ELI5: Explain Like I'm 5

Georges Lemaître

Georges Lemaître was a very smart man who lived a long time ago. He was really interested in space, the stars, and how the universe worked.

One day, he had a big idea that changed the way people thought about the universe. He said that the universe started with a big explosion, which he called the "Big Bang."

Imagine that you have a big balloon, and then you blow it up really fast. That's kind of what happened with the universe, according to Lemaître.

Before this discovery, people thought that the universe was always here and never had a start. But Lemaître showed that the universe had a beginning, just like we do when we are born.

Today, scientists still use Lemaître's idea to help them understand how the universe works. So, we can say that Georges Lemaître was a very important person in the history of science.