Space didn’t used to be a big place

There are few things we can conceive of that are as mind-bogglingly large as space is. Our observable Universe, out to the deepest recesses of space that we can possibly see, takes us out some 46 billion light-years in all directions. From the Big Bang until now, our Universe has expanded while gravitating at the same time, giving rise to stars and galaxies spread across the expanse of outer space. All told, there are presently several trillion galaxies present within it, as for every galaxy we know about, there are perhaps 30 to 100 that are too small, faint, and distance for us to presently observe. And yet, if we go back in time, we learn that not only was our Universe a much smaller place, but that in the earliest stages, the Universe itself was anything but impressively. If the Universe has been expanding and cooling for 13.8 billion years, then long ago, it must have been smaller and denser, implying that there may not always have been such a remarkably large volume to contain all the particles that have existed for so long. Space may not always have been a big place, and it’s only the fact that our Universe has expanded so thoroughly and relentlessly that made it so big and empty today. <a href="https://medium.com/starts-with-a-bang/space-didnt-used-to-be-a-big-place-743e49a933e4">Website</a>