Thursday, April 22, 2010
Joined: 14 Apr 2009
Location: Planet Earth
Re: what shape is the universe?
Postby linford86 on April 22nd, 2010, 10:14 am
Non-embedded manifolds, like the picture I was advocating, are surfaces which do not have exteriors or "interior volumes". They only have surface. That is to say, think of the surface of the balloon and now imagine that there is no outside of the surface. So no inside of the balloon and no outside either, just the surface. It's hard to picture, which is why the balloon analogy is misleading. But it's the picture that has been found to be most useful in describing space-time and it's the picture used in our current formulation of General Relativity (i.e. the theory that lies behind modern cosmology.) We do not, and possibly cannot, know if there is something outside of this universe. But the point that I am making is that there doesn't have to be an outside. Just as the surface of the balloon has no edge on the surface, the space-time we inhabit does not need an outside either. Of course, the universe would be the only shape lacking an outside that we experience. Therefore, we cannot have intuition from dealing with everyday objects.
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I post this as it is to show the state of reasoning by one of the moderators and experts of the sciencechatforum.com Deo Vindice, let us compare my fundamental ideas with the rumor of his and the depth of understanding of space for one who judges others work as not even metaphysics.
Interestingly enough the slinky is a screw that always finds its own level. May he find the light of creative and useful science one day- but I don't blame him perhaps we should blame the state of education or the lack of it in today's world. There are more things dreamed of in the orthodox physics than you can yet imagine friend as "outside your universe".
And days later this interesting post by Lincoln:
Re: what shape is the universe?
Postby Lincoln on April 26th, 2010, 7:02 am
While I agree with Linford, one must caution that this is a theoretical concept.
And, no, this isn't just my theory/experiment thing. We dont' >>KNOW<< that the universe isn't sufficiently large that the differential expansion across our little visible bubble of 28 billion light years across isn't just too small for current instruments. One could imagine some kind of Big Bang that experienced a kind of hyper-inflation to a size that is trillions or quintillions of lightyear across. The uniformity of expansion we observe could be just because we have insufficient precision to measure the gradient across the tiny visible bubble. In this scenario, space is fixed and the material is expanding into space, rather than with space.
I say this not because I believe it to be true. I don't. But if such a measurement was performed tomorrow and a gradient observed, the theory would likely be thrown out and started over. This is the reason that I insist on the cautions and the caveats.
However, caveat aside, Linford is doing a good job of describing how the balloon analogy is often misunderstood.
Is there not some empirical evidence embedded or not of center 65 million years away from us? That is a center on the "baloon"? or for that matter an axis?
Well, let us not blaspheme the scientific faith- just different terms I suppose that God is that whose circumference is nowhere and center is everywhere. And if we imagine one day all we may see is the milkyway as something seems to be shrinking and something else expanding, maybe things seen smaller than an atom and what then so goes the speculation. Is the Spinozean god of Einstein in a sense such a finite god and all that entails?
Analogy, is it true or not exact only in geometry? But such models are really just an other form of our disparate attempt to keep the universe in a descending energetic materialism including the excluding of mental and other interpretations. Maybe Hawkings has caught on to the new religions of quantum mystical esp aliens and all that. Not that such a fuzzy linear view as the party line does help us as hands on engineers make reliable automobiles and economics in the main.
The distinction between how to apply mass and the constant of light to energy is of course a crude approximation with no admission of where the Einstein picture is declared without error when many expert physicists in the mainstream can show this with a little better orthodox methods. Maybe empiricism trumps rationalism but it does not take a logician to see that these crude interpretations of analogies are matters of self fulfilling faith and not fact. The number of god, in his emotional image as lonliness is one or none or many who vanish so all are dead and the science based on this will also vanish along with utility and creativity of our work. But is this not philosophy 101- the creative truth of poetry as is the better science theory is not aesthetically relative to some essential absolute and subject to fads and narrow minded peers in agreement- if the world is intelligible.