1. Formation of the Universe The Big Bang Theory

2. The Big Bang All matter & energy in the universe was compressed into a tiny volume 13.7 billion years ago, all the matter & energy began expanding outward

4. Evidence Discuss with your partner: What evidence do scientists have that supports the Big Bang Theory? Name at least 2 things

5. Evidence There are two things that scientists use as evidence: Red Shifts Cosmic Background Radiation

6. Red Shift & the Doppler Effect Close your eyes and imagine you are standing on a street corner. An ambulance is headed towards you What do the sirens sound like?

7. Red Shift & Doppler Effect Doppler Effect: an observed change in the frequency of a wave when the source or observer is moving. Ex: The abulance is the source, and when it moves past us, the frequency of the sound waves change. The same thing can happen with light waves.

8. Doppler Effect Movie Clip http://www.youtube.com/watch?v=imoxDcn2Sgo

9. Hubble & Star Spectra When the astronomer Edwin Hubble looked at the spectra of stars, he noticed a shift. What did the shift look like? The Red shift that he observed showed that the stars and galaxies were moving away.

10. Star Spectra-Red Shift

11. Evidence #2: Cosmic Background Radiation CBR: radiation uniformly detected from every direction in space Radiation in the form of radio waves First detected in 1965 Formed shortly after the Big Bang

12. Cosmic Background Radiation

13. Temperature of CBR Temperature of the radiation is VERY cold, -273°C If the Universe was VERY HOT after the Big Bang, and takes a very long time to cool, what does this temperature indicate about the age of the universe?

14. Expanding Universe Do you think the universe expands at a constant rate? Do all parts of the universe move away from each other evenly?