The universe has no center and no edge

Ask where the universe began and you expect a location — some cosmic ground zero, a point you could fly to. There isn’t one. The Big Bang happened everywhere at once. It was not an explosion that hurled matter outward from a center into surrounding space; space itself was what expanded, and it began expanding at every point simultaneously.

That means the universe has no center. Look in any direction and distant galaxies are racing away from us, faster the farther they sit. It feels like we’re the hub of the cosmos. But an astronomer in any other galaxy sees exactly the same thing — everything fleeing from them, too. With uniform expansion, every vantage point looks central, which is another way of saying none of them is.

The whole universe is expanding, and it is doing so equally at all places.

Picture dots on the surface of an inflating balloon. As it swells, every dot moves away from every other dot, yet no dot is the center of the surface — and the surface has no edge you could ever reach by walking. The cosmos works the same way in three dimensions.

If the universe contains all of space, time, matter, and energy by definition, then there is nothing outside it to form a boundary. No center, no rim — only expansion, happening everywhere, all at once.