Educator's Guide - Spitz

Dear Educator,

Welcome to the “DarkStar Adventure” planetarium show Teacher’s Guide! Produced bySpitz Creative Media, DarkStar Adventure takes the audience on an unforgettable voyageof discovery through the cosmos. This guide contains content and spectacular activities tosupport your planetarium show experience. We encourage you to do as many of theseactivities as possible before your trip so your students can better understand the conceptsin the show.

The guide contains three main sections:

1. Gravity In and Out2. Bright Stars Tonight3. DarkStar Dead Ahead

Gravity In and Out has fun activities related to Newton’s Law of Motion, escape velocity,and rocketry. Bright Stars Tonight focuses on what we see in the night sky and its meaning.DarkStar Dead Ahead looks at the role gravity plays in the lives of stars, particularly in thedevelopment of black holes. All activities are directly related to phenomena your studentswill experience in the show.

Each section has content pages to help you with the background of each activity. In addition, there are black line masters, where needed, to support the activities. While mostof the acitvities are correlated to the National Science Education Standards for grades 5-8,you’ll find activities appropriate for elementary and senior grades as well.

Enjoy your trip through the universe!

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Spitz, Inc.

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Table of ContentsDescription of DarkStar Adventure Planetarium Show 3

Gravity In and Out 4

Escape Velocity: Discover how to get off the planet 5

Escape Velocity Rocket: Make your own classroom rockets 6

Bright Stars Tonight 7

Star Observations: Help students enjoy the wonder of star observation 8

Star Colors: Observe color changes as temperature rises 9

Star Distances: Examine enormous distances between us and stars 10

Are We There Yet? 11

Are We There Yet? Worksheet 12

DarkStar Dead Ahead 13

Stellar Evolution: Study the forces that make stars collapse 14

Shock Waves: See shock waves produced after supernova explosions 15

Black Holes: Experience the large gravitational force of black holes 16

DarkStar Adventure Planetarium Trip Sheet 18

Glossary and Suggested Resources 19

Description of DarkStar Adventure

Subrah is a mischievous teenage girl who is bored by science. She’s stuck with her father on a distant planetas he studies a nearby star at the end of its life. The impending supernova forces Subrah and her father to quickly abandon the planet, but an accident launches Subrah’s father into space without her! Subrah draws on her science knowledge to explore pulsars, dodge black holes, and harness magnetic fields withher trusty robot friend Sweeps until she is reunited with her father. She’s still not safe though; Subrah needs to come up with one more brilliant and dangerous scheme before they can go home to planet Bekenel.

GRAVITY IN AND OUTWhat is Gravity?Isaac Newton was the first to describe gravity as an ‘attractive’ force associated with mass. We know it asthe force that seems to ‘pull’ objects together or make things fall to the floor or ground. Every object inthe universe that has mass, has gravity. Newton figured that the more massive an object is, the greater itsgravitational pull. Here’s an astronomical example: How much do you weigh? 150 pounds? The moon isone-quarter the size of Earth and has a gravitational pull one-sixth that of Earth. So on the moon you’llweigh just 25 pounds. Think of it as instant weight loss!

Proximity also plays a role in gravitational attraction. As distance increases, gravitational pull decreases.Since Earth itself is more massive than anything on it, all things on the Earth are being pulled to it. Since our sun is the most massive object in the solar system, everything in our solar system is being pulled towards it.

Escape Velocity – Speed needed to escape an object’s gravitational pull.Imagine a cannon on top of a mountain, its barrel pointed toward the horizon.When the cannon is fired, the cannonball, after traveling some distance, will fallto the ground. Fired with more force, the cannonball may travel farther, butgravity will eventually pull the cannonball to rest on the ground. If the cannon-ball can be launched with enough velocity, instead of falling back to earth it willcontinuously fall around the earth!

The circular path described by a projectile fallingaround the earth is called an orbit. For a rocketto escape Earth’s gravitational pull, it needs to travel fast enough to reach escape velocity – thespeed at which an object will leave the Earth’sgravitational influence. An object launched at low speeds will eventually fall back to Earth.

Launching RocketsFor rockets to fly off into space, they obey Newton’s Third Law: For every action, there is an equal and opposite reaction. Our homemade rockets (page 8) illustrate this: air pressure inside the rockets builds andpushes equally on all sides of the interior; when pressure is high enough, the stopper is pushed out, air pushesout the opening but is still pushing against the inside of the rocket. As Newton’s Third Law states (seeAppendix A), the force of air pressure pushing inside the rocket must be equal to the force of the exhaustpushing out the opening. It is the force inside the rocket that pushes it in a direction opposite the exhaust.

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EARTH

For more information about gravity, check outhttp://www.sunblock99.org.uk/sb99/people/RWalsh/gravity/grav1.htmlhttp://brp.arc.nasa.gov/Science/Y_GBL/bsc_resrch.html

For more information about escape velocity, check out:http://quest/arc/nasa.gov/space/teachers/microgravity/3world.html

DARKSTAR ADVENTURE CONNECTION: Subrah mustescape impending doom by propelling her ship to ahigh enough escape velocity to leave a planet.

DARKSTAR ADVENTURE CONNECTION: When stuck, Subrah cleverly tows a useless ship alongand ejects it at the right moment and in the right direction, applying Newton’s third law; theabandoned ship goes off in one direction, pushing her off in the right (opposite) direction.

Newton’s Cannon

ESCAPE VELOCITYObjective: Understand escape velocity by observing a ball drop.

National Science Education Standards:Physical Science: Motions and forcesEarth and Space Science: Earth in the solar system

Materials: Ball, table, chart paper

Things to Discuss Before: Ask students how we launch rockets into outer space. How fast is the rocket traveling? Why do students think the rocket needs to travel so fast?

Things to Do:1. On the floor, lay out a 10-foot strip of chart paper, trailing away from the edge of a table.2. Bring a ball to the edge of that table and let the ball drop. Have students notice the path and

landing point of the ball (it should fall directly below the edge of the table) on the chart paper.3. Push the ball so that it slowly rolls across the table and let it drop. Have students notice the path

and landing point of the ball (it should fall in a curved path and land further away from the table) on the chart paper.

4. Push the ball harder so it rolls faster and observe what happens. Repeat at higher and higher speeds.

Things to Discuss After:Ask students what they noticed and have them draw diagrams of their observations. Ask students whatwould happen if you rolled the ball at even higher speeds and draw a diagram. Discuss why the ball keepsdropping down (gravity). Draw a circle to represent Earth and draw a ball above. Ask students what paththe ball would take if it traveled very fast. Draw, and then repeat with the ball traveling at higher speedsuntil ball orbits Earth. Explain that ball is actually falling towards Earth (due to gravity), but its high speedprevents it from ever reaching the ground. Ask children what would happen if ball was traveling evenfaster; it would escape Earth’s gravity and leave orbit. This speed is the escape velocity.

Extensions:• Attach a ball to the end of a rope and swing in circles to represent the ball orbiting around Earth.

Pretend it is traveling fast enough to escape Earth’s gravity and let go.• Have two students toss a ball to each other and back up until they are throwing the ball over a long

distance. What do students notice about the arc of the ball as distance increases? How about the speed and required force? Can they imagine how much more speed and force is needed to launch a rocket?

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Escape Velocity Rocket

Objective: Discover how rockets work by making your own.

National Science Education Standards:Science as Inquiry: Design and conduct a scientific investigation and make the relationships between

evidence and explanationsScience and Technology: Abilities of technological design

Materials: 15 ml conical tubes with rubber stoppers to fit (enough for every one to four students), Alka-Seltzer tablets (two per group), water, droppers, small trays.

Notes: 1. The 15 ml tubes can also be replaced with clear plastic 35mm film canisters with tightly fitting lids.

The film canisters must be the clear plastic ones, not grey or black. 2. You can use vinegar and baking soda in place of Alka-Seltzer and water. 3. These rockets can hit the ceiling. You may want to launch rockets from the floor or outside.

Things to Discuss Before: Throw a ball up. Ask students how you can make it go higher. How do you have to change your force or your speed? Is it possible it to go higher without increasing speed? Explain that students are going to make their own rockets and must figure out how to make them go as high as possible. Their rocket fuel is limited, so they need to budget carefully as they launch.

Things to Do:1. Have students put a couple squirts of water in tubes.2. Have students break off a very small chunk of Alka-Seltzer

(less than the diameter of a pencil eraser).3. Quickly put Alka-Seltzer in tubes, cap with stoppers, invert

tubes and place on trays, let go, and stand back.4. Observe what happens inside the rockets and note how high rockets fly.5. Let students experiment to figure out how to make rockets fly higher.

Things to Discuss After:How did students make their rockets fly high? Why did their rockets fly? How much more force and speedwould they need to launch their rockets into outer space?

Extensions:• Modify rockets with fins.• Hold a challenge to see who can launch the highest rocket.• Keep track on data sheets amount of water and Alka-Seltzer used in each trial. Experiment and

discover optimal mix of ingredients and technique.• Make other types of rockets. Try the ones at these websites:

http://www.reachoutmichigan.org/funexperiments/agesubject/lessons/other/liquid_bottle_rocket.htmlhttp://www.calstatela.edu/dept/chem/chem2/LACTE/K12.html

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Have students practice capping and standing tubes up without Alka-Seltzer; injuries can happen if therockets fly sideways instead of up.

Rocket Gas Explanation: In both rockets, the gasproduced is carbon dioxide. In the Alka-Seltzer,the gas is released through the reaction of thesodium bicarbonate and citric acid of the Alka-Seltzer tablet when water is added. Carbon dioxide is released from the baking soda/vinegarmixture when the acetic acid of the vinegar reactswith the sodium bicarbonate of the baking soda.

Bright Stars Tonight

Star ColorsWe usually think of stars as twinkling white, but if we look carefully we can actually find stars of several colors. A star’s color is based on its temperature. A very cool star is dull red in color. As stellar temperaturesincrease the colors change from red to orange, then yellow to white, and then blue.

These different colors relate to the star’s “thermal radiation.” As temperatures increase, the wavelength of the emitted thermal radiation shortens, and the colors change.

Star ObservationsIt may seem challenging to observe stars, but all it takes to get started is a good pair of eyes. Star maps(easily obtainable from the Internet or from you local library) and binoculars can help too, but your studentscan enjoy astronomy without them.

You may want to start your students off with quick, five-minute glimpses at the sky to spot some easy-to-find reference points. Can they find the moon? What does it look like? How about planets or stars of different colors? Some easy to find constellations include the Big Dipper, the Summer Triangle, the GreatSquare of Pegasus, and Orion (visible during the school year).

As your students become more comfortable with the night sky, you can expand your search to include binary stars, nebulae, fainter constellations, and other fascinating or ephemeral phenomena such as lunareclipses. You may even want to contact your local astronomy club to hold a star party for your grade oryour school. Often, astronomy clubs enjoy providing telescopic views of various astronomical objects forfree. This exposes your students to a new hobby; children may want to continue their astronomy observationsby attending club meetings. Parents are curious about the night sky too. Take advantage of their curiousityto get them more involved in helping their children observe!

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“Astronomy for Kids” http://www.dustbunny.com/afk/ has wonderfulinformation about constellations and tips for beginning sky watchers.

For some good basic tips on astronomy observations, check out http://www.stargazing.net/david/eyes/index.html

Star Observations

Objective: Examine the patterns and characteristics of stars through observations.

National Science Education Standards:Earth and Space Science: Earth in the solar system

Materials: Blank paper, colored pencils

Things to Discuss Before: Ask children what objects they see in the night sky and list them.

Things to Do:1. From either a classroom window or an outside play or recess area, help students identify different

parts of the sky. a. Horizon – distant horizontal line where the sky meets the ground; b. Zenith – point at the top of the sky directly overhead; c. Nadir – point directly opposite the zenith - under your feet; d. Meridian – imaginary vertical line running head to toe that when extended to the sky

directly ahead of you divides the eastern half of the sky from the western half.2. Have children practice drawing what they see out toward the horizon from the horizon up to their

zenith. Then have children practice doing night sky observational drawing in the classroom; have them pick an area of the room and draw what they see from the “horizon” (the floor) and up, including the ceiling. You may want to hang pictures of stars and the moon around the room.

3. For homework, have children choose an area of sky to observe. Starting from the horizon, have them draw everything they see, including objects at the horizon, bright stars, different colored stars (using colored pencils), and the moon in the correct phase.

4. Repeat the exercise for several nights, observing and drawing the same part of the sky.

Things to Discuss After:What did children notice during their observations? What patterns do they see?

Extensions:• Discuss patterns the stars make, and introduce constellations. Have kids find basic constellations

in the sky (such as the Big Dipper, Orion, Pegasus or Leo).• Look for meteor showers.

Use this link to find what’s available http://dustbunny.com/afk/skywonders/meteorshower/• Encourage students to look

at night sky with binoculars.• Take your students on a

field trip to a local observatory.

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For star maps for kids, go to http://www.dustbunny.com/afk

You can find good, basic sky maps and observing information for beginners at http://skyandtelescope.com/howto/basics/article_1100_1.asp

For detailed sky maps unique to your location and time, check out http://www.fourmilab.to/yoursky/

Star Colors

Objective: Observe color changes as objects are heated, and understand that stars are also different colors

National Science Education Standards:Physical Science: Transfer of Energy

Materials: Objects that change color as they are heated and heat sources (see below), candles or Bunsen Burners

Things to Discuss Before: Ask students what they know about star colors and what they have observed.

Things to Do:1. Show students an object that changes color as it is heated and discuss what may be happening.2. Have students observe candle flames or Bunsen burner flames (can also demo with propane torch)

and hypothesize about the temperatures of the different parts of the flames.

Things to Discuss After:What can students say about colors and heat? How does that relate to stars?

Extensions:• Encourage students to go outside and look for different colors of stars.

Color changing objects as heated:1. Incandescent light bulb turned on and off slowly with a dimmer switch.2. Electric burner or hotplate on stove that is heated and cooled

Just as we can tell temperatures of objects here on Earth by their color, so can we tell the temperature of stars in space. Here’s a guide to help you easily identify star temperatures.

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6000ºF 9000ºF 11000ºF 15000ºF 20000ºF

Bunsen burner, candle, andpropane torch flames have a blue cone surrounded by orange.

For more information about flame colors and star colors check out these websites:http://webexhibits.org/causesofcolor/3B.htmlhttp://www.straightdope.com/mailbag/mhotflame.htmlhttp://www.mira.org/fts0/stars/114/txt001w.htmhttp://www.enchantedlearning.com/subjects/astronomy/stars/startypes.shtmlhttp://www.kidsastronomy.com/stars.htmhttp://www.astronomycafe.net/qadir/q72.html

Star Distances

Distances in space are so vast that ‘miles’ are too small. To measure such vast distances we have to use bigger ‘rulers.’ One way astronomers have found to measure the enormous distances in space is to use“light speed” to describe them. Here’s an example: our own Sun is 93,000,000 miles away. Since light trav-els at 186,000 miles per second, the light from our Sun takes 8 minutes to reach Earth. When we look up inthe sky, we are not seeing the Sun as it is now, but as it was in the past 8 minutes ago!

Other stars are so far away that we use light years to describe them. A light year is the distance light travelsin one year. Since light travels at 186,000 miles per second, one light year is almost 6 trillion miles! Thenearest star, Proxima Centauri, is 4.2 light years away. Aldebaran, one of the brightest stars in our sky, is 68 light years away. Therefore, when we look up in the sky at night, we are actually seeing stars as theyused to be, not as they are now. You could also describe this as looking back in time.

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TABLE OF 20 BRIGHTEST STARS

The Sun - - 1Proxima 4.4 1.5Beta Centauri 526 526 5.5Procyon 11 7Altair 17 11Fomalhaut 23 15Sirius 8.6 23Pollux 35 33Vega 26 53Arcturus 35 100Capella 46 160Aldebaran 68 170Achernar 130 830Canopus 120 2100Spica 260 2300Alpha Crucis 260 3000Antares 420 5700Betelgeuse 522 10000Rigel 800 47000Deneb 1600 67000

Star Distance Brightness Name (light years) (sun=1)

DARKSTAR ADVENTURECONNECTION: Subrahmust grapple with verylarge distances as shetries to get back home.

Source: Ottewell, Guy, 2003, To Know the Stars, Universal Workshop, Middleburg, VA; Observer’s Handbook 2004;Gupta, Rajiv, Ed.; The Royal Astronomical Society of Canada, Toronto, University of Toronto Press, 2003

Notes: 1. Light Year – distance traveled in one year at the speed of light(186,000mph). A distance of nearly 6 trillion miles.2. Brightness – How bright these stars are relative to our sun; the sun represents a brightness unit of 1.

Are We There Yet?

Objective: Help students understand the vastness of space and distance of stars.


Materials: “Are We There Yet?” worksheets, calculators

Things to Discuss Before: Ask students how long they think it would take to go to the sun. Explain that even at the speed of light, it takes 8 minutes to travel between the Earth and the Sun; therefore, we are seeing the sun as it was in the past. If the sun explodes, we won’t know it until 8 minutes later! Ask students to guess how old thelight is from stars.

Things to Do:1. Demonstrate the math necessary to do the worksheet on the following page.2. Have kids fill out worksheets to calculate how long it takes to get to other orbiting bodies by

probe, telescopes, rovers, shuttles, and light.

Things to Discuss After:What did students notice about the age of the light from stars? Were they surprised? Explain that we arelooking at stars as they were many years ago, not as they are now.

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Are We There Yet?

Name: ___________________________________________________________

Calculate how long it takes to get to other stars. For example, Proxima Centauri is 25,000,000,000 milesaway from Earth. Therefore, to calculate how long its light takes to reach Earth, we would divide its distance by the speed of light: 25,000,000,000,000 miles / 670,616,600 mph = 37,279 hours/24 hours per day = 1553 days/365 days per year = 4.2 years

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LIGHTspeed = 670,616,600 mph

4.2 years

CAR speed = 50 mph

Star distance from Earth

Moon 239,000 miles

Sun 93,000,000 miles

Proxima Centauri:25,000,000,000,000miles

SHUTTLE speed = 17,000 mph

DISTANCES AROUND THE UNIVERSE

Venus average 26 million miles

Mars average 50 million miles

Pluto 3.6 billion miles

Polaris/North Star 431 ly

Orion Nebula 1500 ly

Center of Our Galaxy (the Milky Way) 50000 ly

Closest Galaxy – Large Magellanic Cloud 165,000 ly

Closest Spiral Galaxy – Andromeda Galaxy 2.9 million ly

Closest Black Hole – V4641 Sagittari 1600 ly

Closest Quasar 1 billion ly

Edge of the Observable Universe 13-15 billion ly

DarkStar Dead Ahead

The lives of stars are governed by gravity. Gravity causes clouds of gas and dust to collapse and form new stars. A star will shine for perhaps billions of years as fusion reactions in its core change hydrogen to helium. The core is always pushing outward, trying to expand, but is held in check by the surrounding largegaseous envelope pressing inward due to gravity. Now a “main sequence” star, it shines at a steady rate.Our Sun is a main sequence star.

This equilibrium lasts until the core runs out of energy and can no longer push outwards. In very massivestars much bigger than our sun, exciting events rapidly happen. The core suddenly collapses. The gaseousenvelope collapses with the core, sucked in by gravity, but suddenly “bounces” off the core. The gasesshoot out into space in shock waves as the star explodes in a supernova.

While the gases explode outwards, the core collapses in on itself and becomes a very tight, small, and denseball of matter called a neutron star. This neutron star has such a strong magnetic field that it concentrateslight and radiation into cones, much like a double ended flashlight. It also rotates like a lighthouse beam.The combination of the strong magnetic field and very rapid rotation creates a pulsar, a “flashing star”.

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DarkStar Adventure Connection: An exploding supernovaand its shockwaves force Subrah to flee a planet. Shethen collects oxygen for her ship from a pulsar nebula.

For more information about the life of stars check out these websites and books:http://map.gsfc.nasa.gov/m_uni/uni_101stars.htmlhttp://www.geocities.com/thesciencefiles/astar/isborn.htmlhttp://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/background-lifecycles.htmlhttp://nrumiano.free.fr/Eindex.htmlhttp://www.enchantedlearning.com/subjects/astronomy/stars/lifecycle/http://imagine.gsfc.nasa.gov/docs/teachers/lifecycles/LC_main_p1.html

Jarvis, Seth and Jarvis, Nathan Y., Lifestyles of the Big and Powerful, 1991, Capstone Press,Chicago, dist. By Children’s Press, ISBN: 1560650117

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Stellar Evolution

Objective: Understand that massive stars explode as a result of collapsing cores.


Materials: No special materials needed

Things to Discuss Before: Explain that stars evolve as a result of gravity. When stars are at a steady state, like our sun, the core andthe gaseous envelope around the core have equal gravities; they push on each other equally. When starcores run out of energy, however, the gravity forces become unequal.

Things to Do:1. Have two equal sized students stand up and push against each other. There should be equilibrium,

or no movement. Ask students what is going on.2. Swap one student for a much smaller one. Explain that the smaller student represents a star’s core

after it has run out of energy. Now have the students push against each other.

Things to Discuss After:Discuss what happened in the demonstration. Why do stars collapse?

Extensions:• Invite an astronomy club to hold a star party at your school to look for the remnants of exploded

stars. These are called nebulae. • Search the Hubble Space Telescope website for images and descriptions of nebulae and

supernovae remnants. http://hubblesite.org/gallery/

Shock Waves

Objective: Discover why shock waves are produced after supernova explosions.


Materials:Small ball, big ball, shallow trays, water, eyedroppers

Things to Discuss Before:Explain that very massive stars (bigger than our sun) at the end of their lives will explode in a supernova.When the star’s core runs out of fuel, it collapses dramatically.

Things to Do:1. Place a small ball on top of a big ball. 2. Hold balls about a yard off the ground, drop, and observe what happens (the small ball will

bounce much higher than the big ball). Explain that the small ball represents gas bouncing off the core of the sun, or the big ball. The gas explodes into space.

3. Set out trays of water. Have students use eyedroppers to drip drops of water in the middle of the trays. Observe rings of waves.

Things to Discuss After:What do students notice about the rings of water? How do they move? Explain that the rings of water represent shock waves, or the waves of gas produced by supernovas.

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All our heavy elements, from Iron to Lawrencium including the precious metals gold and silver, are produced in supernova explosions. The high-energyexplosions smash atoms together forming small quantities of rare elements.

The core of the sun is shrinking, and the gaseous envelopefollows it (represented by the balls dropping). Eventuallythe gas bounces off the core (represented by the largebounce of the small ball).

For more information check out these websites:http://imagine.gsfc.nasa.gov/docs/teachers/lessons/xray_spectra/background-elements.htmlhttp://aether.lbl.gov/www/tour/elements/stellar/stellar_a.html

Black Holes

A black hole is what’s left over after a big star (at least three times the size of our Sun) explodes in asupernova at the end of its life. The leftover atomic nuclei collapse and condense together, compactingand becoming more and more tightly packed. The result, a black hole, is an object of very high mass andvery high gravitational force: so strong that its escape velocity is higher than the speed of light. Exceptunder very special circumstances, nothing, not even light, can escape from a black hole.

Most popular descriptions of black holes use Newton’s concepts of gravitation to help people understandtheir behavior. Unfortunately, in the case of strong gravity or speeds approaching the speed of light, (two of the main features of black holes) Newton’s principles of gravitation fail miserably. Newton himself wasaware of his theory’s failings at those extremes. Einstein’s general theory of relatively far more accuratelydescribes gravitation as the geometry of the 4-dimensional spacetime within which everything in the universe exists.

Visualizing 4-D spacetime is difficult since common sense can’t help us create that view. A crude modelusing a flexible piece of stretchy fabric and a few manageable masses like sport balls may work.

In the following demo, we use a horizontally stretched piece of jersey to represent space and time. The jersey flexes when we put objects on it, which represents the gravitational forces. A light, less massiveobject bends the jersey very little and has little gravitational force. A more massive object makes a deepdepression in the jersey and has large gravitational force. The massive object represents a black hole. A small object will roll towards the depression and fall, illustrating the enormous gravitational attraction of the black hole.

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For more information about black holes, visithttp://www.geocities.com/thesciencefiles/black/holes.html

DARKSTAR ADVENTURE CONNECTION: Subrah lands on a planet that is being torn apart by a nearby black hole. Sheneeds to launch off the planet at a high enough escape velocityto break away from the gravitational pull of the black hole—which requires double emergency thrust!

Black Holes

Objective: Observe a model of the large gravity force exhibited by black holes.


Materials:Old T-shirts or pieces of jersey (preferably black), cardboard boxes, scissors, tape, balls of various sizes and densities (marbles, small and large steel balls – balls of different masses)

Things to Discuss Before:Explain that when a really big star (three times the size of our Sun) is at the end of its life, it explodes in asupernova, then collapses. The remains of the star become packed together and very dense, creating ablack hole. Objects with large masses, like the Earth, have strong gravity forces. Black holes have enor-mous masses in a small area, so they have extremely strong gravity forces. Not even light escapes, so any-thing close to black holes is trapped. Explain that students will create models where the fabric representswhat Einstein called spacetime. The bending of the fabric represents gravity.

Things to Do:1. In groups, have students cut the T-shirt or jersey into a flat sheet and stretch and tape it over

an open end of box.2. Place a small ball on the fabric and observe what happens. 3. Replace the ball with a larger, more massive ball.4. Add other balls to the sheet and observe how they roll.

Things to Discuss After:What did students notice? How does the massive ball affect the spacetime fabric sheet? How about the lighter balls? How is the massive ball like a black hole?

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You can also do this as a demo. Cut a large, flat piece ofjersey. Have two children hold the fabric taut horizontally.Have other students place balls on the fabric.

Try other black hole/spacetime exercises at:http://www.ktca.org/newtons/11/blckhole.html

DARKSTAR ADVENTURE PLANETARIUM SHOW Trip Sheet

Name: ___________________________________________________________

1. When do you think Subrah was the most resourceful and creative in solving a problem? Why?

____________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________

2. What is your favorite scene in the show? Why?

____________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________

____________________________________________________________________________________________________________________________

3. Draw a supernova, pulsar nebula, or a black hole.

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Glossary

Atomic nucleiBlack holeEscape velocityLight yearMassMagnetic fieldNeutron starPulsarSpacetimeSupernovaVelocity

Appendix A

Newton’s Three Laws of Motion

1. An object in motion will stay in motion. An object at rest will stay at rest.2. Force equals mass times acceleration.3. For every action there is an equal and opposite reaction.

See http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html for more information.

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Educator's Guide - Spitz

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