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I will definitely be looking up some information on space-time. As I have said previously, I am an uneducated thinker, so a bit of a read-up on this wouldn't hurt I think ! In fact if anyone could suggest some good reading material on the subject I would greatly appreciate it!
There is probably also a lot of good resources on the web. The folks at
Physics Forums | Science Articles, Homework Help, Discussion can help you out with some recommendations. For now, try the Ask an Astronomer FAQ, at
http://itss.raytheon.com/cafe/qadir/qanda.html.
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This is difficult for me to put into words (my meaning) - I don't believe that space is "contained" at all, if fact quite the opposite is what I am trying to put across. That there is no boundary, or "container" - this was in response to the theory that space was curved. Again, I will need to read up on space-time in order to understand your reply fully with regard to the curvature.
A universe with hyperbolic curvature can be finite yet have no boundaries. A 2D surface of a balloon has no edge or center, as you would need to go up into the 3rd dimension to find it. Likewise, our universe would have no edge in 3D, and cannot be contained in any 3D space.
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I have read in other threads that the universe started with a "singularity" or, for want of a better term, a "dot". Again, if indeed this was the case, surely this singularity (or the beginnings of the universe) would have had to reside within something?
A "dot" is a terrible way to put it, and is not correct. The classic singularity is a case where the density of the universe becomes infinite and it's volume shrinks down to a point. IOW, a mathematical point, with no size at all. But before you ask how something so absurd is possible, don't sweat it. I don't think any physicist actually thinks singularities exist in the real world. It is more likely they are just a result of applying general relativity where it is no longer valid. The expectation from a theory of quantum gravity is that singularities of the classic equations will be replaced by something without the infinities or zero volumes of the classic (non quantum) theory. Keep in mind though that even with the classic singularity, only a finite universe shrinks down to a point. In an infinite volume of space, each point reaches infinite density, but the overall size remains infinite even to the moment of the big bang. It is also
incorrect to say the big bang implies the universe is finite.
Now, if we imagine a finite universe shrinking down to a minium size, then you might ask what that small universe is contained in. And, what is outside, if not more space? Well, think about it for a moment. If the entire universe is finite, then there is
no outside at all. No beyond either. As counter intuitive as that is, the idea is logically sound. In geomtetry, spaces are defines by there own continuum of points. IOW, a line is difined by it's own length, not what length lies beyond it. It's quite simple when you think of it that way.
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Because I see no point in conjecture. We can't see the "end" or the "edge" of universe - or should I call it "space" . . . all we know from physical evidence is that space is unlimited - ie. no space probes or telescopes are able to see an end, so why would we speculate that there is one ?
We can't "see" infinite space either. Nor do we have any physical evidence for an infinite universe that isn't also compatible with a finite cosmos. It is conjecture, because infinite space by it's very nature, could never be proven. However, it may interest you to know that some cosmologists are in fact looking for signatures in the sky that would likely be conclusion evidence that the universe is in fact
finite. Nothing through yet though.
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