How did scientists reach the conclusion that the big bang was the beginning of our universe?

Question

How did scientists reach the conclusion that the big bang was the beginning of our universe?

In: Physics

Answer 1

Inside our galaxy it doesn’t look like things are getting farther apart because everything is in the same ball of stuff traveling in the same direction at the same speed.

But people figured out how to look at other galaxies. When you look at other galaxies you notice that they’re all traveling away from the same place.

So some smart guys figured that they were actually all in that place in the past.