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A comment on How big is the entire universe?. Parent comment

Re:How big is the entire universe? by bwood on Wednesday July 25, 2012 @01:34PM (#4292017)
If you consider the universe to be a well-defined volume, then there must be some boundary to it. And if there's a boundary, then you can ask the question "What's on the other side of the boundary?". Thinking of the universe as a 2D surface in a 3D space is a way to picture how it's possible to have a finite space with no well-defined boundary.
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Re:How big is the entire universe? by javert on Wednesday July 25, 2012 @03:44PM (#4292655)
Well, it's not clear to me why we would assume there is a boundary. And I don't know what it means to think of a 3D area as a 2D surface anyway. And I don't think it's possible to have a finite space with no well-defined boundary.
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Re:How big is the entire universe? by Ralith on Wednesday July 25, 2012 @04:59PM (#4293009)
> I don't think it's possible to have a finite space with no well-defined boundary.

The 2D space described by the surface of a sphere is one such space.

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Re:How big is the entire universe? by javert on Wednesday July 25, 2012 @11:33PM (#4294284)
In English, "space" is a volume, not a surface.
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Re:How big is the entire universe? by Ralith on Thursday July 26, 2012 @12:22PM (#4296816)
We're not speaking English, we're speaking math.
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Re:How big is the entire universe? by javert on Thursday July 26, 2012 @10:45PM (#4299762)
Oh. Yes, now that you have mentioned it, I do recall "space" being used in math classes in a unique way. It never occured to me that that is how "space" was being used.
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