eli5: if we cant observe all of the universe how do we know its infinite?
In: 3
Measurements indicate the universe is flat. If it is flat *and* finite, then there would be locations near the edge, or near the center. That is, some locations would have a special, unique vantage point.
A general principle that is assumed is the Copernican principle, that no point of view in the universe is more special than any other, which would require a flat universe to be infinite.
Yes, it is an assumption, but we’ve yet to observe anything to contradict it.
Until you can observe the “end”, don’t you have to assume it’s endless, at least until the point it’s verified?
We don’t. But as far as we know, there’s nothing stopping it from being that way, and if it isn’t, it’s still big enough to be physically impossible to go everywhere anyway, so it doesn’t really matter.
Because nothing that we’ve observed has ever made us think that the universe is limited.
All science is always “to the best of our knowledge”. Someone came up with the idea that the universe is infinite; no one has ever proven that to be wrong.
We don’t know that it is actually infinite. We only theorize that it is based on lots of complicated math and observable phenomenon.
We used to think our oceans’ resources were infinite.
Who knows, maybe one day we will discover that the universe is not infinite, either.
“infinite” is a pretty open ended concept. Nothing is a pretty impossible concept. If you got to the edge of the universe and there was nothing there what would you see? The problem is, you can’t really have nothing. An empty box has air in it – an empty box in space still has the vaccuum in it. The empty space isn’t “nothing,.”
Unfortunately, infinite also has it’s problems. Trying to wrap our minds around this has brought up ideas of “recursive” space (Spaceis a 4d sphere, or you get to one “edge” and it connects to the “far” edge). It could aslo be that our universe is an atom making up part of a larger universe that is part of an atom in our universe (that gets confusing and I never understood how the physics work).
Then there are much more complicated mathematical and physics models that have to do with repeating numbers extending outwards.
Latest Answers