OT - Shape of universe

[QuikSand]

Interesting read, for those interested in this sort of thing:

Universe Shaped Like Soccer Ball?

There are a few quotes from here that led me in one inevitable direction:

Imagine a sheet of paper with the left and right edges rolled toward one another to make a cylinder, Weeks suggests. Suppose you could shrink and stand on the paper. Start at the seam and walk west in a straight line.

“Nothing funny happens along the way.” Weeks says. “Then lo-and-behold you’re back at the starting point and surprised to be there.”

Now if you could roll the sheet of paper in two directions — without the inevitable crumpling — so that things moving off the top would appear at the bottom, then you’d have created a universe much like the one Weeks and his colleagues imagine.

The real universe is more complex than a sheet of paper, of course.

Okay... that description is fine (and thanks for that oh-so-helpful clarification at the end). But, for my generation, I keep thinking that this is more trouble than we need you to go to. All we really need is for you to say something like this:

"Atari had it right."

All those games like Combat and Asteroids, where you could just fly off the right side of the screen and re-appear on the left... at the time, we thought they were just silly, but perhaps now science is catching up with Atari. Nolan Bushnell, we hardly knew ye!

[cthomer5000]

As my brain says "What am I supposed to do with this information?"

Absolutely fascinating stuff. I've always thought that the creation of the universe was the only thing truly impossible to imagine for a human mind. My brain literally cannot understand the thought of something (the universe) being created out of nothing.

Now, add in the potential for Asteroid-style "boundaries" to the universe and I have to spend the rest of the day wondering what life is really all about.

[Fonzie]

This is pretty amazing stuff, and I too find it hard to get my head around some of this. Unfortunately it appears that the "soccer-ball"universe theory is about to be proven incorrect, which is too bad as I think QuikSand's "Atari" metaphor is quite elegant. Alas, it's use may have to wait for future theories.

From The New York Times (I copied the entirety of the text here for those without NYT access) :

Cosmic Soccer Ball? Theory Already Takes Sharp Kicks
By DENNIS OVERBYE

Published: October 9, 2003

In an unusual logjam of contradictory claims, a revolutionary new model of the universe, as a soccer ball, arrives on astronomers' desks this morning at least slightly deflated.

In a paper being published today in the journal Nature, Dr. Jeffrey Weeks, an independent mathematician in Canton, N.Y., and his colleagues suggest, based on analysis of maps of the Big Bang, that space is a kind of 12-sided hall of mirrors, in which the illusion of infinity is created by looking out and seeing multiple copies of the same stars.

If the model is correct, Dr. Weeks said, it would rule out a popular theory of the Big Bang that asserts that our own observable universe is just a bubble among others in a realm of vastly larger extent. "It means we can just about see the whole universe now," Dr. Weeks said.

But other astronomers, including a group led by Dr. David Spergel of Princeton, said a continuing analysis of the same data had probably already ruled out the soccer ball universe. They promised to post their results soon on the physics Web site arXiv.org/list/astro-ph.

"Weeks and friends are making a dramatic claim, perhaps one of the biggest science stories of the century," said Dr. Neil Cornish, a physicist at Montana State University, "but extraordinary claims require extraordinary support."

For now, the two groups, who have been in intense communication the last few days, disagree on whether the soccer ball universe has been refuted. What is amazing about this debate, they all agree, is that it will actually be settled soon, underscoring the power of modern data to resolve issues that were once considered almost metaphysical.

"This is what got Giordano Bruno burned at the stake," said Dr. Max Tegmark, a cosmologist at the University of Pennsylvania. "Is space infinite or not?"

In Nature, Dr. Weeks and his colleagues write: "Since antiquity, humans have wondered whether our universe is finite or infinite. Now, after more than two millennia of speculation, observational data might finally settle this ancient question." The other authors are Dr. Jean-Pierre Luminet of Paris Observatory; Dr. Alain Riazueleo of the French atomic energy center CEA, in Saclay, France; Dr. Roland Lehoucq of the Paris Observatory and CEA; and Dr. Jean-Phillippe Uzan of the University of Paris.

The evidence for and against a finite universe resides in a radio map of the baby universe produced last February by a NASA satellite, the Wilkinson Microwave Anisotropy Probe. It shows that 400,000 years after the Big Bang, the event in which space and time emerged, the universe was laced with faint waves and ripples, which are the origin of modern galaxies and other cosmic structures. In an infinite universe, according to theory, waves of all size should appear in the sky, but in the Wilkinson data there was a cutoff: no waves larger than about 60 degrees across appeared in the sky.

If the universe were a musical instrument, it would be inexplicably missing its low notes, perhaps, some cosmologists have suggested, because it is too small to play them. The universe is finite rather than infinite, they speculate. Like a violin that cannot produce deep cello notes, the universe cannot produce waves larger than itself.

In such a universe, if you went far enough in one direction, you would find yourself back where you started, on the other side of the universe, like a cursor disappearing off the left side of a screen and reappearing on the right.

One simple example of this is a torus, or a bagel shape, which is what you get when you wrap the left and right and top and bottom sides of the screen around so that they meet.

In the Nature paper, Dr. Weeks and his colleagues propose that three-dimensional space has 12 sides, like a soccer ball, or more technically a dodecahedron. This model would fit with the cutoff of large waves observed in the Wilkinson satellite data. Each face is "glued" to its opposite number. (Don't try this at home.) A spaceship crossing one face or panel of the soccer ball would enter the other side of the ball. After traveling 74 billion light-years it would find itself back where it had started.

While the lack of cosmic low notes is suggestive, cosmologists say there is a definitive test of finite universes in the Wilkinson map. When the cosmic radiation intersects the edges of the universe, it would make identical circles, like a balloon squashed in a box, on opposite sides of the sky. In the case of a bagel, there would be two circles in the map, on opposite sides of the sky. In the case of Dr. Weeks's dodecahedron, there would be six pairs of circles, each about 35 degrees in diameter.

"This is a much higher bar to clear," Dr. Cornish said.

Dr. Tegmark said: "What's nice is it's so testable. It's the truth or it's dead. The data is even out there, on the Internet. It's just a question of sifting through it."

But so far the circles have not showed up.

Earlier this year, Dr. Tegmark and his wife and colleague Dr. Angelica Oliveira-Costa, Dr. Mattias Zaldarriago, of Harvard, and Dr. Andrew Hamilton of the University of Colorado, searched the Wilkinson data for oppositely matched circles. The results, they said, ruled out the possibility that the universe was shaped like a bagel, no doubt disappointing New Yorkers who would like to have imagined a cosmic connection with their breakfast.

Dr. Tegmark said that the results also ruled out Dr. Weeks's dodecahedron. "We ought to have seen those circles in our study," he said.

Meanwhile, a more thorough analysis of the data, looking for all possible circles, has been undertaken by Dr. Spergel, who was part of the original Wilkinson team, Dr. Cornish, and Dr. Glenn Starkman of Case Western Reserve University in Cleveland. The study, about two-thirds complete, had already eliminated many simple models of so-called "small universes," including a dodecahedron when the Nature paper hit their desks last week, Dr. Spergel said.

"No soccer ball, no doughnuts, no bagels," he said.

But Dr. Weeks said there were potential gaps in the circle search methods. For one thing, if the dodecahedron were slightly larger, he said, the circles would be smaller and would not show up in Dr. Spergel's search. But until all the papers are posted on the archive or published where everybody can read them, these claims cannot be evaluated.

Dr. Weeks said that astronomers from both teams would join this fall to test the circle search, using simulated data. If the models are false, they could be ruled out as early as November, he said.

Dr. Cornish said that, although it was the scientific community that would ultimately decide, his team was confident of its results. "I don't see any wiggle room," he said.

But because it is such a "truly spectacular claim," he said, they are planning in the next few days to run a special test focused on the particular model. The test could detect very small circles. "We can push it to where there's no chance," Dr. Cornish said.

The prospects for the finite universe, he added, look bleak.

The stakes for cosmology, should the soccer ball or some other variety of small universe prevail, are not small at all. A small universe, everybody agrees, would present severe problems for the prevailing theory of the Big Bang, known as inflation, which posits that the cosmos underwent a burst of hyperexpansion in its first moments.

Moreover, Dr. Weeks said, a small universe would eliminate one popular variant of the theory known as eternal inflation, in which bubble universes give rise to one another endlessly in what some cosmologists call a "multiverse."

"This puts the whole universe in view," he explained. "It wouldn't rule out other universes. There could be others. They would be totally unrelated, without any contact between them."

--------------------

I'm still pulling for the doughnut-shaped universe, if only because of my love of Homer J. Simpson.

[Cringer]

My simple-minded take on he universe......

IT'S REALLY REALLY REALLY BIG!!!! And i won't see 1% of it in my life.

[Karim]

I can't visualize a finite universe. No matter exists on the other side of the finite boundary? That's hard to understand. As strange as the concept of infinity is, it seems more applicable when applied to the ideas of the universe.

[John Galt]

I remember studying math in 4+ dimensions in high school and what these scientists seem to be describing is a hyper-sphere (a four dimension sphere). Hyper-cubes are usually easier for people to grasp, and they have some of the looping type effect. It is also pretty easy to draw and visualize a folded or unfolded hyper-cube, but a hyper-sphere was always the most confusing to wrap your mind around. Anyway, when I have time I want to read more to see if anyone is talking about this in terms of 4 dimensions (or maybe I'm just crazy).

[EagleFan]

Great, I had a headache going into this and this sure didn't help. I finally stopped reading when I thought to myself "How will either theory being correct change my life?".

I have to say infinite, it's really the only thing that can truly be comprehended when talking about the universe. Of course those scientist have found one hell of a scam, take large government grants to try to 'prove' something that will never be really known. This planet, and everyone on it, will be long gone by the time we ever get remotely close to knowing how the universe works.

[Fonzie]

I know how the universe works!


But I'm not telling.

[Drake]

Believe nothing that Dr. Jean-Pierre Luminet says. He's a noted Freemason and Occultist and is partially responsible for the French Government's cover-up at Rennes-le-Chateau.

[cthomer5000]

Originally posted by Karim
I can't visualize a finite universe. No matter exists on the other side of the finite boundary? That's hard to understand. As strange as the concept of infinity is, it seems more applicable when applied to the ideas of the universe.

Agreed. My brain tells me that naturally there would have to be something on the others ide of the universe...

Amazing how it's easier to accept the thought of inifinity in this case.

[Fonzie]

Originally posted by cthomer5000
Amazing how it's easier to accept the thought of inifinity in this case.

I find it easier not to think of Journey albums at all.

I agree that thinking about these cosmological concepts too much makes my head spin. So much so that sometimes I suspect our universe is but a tiny bubble in a test tube-based chemistry experiment conducted by some super-gigantic 6th grader. And one of these days he/she/it will get bored with this experiment and flush us all down the drain.

[Daimyo]

I think when they say the universe is finite it doesn't mean that there is nothing on the other side of the "edge," just that it is impossible for information (or anything else) to cross that boundary. Sort of like how there may have been events before the Big Bang, but there would be no way to determine what they were because no information could have possibly survived it.

[Drake]

Originally posted by Daimyo
I think when they say the universe is finite it doesn't mean that there is nothing on the other side of the "edge," just that it is impossible for information (or anything else) to cross that boundary. Sort of like how there may have been events before the Big Bang, but there would be no way to determine what they were because no information could have possibly survived it.

Believe nothing that Daimyo says. He's a noted Freemason and Occultist and is partially responsible for the French Government's cover-up at Rennes-le-Chateau (too).

[Karim]

Originally posted by Daimyo
I think when they say the universe is finite it doesn't mean that there is nothing on the other side of the "edge," just that it is impossible for information (or anything else) to cross that boundary. Sort of like how there may have been events before the Big Bang, but there would be no way to determine what they were because no information could have possibly survived it.

Then it isn't really finite? We intuitively know that there is something beyond this "boundary", but we just can't access it.

I remember hearing we can describe the nature of the universe (in terms of gas composition, etc.,) nanoseconds (or better) after the Big Bang, but can't get to that starting point (assuming it is the starting point).

No matter how far back you go, there is always something before it. Something initiates every event. It's the only way my puny brain can make any sense of it.

Of course, humans may not be able or supposed to decipher the secrets of the universe.

[QuikSand]

I think that part of the problem is that when scientists use the word "universe" we tend to think more in terms of what might be called "existence." Therefore, we start asking questions about the "there" on the other side of the boundary of a finite universe... without being able to reconcile that there simply is no "there" within the finite system being described. It certainly can make your hair hurt.

[sabotai]

"I think that part of the problem is that when scientists use the word "universe" we tend to think more in terms of what might be called "existence." "

I think another part is that people try to equate the shape of the universe with a known shape like a soccer ball or sphere or whathaveyou (when in reality, they (the scientists) use those terms to try to analogize (is that a word?) what they are finding with a physical, known thing). And so people start talking about the "edge" or "boundry" of the universe when we have no idea if there is an physical boundry or how it "works"...people think "Soccer ball...so the universe is inside the soccer ball, what's outside of it?"

God damn I'm so bad at explaining this astrophysics stuff...I hope I made some sense.

[Fonzie]

Sabotai -

I think what you're getting at is a fundamental problem in cosmology - how does a brain that's evolved to process information in ways relevant to our immediate, three-dimensional earth-based environment try to explain very, very extraterrestrial phenomenon? The answer is, as you suggest: by analogy. Or I should say that the few minds who might understand this stuff for what it is try to explain it to the rest of us by analogy, and something gets lost in the process.

Usually what gets lost is me, unfortunately.

I suspect that the people receiving the analogic (analgesic?) explanation bring the assumptions of the phenomenon they understand along when they try to understand the new phenomenon. Thus the notion of a universal boundary and whatnot. Is what I just said what you were trying to say? Sorry if I was being repetitive.

I love this mind-bending stuff, but sometimes my mind gets a bit too bent, especially when they start talking about 12-dimensional space with 8 of the dimensions curled up into little "loops" and multiverses and such. Yeesh.

[CHEMICAL SOLDIER]

bump

[Fonzie]

Originally Posted by CHEMICAL SOLDIER

bump

Hey now - I had a perfectly good threadkill there. Why'd you have to go and ruin it?