1. Evidence for the big bang
subtitle

2. Amounts of elements in our universe
In the beginning of the big bang, relative amounts of hydrogen and helium were:
H: 76%
He: 24%
Other: Trace amounts, less than 1%
Currently, due to nuclear fusion in stars since the big bang:
H: 73%
He: 26%
Everything else: 1%  all the air you breath… all the food you eat… all materials that make up your car/house

3. Cosmic microwave background radiation
Big Bang released a lot of energy.
Billions of years later, the radiation is moving so fast away from us, that the light has shifted from visible to microwave

4. The same thing happens in light— with color!
THE DOPPLER EFFECT
Observed whenever the source of waves is moving with respect to an observer.
As the source comes towards you, the frequency increases (higher pitch)
As the source moves away from you, the frequency decreases (lower pitch)
The same thing happens in light— with color!

5. Blue shift
Red shift
Light emitted from an object moving towards you will have its wavelength shortened (higher frequency).
Light emitted from an object moving away from you will have its wavelength lengthened (lower frequency).

6. Summary
In your own words, describe the three types of evidence for the Big Bang Theory?

7. Not moving (Un-shifted) Moving toward you (Blue shifted)
Moving away from you (Red shifted)
Pg. 30
Draw H:
Red/Blue shift worksheet: tape as a flip