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The Universe May Be Shaped Like a Doughnut
NewbieV writes "The NY Times (reg., etc.) is reporting that data from the Wilkinson
Microwave Anisotropy Probe may suggest that the universe might be shaped like a doughnut or a cylinder: it might be possible, like in the old video game Spacewar, to drift off one 'side' of the Universe and reappear on the other."
...the Cop of the Universe?
damn stephen hawking!
(ps. - third?)
homer was right!
moo
Mmmm... Universe... (knew someone would do this, thought I'd try to get in first)
The Krispy Kreme Endowment for Excellence in Cosmology.
2 dimensional universes are shaped like donuts. 3 dimensional ones like ours are shaped like hyperspheres.
I guess they forgot to carry the 1.
I have been pwned because my
In this case, the obligatory Simpson's references really *are* obligatory.
Those of us who have played games like Space Wars, Asteroids and Star Castle were already well aware of the toroidal truth.
no registration required link in printer friendly format (otherwise it's five pages)
More images from probe homepage
....cosmic size donut with solar sprinkles.
/me drools
Then in theory, we'd be able to see the same part of space from two vantage points, assuming that they're not farther away from us than the distance that light could have travelled since the universe came into being, assuming that one believes in the big bang theory.
So, would this mean that if we can't see one point from two directions now, that if we suddenly can, we've reached the halfway point of the life of the universe? Would we lose the redshift in favour of a green shift?
IBM had PL/1, with syntax worse than JOSS,
And everywhere the language went, it was a total loss...
Comment removed based on user account deletion
That is kinda vague. What kind of donut, as we all know the jelly filled ones take on a different shape than a fritter.
Did anyone here actually *read* A Brief History of Time? Hawking described how the gravity of the universe may be so intense that it causes the universe to wrap around into a spherical shape. Of course this was just a theory back when he wrote the book.
At BASF, we don't make the Universe, we make it, more doughnut like.
"I didn't come here to tell you how this is going to end. I came here to tell you how it's going to begin"
Namaste
Coffee? Void? Dark Matter? Does that question even make sense? I'm not up on this and would be most interested in getting a better understanding of this.
Actually....in the episode where the Mensa society runs Springfield, Stephen Hawking shows up, and at the end says: "Homer, your idea of a doughnut-shaped universe is intriguing. I must steal it for my next book."
I'm out of my mind right now, but feel free to leave a message.....
But then what the hell is the jelly?
"I only speak the truth"
Karma: null(Mostly affected by an unassigned variable)
Voyager could also become the first device of our civilization to sail around the entire universe?
This also reveals that the ultimate demise of the Universe is a Big Crunch.
To-do List: Receive telemarketing call during a tornado warning. Check.
We're talking about a Torus, not a spherical universe. If true, the universe is still 'flat', there's no 'wrapping' as you put it, it just repeats in all directions.
I am a science fantasy fan
The article says that an experiment is going on that could find this out, but it is only possible to measure up to 28 billion light years which is most likely too small, even if the universe is finite.
if (particle->position.x < LEFT_LIMIT)
particle->position.x += RIGHT_LIMIT - LEFT_LIMIT;
else if (particle->position.x >= RIGHT_LIMIT)
particle->position.x -= RIGHT_LIMIT - LEFT_LIMIT;
.... ... }
int main (void) {
I've admired Dr. Tegmark's home page since he was a grad student, not so much for the design skills (ha!) but as an exemplar of mixing serious and non-serious publications for other colleauges and onlookers to enjoy, explore, and learn from. Tegmark gets the web. As for the science, some of it I can actually understand.
I would also commend to the curious Slashdot reader a couple items I found facinating from the 'non-serious' section of his website:
a very cool diagram of "Relationships between various basic mathematical structures" from his Theory of Everything paper
and another paper addressing the question: Why does the universe have 3 spatial and 1 time dimension?
--LP
Space is a toroid with finite size? Augh, I must be trapped in a static warp bubble! CleverNickName, this is all your fault!
-Begin Jargon-
A torus (dougnut) is topologically equivalent to a square with sides identified (like the Space War).
-End Jargon-
Discontinuous or stuff like that is not really important concept. Whether you are "magically" transported or not when you reached the end is just a matter of choosing the right coordinates.
Also, curved universes do not enter the argument. Curvature is a statement on Geometry of the Universe, while being a Dougnut is a Topological Statement.Both of completely independent of each other. A Toroidal Universe can be flat (like, hey , a square with sides identified!). A curved universe can be a plain sphere.
Mode (3) smart-aleck mode. Press * to return to main menu.
Imagine you're a 2-D dude wandering the earth (which is really a 3-D globe like you'd find in a classroom). You can walk and walk and never hit a wall but there's a finite amount of 2-D space. Now imagine you're a 3-D dude... This is where my feeble brain says 'help!'.
The analogy would seem to back up the article; whatever direction you take if you walk long enough you end up where you started.
It was discovered that the internet is shaped like a pringle.
I think the Flintstone's house is it's own tightly bounded universe with high curvature... notice when they run in a straight line, they nevertheless keep passing the same circular window and pelican ash tray? Perhaps they have floating bubble universes they get trapped in from time to time.
"I would say that 99 per cent of what my father has written about his own life is false." - L. Ron Hubbard Jr.
On learning of this news Ford Motor Company immediately sent the universe a "cease and desist" letter, claiming violation of their trademark "Taurus."
While someone was trying to explain to a Ford executive that "Taurus" was a different word, and only applied to to an abstract portion of space, not the universe, and the word "Torus" refered to a donut shaped object, said executive got a blank look in his eye, muttered the words, "Hmmmmmmmmmmm, Donut," and wandered off.
KFG
I wonder what color our sprinkles are.
paintball
Interesting... let's assume for a moment that the universe's expansion was frozen.
... hmmmmm... I'm having trouble picturing what this 3-d curvature would look like. Anyone have a helpful mental image of this?
Now, if I threw a baseball in a straight line from point x,y,z in the universe, at some point, that baseball would again pass through one of the planes of its starting location? (I'm neglecting all interferences, including gravity)
3-d space curving
Actually it's a fine analogy. The problem is the display screen, not the Space War universe. If you were to map a torus onto a flat display, it would seem that you're magically transported. In reality, the discontinuity is the display, not the universe. (In similar games, I'm not sure about this one in particular, you can be "right on the border" and see your ship halfway on either edge. Perhaps Space War lacks this "sophistication".)
Anyway, this is like saying "that is not a picture of something 3D, because the picture is 2D". Just because it's 2D doesn't mean it can't represent something 3D.
Besides, if you want to be really pedantic, the real problem would be the dimensions of the toroid universe in question... it wouldn't really map exactly to a rectangular screen unless you changed a few "universal constants". ;-) (Not that I have a problem with this. ;-))
Don't think of it as a flame---it's more like an argument that does 3d6 fire damage
the donut analogy is a bit of a gloss. The interior space of the torus dosen't represent the three dimentional space we inhabit, rather, the path you take around the inside of the torus is supposed to represent all three dimentions, simplified as a vector in the torus...so, picture being inside the torus, and travelling all the way around the interiour of it and coming back to where you started...well..there's no way to visualize this situation for all three dimentions, but the torus is as clear as you can make it. Don't think about what happens if you travel to the inner or outer wall, that would be equivilant to "leaving" space in this simplified abstraction.
Hawking described how the gravity of the universe may be so intense that it causes the universe to wrap around into a spherical shape.
IIRC, Hawking was talking about the shape of spacetime in that section. And in fact, the results from WMAP indicate that the universe will expand forever, contradicting that particular model of spacetime.
When these people say that the universe may be shaped like a donut or like a cylinder, they are supposing that spacetime can be expressed as the product of a space part and a time part, and that the space part is shaped like a donut (or whatever).
In this model the space part would be the 3-torus T^3, the time part would be an open interval I, and spacetime would be IxT^3. Good luck on visualising that!
They are sound waves in the looses sense of the word.In the sense that you have stuff (the photon-baryon fluid) and a wave is travelling through it (like sound waves travelling through air).
Gravity waves exist of course, but we have no way of detecting them yet since their signature is much much much harder to detect.
Mode (3) smart-aleck mode. Press * to return to main menu.
In an infinite volume, he pointed out, anything that can happen will happen.
"Somewhere there are two guys having this same conversation," Dr. Starkman said in a telephone interview, "except that one of them has a purple phone."
Whoa!
And that, my liege, is how we know the Earth to be banana shaped.
;-)
Someone had to say it.
Remember the rubber-sheet/morning glory shaped deformation model of gravity? Some time back I recall a description of a black hole as dropping such a BIG marble on the rubber sheet that it keeps going down, stretching the "rubber sheet" forever, at least as fast as the speed of light. Think a "taffy sheet", or a "stem" of the "morning glory" stretching like a stream of honey.
It's easy to see why enough gravity keeps light ORBITING the gravity from spiraling out and away. But this also explains why light going STRAIGHT AWAY from the center of the hole never gets out - space is being stretched at least as fast as it moves (or maybe even faster), so it never makes it out of the hole.
Well, this got me thinking: "What does a black hole look like from the INSIDE? What would one see from the viewpoint of the matter that was already there when the event horizon formed?"
And the answer seemed to be: "An expanding universe, starting from a very small but finite volume and expanding indefinitely, containing a large-but-finite amount of matter, which was initially compressed into an EXTREMELY dense lump - perhaps a quark fluid or denser."
In other words, something like the current universe. Perhaps with the moment of the formation of the event horizon corresponding to the end of the big-bang model's "inflationary period", but eliminating the need for a faster-than-light inflationary period.
Cosmic background becomes the layer of matter and energy just below the event horizon, which is just getting here now. Cosmic background structure represents the matter distribution at that level at that time - a fossil of the orbital dynamics of the accretion cloud. (I don't think you get to see an "inside view" of the infalling half of the Hawking radiation.)
You can go in any direction at up to the speed of light and never reach "the edge", which is (from your viewpoint) receeding at lightspeed.
Not being a professional physicist, at this point I haven't attempted any mathematical models or resolutions with any of the current cosmological models. So I have no idea if I'm just spinning a yarn or if this can be pounded int shape for testing against the real universe. But it might be interesting to try some time.
(The concept of gravity indefinitely stretching the coordinate system also leads to another possibility: Can gravity be modeled as masses constantly "sucking up" the coordinate system, which stretches between them meanwhile?)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
except that there are theories that other 'insides' exist in the 'outside'....complicated as that may seem
I'm out of my mind right now, but feel free to leave a message.....
oops..i got it backwards.
imagine travelling across the SURFACE of the torus.
whoops!
Mmmm, universes...
"Accept that some days you are the pigeon, and some days you are the statue." - David Brent, Wernham Hogg
From their site:
"The Inflationary Theory, an extension of the Big Bang theory, predicts that density is very close to the critical density, producing a flat universe, like a sheet of paper. WMAP has determined, within the limits of instrument error, that the universe is flat"
Last I heard doughnuts aren't flat.
Best. Webhost. Ever. Dreamhost.
Even if the hypertori topology of the universe is correct it doesn't imply that the universe has any particular curvature, it's still possible that it has positive, negative or flat intrinsic curvature.
You have to remember that the curvature of a torus embeded in 'flat' 3 space is purely an artifact of that embeding and not intrinsic in the topology of the torus. More specifically, there exist mappings from the embeded (intrinsicly curved) surface of the three dimensionally embeded torus to topologically identicle spaces that have everywhere flat intrinsic curvature.
As a thought experiment, consider a cube where the faces are portals to their oposites. Internally, this construct has the topology of a hypertorus but an everywhere flat topology.
For some nice diagrams and comentary that explain curvature (of the important, intrinisic kind) rather well, take a look at this, just skip over any of the math thats beyond your abilities, it's not really needed to understand the concepts.
Realities just a bunch of bits.
Donuts. Is there anything they cant do?
Manipulate the moderator system! Mod someone as "overrated" today.
10 print "Oh no, Homer was right!"
20 print "Mmm... Universe."
30 goto 10
or, better yet....
for (i=0; i < 1; i--)
cout << "Oh now, Homer was right!\"\n"Hmm... Universe\"\n
From reading the title of this article, that there was going to be a string of Homer Simpson references. Woohoo!
"Actually, it's shaped like a burrito"
OK, we have found God's doughnut. Where is the coffee mug that he is dunking it into ?
I just knew the old video games had to be right !
Now all we can do is wait until pacman passes and eats the earth ?
Learn about pinball machines on www.flippers.be
Since when do jelly donuts have holes?
... ... as well as SpaceCorps directive 97G!
You're violating the fifth law of thermodonutdynamics here
(97G: No officer will false teeth shall attempt oral sex in a zero gravity environment.)
And er Stephen Hawking was hardly the first to suggest this.
I Will Not Hang Donuts On My Person
I Will Not Hang Donuts On My Person
I Will Not Hang Donuts On My Person
I Will Not Hang
--
"Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next.