We've already seen stuff like it in computer games on occasion -- go off one side of the map and show up on the other side. But check this out:
quote:Imagine that the Spacewar screen is wrapped around to form a cylinder or a section of a doughnut so that the two edges meet.
That is the picture of space, some cosmologists say, that has been suggested by a new detailed map of the early universe. Their analysis of this map has now provided a series of hints � though only hints � that the universe may have a more complicated shape than astronomers presumed.
Rather than being infinite in all directions, as the most fashionable theory suggests, the universe could be radically smaller in one direction than the others. As a result it may be even be shaped like a doughnut.
"There's a hint in the data that if you traveled far and fast in the direction of the constellation Virgo, you'd return to Earth from the opposite direction," said Dr. Max Tegmark, a cosmologist at the University of Pennsylvania.
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The simplest of these compact universes is something called a 3-torus, a doughnut wrapped in three different dimensions. This object is essentially impossible to visualize: it is the equivalent, in a way, of a cube whose opposite sides are somehow glued together. In two dimensions it works just like the Spacewar screen.
Living in such a universe would be like being inside a hall of mirrors, Dr. Tegmark said. Instead of seeing new stars deeper and deeper in space, you see the same things over and over again as light travels out one side of your cube and back in the other.
I'm not quite sure that I can wrap my mind around that concept. This article is mind-boggling even for a general-consumption publication like the New York Times. It's got string theory and ten-dimensional space and other wacky ideas.
I guess it's comforting to know that even in the 24th century, they won't quite be able to figure that out (if the encounter with Nagilum is any indication). Posted by Da_bang80 (Member # 528) on :
Thanx, but I don't want to register at nytimes.com. But this topic is interesting, so if you would be so kind as to fix the link, I wanna read what it says.
Posted by Vogon Poet (Member # 393) on :
So Hawking DID steal the idea, just like he said he would! Bastard!
Posted by Sol System (Member # 30) on :
...but where are the rainbow sprinkles? No donut is complete without rainbow sprinkles.....
Posted by Da_bang80 (Member # 528) on :
what about chocolate frosting? can't have sprinkles without chocolate frosting!
on a more serious note: I have a bit of a problem trying to buy this. For some reason the idea of being able to fly in one direction from earth and arrive at earth in the opposite direction it seems to violate the laws of nature to me. I just can't see it hapening... Posted by MinutiaeMan (Member # 444) on :
I can give you an Earthly analogy. Start at a specific point. Head directly south for 3 kilometers. Then turn and head directly east for 3 kilometers. Finally, turn directly north and go for 3 kilometers. You will end up in the same place where you started.
Any high school geometry student can tell you that a triangle will only have a total of 180 degrees, but the above scenario gives you 270. The answer? Add in a third dimension. The point you started from and ended at is the North Pole!
The only problem is that we all have trouble visualizing more than three dimensions (or four, if you count time).
Posted by Da_bang80 (Member # 528) on :
Math was never my strong point. But you're example helped me a bit. But it doesn't quite explain how travelling in one direction with no course changes can return you to the same point in the universe. for an earthly analogy, it would be like walking around the world at the equator, you'd eventually find the place you left.
But does that work the same way if you scale it to universal proportions?
I could see the universe as a donut expanding outward from the point of the Big Bang, with the galaxies and other space-crap as the filling, but I don't see how it's physically possible to leave earth in one direction, and approach it at the end of the journey from the opposite direction with out making course changes along the way. I don't know, maybe it doesn't violate any laws, or maybe we just don't know the laws as well as we need to, to be able to understand the concept.
Until I learn more, I'll stick with the more traditional veiw.
Posted by Sol System (Member # 30) on :
A few links about topology as it relates to the shape of the universe. Sort of.
I suppose those may not be all that useful after all. But, you know, it's just like Asteroids. Topology is fun! Or, so I hear.
Posted by Cartmaniac (Member # 256) on :
Hyperdimensional topology is headache-inducing.
Posted by TSN (Member # 31) on :
Da_bang: I find that the only way to imagine four-dimensional space is to imagine what three dimensions would seem like to a two-dimensional being. Then just tell yourself that the same relationship is analogous to a three-dimensional being perceiving four dimensions. Like this:
Imagine a two-dimensional person living on a flat Earth. Basically, their Earth is identical to a flat map of the Earth. If they stand in California and look straight east, they'll see in a straight line across the the US, across the Atlantic, across the Mediterranean, the Mid-East, China (let's assume the "map" has the prime meridian in the center). Since this being can only perceive two dimensions, they view the whole world as being on one plane. Somewhere out east of China, the world just stops. Same thing west of California. No way could you head off east from China, step off the edge of the world, and show up at the other side in California.
But, in three dimensions, if we roll up the map so the two ends meet, such a feat would be possible. However, since the 2D being can't see the third dimension, it still sees a flat world. It's line of sight gets curved along w/ the 3D curve of the map, so it perceives this curve as still being a straight line. So, suddenly, if it keeps heading east in a straight line, it ends up where it started, and gets confused.
That's what the theory says about our universe. There's a fourth-dimensional "curve" to space, but our line-of-sight gets curved along w/ it. As far as we can tell, we're looking in a straight line. But, in a dimension we can't see, the light we're looking at is actually curving around and coming from behind us.
This would be much easier to explain w/ visual aides, I think.
Posted by Mucus (Member # 24) on :
Hmmm, its been an old assertion of mine that the more people I meet, the more people I find that look rather similar with just small "tweaks." This leads me to believe that the Earth is running out of its equivalent of texture memory and is reusing textures. Now I find out that the universe isn't even infinite, and wraps around. In effect, your displacement in the universe is subject to overflow errors. Man, this is one sucky universe we live in. Whats the next lazy programming decision God made with our reality? Posted by Shik (Member # 343) on :
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