1. 15-4 (part 1) | Formation of the Universe

2. A long time ago In a galaxy far, far away Well, even earlier than that…… There was the Big Bang.

3. The Big Bang Theory
To understand how the universe was formed, scientists study the movement of galaxies
Careful measurements have shown that most galaxies are moving away from each other

4. Having discovered that the universe is expanding, scientists have worked backwards to see how the universe was formed
Research shows that all matter was squeezed into a small space

5. This theory states that all matter and energy in the universe was compressed into an extremely small volume that exploded and began expanding in all directions

6. A Tremendous Explosion
About 14 billion years ago, all contents of the universe were compressed under high pressure, at a high temperature, and high density into a very small volume
Then the universe rapidly expanded and cooled

7. Within the first 3 minutes of this “big bang”, the initial elements, forces of nature (like gravity), and seeds of galaxy formation were determined

8. Cosmic Background Radiation
The energy from the original explosion was distributed in every direction as the universe expanded
This is called cosmic background radiation

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