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If you are a one dimensional being living on a circle like universe. The circle has no end, yet it is finished.
If you are a 2 dimensional being living on a sphere or a doughnut like universe, your universe has no end yet it is finished.
There is a good chance we live on some kind of hypersphere...
The question here were to make you think. It failed apparently.
To be exact not a 3D space floating in a 4D universe.... a 3D universe of its own with such properties as a 3D sphere in 4D universe...
Assuming that you're not trolling ...
Just because something is not infinite does not mean that it isn't endless.
A loop is not infinite (inasmuchas it has a measurable size) but doesn't have an end either.
The Cosmos (and others) talked about this rather nicely with the 2D version of reality called Flatland. A Flatlander's reality could be mapped into our 3D reality by visualising it as inhabiting the surface of a sphere. The Flatlander walks and walks and soon finds themselves where they started. Seems infinite, but in fact is not.
If you map our 3D space into a higher dimensional reality (which would be difficult for us to imagine and really requires pure mathematics to explore) then we could travel in any direction and end up where we started, the implications of which would be very hard for our puny 3D brains to comprehend. The Universe seems intuitively infinite because otherwise we assume that there must be an "edge" but there probably isn't.
> What is wrong with people on the internet. As soon as someone disagrees with you they must be trolling?
That was actually a joke. Don't take me too seriously.
> I disagree. If you pick a point on the loop and call it the starting point, you can quickly see that there is also an endpoint.
In that case, you could arbitrarily call anything an "endpoint". I think what most people intuitively call an "end" in the context of this discussion, is somewhere you cannot go beyond, a point beyond which nothing exists. At least that's how I would interpret it.
Interestingly though, although people can conceive of an end of a universe as a concept, I don't know if they could actually describe what it would be like. Perhaps it would a big wall. Perhaps it would be just a void-like nothingness, but surely that would be just space with nothing in it and therefore not and end at all?
Sometimes trying to describe something precisely betrays our ignorance of what we actually mean.
>Yes. Because if you also pick an arbitrary starting point and then follow around the loop you'll end up at points you have already visited, thus you must have passed the end point.
Sounds like we're only disagreeing on what the word "end" means then and whether or not you can go beyond it.
If, in travelling in any direction, you arrive where you started after some fixed time interval, then the Universe must be finite because you could measure the distance that you travelled and therefore determine the Universe's "size". It could be that there are physical reasons why this is impossible to do in practice analogous to moving faster than c. We do have good reasons for thinking that the Universe is expanding so measuring the size of the Universe might be difficult.
It might also be difficult to come up with a measurement unit to describe the size of the Universe since all measurements of anything are relative.
Possibly not. In which case, what is beyond the edges of this non-infinite universe? More universes? If so, what demarcates the edges of this one and the edges of the others? Can they not all be part of a larger universe?
PS. My finite brain has just thrown a "Value out of range Exception"!
- I would love to change the world, but they won’t give me the source code.
Perhaps more realistically or at least more philosophically pleasing, a finite universe could still be unbounded, for example if it is a 3-ball or 3-torus or something like that. That would mean that you could travel an infinite amount in any direction and never find "the edge" (since there is no edge) but you may find yourself returning to a place you've been before. The volume would be finite that way, but you don't have to worry about how space itself can even have an edge at all and what that might look like.
But it isn't really known whether it's finite or not in the first place. It seems to be flat and isotropic, if it actually is flat and isotropic then it is infinite. But it might not be exactly flat, it might be curved less than could be measured so far. Or it might not be isotropic, or both.
My theory: The universe is like an expanding balloon with everything that currently exists sitting on the surface. Heavy objects like black holes, stars, and planets sink into the surface warping space-time to create gravity. If you could travel at a rate faster than expansion, you would eventually come back around to the starting point. The interior of the balloon is the past.
what is beyond the edges of this non-infinite universe?
IMO, the question cannot be answered because nothingness is still conceptually "the lack of something", so there is no "beyond," but that's similarly a null reference exception! But realistically, I suspect no one, even given an infinite amount of time, would ever be able to know, because the universe will end before we can reach even the point where light from the edge could reach us.
Now, that's another conundrum -- if the universe ends in time, what does it end as?
Einstein wasn't sure: "Two things are infinite, the universe and human stupidity, and I am not yet completely sure about the universe"
(Allegedly; it quoted in the book Gestalt Therapy Verbatim by Frederick S. Perls, but the attribution is disputed)
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