Big Bang

How is the Universe Expanding?

Illustration representing the mesh used to describe gravity.

Create An Expanding Universe

You have likely heard about the Universe expanding. Or that redshift can tell us about the movements of galaxies. Both are difficult ideas to imagine and understand.

Cartoon of a person blowing up a balloon. The balloon is covered with galaxies.

Big Bang

The evolution of the Universe.
Credit: NASA

The Big Bang is the explanation for how the Universe started. Astronomers think that everything started in a single point. Then everything expanded and stretched to grow into the huge Universe we see today.