https://nautil.us/what-is-our-universe-expanding-into-258168/
The Big Bang didn’t happen in one location in space. The Big Bang happened everywhere in the cosmos simultaneously. The Big Bang was not a point in space. It was a point in time. It exists in all of our paths.
When we say the universe is expanding, we mean that if you map a bunch of galaxies and measure the average distances between those galaxies, you’ll get a number, and then you wait a little bit, a year, a billion years, whatever, and then you go to make the same measurement. Those distances, the average distances, are going to be larger. When we say we live in an expanding universe, we’re saying that the distances between galaxies, on average, grows with time. And that’s it. There’s no center, there’s no edge.
