.

www.genome.gov/Pages/Hyperion/DIR/VIP/

Glossary/Illustration/Images/dna.gif.

22




Conservation ConundrumBefore you think about that equal sign in Einstein’s equation, reconsider the idea of conservation of mass and energy in normal chemical reactions. For the following activity, you will need a water bottle filled with 30 ml of water; an Alka-Seltzer tablet; and a small, round balloon. Alka-Seltzer is made of sodium bicarbonate and citric acid. In water, the tablets react to form sodium citrate. Carefully mass each component and fill in the chart below.

Material Mass in Grams

Balloon

Alka-Seltzer

Bottle+water

Total

Stretch the mouth of the balloon to make it more flexible. After that, break the Alka-Seltzer tablet over a bit of paper and put the entire tablet into the water. Immediately put the balloon over the bottle, watch the reaction, and then feel the bottle. Answer the following questions:

1. Does the bottle get warmer or cooler? Why?

________________________________________________________________________

When the reaction is done, estimate how much volume has been added using the formula for the volume of a sphere: V=4/3πr3. Then mass the total.

2. How close is the mass to the original?

________________________________________________________________________

3. Has energy gone in or come out of the system?

________________________________________________________________________

4. Where did that energy come from?

________________________________________________________________________




22

VocabularyConservation of energy• Conservation of mass•

Online Learning ToolsApplet: Ideal Gas www.lon-capa.org/~mmp/applist/pvt/pvt.htmConservation http://library.thinkquest.org/3042/conservation.html

EvaluationEinstein wondered why the energy contained in every gram of material went unnoticed for so long. Many natural phenomena are misunderstood, and people tend to believe “old wives’ tales” or assumptions without really examining them. Think of something you know about science that many people don’t believe or understand. Think of a short YouTube video that you could make to explain it to an uninformed person.

23



On the Way to War (a List of Happenings)

Mapping the PlayersUse the map below to outline and identify the Axis powers and the Allied forces in World War II. Mark the sites where each phase of the war began.

VocabularyDigital computer•

For Further InvestigationThe Manhattan Project: An Interactive History www.cfo.doe.gov/me70/manhattan/index.htmManhattan Project www2.scholastic.com/browse/article.jsp?id=5203The Perilous Flight: America’s World War II in Color www.pbs.org/perilousfight

EvaluationDraw a fishbone diagram (you may use the example as a guide) to show the events that led to the war.

24



The Fission Vision

Fission SimulationWith the help of your teacher, you can model nuclear fission with your class. Each student will represent a uranium atom, either U-235 (which is fissile) or U-238 (which is nonfissile). Your teacher will mimic the neutron. First, take a card from your teacher, but don’t tell the other students what role you’ve drawn. Then, in a wide-open space arrange yourselves in a matrix; make sure you stand about 1 m from one another. As you take your places, consider how the “structure” you’re creating compares to a crystal. Once everyone is ready, your teacher initiates the reaction by walking into the formation in a straight line and touching a student at random. If you are touched and you’re a nonfissile atom, remain totally still. If you are touched and you’re a fissile atom, silently count, “One tomato, two tomato, three tomato,” then shout, “Bang,” and quickly (but gently) tag all the other students within arm’s reach. With the help of an audio or video recorder, log the number of generations of bangs that occur until the process stops. Complete this process three times, and each time draw a new role. At the end of the three rounds, summarize your data in this chart:

% Fissionable

# of Generations

of Reactions

25

50

75

1. What percentage of fissile atoms produced the longest/strongest chain reaction?

________________________________________________________________________

2. Why?

________________________________________________________________________

3. On the news you often hear the term enriched uranium. Why do scientists enrich uranium before fission can occur?

________________________________________________________________________

________________________________________________________________________


The Fission Vision


24

Next, grab a calculator and look carefully at the diagram on page 217 of Einstein Adds a New Dimension. It represents a chain reaction. Note that when the first neutron hits the uranium-235, two neutrons are released in addition to the original one. In the next reaction, potentially nine neutrons are released. Complete the table showing the reaction number and number of free neutrons:

Reaction # Free Neutrons

1 3

2

3

4

5

6

7

•

•

•

n > 1 million

4. How many reactions are required to release at least 1 million free neutrons?

________________________________________________________________________

5. Graph the number of free neutrons in each reaction. What is the shape?

________________________________________________________________________

6. If each reaction takes about 10–7 second, how long will this process take?

________________________________________________________________________

7. In fission reactors, rods are sometimes used to slow reactions. If a rod absorbed one of every three released neutrons, how would the shape of the graph change?

________________________________________________________________________


The Fission Vision


24

VocabularyFission• Fusion•

Online Learning ToolsChain Reaction: Mouse Trap Model www.physics.umd.edu/lecdem/services/demos/demosp4/p4-62.htmNuclear Fission www.lon-capa.org/~mmp/applist/chain/chain.htm

For Further InvestigationEinstein’s Big Idea: Messing With Mass www.pbs.org/wgbh/nova/teachers/activities/3213_einstein_03.htmlNuclear Science in Society: Student Fission Activity http://old-www.ansto.gov.au/edu/pdf/stu_act1_9.pdf

EvaluationPhysicists love to do rough, “back of the napkin” estimates. These are often called Fermi Questions after Enrico Fermi. Here’s a Fermi Question for you: Look at the chart below. It shows the energy needed to get from Earth to the dwarf planet Pluto, at the edge of our solar system, if we were to harness the energy of a fission reaction. Compare that to the energy available in gasoline. If we could somehow create a gasoline-powered rocket, how much fuel would we need to get to Pluto? How much mass would that represent?

Fuel

Mass (g) per

Molecule or

Reaction

Energy Released

per Molecule/

Reaction (eV)

# of Reactants/

Reactions Needed

to Get to Pluto

Total Mass of Fuel

Needed

Fission 4 x 10-23 2 x 107 3.5 x 1024 680

Gasoline 1.9 x 10-22 66

Source: Adapted from NOVA, “A Trip to Pluto.” www.pbs.org/wgbh/nova/teachers/activities/3213_einstein_05.html, where complete answers,

explanations, and extensions can be found.

25



presidential power

The Manhattan Team Use a concept map to describe the contributions of the scientists in this chapter. You can add a circle for each scientist you would like to investigate. How are social relationships among scientists important for the development of ideas?

VocabularyDeuterium• Heavy water•

Online Learning ToolsHow We Know What We Know (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxYo-Yo Animation www.rotatingobjects.com/animation4d.html

For Further InvestigationThe Physics of a Yo-Yo http://clackhi.nclack.k12.or.us/Physics/projects/Final%20Project-2005/2-FinalProject/yoyo/

physics%20of%20yoyo.htm

EvaluationWhat are the key characteristics of a scientist? One trait is curiosity. Einstein wondered about light, the universe, and yo-yos. Study a yo-yo or go to the Yo-Yo Animation website above to complete the activity.

Put the loop on your finger. Why does the yo-yo move down?

__________________________________________________________________________


presidential power


25

Predict how far the yo-yo will move back up the string.

__________________________________________________________________________

Then let the yo-yo fall without moving your hand. Was your prediction correct?

__________________________________________________________________________

Repeat the motion. Does the yo-yo move the same amount up the string each time?

__________________________________________________________________________

Write a paragraph explaining the motion of a yo-yo. (Use velocity and momentum in your explanation if you can.) Illustrate your paragraph with a picture.

26



Manhattan on a Mesa

Debate Beneath the MesaFor reasons of security, the scientists of Los Alamos were strictly isolated as they worked on the Manhattan Project. Imagine the conversations they might have had. For this activity, assume the role of any of the scientists represented in the concept map developed for Chapter 25. Research the scientists’ backgrounds and skills, and then imagine a conversation about the nature of matter and energy from each of their perspectives. For example, suppose Oppenheimer (expert in Sanskrit) had told his colleagues: “The founder of the Vaisheshik Darshan school of Hindu philosophy was Acharya Kanad. He described atoms in the 9th century BC. He classified all objects in creation into nine elements—earth, water, light, wind, ether, time, space, mind, and soul—and said: ‘Every object of creation is made of atoms, which in turn connect with each other to form molecules.’” How would the other scientists respond to Oppenheimer’s statement? Create a short, imaginary conversation among the Los Alamos scientists to illustrate how their approaches might have differed.

Online Learning ToolEinstein’s Big Idea: The Power of Tiny Things www.pbs.org/wgbh/nova/einstein/tiny.html

EvaluationBelow is an excerpt from a poem that Richard Feynman wrote as part of his “The Value of Science” address to the autumn meeting of the National Academy of Sciences, in 1955:

Deep in the seaAll molecules repeat

The patterns of anotherTill complex new ones are formed.They make others like themselves

And a new dance starts.Growing in size and complexity

Living thingsMasses of atomsDNA, protein

Dancing a pattern ever more intricateOut of the cradleOnto dry land

Here it isStanding

Atoms with consciousnessMatter with curiosity.

Stands at the sea, wondering: IA universe of atoms

An atom in the universe.

Write your own poem about humans from the perspective of quantum physics.

27



Quantum Electrodynamics? Surely You’re Joking

Life’s a Game—and a Dance!Most people think scientists conduct “controlled experiments” all day. But that’s not how particle physicists work at all. Read “Adventures in Particle Research” on page 259 of Einstein Adds a New Dimension, and then go to the Fermilabyrinth website (see address below) to play “games” that simulate how particle physicists work. Visualize elementary particles by dancing with the quarks at “QuarkDance.org” (see “Online Learning Tools,” p. 46). After you have enjoyed the quark dance, visit “The Particle Adventure” website (see “Online Learning Tools,” p. 46) to help you answer the following questions. Be as specific as you can in your answers.

1 1. What does fundamental mean?

________________________________________________________________________

________________________________________________________________________

1 2. What particles are fundamental?

________________________________________________________________________

________________________________________________________________________

3. What forces are fundamental?

________________________________________________________________________

________________________________________________________________________

4. Where do these forces act?

________________________________________________________________________

________________________________________________________________________

5. Which fundamental force is the strongest?

________________________________________________________________________

________________________________________________________________________




27

1 6. Which is the weakest?

________________________________________________________________________

7. Does this surprise you? Why or why not?

________________________________________________________________________

________________________________________________________________________

8. How many quarks are there? What are their names?

________________________________________________________________________

________________________________________________________________________

9. Do quarks pair up? How?

________________________________________________________________________

________________________________________________________________________

10. What is meant by “color charge”?

________________________________________________________________________

________________________________________________________________________

VocabularyElectrodynamics• Fundamental particle• Quantum mechanics•

Online Learning ToolsAnimations for Breaking Spacetime Symmetries http://physics.indiana.edu/~kostelec/mov.html#5Fermilabyrinth http://ed.fnal.gov/projects/labyrinth/games/index1.htmlHow We Know What We Know (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx




27

QuarkDance.Org http://pdg.lbl.gov/quarkdanceThe Particle Adventure http://particleadventure.orgTiny Machines—The Feynman Lecture on Nanotechnology www.photosynthesis.com/flash/tiny-machines/video.html

EvaluationWrite a “Want Ad” for a job for a particle physicist. List the qualifications, the rewards, and the challenges.

28



those relatives:galileo and albert

Perspective—It’s All RelativeIdentify a tree on the school property within sight of the bleachers. Your teacher will divide your class into groups of three. One student from your group will stand under the tree, one as far as possible from the tree, and another on top of the bleachers (be careful on the bleachers). Once situated, draw a picture of the tree from your individual perspective. Once back in the classroom, compare the different “frames of reference” with the other members of your group. Answer the following questions:

1. How does the picture vary from the different perspectives?

________________________________________________________________________

2. How does frame of reference determine what information you receive?

________________________________________________________________________

________________________________________________________________________

VocabularySpeed• Velocity• Acceleration•

Online Learning ToolsAnimations for Breaking Spacetime Symmetries http://physics.indiana.edu/~kostelec/mov.html#5EinsteinLight: Relativity in Brief. Module 1: Galileo www.phys.unsw.edu.au/einsteinlightEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.htmlWelcome to the Space-Time Lab www.its.caltech.edu/~phys1/java/phys1/Einstein/Einstein.html

For Further InvestigationGalileo’s Spacetime: Introducing the Principle of Relativity (includes Galilean Map Reading 201) http://physics.syr.edu/courses/modules/LIGHTCONE/galilean.html

EvaluationWitnesses to a crime often have totally different views of what occurred. Imagine you are a prosecutor and explain to a jury how “frame of reference” matters.

29



relativity: it ’s about time

Flash! Bang!On Earth, light is almost instantaneous. You are probably familiar with the “scout trick” of watching for a flash of lightning and then counting the seconds until a crack of thunder is heard. Sound travels at an average of 1,125 ft./sec., though the actual speed depends on temperature, humidity, and other factors. The distance to the storm cloud can be determined by multiplying the delay (in seconds) by 1,125. Make the same experiment more precise by using two computer-interfaced probes, one for light and one for sound. After experimenting with the computer-interfaced probes, discuss whether light moves instantaneously and answer the following questions:

1. Why does this method work?

________________________________________________________________________

________________________________________________________________________

2. Does light move instantaneously?

________________________________________________________________________

________________________________________________________________________

3. How does the medium affect its speed?

________________________________________________________________________

________________________________________________________________________

4. How does the medium affect its wavelength?

________________________________________________________________________

________________________________________________________________________

5. Can you think of a simple example that illustrates this?

________________________________________________________________________

________________________________________________________________________


relativity: it ’s about time


29

VocabularyGravitation• Speed of light• Speed of sound• Thought experiment•

Online Learning ToolsEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.htmlLightning Distance Calculator www.csgnetwork.com/lightningdistcalc.htmlWelcome to the Space-Time Lab www.its.caltech.edu/~phys1/java/phys1/Einstein/Einstein.html

EvaluationIt’s a common insult to say, “You think the world revolves around you!” But, in fact, nearly everyone in Newton’s time believed Earth was the center of the universe. Imagine you are debating an Aristotelian traditionalist in Newton’s time. Explain all the ways in which you are moving every second of every day. (Review “Hold on to Your Hat” on p. 29 of Einstein Adds a New Dimension.)

30



An event? to a physicist it ’s not a party

800

600

400

200

00

900 600 6003001200 120015001800 00300 900

200

400

600

It’s All in How You Look at ItNewton could never have explained his ideas without inventing calculus. Modern physicists rely on many other forms of mathematics, including non-Euclidean geometry (see “Math Matters” on p. 282 of Einstein Adds a New Dimension). Take a look at the maps below. The one on the left is a Hammer-Aitoff projection, and the one on the right is a Mercator projection. Compare the proportions of sizes of the United States at the 30th and 60th parallels (N). Use a bit of yarn to compare the proportions of various continents on the flat projections and on the globe.


1. Which is closest to the actual proportions of a (round) globe?

________________________________________________________________________

________________________________________________________________________

2. How does the shape of the surface affect the accuracy of a map?

________________________________________________________________________

________________________________________________________________________

3. Is there one single correct way to draw a spherical Earth on a flat piece of paper?

________________________________________________________________________

________________________________________________________________________

4. Imagine that two airplanes want to fly parallel courses along different lines of latitude from East to West on Earth. Would they fly straight lines?

________________________________________________________________________

________________________________________________________________________


an event? to a physicist it ’s not a party


30

5. How could non-Euclidean geometry like that described on page 283 help us analyze such maps?

________________________________________________________________________

________________________________________________________________________

VocabularyEuclidean• Geometry• Non-Euclidean•

Online Learning ToolsEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.htmlHow We Know What We Know (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxThe Light Cone: Events and Spacetime http://physics.syr.edu/courses/modules/LIGHTCONE/events.html

For Further InvestigationGeometry in Space http://universe.sonoma.edu/activities/geometry.html

EvaluationWrite an advertisement for three kinds of maps, two flat projections and a globe. Describe why each is good for a specific purpose.

31



timely dimensions

Daydreaming Away Time and SpaceEinstein famously liked to participate in “thought experiments.” For this activity, examine one of his thought experiments: A train is pulling away from a station platform. A passenger stands at the center of the moving train, and an observer stands on the platform next to the tracks. Lightning strikes both ends of the train, in a way that seems simultaneous to the person on the platform. How does the lightning appear to the person on the train? Draw the scenario and write a trial explanation. Show your drawings and explanations to other students.

__________________________________________________________________________

__________________________________________________________________________

VocabularyDimension• Simultaneity• Space-time•

Online Learning ToolsAtomic Clocks in Space http://physics.indiana.edu/~kostelec/mov.html#5Chasing a Beam of Light: Einstein’s Most Famous Thought Experiment www.pitt.edu/~jdnorton/Goodies/Chasing_the_light/index.html

EvaluationA very important part of scientific work is attending conferences and meetings. Imagine the program of the Solvay Conference of 1911. Einstein was the youngest participant, but he was selected to give the “grand finale” speech. Write what might have been in the program describing what the older scientists were about to hear.

32



a man in a red hat

Tracking AccelerationFor this activity, try to think like the scientists who built a linear accelerator in the 1930s, scientists who tried to find and measure the tiniest particles in the universe. A tiny particle is made to go faster and faster by electromagnetic forces accelerated almost to the speed of light. Draw and explain what happens to that particle.

Why is Einstein’s theory absolutely necessary for these scientists?

__________________________________________________________________________

__________________________________________________________________________

Online Learning ToolEinstein’s Rocket http://physics.ucsc.edu/~snof/Tutorial/index.html

EvaluationRemember the train in Einstein’s thought experiment? Now, instead of watching lightning, both the passenger on the train and the observer on the platform are juggling. Explain the movement of the balls.

33



the paradox of the twins

Time TravelersCan you tell the story of the twin paradox as Einstein might have told it? Write captions for each panel below.

VocabularyInertia• Paradox•

Online Learning ToolEinstein’s Big Idea: Time Traveler www.pbs.org/wgbh/nova/einstein/hotsciencetwin

EvaluationHas Einstein’s twin paradox been proved? Think about the experiments done at accelerators like Fermilab. (If you’ve forgotten them, review pp. 170 and 173 in Einstein Adds a New Dimension.) Write a letter to a skeptic explaining why you think Einstein’s theories have been supported.

34



relative gravity

Inertia

Gravity

Car’s Motion

Toys in SpaceGravitation is a law that is consistent throughout the universe. That’s why it is so interesting to study gravitation on Earth. Begin this activity by becoming familiar with how the following toys work in normal (Earth) gravity.

Write a hypothesis about how the toys would work in microgravity—not zero gravity, but the much lower gravity of the space shuttle. Then watch the videos on the NASA websites listed below to learn more about how the toys work in microgravity. For each toy, compare your hypothesis to your observations.

Online Learning ToolsForce and Motion (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxLiftoff to Learning: Toys in Space 2 http://quest.nasa.gov/space/teachers/liftoff/toys.html

EvaluationEinstein used the image of a free-falling elevator as a thought experiment. (Don’t worry, modern elevators don’t free-fall.) Write a few paragraphs of a horror story, describing a person falling in an old-fashioned elevator. Or pretend you are a guidance counselor. You have a student who does not want to take academic courses like math or physics, because he or she wants to be a NASCAR driver. Convince the student that you need physics to drive a race car.

35



warps in spacetime

Warped ImagesFor this activity, you will build a model of how mass can warp space-time. Take a very pliable piece of rubber and mark parallel lines on it when it is flat. Then place massive objects (stones or large ball bearings to modify the model) on the rubber. (Cling wrap may be used in lieu of rubber.) For an example of what the model should look like, refer to the image on p. 313 of Einstein Adds a New Dimension.

After you make the model, answer the following questions:

1. What does the rubber represent?

________________________________________________________________________

2. What does the stone or ball bearing represent?

________________________________________________________________________

3. How does the nature of “parallel” change?

________________________________________________________________________

4. How does the heavy object move when the rubber is flat on a table?

________________________________________________________________________

5. What law of traditional physics would this represent?

________________________________________________________________________

Source: NASA/HONEYWELL MAX-Q DIGITAL GROUP/DANA BERRY, NASA/Goddard Space

Flight Center. www.gsfc.nasa.gov/gsfc/spacesci/structure/spinningbh/spinninghpix.htm.


warps in spacetime


35

6. How does the model change in Einstein’s universe, when space is allowed to flex?

________________________________________________________________________

7. What modification of the laws of physics does this represent?

________________________________________________________________________

VocabularyEclipse•

Online Learning ToolsEvents and Space-Time http://physics.syr.edu/courses/modules/LIGHTCONE/events.htmlFluid Dynamics to Study Stars www.nsf.gov/news/mmg/mmg_disp.cfm?med_id=57213One Universe: At Home in the Cosmos: Gravity and Light www.nap.edu/html/oneuniverse/linked_motion_40-41.htmlRelativity of Simultaneity www.control.co.kr/java1/masong/relativity.html

For Further InvestigationPaper “Embedding Diagram Models” of Black Holes www.sff.net/people/Geoffrey.Landis/blackhole_models/paper_blackholes.html

EvaluationTo demonstrate his ideas, Einstein predicted the bending of light in an eclipse in 1919. His predictions were not exactly correct, but once he realized his error, a new understanding of his theories resulted. Describe a mistake you’ve made that resulted in better understanding.

36



Does it Change? Or Is It Changeless?

Relying on PhysicsIn the familiar patch of the universe that we inhabit, we rely on the constant laws of physics. To illustrate this, go outside to the playground with your class and swing as high as you can (be careful as you swing). Formulate a good explanation for why you don’t fall off the swing. You can also explore the physics of a roller coaster by watching a video of a roller coaster or using the interactive website “Amusement Park Physics: Roller Coaster,” see “Online Learning Tools.” Carefully describe the laws of physics that keep you from falling out of the roller coaster. You can also think about a roller coaster on Saturn’s moon Titan. How would the roller coaster act? How do you know?

VocabularyInfinite•

Online Learning ToolsAmusement Park Physics: Roller Coaster www.learner.org/interactives/parkphysics/coaster.htmlForce and Motion (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

EvaluationSome shapes have edges; some don’t. Some are real; some are imaginary. Look at this one carefully. Can it exist? Why or why not?

37



expanding times

By the Light of Ancient Stars Starlight can be investigated in number of ways. For this activity, you will compare luminosities using a standard bathroom light bar. Your teacher will put a variety of 25- to 60-watt lightbulbs in the bar. Loosen all but one bulb at a time to make measurements. Use a photo light meter or computer-interfaced light probe to measure the illumination from each bulb as distance increases. Graph your data. Ask a partner to tighten a bulb at random and then measure the luminosity at a specific point. Answer the following questions:

1. Can you predict which bulb it is from one measurement?

________________________________________________________________________

2. How would you get data on distance to the star?

________________________________________________________________________

Use a handheld spectroscope to compare the light given off by standard incandescent bulbs with that of new fluorescent energy-saving bulbs.

3. What is the difference?

________________________________________________________________________

Draw, color, and identify the wavelengths of the spectra of light on the form provided (p. 23 of Einstein Adds a New Dimension can be used as a reference).

4. What are the longest wavelengths?

________________________________________________________________________

5. The shortest?

________________________________________________________________________

6. What is the meaning of the prefix “infra” in infrared?

________________________________________________________________________


expanding times


37

7. What is the meaning of “ultra” in ultraviolet?

________________________________________________________________________

8. Think back to the familiar Doppler effect; what change occurs when a train passes?

________________________________________________________________________

9. If the wavelengths of these colors get longer, toward what (visible) color do they move?

________________________________________________________________________

10. Look at page 127 in Einstein Adds a New Dimension. Imagine you are observing the spectrum of hydrogen from a star that is moving away. How would it change?

________________________________________________________________________

VocabularyCosmological constant• Lambda• Redshift•

Online Learning ToolsAmazing Space http://amazing-space.stsci.eduIntute: Redshift www.intute.ac.uk/sciences/spaceguide/redshift.htmlThe Sun as a Star (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

For Further InvestigationDetermining Redshift in a Receding Star www.pbs.org/deepspace/classroom/activity2.html

EvaluationAstrophysicists have two basic scientific methods, observation and inference. It’s not enough just to “see” and measure the universe. They must also understand it, interpreting the data and making inferences. Look at the following chart and think about what aspects of theoretical cosmology the observations in the first column imply or prove.


expanding times


37

Observations/Measurements Interpretations/Inferences

The light emitted from almost all galaxies shows redshift.

The farther away a galaxy is, the greater the redshift.

For every kiloparsec of distance of a galaxy, the speed at which the galaxy is moving increases by 50 to 100 km/s.

In the most empty areas of deep space, there is still some heat (temperature).

Source: Adapted from Ceres: The Expanding Universe, http://btc.montana.edu/ceres/html/Universe/uni1.html.

38



an expanding universe

Stretching Your Mind and the UniverseTake a noninflated small balloon and draw several galaxies on it with indelible markers. Measure the difference between five pairs of galaxies on the balloon and then blow up the balloon. Measure the distance again once the balloon is inflated and explain to a partner how the demonstration illustrates Lemaître’s theory. Enter your measurements in the table below.

Galaxies Distance Before Infl ation Distance After Infl ation

VocabularyGalaxy• Universe•

Online Learning ToolsAmazing Space http://amazing-space.stsci.eduExpanding Universe Animation http://bccp.lbl.gov/Images/990404b.gifThe Universe Beyond Our Solar System (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

Source: “Dr. Nicholas Short’s Remote Sensing Tutorial, Section 20: Astronomy and

Cosmology: The Description, Origin, and Development of the Universe,” NASA/

Goddard Space Flight Center. http://rst.gsfc.nasa.gov/Sect20/A1a.html.

38


For Further InvestigationThe Expanding Universe http://btc.montana.edu/ceres/html/Universe/uni1.html

EvaluationUsing a search engine such as Google, look for images that illustrate an expanding universe using public domain sources (primarily websites that end in “.gov”). Create a PowerPoint presentation of five slides that demonstrate the concept.


an expanding universe

39



A Luminous Indian

Sky ArtUsing the images at http://spaceplace.nasa.gov/en/educators/teachers_star_images.shtml, or any other images from NASA’s web sources, create a mobile of galaxies. Before you begin, determine a standard scale that everyone in the class will use for the actual galaxies. When the mobiles are done, use the same scale to estimate how far apart the galaxies would actually have to be to represent their true distance from one another in the universe. Finally, write an explanation of your scale and a disclaimer for the parts of the model (scale between galaxies and movement) that you cannot achieve in the classroom.

VocabularyNeutron star• Red giant• White dwarf•

Online Learning ToolsBirth, Life, and Death of Stars (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxImages for the Classroom: Stars, Galaxies, and Nebulae http://spaceplace.nasa.gov/en/educators/teachers_star_images.shtmlAstronomy Picture of the Day: Kepler’s Supernova Remnant in X-rays http://antwrp.gsfc.nasa.gov/apod/ap070116.html

EvaluationIn Chapter 48 you’ll speculate whether there is life on other planets around other stars. Before you get there, take a survey of people by asking, “Do you believe there is life on other planets?” When you analyze this data, divide the respondents by age and by how much background they have in astronomy. As a class, create a question or two for determining whether people have a realistic idea of how far away stars are. Keep track of all answers for each respondent.

Source: NASA Goddard Space Flight Center. http://imagine.gsfc.nasa.gov/

Images/basic/xray/supernova_cycle.gif.

Going, Going, Gone…For this activity, refer to a diagram of the electromagnetic spectrum (see p. 23 of Einstein Adds a New Dimension). The Chandra probe measures x-rays. Add x-rays to the diagram you made for Chapter 37.


1. How would the redshift phenomenon affect x-rays?

________________________________________________________________________

You can demonstrate the effect of a black hole on light near it using the back side of the same flexible rubber that was used in the Chapter 35 activity. Draw a spectrum of visible light with indelible markers.

2. What do the colors represent?

________________________________________________________________________

3. What color of visible light has the longest wavelength?

________________________________________________________________________

4. The shortest?

________________________________________________________________________

5. Stretch the rubber. What does the stretching represent?

________________________________________________________________________

40



Explosive? And How!

Source: Gravitational Astrophysics Laboratory, Astrophysics Laboratory,

Astrophysics Science Division, NASA/Goddard Space Flight Center.

www.universe.nasa.gov/gravity/research.html.


EXPLOSIVE? AND HOW!


40

6. How do the colors change?

_________________________________________________________________________

7. Imagine you are observing the light from a luminous body that is being drawn into a black hole. What effects do you expect to see?

_________________________________________________________________________

VocabularyPulsar• Quasar• Supernova•

Online Learning ToolsBirth, Life, and Death of Stars (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspxCosmicopia http://helios.gsfc.nasa.gov/cosmic.htmlNeutron Star Animation http://universe.nasa.gov/press/images/neutronNeutron Star Collision http://svs.gsfc.nasa.gov/vis/a000000/a000500/a000560The Universe Beyond Our Solar System (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

EvaluationWilliam Blake’s “The Tyger”—which begins, “Tyger, tyger, burning bright/In the forests of the night”—offers a literary perspective on a natural phenomenon. Read his poem, and use it as inspiration for a poem of your own that describes another natural phenomenon, the explosive life cycle of a star. Record your verses on a podcast.

Modeling a Black HoleFor this activity, you will need 10 screw eyes, masking tape, measuring tape, a large clear plastic cup, four sturdy paper plates, and a ball of yarn. Begin by tracing the circumference of the rim of the plastic cup on the center of each of the plates. Cut out the circles you’ve drawn and make a small hole in the bottom of the cup with a screw. Pile the four plates on top of one another and put the cup (rim up) in the holes you’ve created. (If the plates don’t fit tightly, you can use a bit of masking tape to make a tight fit.) Lightly draw a spiral from the edge of the cup to the rim of the plates. Then, place the screw eyes in the plates following the spiral line and use masking tape to cover the points of the screws where they come through. Thread the yarn through the screw eyes (outside first), around the spiral, and end in the hole in the bottom of the cup. Make sure to leave the ball attached.

The ball represents a companion star and the cup represents a black hole. The string is the accretion disk. The bottom of the cup is the event horizon. Slowly pull the yarn through the bottom of the cup. Answer the following questions:

1. What happens to the mass of the companion star over time?

________________________________________________________________________

2. How is the model like a black hole?

________________________________________________________________________

3. What part might represent the singularity?

________________________________________________________________________

VocabularyBlack hole• Singularity•

41



Singular Black Holes

Source: “High Energy Groove X-ray Binary,” NASA/Goddard

Space Flight Center. http://heasarc.gsfc.nasa.gov/docs/xte/

outreach/HEG/bhm/black_hole_mass.html.


singular black holes


41

Online Learning ToolsMatter Surfs on Ripples of Space Time Around Black Hole www.nasa.gov/centers/goddard/universe/blackhole_surfing.htmlFalling Into a Black Hole http://casa.colorado.edu/~ajsh/schw.shtml

Evaluation How is the illustration in the previous chapter (or the one on p. 357 of Einstein Adds a New Dimension) like the model you just made? How is it different? You may wish to consult the image from Chapter 40 of your materials as a reference.

42



Gravity Waves?

Source: www.mpa-garching.mpg.de/

HIGHLIGHT/2000/highlight0005_e.html.

InteractionsWhat we might call forces are really interactions. For this activity, list at least two examples of each interaction.

Interaction Illustration Examples

Strong Carried by mesons, holds the nucleus together

Electromagnetism Carried by photons

Weak Radioactivity and nuclear fusion

Gravity Curves spacetime

VocabularyForce• Interaction• Strong (Interaction)• Electromagnetic (Interaction)• Weak (Interaction)• Gravity (Interaction)•

Online Learning ToolAtoms—The Inside Story: The Standard Model http://resources.schoolscience.co.uk/PPARC/16plus/partich6pg2.

html

EvaluationThere have been a number of supernovas mentioned throughout history. Pictured is part of a record from China in 14th century BC. Research the evidence that this was a supernova. Without using information that would have been out of time or place, write a news article that describes what the discovery of a supernova might mean.

43



A SINGULAR BANG WITH A BACKGROUND

Out of (Supposedly) Nothing—Heat!Develop your own map of the universe. First establish a color code by putting this image into a drawing program such as Paint and selecting four different color areas. (Remember, you are arbitrarily dividing a continuous spectrum of radiation frequencies into categories.) Outline the color areas with the drawing (pen) tool in the program. Then use the sampling (eyedropper) tool to match your color selections and create a key. Finally, go to http://aether.lbl.gov/www/projects/cobe and read about the COBE program. Then write an explanation for your color key and a description of what the COBE project achieves. Explain what the model tells us about the universe by answering the following questions:

1. Why is the image an oval?

________________________________________________________________________

________________________________________________________________________

2. The average temperature of almost all of the universe is about 2.725°K, but the operative word is about. What do the slight variations in temperature imply?

________________________________________________________________________

________________________________________________________________________

3. Why is there an inverse relationship between temperature and density?

________________________________________________________________________

________________________________________________________________________

4. What is the advantage of enhancing the data collected by instruments with “false” digital coloration?

________________________________________________________________________

________________________________________________________________________

Source: Wilkinson Microwave Anisotropy Probe, NASA/Goddard

Space Flight Center. http://wmap.gsfc.nasa.gov/media/030653/index.

html.


a singular bang with a background


43

VocabularyBaryon• Big bang• Cosmic microwave background (CMB)•

Online Learning ToolsCOBE Satellite Launch Movie http://lambda.gsfc.nasa.gov/product/cobe/c_edresources.cfmCosmic Background Explorer http://lambda.gsfc.nasa.gov/product/cobe

EvaluationEinstein Adds a New Dimension includes many examples of experiments that didn’t work the way they were intended but that provided amazing insights nevertheless. Recall the Michelson-Morley experiment. How was it similar to the work of Penzias and Wilson? How was it different?

44



inflation? this chapter is NOT about economics

Pure Science—Pure TheoryNASA has developed a number of important experiments to investigate the beginning of the universe. Investigate each of these projects online and fill in the chart below.

Project Instrument Purpose

COBE (Cosmic Background Explorer)

DIRBE

DMR

FIRAS

BOOMERANG (Balloon Observations of Millimetric Extragalactic Radiation and Geophysics [over the South Pole])

Balloon

WMAP (Wilkinson Microwave Anisotropy Probe)

Probe

IRAS (Infrared Astronomical Satellite)

A liquid helium–cooled 0.6 m Ritchey-Chrétien telescope

SWAS (Submillimeter Wave Astronomy Satellite)

Elliptical off-axis Cassegrain telescope

Relikt Experiment Dicke-type modulation radiometer

VocabularyHorizon distance• Inflationary universe•

Online Learning ToolsLAMBDA—Legacy Archive for Microwave Background Data http://lambda.gsfc.nasa.govOrigin and Evolution of the Universe (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

EvaluationPaul Steinhardt and João Magueijo have produced alternative theories that may resolve some of the difficult contradictions in the big bang theory. Can you think of another scientist who boldly offered an unpopular variation of commonly accepted theory? How should such scientists be received by “the establishment”?

45



Entanglement? Locality? Are We Talking Science?

Here and ThereMuch of what we imagine about “outer space” comes from books, movies, or television shows. Could teleportation really exist? Could humans really reach another galaxy? Individuals seldom use their scientific background knowledge when they watch television or a movie. For this activity, you will analyze fictional scenes from a scientific perspective. Begin by considering a “transporter.” It involves changing matter to energy and back again. To get a sense of how practical a transporter is, you can do a Fermi Question (a “back of the napkin” estimate). Answer the following questions:

1. What is the mass of your body?

________________________________________________________________________

________________________________________________________________________

2. Using Einstein’s equation E=mc2 how much energy would be produced if the mass was all changed to energy?

________________________________________________________________________

________________________________________________________________________

3. How does this compare with the energy emitted by the Sun? Do you believe it’s practical?

________________________________________________________________________

________________________________________________________________________

Choose another “impossible” scene from a familiar science-fiction movie. (You may even find a clip of the scene on YouTube.) Research the views of a professional scientist as to whether the scene could actually take place in the future. Describe or show the scene from the movie to the class and discuss whether you think the scene is possible from a scientific perspective.

VocabularyString theory• Unified field theory•

Online Learning ToolsSpin-Precession Effects http://physics.indiana.edu/~kostelec/mov.html#2String Theory: A Multihistory http://superstringtheory.com/theatre/stringmovie.html


Entanglement? Locality? Are We Talking Science?


45

EvaluationDevelop a code that depends on the orientation of letters. Send a coded message to a friend, along with information on how to decipher the code.

Inside a StarYou will receive an index card from your teacher that contains one of the following labels: hydrogen-1 (1H), helium-4 (4He), carbon-12 (12C), magnesium-24 (24Mg), oxygen-16 (16O), sulphur-32 (32S), neon-20 (20Ne), silicon-28 (28Si), nickel-56 (56Ni), cobalt-56 (56Co), iron-56 (56Fe), iron-57 (57Fe), iron-58 (58Fe), iron-59 (59Fe), neutrons (n), positrons (e+), or neutrinos. (Your teacher may decide to hand out only the cards in bold.) At the front of the room, you will find a separate set of color-coded cards that indicate arrows and energy. Join with other students, use both your element cards and the color-coded cards at the front, and form equations that might happen inside a star. When you’ve decided on the right combinations, display your equations in a visible area of the room and prepare to explain them.

When you are satisfied that you have found a reaction, link it to an area of the star pictured above. In what type of star (life cycle) does this occur?

VocabularyDark energy• Dark matter•

46



Super Stars

Source: “NASA’s Imagine the Universe! Fusion Reactions,” NASA/Goddard Space

Flight Center. http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/activity-

fusion.html.


super stars


46

Online Learning ToolsLAMBDA—Legacy Archive for Microwave Background Data http://lambda.gsfc.nasa.govThe Sun as a Star (NSTA Science Objects) http://learningcenter.nsta.org/products/science_objects.aspx

For Further InvestigationFusion Reactions http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/activity-fusion.htmlX-ray Spectroscopy and the Chemistry of Supernova Remnants http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/spectra_cover.html

EvaluationRead Robert Frost’s poem “Fire and Ice,” which can be found online. Find images of objects from the farthest reaches of space from NASA to illustrate the poem. Use the Picasa program (free from Google) to coordinate an oral reading with your images.

47



A Surprising Information-Age Universe

Play a Google GameWhen your teacher was your age, he or she may have studied Boolean logic and likely found it frustrating. Your teacher may have even asked, “Why do we have to learn this?” Today you use Boolean logic every day! Go to Google or another search engine and type in one common science term. Record how many hits you get in the chart below. Then type another term into the search engine and again record the number of hits.

Term Number of Hits

AND

OR

Next conduct an “Advanced Search.” Think about what the difference is between “At least one of the words” (or) and “Both of the words” (and). Finally, find examples of 10 different astronomical objects in the sources that you’ve studied. Develop four different examples of Boolean searches. Share your examples with a partner.

VocabularyInformation theory•

EvaluationMuch of an organism’s DNA doesn’t make much sense to biologists; it doesn’t contain a “genetic code.” But information scientists (mostly electrical engineers) say the patterns are predictable. What else could the “nonsense DNA” be telling the cell? Imagine you are the head of a team of physicists investigating mysterious DNA. Write a memo to the human resources department of your institution and explain why the biologist should work in partnership with an information scientist.

48



Is anyone out there?

The SearchIn 1961, Cornell astronomer Frank Drake developed the Drake equation (p. 442 of Einstein Adds a New Dimension), which estimated the number of civilizations in our galaxy. Since that time, a number of Earthlike planets have been discovered. Does that mean that intelligent life is much more likely? In Chapter 39, you designed a survey that measured whether people have realistic ideas of the vastness of space and whether they believe that humans will encounter intelligent life anywhere else in the universe. You also recorded the age of the respondents. Now it’s time to disaggregate the data. First, determine parameters for dividing your respondents into those with “good” backgrounds and those without. You will have to decide whether people who have good ideas about the size of the universe are more or less likely to believe in intelligent aliens. You’ll also have to see if the age of the respondents makes any difference. Develop a rubric to divide respondents into those who have a good sense of distance and those who don’t. Write a summary of your results:

________________________________________________________________________

________________________________________________________________________

For Further InvestigationSETI and the Search for New Homes in Space www.pbs.org/deepspace/classroom/activity8.html

EvaluationLook at the image pictured here. It’s the message that was placed on the Voyager space probe many decades ago. Write an essay explaining what it says about us and the assumptions that we make about other life-forms. Then design your own plaque for a future space probe.

49



this is the last chapter, but it ’s not the end

Taxing for Theoretical ResearchIn the survey in the last chapter, you may have found a great difference in opinions of citizens on what’s out there in the universe. There are also great differences in people’s opinions about how much effort we should make on research here on Earth. Here’s an imaginary scenario: Congress is discussing a future budget allocation for basic research. Physicists have proposed expensive new probes and a totally new space telescope program. Your teacher will hand out cards with specific roles on them. Assume the role you are assigned. You can put a few notes about your role on one side of the card to help you make a five-minute presentation to an imaginary Senate hearing. Argue for or against the telescope program (depending on your role). Be prepared, incorporate facts, and make sure your arguments are consistent.

Online Learning ToolsContemporary Physics Education Project www.cpepweb.orgPhysics 2000 www.colorado.edu/physics/2000/index.pl

EvaluationWrite a letter to the editor of your local paper in the year 2020. More funding for basic research has been approved since the year 2010, and now the legislature must approve it again. Begin your letter with the following prompt: “In 2010 the United States approved a significant appropriation for basic research on the nature of our universe. In the years since, we’ve discovered…We should continue this program because we can discover…in the future.” Use your imagination to fill in the blanks.



References

ReferencesHakim, J. 2007. The Story of Science: Einstein adds a new dimension. Washington, DC: Smithsonian Books.

Hawking, S. 2003. On the shoulders of giants. Philadelphia: Running Press.

Nestle. 2003. Classic recipes. Lincolnwood, IL: Publications International.

NSTA Story of Sci Einstein

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