Is the Universe a Hall of Mirrors? 395
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."
This is silly (Score:3, Funny)
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Not a chance man. If it was, the elephants would have eaten it already.
Re:This is silly (Score:4, Insightful)
No, that would be if it were peanut shaped.
Monkeys would eat a banana shaped universe. And there just may not be enough monkeys far enough back in time when the universe was small for them to eat it.
Re:This is silly (Score:4, Funny)
>> eaten it already.
> No, that would be if it were peanut shaped.
> Monkeys would eat a banana shaped universe. And there
> just may not be enough monkeys far enough back in time
> when the universe was small for them to eat it.
Whether space-time is infinite, or finite but spheroidal (space-time circling back on itself), the effect is the same: any number of monkeys has the effect of an infinite number of monkeys. A banana shaped universe would be eaten by them, and not exist, but then they would not and so could not eat it. Paradox. Or so the traditional physical thinking would go. But you can't have the paradox occur until some time during the first go round. For the paradox to occur, as it must given the infinities, the first universe must exist. The infinite number of monkeys must even now be eating the universe. While doing so they are generating an enormous amount of waste in the form of metabolized entropy, which is information. I offer as evidence a Google search for "a" resulting in "about 6,560,000,000" hits, as well as the volume of
The counter argument that something must be informative to be information is obviously flawed, as the evidence shows that non-informative
The counter argument that we are not monkeys, whether finite or infinite, is an argument regarding evolution, and is off topic here. It would be moderated out of existence, but the moderation would be generative information replacing it, supporting the first assertion against counter argument.
On the other hand, elephants eat bananas too.
On the gripping hand, turles eat neither bananas nor peanuts. This accomplishes in one sentence reference to two different science fiction entities, the geek value of which makes it appropriate to
You may all now resume typing. We have a long way to go. I'll start.
"What a piece of work is Man,..."
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Bable Fish translation ... (Score:4, Funny)
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Re:Bable Fish translation ... (Score:4, Funny)
Everyone knows the TRUE shape of the universe... (Score:5, Funny)
Re:Everyone knows the TRUE shape of the universe.. (Score:5, Funny)
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I have a +8 turd of bullshit artistry. If I win a battle against a coprophiliac, how much bullshit do I have left?
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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.
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BTW: Put down the slide rule, you just need to realise every edge has exactly two adjacent faces.
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Damn it, Wesley! Stop playing with static warp bubbles.
Re:Everyone knows the TRUE shape of the universe.. (Score:2)
Simulation? (Score:2)
If our universe resembles a video game, could it actually be a video game?
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World peace can be achieved by transferring to a carebear universe
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Re:Simulation? (Score:5, Insightful)
That logic is fallacious, even if the observable universe is a "simulation", then this simulation runs inside a real universe, and we're at the start again figuring out what the universe is.
Plus I subscribe to another logic: if the universe is similar to a video game, then it's because as video games increase in complexity they start to approach the model of a little universe
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Re:Simulation? (Score:4, Insightful)
If we live inside a simulation, then, to us, that simulation *is* the universe. What lies "outside" of it can only be determined if the creators of such a simulation wanted us to do so. Is it possible for a video game character to leave a computer game and enter the real world (or at least what we consider to be the real world)? Only through the intervention of it's creators (i.e. us). The same would occur if we ourselves are constructs of a simulation.
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Amazing how many armchair philosophers come out of the woodwork when a movie has kung-fu and guns in it.
Re:Simulation? (Score:4, Informative)
http://www.simulation-argument.com/ [simulation-argument.com]
Re:Simulation? (Score:5, Interesting)
Hm. That's an interesting idea. One of the articles [simulation-argument.com] 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?
Finite things can grow (Score:3, Interesting)
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.
Re:Finite things can grow (Score:4, Informative)
Of course it can, and the universe is expanding in exactly this way.
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?
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That's incorrect. While it is impossible for something with mass to move faster than the speed of light, if you and I are five feet apart, and we each move away from each other at seventy-five percent of the speed of light, eventually we will no longer be able to see one another, because the photons bouncing off of you will, from my frame of reference, be moving too slowly to ever catch up.
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No, that is completely incorrect. The whole point of Relativity is that nothing can exceed the speed of light, in any frame of reference. The situation that you describe, where Newton's laws of motion would imply the relative speed of the two observers is greater than the speed of light, never occurs because instead the passage of time is affected by the motion. If you had a clock, and were transmitting to me what the current time was, your clock would appear to me to be running too slow. And vice vers
Re:Finite things can grow (Score:4, Insightful)
First, think of good old Zeno's paradox (well, one of them), where you have Achilles chasing a tortoise. The tortoise has a head start. When the starting gun sounds, Achilles crosses the short distance to the tortoise's starting position quite quickly, but when he arrives he finds that the tortoise has moved on. So he crosses this short distance even more quickly, only to find that the tortoise has moved a tiny bit further. And so on ad infinitum. Zeno concluded that Achilles could not catch the tortoise, but since we can easily observe that any person can catch the tortoise, Zeno called this a paradox.
Now, Zeno's paradoxes really aren't worth that much, it turns out. However, now let's put a jet pack on the tortoise. This jet pack is constrained to never let the tortoise move as fast as Achilles can run (don't ask how), but it will perpetually bring the tortoise closer and closer to Achilles' speed. Now, Achilles runs to the tortoise's starting position, and finds the tortoise has moved on a short way. So, he then looks at the tortoise's new position, and runs to that position. The tortoise now has a new position, so Achilles runs to there. In the original scenario with constant speeds, the time it took Achilles to reach each new position was smaller, in fact greatly smaller. The times form a geometric series, which converges nicely. However, with this supercharged tortoise, Achilles finds that the times to catch up do not form a convergent series. That is, the total time for Achilles to catch the tortoise diverges, or is infinite.
Now let Achilles be a photon, and let the tortoise be a spaceship. The spaceship has an unlimited amount of fuel, and can keep up a constant acceleration for as long as the pilot likes. So, the pilot looks out his back window, and sees nothing. The photons behind him (well, the ones that started far enough away that is) can never catch him. It looks like there is a black hole following him. In fact, what with the equivalence of acceleration and gravity, from the astronaut's frame of reference, there IS a black hole following him! Of course, if he gives up trying to escape it, and just lets himself fall back into it, then he stops accelerating, the photons can catch up, and the black hole disappears.
So, the GP was wrong. But the parent isn't completely right either, unless his "unless they pass the event horizon of a black hole" was intended to include accelerational black holes like this.
My example was taken (in essence, not in text) from Nigel Calder's Einstein's Universe, an excellent book if you're bored.
Re:Finite things can grow (Score:5, Funny)
Ahh, you are referring to the Gang Bang theory?
Gravity (Score:4, Interesting)
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.
How the Universe Got Its Spots (Score:5, Insightful)
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As if the book is the final authority in making those questions go away. We need to keep asking the "nonsensical" questions, because sometimes we end up with new answers.
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Oh, great. Nooooooow you tell me.
KFG
Old Article (Score:5, Informative)
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Re:Old Article (Score:5, Informative)
For instance, witness this "debunking" of curved space, also from his site:
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.
Running with it (Score:5, Funny)
soccer-ball shaped
I think these cosmic topologists are going to have to kick this theory around for a while before they achieve their goals.
WMAP 3-Year Data? (Score:5, Interesting)
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.
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Fuck it, then.
CAN'T YOU SEE THAT CUBE IS TRUTH???!!! IGNORE ME AND DIE!!!
Re:WMAP 3-Year Data? (Score:4, Interesting)
Seriously, though, I understand something about these topics, and a) I wouldn't be surprised at all if that knifepoint was where the damn value stayed for another decade or so, seeing as Nature (the bitch, not the magazine) seems to quite enjoy placing these geometry-of-space constants so close to the critical values that we can't say a thing for sure. b) is that it's a cute theory and an interesting geometry, but frankly I haven't seen anything so far that convinces me that it's right.
But either way, you're correct - this does not appear to be crackpot stuff (I haven't read the peer-reviewed article, but I'll trust that it's there). You can always tell, because the real loonies always talk about how wrong Einstein was.
Timecube sig:
Ignorance of 4 days is evil, Evil educators teach 1 day. 1 day will destroy humans.
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But I was trying to yell.
Einstein was right... (Score:5, Funny)
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It's called soccer, because the players wear soc...uh never mind.
Soccor Balls (Score:4, Interesting)
Not mirrors (Score:3, Funny)
The shape of the universe is (Score:3, Funny)
Fascinating stuff, but rotten analogy (Score:2)
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no, only academia (Score:5, Insightful)
It's probably best not to have a firm opinion on the shape of the universe until a lot more data is in.
Re:no, only academia (Score:4, Insightful)
Would not surprise me. (Score:2)
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History (Score:5, Interesting)
http://www.kheper.net/topics/cosmology/solids.htm
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1: "Guys... We need a theory. Our funding is gonna get cut."
2: "What about the shape of the universe, that hasn't been done for a while?"
1: "What's Google say?"
2: "Hmmm..." http://www.google.com/search?q=shape+of+the+univer se+dodecahedron+-wmap&btnG=Search&hl=en&lr= [google.com] (Because WMAP is the only other reference that says this, I removed it from the search.
2: "Dodecahedron. But there's no proof, and it's an ancient myth-thing."
1: "I think we could prove that
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BTW: Your point numbering system is as fucked up as that old funding "joke".
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So... just how "real" is this theory, anyway? (Score:2)
Any insight from the physics nerds? Is this just a way of dealing with all the (so far
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It's beginning to look a lot like Christmas!
On the subject of universe topology: (Score:2)
What was the name of that short story about a guy that was driving his car round a particular mountain bend and accidentally finds a tiny pocket universe?
Anyone remember?
I've been reminded of it by this story and now I NEED TO KNOW, dammit.
Obligatory reference (Score:5, Informative)
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? (Score:5, Insightful)
As to what this soccer ball universe could floating in, well, the question itself is probably the largest issue. We don't know the answer, but the it could very well be that there is no "outside of the soccer ball". The universe could be all that there is. There could be no "beyond" the universe or "outside" of the universe. It is hard concept to visualize, but that is pretty much true of any concept that outside of the traditional Newtonian world.
Once you leave the safe world of Newtonian physics you need to develop a superhuman ability to try and NOT visualize the universe on the grand scale of the quantum scale. Human intuition and visualizations is was built for Newtons world. Once you leave that world, it breaks down and fails to be much help.
Re:if it is finite than what is holding it? (Score:4, Interesting)
Maybe not a big issue for a spacecraft but what happens if a neutron star hits a boundary?
Re:if it is finite than what is holding it? (Score:5, Interesting)
Re:if it is finite than what is holding it? (Score:5, Informative)
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 [mathsisfun.com]) 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.
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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 (tim
Re:if it is finite than what is holding it? (Score:4, Insightful)
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The fact that two particles that were very close to each other before they entered separate tubes has no bearing at all on how far they will be after they enter the tubes.
Well, they will at no point be further away then ct where c is lightspeed and t is the time elpased, even if they traveled trough different "tubes".
basically, every "mirror" particle has to be accounted for, including the infinite copies of the particle itself
There is only one particle. One might think that because of the mirrors there are an infinite amount of particles because one can "see" an inifinte amount of them but this is no different from standing in a mirror-room, there are no extra copies of you even tough you see loads of them.
It may have great bearing on the details of the force laws that they interact under
I agree on this one.
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You trip... (Score:3, Funny)
Re:You trip... (Score:5, Funny)
Re:if it is finite than what is holding it? (Score:5, Interesting)
Re:if it is finite than what is holding it? (Score:5, Funny)
I knew it! The universe is shaped like a game of Pacman. I didn't waste the 80s on nonsense time-wasting after all.
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Once you leave the safe world of Newtonian physics you need to develop a superhuman ability to try and NOT visualize the universe on the grand scale of the quantum scale. Human intuition and visualizations is was built for Newtons world. Once you leave that world, it breaks down and fails to be much help.
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 Bo
Re:if it is finite than what is holding it? (Score:5, Insightful)
Anyone can tell you what happens when you hit one object against another or toss one object against gravity at a certain angle. Even small children know roughly where a baseball is going to end up the second you release it from a throw despite the fact that the real calculation would take someone a few minutes to make. With quantum mechanics, you are never going to have that child like grasp of what happens when two atoms start interacting.
While we do make visual models to understand quantum mechanics, they really are only a crude ways to give our poor mammalian brain some straws to grasp at. We can visualize orbitals to some extent, but anything deeper then that kicks human intuition which has been developed to deal with a Newtonian world in the balls. You really can only truly 'understand' quantum mechanics and general relativity with math. And not just simple math, but ugly math that kids go to college for years to understand.
Without the hardwired machinery to give us answers like what we have for Newtonian physics, there is no ability to develop and "intuition" for quantum mechanics. Quantum mechanics is ugly math combined with concepts that have no Newtonian world analogy. Let the kids know that this stuff exists, but keep them in their happy Newtonian world where their hardwired physics engines can pick up the slack. Save quantum mechanics for after they know calculus.
Re:if it is finite than what is holding it? (Score:5, Insightful)
Yes, they can, but that does not make them "hardwired" to do Newtonian physics; physics is the mathematical description of the real world, and so someone who lives in the real world and experiences it will have intuition into how physics works. If we lived and experienced in the quantum or the relativistic, we would have intuition into how that works as well. However, if you have never experienced something (even Newtonian physics), then you have no intuition about it because it is not something hardwired. Examples: on this very site a while back, there was a heated discussion about what would happen if there were a a tunnel bored completely through the Earth and you fell it in. What would happen? People disagreed. Also, Total Internal Reflection. I don't think that a dog, or a child, or anyone who hasn't taken a physics course or read about fiber optic cables would know about this. There is no intuition about it, but it is Newtonian physics. Physics is not hardwired into anybody's or anthing's brain. Our seemingly innate grasp is the ability to find patterns in the behavior of things, which is why the dog will know when to jump to catch a ball, or why the child knows where the ball will land (approximately). If we have no experience to find patterns in, we won't know our heads from our asses, metaphorically speaking.
As a consequence, you can grow intuition as you work with something. Which is why if you do enough quantum mechanical calculations, you will begin to have a sense of "what looks right," to have intuition about how quantum mechanics works. True, because we can only express quantum mechanics, our intuition in mathematical, but just like the physics student can translate the mathematical expressions of Newtonian physics into consequences in the real world (i.e. if the momentum of A is bigger than B, then they will both move mostly in the direction of A if they have an inelastic collision), the student of quantum mechanics can say "This Hamiltonian of an electron doesn't have any nodes. Then it must be in an s-orbital." Just because we are not as intimately familiar with quantum mechanics as we are with Newtonian physics because we live in the latter, not former, doesn't mean we can develop an intuition into how the former works.
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That is not quite true. Quantum mechanics technically still holds at the macroscopic level. However, Newtonian physics is an "approximation" that is incredibly good in intermediate scales (i.e. not relativistic or quantum).
Of course the universe isn't truly Newtonian. That said, Newtonian is how we perceive it in our day to day lives. Sure, there are electrons and atoms bouncing all around me, but the only thing I see is a flat desk with gravity pointed straight down.
I can guarantee you that the dog is not doing newtonian physics in his head; neither is he hardwired to do it that way. If you throw a ball at a puppy, he will not be able to catch it right away. Just like a little kid can't. We aren't hardwired to "think Newtonian." As it is, Newtonian physics are a representation of the world we live in, not the world itself.
Do you truly and honestly believe that in the millions of years of evolution in a world that looks like a teenagers physic books opening lessons that nothing has been hardwired to deal with a Newtonian outlook on the world?
Take a gazelle. Drop it out of its
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What, you mean let your kid get stoned every day?
Re:if it is finite than what is holding it? (Score:5, Interesting)
"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.
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Obviously someone has though of that already, so is it impractical because the universe is too young for the light to have wrapped around and reached us, or because the universe is just too big to see things that far away?
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More proof! (Score:3, Funny)
A: Therefore, God exists.
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Oblig. Simpsons (Score:2)
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*drool*
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A giant space turtle of course. And before you ask what the turtle is standing on - it's a TURTLE, it doesn't need to stand on anything. It just swims through space going about it's business. Probably the only creature that knows exactly where it's headed, too. (Apologies to Terry Pratchett).
Moriarty Explained - Re:Vote for Pedro! (Score:2, Informative)
That's probably what the person who modded my parent post down was asking themselves, too, I'd guess. Shame on those of you who missed the ST:TNG reference!
Please see the Wikipedia page for Professor Moriarty [wikipedia.org] and on that page, scroll down to where it says "Moriarty in pop culture" where it includes the bit about the ST:TNG episode where "the three trapped crewmembers programmed the holodeck inside the holodeck to create a holographic simulation of the outside world, leaving Moriart
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False, in general (I'm not sure about this specific case, however). Go look up a Klein bottle. It is a mathematical object with no defineable interior or exterior (which makes it very hard to integrate over, in the traditional sense. Damned non-orientable objects.)
Futurama depiction [wikipedia.org]