What do you think of when you look at the night sky?

http://www.astro.ufl.edu/~lada/ast3018/lectures/ast3018lecturestarform.pdf

What is Space?• Not really empty• Stars, planets, etc.• Interstellar medium

• Dust and Gas• Nebulas

Orion Nebulahttp://hubblesite.org/gallery/album/nebula/pr1995044a/

Large Magellanic Cloudhttp://hubblesite.org/gallery/album/nebula/pr2006055a/

Nebular Hypothesis• Random collisions of atoms

• Areas of growing mass• Spherical shape• Pull in more matter• Increase in

• Temperature• Pressure

• Spin• Creates a bulge in the sphere

http://physics.uoregon.edu/~jimbrau/BrauImNew/Chap06/FG06_17.jpg

Nuclear Fusion• High temperatures• 2 particles become 1• Releases a lot of energy• Video clip

• Particle accelerators• Man-made• Create new elements• Find smallest particles

Fermi National Labhttp://www.wired.com/playbook/2012/08/olympics-physics-hammer-throw/

http://www.universetoday.com/52696/nuclear-fusion-power-closer-to-reality-say-two-separate-teams/

Spectroscopy Activity

•Draw the lines that you see• Make sure the # of lines, color of the lines and order is accurate

•Write a conclusion – based on your observations what can you conclude about the different materials and light you see the material produce

Warm Up #1

•Clicker Quiz •Compare conclusions from the spectroscopy activity

What does a spectrum tell us?• Each chemical/atom has a unique spectrum• Like a fingerprint

• What chemicals are present

http://www.umsl.edu/~physics/Lab%20Connection/Electricity%20and%20Magnetism%20Lab/12-lab13.html

How is a spectrum created?• All objects emit light• Pure light from a source• Continuous spectrum

• If light passes through gas or dust• Light absorbed• Excites/heats atoms• Emit own light• Makes an emission spectrum

• Unique

https://www.cfa.harvard.edu/~jbattat/a35/cont_abs_em.html

How do astronomers use spectra?• Look at light from

• Stars (gas in outer layers)• Nebula• Planets

• Determine chemical composition• Can also determine movement of object• Activity

http://www.eso.org/public/outreach/eduoff/cas/cas2004/casreports-2004/rep-236/

Warm Up #2

•Why are emission spectra important?•How are emission spectrum created?•What 2 things can astronomers learn by looking at the spectrum from a star?

H-R Diagram Graphing Activity

•Look for patterns

http://www.rootstown.sparcc.org/mattjust/h-r-diagram

Color and Temperature• What did you see as a pattern?• Objects give off a variety of light• Peak depends on temperature

• Peak shows most common type of light

http://docs.kde.org/stable/en/kdeedu/kstars/ai-colorandtemp.html

Main Sequence Stars• Find group on H-R

diagram• Wide variety• Highest # of stars• Stars stay here the

longest• Actively fusing hydrogen

into helium• Outward pressure from

fusion• Inward pressure from gravity• Equal in these stars• Maintain size

http://www.rootstown.sparcc.org/mattjust/h-r-diagram

http://www.thenakedscientists.com/HTML/articles/article/the-science-of-the-supernova/

What happens to our Sun?

• Form red giants• Fusing helium• Core collapsing• Outer layers

spread out• Cools

http://flightline.highline.edu/iglozman/classes/astronotes/media/2paths.jpg

http://www.physics.uc.edu/~hanson/ASTRO/LECTURENOTES/StarLife/Page7.html

What then?• Forms a white dwarf

• Ran out of helium• No more fusion

• Outer gasses moving away• Planetary nebula

• Leaves a hot, dense corehttp://chandra.harvard.edu/xray_sources/white_dwarfs.html

Ring Nebulahttp://hubblesite.org/gallery/album/nebula/planetary/pr2004032d/

Cat’s Eye Nebulahttp://hubblesite.org/gallery/album/nebula/planetary/pr2004027a/

Warm Up #3

•What makes a star a main sequence star?

•Why does the size of the core of a main sequence star not change?

•What will eventually happen to our Sun and why?

What about the fate of larger stars?• Become red supergiants

• Fuse elements larger than helium• All the way to iron

• Short lives• Supernova

• No more fusion• Core violently explodes• Fuses heavier atoms• Very bright, short time• Spreads out material

http://flightline.highline.edu/iglozman/classes/astronotes/media/2paths.jpg

http://hubblesite.org/gallery/album/nebula/supernova_remnant/pr2005037a/

What then?• Forms a neutron star• If a lower mass core• Very dense

• Not very big• Lots of gravity

• Can produce gamma and x-rays when it pulls items into it

Neutron star in supernova Cassiopeia Ahttp://www.space-pictures.com/view/pictures-of-space/pictures-of-stars/neutron-star/index.php

http://www.clccharter.org/maya1/Supernova/supernova.html

Or…• Forms a black hole

• Higher mass cores• Infinitely dense• Need to travel faster than the speed

of light to escape• How can we see?

• Will bend light from nearby stars• See dust and gas swirling around

• Hot enough to give off x-rays

• Probably at the center of most galaxies• Including ours!

• Video

Whirlpool Galaxyhttp://hubblesite.org/gallery/album/pr2001010a/

http://www.space.com/15421-black-holes-facts-formation-discovery-sdcmp.html

Warm Up #4• What is happening inside a red supergiant star?

• What happens in a supernova?• How is a neutron star different from a black hole?

• Why should we not be able to see a black hole?

• Why can we “see” a black hole?

Warm Up #5

•Clicker Quiz

How do we know how far away that is?• Parallax effect

• Compare distant stars to nearby stars

• Measure shift as Earth orbits the Sun

• Calculate the distance• Further away = less of a shift

• Better technology = see smaller shifts = measure larger distances

http://lifeng.lamost.org/courses/astrotoday/CHAISSON/AT301/HTML/AT30105.HTM

http://astronomy.nmsu.edu/aruiter/ASTRONOMY110/parallax.gif

Looking Back in Time• If a star is 10 light years

away• How old is the light we see

today?• Is that star still there

today?• If an alien is on a planet

10 million light years away• If they could see with the

Earth with great detail, what would they see right now?

• When we observe light from a star 2 billion light years away….what does that mean?

http://www.spacetelescope.org/images/heic1214c/

How has our “picture” of the universe changed?

• Greeks• Rotating spheres

• Earth centered

Early Scientists

•Galileo•Copernicus•Kepler•Newton

• Mathematical laws about movement of planets

• First telescope• Calculation of gravity

• Sun centered universe

Next generation of scientists…• Einstein

• Calculations• Universe changing size• Disbelieved

• Added a constant to his equations

• Results = static universe

• Friedmann• Russian• Removed Einstein’s constant• Universe changing shape• Won Einstein’s approval

http://wouterdeheij.wordpress.com/2013/04/27/famous-innovation-quotes-from-steve-jobs-gunter-pauli-einstein-henry-ford-and-many-others/

http://en.wikipedia.org/wiki/File:Aleksandr_Fridman.png

The Big Bang Theory• Lemaitre

• Priest and physicist• Universe began as a

single point• Expanded since that time

• Hubble• Astronomer• Published around same

time• Provided evidence

http://scienceblogs.com/startswithabang/2011/01/05/q-a-how-is-the-universe-so-big/

Warm Up #6

Hubble’s Evidence - Redshift• Change in emission spectrum

• Same pattern• Shifted from where it should be

Same thing happens with sound…• Doppler effect• Object moving past a stationary object• Waves get shortened in front

• Higher pitch• Waves get longer in back

• Lower pitch• Inside the source – no change

http://archive.ncsa.illinois.edu/Cyberia/Bima/doppler.html

Relating back to light…• Blue-shift

• Wavelength shortens• Moving towards us

• Red-shift• Wavelength lengthens• Moving away from us• Bigger the shift the further

away it has come from• Hubble only saw red-shifted

spectra

Hubble’s Conclusions• Universe

moving away from us

• Things further away are moving away faster

• Expansion rate has

since beginning

https://www.e-education.psu.edu/astro801/book/export/html/1967

• Started as a single point• Expansion

• Explosive at first• Evidence

1. Red-shift

The Big Bang

Cosmic Microwave Background Radiation• Further evidence of the big

bang• Picture =

• Universe all same temp• Very cold• Not what we actually see

• Where else could the microwaves come from?• Extreme red-shift

• From a high energy wave• Travel long distances• Oldest light we observe• Time when universe was all the

same temp.• The Big Bang

Age of the Universe• Rocks on Earth

• 4.2 billion years• Oldest stars

• 10-12 billion years• Universe must be older• Estimate

backwards• 13.8 billion years

http://www.universeadventure.org/big_bang/conseq-ageofuniv.htm

http://scienceblogs.com/startswithabang/2009/07/31/the-size-of-the-universe-a-har/

What happens next?• Big Crush

• Stops expanding• Gravity causes to crush• Repeat the process

• Big Chill• Expand at slowing rate• Get cooler as expands

• Big Rip• Expand at increasing rate• Everything gets ripped

apart

http://sandeepdmisra.wordpress.com/2011/04/

http://ffden-2.phys.uaf.edu/212_fall2003.web.dir/eli_sonafrank/Expansion_-_Fate_of%23168EE9.html

What else is out there?• Visible matter• Dark matter

• Does not give off light• Things weigh more than they should

• Dark energy• Causing the increase in expansion

rate seen in most recent data• Thus fate of the universe is…

• Big Rip

• Adding these items makes models better fit actual observations

http://hubblesite.org/hubble_discoveries/dark_energy/de-what_is_dark_energy.php

What helps us understand space?• Telescopes

• All wavelengths of light• Actual samples from space• Particle accelerators

Review #7• Describe how the Doppler effect and redshift are similar,• What are the two pieces of evidence that support the Big

Bang theory?• Who first wrote the Big Bang theory?• How old is the universe?

• What is the current theory of the fate of the universe?• What are dark matter and dark energy?• What items are used to help us understand distant objects

in space?