1. Universe

2. How Big is Our Universe What is the universe?
Everything: All Space (objects in space) and all time
How Big is the Universe?
We are not certain. Our sight is limited by time.
We only see things that have been around long enough for their light to reach us. (the visible known universe)

3. What is a Fingerprint?
Unique pattern of ridges on fingers that can be used for identification.

4. Electromagnetic Spectrum
The Only difference between different types of light is wavelength and that visible white light is all colors of light together.
Scientist can separate light into the wavelengths that make up that light by using many devices, one of which is called a spectroscope.

5. A Star’s Spectrum
Each element produces a different set of spectral lines when it burns.
This set of lines could be called a “fingerprint” of that element.
By looking at stars with very advanced spectroscopes scientists can identify what a star is made from.

6. Mystery Gas

7. Neon Helium Carbon Dioxide Water Vapor Air Argon Hydrogen Nitrogen
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Neon
Helium
Carbon Dioxide
Water Vapor
Air
Argon
Hydrogen
Nitrogen

8. What is the Doppler Effect?
As an object moves toward you, the sound and light waves it produces are “squished together” and have a higher frequency. It’s the opposite with an object that is moving away from you.

9. Light Doppler
kipedia/commons/9/93/Suzreds hift.gif
What is redshift?
Red shift' is a key concept for astronomers - the wavelength of the light is stretched, so the light is seen as being 'shifted' towards the red part of the spectrum.

10. How can you remember Red Shift?
Think of Tail Lights. As the car moves away from you they are red.

11. Everything appears to be moving away.
What would it mean if astronomers saw almost all red shifts when they look into the cosmos?
Everything appears to be moving away.

12. Hubble’s Expanding Universe
What did Hubble discover?
Universe is really big
Universe is expanding
What similarities exist between Hubble and Galileo?
video
Gravity and Expanding universe
Video

13. Big Bang

14. The Big Bang Theory
Roughly 13.8 billion years ago, the universe was all together, extremely hot, dense, and compact.
It suddenly began to RAPIDLY expand.
At first, the universe was nearly entirely energy.
E=mc²

15. The Big Bang Theory Cont.
The first atoms were hydrogen with very small amounts of helium and lithium. All of the hydrogen in the universe was formed at the big bang. There were no heavy elements (atoms that have more protons in their nuclei) until stars formed.
Eventually gravity began pulling materials together, forming stars, galaxies, planets and all types of objects.

16. What kind of evidence would you look for to prove the Big Bang explanation wrong?
What kind of evidence would you look for to prove the Big Bang explanation right?

17. Evidence for the Big Bang #1
We see many red shifts in the universe, and very few blue shifts.

18. Evidence for the Big Bang #2
Scientists predicted that the energy from the big bang would still be found in the universe, but would have cooled significantly as the universe expanded.
Arno Penzias and Robert Wilson discovered the leftover energy accidentally. They found a fairly even level of energy scattered throughout the entire universe. It is leftover energy of the big bang and perfectly matches the predictions of other scientists.
Cosmic Microwave Background Radiation.

19. Evidence for the Big Bang #3
Hydrogen is by far the most common element in the universe. This is what we would expect because hydrogen was the element formed early after the Big Bang.