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The universe is, essentially, spacetime with fillings. It doesn't make much sense to ask what space and time are made out of. "Not physical" is not the description I'd use given that your alternative is metaphysics, but it's not like "one big physical object", more like "the space in which other things are" (plus the things, just to be all-inclusive).
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This has been very good discussion. Thanks for adding so much to the discussion. I have really enjoyed it.
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harold aptroot wrote: The rule is that measurable quantities cannot be infinite, but an infinite universe doesn't have a proper size
This is a very interesting point too, because it feels similar to "a system under observation changes".
As if the size of the Universe changes to finite when we find the end or measure it, but is conceptually infinite.
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The inability to form an infinite sidewalk from a finite amount of matter doesn't prove the universe to be finite.
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I know.
I was providing something for you to walk on.
The point is if you could travel faster than the speed of light toward the end of the Universe then at some point all energy would be exhausted (not from travel but from the limit naturally created by an end of energy and you'd be at the end of the Universe. A physical thing must have an end -- a physical thing without an end is only theoretical. That is why we call it physical and not metaphysical.
And I'm not saying that only in theory does the Universe end, I'm saying in fact it does because it is a physical object (we physical objects know this and study this and have our existence in a physical Universe). The instant you say the Universe is otherwise is the same instant it becomes non-physical and my final point then is that "all bets are off".
So, the Universe (as studied by Scientists,Philosophers and Mathematicians) is a physical beast and as such has a limit and so has an end.
Now you've heard the end of this discussion. Since, I've decided I am right. Yes, I'm kidding, but I do think what I've said makes sense.
The Universe, if physical -- and it is, must have a limit.
And if it isn't physical, then we aren't either.
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Let me see if I've understood your argument:
- We are physical;
- The universe is physical;
- We have a finite size;
- Therefore, the universe must have a finite size.
Is that an accurate summary?
Because if it is, I could replace "finite size" with "bumhole", and the argument starts to look rather silly.
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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No.
I'm saying, The Universe is physical and mechanical, therefore finite.
I believe that most of your major scientists believe this too.
They speak of "almost" infinite but never infinite.
I don't believe anyone other than school children actually believe in any physical object that is infinite.
Infinite is just a concept, but not reality in the mechanical universe.
All physical (non-philosophical conceptual) things have limits. That's all my point is.
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That still leaves the question: if the universe has a finite boundary, what is beyond that boundary?
Or are you saying that spacetime is a localized concept that has no meaning "outside" of our universe? (Not that there would be an "outside" in that case. Or a "before".)
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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Richard Deeming wrote: That still leaves the question: if the universe has a finite boundary, what is beyond that boundary?
This too is a point I was attempting to drive toward in a logical manner.
Though I freely admit my knowledge of any of this is very, very basic.
This was an idea too that at some point studying the physical mechanical universe becomes a study of metaphysical properties (when you reach the end of the physical).
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raddevus wrote: All physical (non-philosophical conceptual) things have limits
Prove it.
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raddevus wrote: The Universe, if physical -- and it is, must have a limit.
No.
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PIEBALDconsult wrote: No.
The best and most rational argument in the entire conversation so far.
To which I reply, with a most stunningly intelligent answer:
Yes, infinity +1!
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The universe could be infinite...
Or it could just loop on itself like a circle.. or the surface of a doughnut....
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Super Lloyd wrote: or the surface of a doughnut.... So when we find the end of the universe the other side will be the counter of a bakery?
There are two kinds of people in the world: those who can extrapolate from incomplete data.
There are only 10 types of people in the world, those who understand binary and those who don't.
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Imagine you are an ant on the surface of the doughnut.... What do you find at the end of the doughnut? where is the end? what is the sound of one handed man clapping?
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Super Lloyd wrote: Imagine you are an ant on the surface of the doughnut.... What do you find at the end of the doughnut? I see empty space above the doughnut. But perception does not change reality in this case.
There are two kinds of people in the world: those who can extrapolate from incomplete data.
There are only 10 types of people in the world, those who understand binary and those who don't.
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Out of curiosity.. didn't you understand my explanation? or are you trolling?
I am really confused whether I need to explain or not...
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Super Lloyd wrote: didn't you understand my explanation? I guess not. You asked a bunch of questions so I don't see that as an explanation.
There are two kinds of people in the world: those who can extrapolate from incomplete data.
There are only 10 types of people in the world, those who understand binary and those who don't.
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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...
modified 17-Jun-17 8:45am.
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Super Lloyd wrote: It failed apparently. Indeed.
There are two kinds of people in the world: those who can extrapolate from incomplete data.
There are only 10 types of people in the world, those who understand binary and those who don't.
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Super Lloyd wrote: what is the sound of one handed man clapping?
Piece of cake[^]!
"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer
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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.
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Ralph Little wrote: Assuming that you're not trolling What is wrong with people on the internet. As soon as someone disagrees with you they must be trolling?
Ralph Little wrote: A loop is not infinite (inasmuchas it has a measurable size) but doesn't have an end either. 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.
There are two kinds of people in the world: those who can extrapolate from incomplete data.
There are only 10 types of people in the world, those who understand binary and those who don't.
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> 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.
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Ralph Little wrote: you could arbitrarily call anything an "endpoint". 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.
Ralph Little wrote: but surely that would be just space with nothing in it and therefore not and end at all? Precisely. Our brains cannot conceive, IMO, an end to space.
There are two kinds of people in the world: those who can extrapolate from incomplete data.
There are only 10 types of people in the world, those who understand binary and those who don't.
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