The universe likely got started off with a bang. A big one, at that. That Big Bang saw all of existence go from being subatomic to stretching over billions of lightyears in the blink of an eye. The energy and force of that explosion caused cosmic background radiation that humans are still picking up to this very day. Needless to say, it was a pretty big deal.
All of the observable universe came into being in a matter of moments. What’s more, that explosion is far from over. Though it’s been billions of years, the universe is still expanding out in all directions. So fast, in fact, that it’s actually impossible to travel from our local group of galaxies to any other galaxy clusters. The issue? The universe is expanding so fast that those galaxies are moving away from us faster than the speed of light.
Of course, this is all relative. It’s almost inaccurate to describe the “speed” with which the universe is expanding, as that’s not quite the right term. However, the important part, for our purposes, is that the local group is stuck with its neighbors. And, eventually, even the nearest galaxies to us will begin to grow apart, thanks to the ever-expanding cosmos.
Currently, the gulfs between the Milky Way and our neighboring galaxies is vast. Unfathomable stretches of inky black nothing fill the void between galaxies, and it’s a stretch of existence so dark and imposing that it’s hard to accurately describe just how empty it is. However, with time, that inky black void will appear to be the only thing beyond the boundaries of the Milky Way.
As time passes, millions of years from now it will seem as though the Milky Way is alone in an endless expanse. Whatever intelligent life there is in this galaxy will gaze out into the stars and see their own neighboring celestial objects, but nothing else. If they are aware that there is more in the universe, it will likely only be due to star maps and records left behind by other intelligence civilizations like our own.
This might seem like a rather depressing fate, but remember, humans have never even left this solar system, let alone though about diving beyond even this galaxy. The universe is impossibly vast. While we may never even begin to reach out from our little pocket of existence, there is plenty within our grasp here on Earth and in our home galaxy.