2 THE BIG BANG THEORYTo understand how the universe was formed, scientists study the movement of the galaxies.Careful measurements have shown that most galaxies are moving away from each other.
3 Having discovered that the universe is expanding, scientists have worked backward to see how it was formed.This research showed that all matter was squeezed into a small space.
4 The BIG BANG TheoryThis theory says that all matter and energy in the universe was compressed into an extremely small volume that exploded and began expanding in all directions.
5 A Tremendous Explosion About 14 billion years ago, all contents of the universe were compressed under high pressure, at high temp., and high density into a very small volume.Then the universe rapidly expanded and cooled.
6 Within the first 3 minutes of this ”big bang,” the initial elements, forces of nature, like gravity, and seeds of galaxy formation were determined.
7 Cosmic Background Radiation The energy from the original explosion was distributed in every direction as the universe expanded.This is called cosmic background radiation.