PiOfHouseDust :
This is because of what we know as the "known universe". Simply put, we can see a lot of the universe, but that doesn't mean that what we see is the entire universe. Instead, it's more that light can only travel so far through space, and there is a certain point where the light simply can't reach us anymore, and everything beyond that point is, and will forever be, unreachable and unseeable to us. Fun, though kinda scary, fact: everything in the universe, with the exception of the milky way (our) and Andromeda (neighboring) galaxies, are slowly moving away from us. And as they do so, they slowly approach the line of "known universe", and so, over the course of millions and millions and millions of years, little by little, more and more of the universe will slip past this line, at which point we will not be able to see or reach them ever again. And so, by extent, one day, in the very, very, very, very, very, very far future, some future relative of the human species will look out at the universe, and literally see nothing past the milky way/Andromeda galaxies.
2025-07-25 12:22:03