1. How did the universe begin?

3. How do we know? Doppler Shift Lower pitched, longer wavelength Higher pitched, shorter wavelength

4. Longer wavelength--> Shorter wavelength--> Redshift & Velocity

6. Distance & Brightness Relationship Surface Area ~ r 2 Brightness ~ 1/r 2

7. Mass of H: 1.0079 Mass of He: 4.0026 How stars burn: 4H → 2He Super Novae are standard candles

9. Hubble's Law

10. 1) The universe is expanding (Hubble's Law)‏ - We can measure galaxy redshifts (velocities)‏ -We know about spectral absorption lines. -We understand how these lines are redshifted. - We can measure luminosity (brightness)‏ - We can connect luminosity to distance (Super Novae)‏

11. Evidence for Dark Matter

12. How fast do you have to travel to leave the Earth? Fun with cannons! http://galileoandeinstein.physics.virginia.edu/more_stuff/Applets/newt/newtmtn.html

13. How fast do you have to travel to leave the Earth? Kinetic (moving) Energy Potential Energy (height)‏ Energy Conservation

14. How fast do you have to travel to leave the Earth? Kinetic (moving) Energy Potential Energy (height)‏ Energy Conservation 7 miles/s

15. Binary Stars

17. Dark Matter Rotation Curve

18. 2) There is more mass in galaxies than can be explained by starlight alone (Dark Matter)‏ -We know the star-mass in galaxies because we can measure binary star system masses and luminosities -We know how fast galaxies are moving -We know the required mass because we understand escape velocities

20. The Bullet Cluster

21. Gas Dynamics

22. 15 February 2008Richardson-McDaniel22 What is Gravitational Lensing?

23. 15 February 2008Richardson-McDaniel23 Strong Lensing Effects Einstein Ring Multiple Images, Arcs

24. 15 February 2008Richardson-McDaniel24

25. What is Dark Matter?

26. Summary 1) The universe is expanding (Hubble's Law)‏ - We can measure galaxy redshifts (velocities)‏ - We can measure luminosity (brightness)‏ - We can connect luminosity to distance (Super Novae)‏ 2) There is more mass in galaxies than can be explained by starlight alone (Dark Matter)‏ -We know the star-mass in galaxies because we can measure binary star system masses and luminosities -We know how fast galaxies are moving -We know the required mass because we understand escape velocities 3) Dark matter is not ordinary matter -We understand gas dynamics -We can use gravitational lensing to measure mass