Look, the universe is big, it has to constantly prove that by being both infinite, expanding, and accelerating that expansion. It used to be very small and now it’s clearly overcompensating.
Time to reverse that insecurity with yo momma jokes about the universe.
If we are considering "the universe" to mean the spacetime that we exist in, there could be an "outside," but we just don't know, and there's no indication of such an outside, or anything about what it would be like.
By way of infinite spacetime, yes, there is only a part of spacetime that we can observe, because the farthest part is moving away from us faster than the speed of light. I seem to recall there having been some estimations of how large all of spacetime is, observable and unobservable, and that it has a finite size.
That said, there does not appear to be a limit to the size of spacetime. Based on what is currently known, spacetime is expanding, the expansion is accelerating, and there is no limit to the expansion.
One day......we're going to observe the non-observable universe, and discover that it's exactly like this universe, except it"s last week. And then we'll do it again in a different direction, and it'll be next week. And we'll do it again, and again, and again, and again, and eventually figure out that everything we do, ever have done, or ever will do, only applies to THIS observable universe. And that we're one of an uncountable number of universes. Each a slightly different time than ours.
And no, it's not time travel. If you go to another universe, and kill Tom, then come back here, Tom is still alive. If you go back to that universe, Tom is still dead and you get arrested.
Itself. The distance between objects at inter-galactic scale is expending regardless of their relative movements.
P.S.: and the speed of expension is proportional to the distance between the objects.
This video goes into the expansion of spacetime as well as cover how internally those forces don’t affect local spacetime because of the mass/spacetime curvature.
Although I have to agree with the top comment regarding this being my favorite channel I don’t understand. But the more I watch it the more I start to get a sense of a lot of it and I actually am understanding some of it
And yeah, we don’t know what, if there’s anything, it’s expanding into.
Nothing. It’s the same nothing that existed where we are right now, right at the moment the Big Bang occurred. It’s so nothing, that astrophysicists theorize that time doesn’t even exist there yet.
There are an infinite number of numbers between 1 and 2. Infinite doesn't mean boundless. So if you had a number line, and you place an infinite number of points on that line, you could then extend that line to be between 0 and 3. There would still be an infinite number of points, but those points would be further apart.
Likewise the Universe is infinte in time and space. There's always more time, more space, but also the time between points in time can grow and shrink, and the space between points in space can grow and shrink.
The one that gets me is that if the Universe is infinite but how matter can organize itself is finite (albeit a very large number) then there is another galaxy just like ours, another Earth just like ours, and there is another GoofSchmoofer writing this exact some thing in the exact same way somewhere out there.
And if this is true then how many GoofSchmoofer's are there in this infinite Universe?