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Published online 23 May 2008 |
Nature
| doi:10.1038/news.2008.854
Corrected online: 28 May 2008
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Doughnut-shaped Universe bites back
Astronomers say Universe is small and finite.
The doughnut is making a comeback – at least as a possible shape for our Universe.
The idea that the universe is finite and relatively small, rather than infinitely large, first became popular in 2003, when cosmologists noticed unexpected patterns in the cosmic microwave background (CMB) – the relic radiation left behind by the Big Bang.
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If the universe is 14B yrs old and it could be 56B light years across, then why would cosmologists expect a hall of mirrors?
I find the 3-torus a rather interesting topology. What dimensional space would the 3-torus be imbedded in? How does compare with 10-D string space, 8-D twistor space, or 4-D Minkowski space-time?
I do find this idea to be quite interesting. However, it leaves a lot of questions unanswered, and in some cases contradicts itself. I don't really mean to say that it contradicts itself, but rather, a lot of "common" sense. Maybe this is just me, but if our universe was indeed "donut" shaped, there wouldn't really be a convergence point, or a "center" of the universe. If we were to build on this idea a little more then I think we could put two and two together... but for now, it's more or less a comforting idea to assume that our universe might be infinite versus an actual theory or statement.
Okay, assuming the universe is a doughnut shape--what's in the hole? A gigantic lump of dough? And is it edible?
Chuck, as far as I know, it is not necessary that a space be imbedded in another.
"The team has even been able to pin point the probable size of the Universe, which would take around 56 billion light years to cross." If it is donut shaped, how can you cross it? I have calculated the universe to be football/doughnut shaped. I have surmised that the football shaped bits stick through the donut. So I think the universe looks like a double pointed top.
I believe the universe IS donut shaped. That's because the closest 'other' universe is shaped like a giant cup of hot coffee - and we're headed straight for it.
I think Ribs and Chicken with Honey Mustard Hot Sauce is much tastier than Roasted pork with a " mango " sauce.
long long ago ,none believe our world is a ball.but it's true. the universe is mysterious,we will explore it forever.
"Okay, assuming the universe is a doughnut shape--what's in the hole? A gigantic lump of dough?"QUOTE GILL AVILA -------------------------------- --------- Hole's in our understanding are the domain of creationists.
The paper mentions that there are a limited set of orientations for the axes of the fundamental cell that provide an especially good fit to the data, but doesn't seem to elaborate much. How accurately might these be determined with the expected Planck data? Is it conceivable that any local physical process could differ measurably along one of the axes or between them? This isn't my field, but an "Asteroids" universe inspires the imagination.
Kudos to Nature for posting this very interesting article: For more on this type of universe, See: http://tinyurl.com/563rpm See: http://arxiv.org/ftp/physics/papers/0606/0606138.pdf
Anything exists beyond this 'Doughnut'? Where this doughnut hanging?
There is only one problem with this scenario. It assumes that the universe is continuous. Any scientist worth his or her Phd should know by now that continuity (infinite divisibility) leads to an infinite regress and is thus unacceptable. Worse, space itself (i.e., distance) is an illusion since its existence, too, leads to an infinite regress. I'm afraid that physicists need to reconsider some of their more cherished assumptions about reality because these kinds of conjectures about the shape of the universe are reminiscent of Star-Trek physics. This is the sort of things that undermine the thinking layman's respect for scientists in general. Nasty Little Truth About Space: http://www.rebelscience.org/Crackpots/nasty.htm#Space
So the universe is a doughnut. Does this mean God is a policeman after all?
Could somebody explain why the universe would take a 3-torus shape. ie what natural forces would make it assume that shape?
My perception: Relativity states the diameter of the universe can only be the age of the universe X the speed of light, right? Light can only travel in opposite directions from a source at the speed of light. If the universe is only about 13 billion years old, wouldn't the diameter be limited by 13 billion light years?
If the universe is 14B yrs old and it could be 56B light years across, then why would cosmologists expect a hall of mirrors? Ben Kamins Can anyone answer this? I have the same question.
Mr. Wilcox raises an important point. Assuming an age for the universe of 13 billion years, how is it that the universe can be any more than 13 billion x 2 = 26 billion light-years across? Unless, of course, matter travelled faster than light speed at some point and for some particular amount of time...which is not possible, according to Einstein. Correct? I'm confused.
Regarding Eric Wilcox's point, the answer is that expansion can exceed light speed if instead of matter being accelerated, space is being created "in between the stars".¶ The implications of this is that there is plenty of matter in this universe that we will never reach.¶ Perhaps this also addresses Ben Kamins's comment. If things were nearer in the past, perhaps we can see systems that could never see us observing their past. The hall of mirrors would occur looking 'towards' the big bang.
If the universe is shaped like the authors describe, what `s out side of the "doughnut". Can it be indirect evidence for "multiverse"?
In which pot is the doughnut kept? Or is it floating in an ocean of free energy? Lookout that it does not float into a big cup of coffee - the anti-matter universe.
For those who see a contradiction is the diameter of the universe being greater than the distance that light could travel through it (or twice that): I would like to point out that the behavior of spacetime is not limited by the behavior of the matter and energy within it. There is nothing wrong with the distance between two positions increasing faster than a beam to light can travel between those positions. In fact, I long ago concluded that in order for the universe not to need a "globally" preferred reference frame, that its size must be at least 4 times that of its ago time the speed of light. The 56B light-year diameter being discussed here is exatly that minimum size.
This is a good article that raises fundamental questions about the shape of our universe. There's nothing weird about the 3-torus shape but we need to brush up our topology before commenting here!
I've believed for about 7 years the Universe is a bit like an expanding spiral torus-genus type 1. Imagine a parking deck that spirals in an increasingly expanding 'nature' both unidirectionally(primarily) and 'outward' in the nonuniverse. Is the "hole" necessary? Not necessarily. I have created reams of paper files on my treatment of this concept. It would help explain the inflationary period of VLS of super-inflation proposed by Guth of MIT as well as WMAP asymmetries in wavelenths and temperature. When analyzed it contains portions of all the other proposed shapes as flat, saddle-shape, etc and includes holographic illusions that may 'appear' in an event approach but disappear as one crosses the 'mirage' horizon. However this in only very particular events in spacetime. Do not get sidetracked by that point. I could go on and on but with keep it finite both temporally and spatially. :)