3 discoveries that change the way we think of the Universe

Ethan Siegel : Where did the universe come from? Is no longer a question for poets and theologians and philosophers.

He says we have amazing scientific answers to this question that have defied even the wildest of our expectations.

Siegel is a theoretical astrophysicist and science communicator, author of the James Webb Space Telescope book Infinite Cosmos .

Alexander Friedman was the first one to say, if you have a universe that's uniformly filled with any type of matter or energy, it's going to either expand or contract.

But what if the universe wasn't filled with matter or radiation? Einstein didn't even know it, but he first put forth this possibility way back with the general theory of relativity.

One theory is before The Big Bang was a period of cosmic inflation.

Inflation gives us this specific prediction that when we look at the fluctuations imprinted on the universe, they should be almost perfectly uniform on all scales except on smaller scales.

We've now been able to go out and test those predictions of inflation against the singular Big Bang without inflation.

So far it's passed 100% of those tests.