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

5. Red Shift & Doppler Effect
Doppler Effect: an observed change in the frequency of a wave when the source or observer is moving.
The same thing can happen with light waves.

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. Doppler Effect Movie Clip
Ex: The abulance is the source, and when it moves past us, the frequency of the sound waves change
Car horn BBT dopler

8. 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.

9. Star Spectra-Red Shift ask an astronomer

10. 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

11. Cosmic Background Radiation

12. 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?

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