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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."
If the universe has 12 faces what happens to you if you exactly hit a boundary between faces? Do different bits of you come out of different opposing faces? If so, where does the energy come from to break you into components?
Maybe not a big issue for a spacecraft but what happens if a neutron star hits a boundary?
http://michaelsmith.id.au
If you can infate a soccer ball and make it grow, certainly I would imagine the Universe can grow.
Maybe there is currently a finite amount of material. Who says that material can't get relatively further apart from itself? Either things can be moving away from each other occupying more space, OR the material itself, the "dots", are getting smaller and smaller making it appear we are gaining space.
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. How many mutli-player online gamers have an ever-expanding world? New levels are constantly being added.
This article is about 15 months old and discusses this in the context of 1 year of WMAP data. Since then, the WMAP 3-year data has been released. I would be curious to see how this affects the theory. I believe that the WMAP 3-year data gave something like Omega = 1.010 +/- 0.001. Thus this theory seems to balanced on the knife edge. It's an interesting idea, but I have my doubts.
Soccor Balls are not dodecahedra. They're truncated icosahedra.
Hmm.. just counted the edges on a d12. Maybe there are 30 after all.
Software patents delenda est.
I do not know the details of this, but I strongly suspect that the universe is still continuous in this model. In that case things are set up so that if you hit a boundary between two faces, then the two corresponding faces that you come out of are also adjacent, meaning that you would not notice that you have hit a boundary. Possibly the faces are just a way to explain what is going on, and there would not need to be any actual boundaries that could be detected.
Bjarke Roune
The freaky thing is that the dodecahedron has been associated since ancient times as representing "the Universe".
l
http://www.kheper.net/topics/cosmology/solids.htm
We know where leadership by an anti-intellectual "strongman" who scapegoats minorities and likes boisterous rallies goes
#1) Respect the privacy of others. #2) Think before you type.
I've always wondered if you raised a kid the right way if he would be able to have a quantum intuition. I mean, despite not being known directly to me, having been taught very early in my life about (the classical model of) atoms makes them seem intuitive, even though I would imagine they would not be to someone 500 years ago.
Of course, it might all be wasted if our final Theory of Everything has a new way of looking at quantum effects. Which I, personally, think it will. My personal candidates include Bohm's interpretation (which goes a lot deeper than Wikipedia will tell you; see Wholeness and the Implicate Order's later chapters for details), Heim theory, loop quantum gravity, and string theory. But I am fairly confident that at least the last of these, and probably all of them, will not survive in their current forms; they will have to merge and evolve first. (IANAP, but IAA Caltech undergrad planning on majoring in/doing research in physics for what that's worth.)
"May the days be aimless. Let the seasons drift. Do not advance the action according to a plan."
Strangely the boundary between 2 faces is actually shared by 3 faces. Here's a figure of it. See for example how the edge "g" is a boundary between faces IV and V, faces V and VI, and faces VI and IV.
The answer is always 42, you can't argue with Douglas Adams.
BTW: Put down the slide rule, you just need to realise every edge has exactly two adjacent faces.
And did you exchange a walk on part in the war for a lead role in a cage? - Pink Floyd.
Hm. That's an interesting idea. One of the articles at that site includes the observation that such a simulation wouldn't have to simulate everything down to the greatest level of detail at all times, but could conserve computing power by just simulating things that are under direct observation.
Isn't that what actually happens in quantum-level experiments? If we are observing the double slits, the photons do one thing, but if we're not watching the slits, they do something else?
The issue of "what is the soocer ball contained in?" is answered by the fact that the soocer ball is the universe, ie. All of space and time. Space doesn't exist outside the universe, therefore there is no need for the universe to be contained in anything.
...and that is all I have to say about that.
http://jessta.id.au
I think the word I'm looking for is hypercube, but I mean to apply it to the number of sides a dodecahedron has.
Going through one side will result ending up coming through another side. (Anyone ever have dreams of being stuck in a room, you go through the door, only to end up in the same room as before?)
Picture yourself in an empty room like this. You can see through the sides, and you see yourself like in a hall of mirrors. You pass through the walls only to end up in the same room.
Imagine release millions of tiny superballs, which we will call photons, in the room. Now, imagine there is another object, a big round object in the room, that isn't moving to start with.
All these superballs going in every single direction start bouncing off you, pushing you around. However, since there were few, if any, superballs between you and the big round object to begin with, there is less "pressure" inbetween you and the object, so the superballs on the outside push you towards it.
The big round object is moving slower as the superballs bounce off of it because it has more mass, however, you are pushed towards it ever quicker. More and more, you fall faster and faster towards it.
"Paging Mr. Dick, Paging Mr. Phillip K. Dick, you have a visitor at the front desk."
An individual with a quantum-intuitive understanding of the world might be very difficult for the rest of us to recognize. Such a person would have a lot of trouble perceiving cause and effect in the way we do, and would probably have no concept of determinism or even certainty. They would be able to see more dimensions than us (if such theories are physical), and would be unable to correlate these dimensional relations to objects within our understanding: if you are a sphere, you can describe yourself to a plane by saying "I'm a bunch of circles," but this really is incomplete and the plane really would be hopeless to have a complete understanding of you. Such a person may appear at times clairvoyant or at least extremely intelligent, but much of the time incoherent and simply apart from the human race.
In short, such a person would either be autistic or the Mua'Dhib. Read PKD's "Martian Time-Slip" or "Dune" for examples of people with quantum knoweldge or understanding, and how is basically makes them appear mad much of the time.
Don't blame me, I voted for Baltar.
I seem to remember a speculative fiction novel in which the protagonists are on a ramscoop ship whose drive goes funky and won't shut down. (it's lurking on my shelves somewhere; but I cannot remember the title yet)
Long story short: they keep increasing in speed, ever nearer 'c' (the scoop field strengthening with the increasing speed so they don't collide or get fried), and eventually end-up 'wrapping around' the universe and seeing how things have changed each time they pass certain galaxies/clusters (time dilation helps here). As the wrapping progresses, they also notice all else 'cooling down' and regressing back to Origin where there is eventually another 'big bang', they get their drive fixed and start to slow down, and ultimately (conveniently) find an earth-type planet to land on.
Sound familiar to anyone?
"It's time to take life by the cans." ~ Bender ("Bendin' in the Wind", ep. 3-13)
"Asteroids" the video game takes place on a toroidal surface. You go in any one direction and eventually come back from the direction you were heading away from. The "torus", if considered as a 2D surface embedded in 3D space, can have its hole in the yz plane, the xz plane, or any plane really that contains the z axis, perpendicular to the screen. Within the 2D space defined by that donut surface, the orientation of the hole in the higher 3D space has no observable effect. Pac-Man, for its part, can be considered to have taken place on the surface of a cylindrical 2D surface embedded in a 3D space, not necessarily a toroidal one, since there was no magic tunnel connecting the top and bottom of the maze.
This is different: "an object that travels away from the Earth in a straight line will eventually return from the other side of the universe, having been rotated by 36 degrees in the process". So, it's just like Asteroids except the ship is pointing in a crooked direction when it reappears, off by some predictable angle. This would be a real problem for a game like Pac-Man, because of the way the controller works. Asteroids could accomodate the situation rather easily since left and right in that game control rotation instead of absolute direction, and applying continual thrust will keep the ship going straight even if it comes back with a cockeyed trajectory. Also, the maze and controller in Pac-Man, entirely based on NSEW directions, would present real headaches. Asteroids has no maze and the ship can point in any arbitrary direction, not just four.
The minimum radius of the soccer ball (according to this group) is 43 billion light years. The Big Bang was 13.7 billion years ago, but the actual horizon is 53 billion light years and not 13.7 billion since the universe wasn't always this big and the first few light years covered by the earliest photons have expanded to have a large contribution to that 53 billion. This little detail would present a challenging user interface problem for Asteroids. Now that I think about it, that might be less lame than the original Asteroids.
From any vantage point the furthest radiation visible is the microwave background. Beyond that, the light would have had to have been emitted earlier, at a time when the universe was more opaque. (Charged particles had yet to combine and emit background-radiation to form neutral, transparent matter less efficient at scattering light.) Past the microwave background, we "see" the early universe along all lines of sight as a completely opaque, black sheet, which emits no light of its own, absorbs all light, and which lines the boundary of what is for us the observable universe. It's like, how much more black could this be? and the answer is none. None more black. But these guys are saying that since 43 is less than 53, you can see the same patterns of microwave background radiation being emitted from various points in the sky, inside this opaque layer, in a pattern consistent with this dodecahedral symmetry. It's like God really does play dice, except he plays with those geeky 12-sided Dungeons and Dragons dice. Stuff like this has to make you wonder. Why 12? Who ordered that? What would have been wrong with a flat, spherical, tetrahedral, cubic, octahedral, or icosahedral universe? From a video game design perspective, a cubic symmetry would have been so much easier. In my humble opinion, God should have seriously considered creating a six-sided universe instead.
Even if you could reach the "edge", it's not like you would even notice anything, like a lot of these posts seem to be assuming. You wouldn't hit some sort of wall and go "splat". You'd just sort of relocate, rotate, and keep chomping away obliviously like Pac-Man does when he does his thing. We have no evidence that some anisotropy exists in the topology of the universe everywhere but here as if the universe really is centered on us and our galaxy, so that it changes somehow within a sphere that surrounds us. There's most l