Our “universe” is only a part of the universe: all matter and energy, space and time. This is because our view of the universe is limited. We only see a small part of it: the result of the age of the universe, the expansion of the universe and the speed of light.
The fraction we see is known as the observable universe. And from what we see, it’s the same. Everywhere we look, there’s the same mix of galaxies and empty space, of stars and clouds of gas. And everything seems to follow the same laws of physics.
But we don’t know what’s going on in the rest of the universe, everything beyond the “cosmic horizon,” the limit of our range of vision.
Logic suggests that everything beyond this horizon is like everything in the observable universe. There is no reason why the “bubble” of the universe we inhabit should be any different from the universe as a whole. But we don’t know for sure, and probably never will.
However, scientists can try to draw some inferences. If they observe a galaxy cluster that is 10 billion light-years away, for example, it has its own observable universe. Some of them overlap ours, but others extend far beyond it. If the cluster is stretched into the region we can’t see, scientists might conclude that it has been pulled by the gravity of something big and heavy, perhaps a giant galaxy cluster far from the observable universe, which has never we will see.
Screenplay by Damond Benningfield