1. Our Universe Exploring our universe
Lesson objective: Explain the evidence for an expanding universe
Describe the formation of the universe and the big band theory.

2. How did the universe begin?

3. Evolution of the Universe
Contains all the star systems, galaxies, gas and dust.
Contains Earth at the center, the Sun, the Moon, five planets
Study of the universe is called cosmology

4. Expansion of the Universe
Edwin Hubble (20th century) used a telescope to find other galaxies
He demonstrated the existence of galaxies
These galaxies where 2 million light years away
We live in the Milky Way Galaxy

5. Expansion of the universe
Edwin Hubble created Hubble's Law: farther away a galaxy is, the faster it is moving away from us.
This means the universe is expanding.
Example is inflating a balloon, and mark dots on the balloon before inflating, notice the distance of the dots.
Edwin Hubble compiled measurements of redshift and distances to galaxies. Through these measurements, he concluded there was a relationship between speed and distance between galaxies. This is called
Hubble’s Law.  Hubble’s Law states that the farther away a galaxy is, the faster it is moving away from us.  This is one of the major reasons to why astronomers believe that the universe is expanding.

6. Think of the expansion of the universe as an inflating balloon
Think of the expansion of the universe as an inflating balloon. As a balloon is inflated, it expands in all directions. The universe also expands in all directions.
Redshift
 Redshift occurs when a light source is moving away from the observer. This occurs because as an object moves away from you, the wavelengths of visible light are stretched. Light of lower frequencies are on the red end of the spectrum. o Because we can observe redshift in galaxies, scientists believe that the universe is expanding.  

7. Big Bang Theory
Most widely accepted explanation of how the universe is formed.
Began 13.7 billion years ago.
Universe is always expanding so what is there now will soon be further away.
The Big Bang theory is used to explain the creation of the universe and all the planets, galaxies, and stars within it.

8. Big Bang

9. After Big Bang Theory
After only a few seconds, protons, neutrons, and electrons could form
Then came together created hydrogen
Then nuclear fusion and hydrogen fused then would cluster together to create stars.

10. Now lets review What is the universe? Who found other galaxies?
Symphony of Science, The Big Beginning:
What is the universe?
Who found other galaxies?
What is the Big Bang Theory?