Is the Universe a Hall of Mirrors?

PhysicsWeb is running an article by one of the researchers who has developed the theory that the universe may be finite, rather small, and soccer-ball shaped. The question is still open; it's one theory that fits cosmic microwave data from the Wilkinson Microwave Anisotropy Probe (WMAP). Apparently testing the theory by looking in the indicated way through the WMAP data would so far be computationally prohibitive. From the article: "The Poincaré dodecahedral space can be described as the interior of a 'sphere' made from 12 slightly curved pentagons. However, there is one big difference between this shape and a football [soccer ball] because when one goes out from a pentagonal face, one immediately comes back inside the ball from the opposite face after a 36 degree rotation. Such a multiply connected space can therefore generate multiple images of the same object, such as a planet or a photon. Other such well-proportioned, spherical spaces that fit the WMAP data are the tetrahedron and the octahedron."

Comments

Old Article

[Epicyon]

The article mentioned is well over a year old. The outstanding analysis of data due in 2004 has been completed. The validity of the information is being questioned Although it would be fun living inside a football.

Re:Old Article

[krymsin01]

Just to point out something that might be obvious if you look around the website you linked a bit more, that particular guy doesn't know what he's talking about.

For instance, witness this "debunking" of curved space, also from his site:

Curved Space: The concept of a 'curved space', which is essential for present cosmological models, is logically flawed because space can only be defined by the distance between two objects, which is however by definition always given by a straight line. Mathematicians frequently try to illustrate the properties of 'curved space' through the example of a spherical (or otherwise curved) surface and the associated geometrical relationships. However, a surface is only a mathematical abstraction within the actual (3-dimensional) space and one can in fact connect any two points on the surface of a physical object through a straight line by drilling through it.
Strictly speaking, one can not assign any properties at all to space (or time) as these are the outer forms of existence and it makes as much sense to speak of a 'curved space' as of a 'blue space'. Any such properties must be restricted to objects existing within space and time.
The concept of a distorted space around massive physical objects for instance, as promoted by General Relativity, is therefore also inconsistent and should be replaced by appropriate physical theories describing the trajectories of particles and/or light near these objects.

Re:Finite things can grow

[IWannaBeAnAC]

Who says that material can't get relatively further apart from itself?

Of course it can, and the universe is expanding in exactly this way.

Isn't there a multi-big bang theory that states that new material can enter our Universe in this fashion? Perhaps our current Universe had no single beginning, but new stuff is being added to it all the time.

The steady-state theory proposed that new matter was being created all the time, at a very slow rate. This was disproved by the cosmic microwave background, that instead agrees exactly with the preductions of the big-bang theory. I think, the inflation theories allow new material to enter at any time, but the idea there is that the initial expansion of the universe was so fast, that any other matter (say, from another big-bang) would be so far away that it would not ever be possible to detect it. But if the universe is finite, and it is possible to see the periodic boundaries, then surely it disproves inflation? cosmologists out there?

Re:Simulation?

[Troed]

Yes, maybe it's even likely.

http://www.simulation-argument.com/

Re:Everyone knows the TRUE shape of the universe..

[osu-neko]

Err... the edges are shared, so there are less than 30. I'm trying to figure out the exact number but my maths is too stale.

No, the exact number would in fact be 30. The edges are indeed shared, which is why there are less than 60 (5 * 12) edges.

Obligatory reference

[12357bd]

'The Road to Reality' (Roger Penrose) http://www.amazon.com/Road-Reality-Complete-Guide- Universe/dp/0679454438/
Great discussion about physics laws and math, one of the bests titles of Mr Penrose, and yes, the ' dodecahedral/tetrahedral/octahedral space' possibilities are also explained from the ground up.

Re:if it is finite than what is holding it?

[Coryoth]

You're essentially correct, under this model you end up with a continuous space. Perhaps the easier way to see how it works is with a simpler example like a torus: you can make a torus (donut shape) from a flat piece of paper by first rolling it up into a tube (identifying the top edge with the bottom edge) and then looping the tube around (identifying the two ends of the tube with each other). Thus you can think of the flat piece of paper as a torus by imagining that when you pass off the top edge you appear at the bottom edge, and when you pass off of one side you appear on the other. Now, what happens at the corner (the equivalent of an edge of the dodecahedron)? A quick check and you'll see it all works out: in some sense you might be "broken up" with half of yourself on one side of the paper, and half on the other, but remember those sides are connected together, so so are you.

The same trick works with the dodecahedron, you just have to get the identification of faces right. On passing out through a fae you'll appear on the opposite face, rotated. Take a quick look at a dodecahedron (here's an example that is translucent and rotatable so you can look around) and you'll get the idea. Looking through the dodecahedron from one face you can see the opposite face doesn't align: it's at an angle - hence the rotation. Visualsing where you'll come out as you approach an edge (and where the other face of that edge will result in you appearing) you'll see that the whole thing in indeed continuous; the edges present no problems.