Slashdot Mirror
Manyfold Universe Theory
Geek-from-parallel-Universe writes "In the HEP preprints database a preprint
">appeared
in which the authors propose that a world is a brane folded many times in extra sub-millimiter spatial dimensions. We see other folds only
through gravity as a dark matter because light must go around the folds. If this is true then I am waiting for Star Trek-like devices:
'portable submillimeter wormhole generator' and 'personal parallel
universe transmitter' to appear on the market. :-)"
The preprints database is a joy to behold; it regularly contains off-the-wall theories that may or may not be worth considering.
As for the manyfold theory: this (to my untrained and feeble mind) sounds a lot like M-theory, which is string theory with an extra dimension.
It presents us with a new dark matter particle and a new framework for the evolution of structure in our universe.
Cool. Predictions always make a theory more worthy of consideration.
I also learnt the word 'phenomenology' which I'll have to use somehow today. Damn!
I really hate the way people wonder along with some new idea and say 'science teaches this' - 'science teaches that'. In reality the entire scientific community is bunch of argumentative ego-maniacs (who will be first against the wall when the revolution comes). Just look at the expanding / contracting universe theory, some scientist (who shall remain nameless) proposes that if the universe stops it's expansion and start contracting then time will start to run in reverse. Five minutes after this was suggested the scientific community disregarded it and the original author retracted it. Five years later it's still in popular culture with 2 dozen film's using it and 3 dozen books using it is a central story.
I suggested reading this nice document on "Time Paradox" dealing with the grandfather paradox etc, its just as much crap but it has nicer formatting and pretty side bar.
What's the new thing with this brane theory? Is there more dimensions, or are the scales more macroscopic?
Strange that they claim (implicitly) that Newton's inverse square law was correctly deduced because gravitional interactions with branes make a difference only at the sub-millimeter level. But then they go on to say that gravitional interaction with branes can be shown by "unusual" behaviour of objects -- and they gave the example of the rotation of galaxies. Now I'm sure that's not on the sub-millimeter scale! What's going on here?? I must be missing something... why is it that branes don't make enough difference outside the sub-millimeter scale that Newton could still deduce an inverse square law consistent with observations, yet at the same time branes are supposed to account for the way large objects like galaxies behave??
mikre he sophia he tou Mikrosophou.
Data: Captain, we're picking up a strange anomaly on radar
...
Picard: On screen
Data: It can't be
Picard: It is..! Another wild theory captured by the media-machine and blown out of all proportion.
Data: What's your order, sir?
Picard: Shields. Lock phasers
Picard: Mr Scott, Warp 4. Get us out of here. And avoid that trans-dimensional worm hole, damnit.
'Course, I'm no physicist. But, if you could send matter into a parallel universe, wouldn't that violate the conservation of mass and energy?
The other problem I have with the theory is, if the parallel dimensions are a millimeter from our own, wouldn't stuff randomly explode throughout the Universe? With gravity being the only force able to pass through, and at such short distances, what would happen if a massive, starlike object would pass 1mm from a star in our own Universe? Wierd, random-seeming intant catastrophic destruction, that's what.
Plus, with gravity passing through the brane, I'd be interested to see how something would react to being pulled in a "direction" that doesn't exist in our Universe.
-Omar
Reversing the polarity only works for the neutron flow. :)
IMHO, though, nothing beats Block Transfer Computations for wierd energy effects. :) Just don't plug them into a computer.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
If this is true then I am waiting for Star Trek-like devices: 'portable submillimeter wormhole generator' and 'personal parallel universe transmitter' to appear on the market.
Better not start using these just yet. We wouldn't want Windows 98 to contaminate other universes. Wait 'till AFTER the antitrust thing is done.
Is it just me or does this article read a bit like a Terry Pratchett novel? :-)
:-P
I thought this was particularly entertaining:
``You might produce nothing but black holes,'' Dr. Lykken said. ``So physics could look very surprising in this scheme.'' Such mini-black holes would probably go poof in a instant, producing a burst of radiation that scientists could immediately recognize as a black hole's signature.
``You'd say, `Aha! I've made a black hole,'''' Dr. Lykken commented.
"Oh dear, I appear to have accidentally ripped the fabric of space-time. Damn."
When some bright lad tries to split the graviton, I'm outta here.
---
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
One thing you must remember about dimensions:
:-)
A dimension is at right angles to all other dimensions. Not curled up, or anything of that sort. A small dimension (around 1 mm or what have you) is enough to hold an infinite number of 3 dimensional universes, because a 3 dimensional universe has zero size in that dimension.
Tricky shit, huh?
Anyway, this postulates that gravitons do travel along a 4th dimension (not time, thank you) to affect other universes. If that's the case, then that's probably what's on the other side of the singularity of a black hole. A different universe. Of course, I'm just making this all up as I go along, but it's still pretty interesting.
---
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
Topology is very interesting. You can think of further dimension as "casting a shadow" to lower dimensions. For instance....the shadow of a sphere is 3d is a circle in 2d. The shadow of a 4dSphere is thus a 3d sphere in 3 dimensions. Quite a while ago (1996?) I read an article in a scientific journal in which a dance of the honeybee corresponded directly to a "shadow" of the Flag Manifold. The article suggested that there were interactions on the quark level that effected our 3d world, and hence the bee gets its dance.
h tml
http://www.physics.helsinki.fi/~matpitka/honey.
I read an awesome book on the field of topology but I forget the title now. What they were explaining and attempting to describe on paper no less, what really mind-expanding for me. To think...all these weird things we can't quite reconcile with each other may just be because of a greater scheme outside our perception...that we are just the shadow of an even greater and more complicated play. That when things mysteriously "disappear" and "reappear" at the quantum level, that it could possibly be because they are "shifting" in a dimension we can't percieve. A good way to think about extra dimensions is to give them names of other continuims...like "color"....e.g. This particle is at location (1,2,1,red). Very interesting stuff. I have to find that book again...amazing diagrams of 4th and xth dimensional objects.
It's 10 PM. Do you know if you're un-American?
The Theory of Sub-millimeter Extra Dimensions is a neat way of explaining what is called the "hierachy problem", mainly why the Plank scale 2*10E18GeV is so high. We have found most of the elementary particles with the number and properties of the Higgs particle(s) and possible supersymmetric partners the most reasonable "undiscovered" particles left. All these particles even the undiscovered ones stay with their mass below a few 1000GeV. So why is there a "Desert" that spans 1000000000000000GeV of the energy scale befor something happens to the particle content again? Small Extra Dimensions are an elegant way of solving this problem without introducing lots of new particles and interactions. I really like the idea because it is so simple, I distrust it partly because it can be used to give almost any kind of physics i.e. it always works and it is difficult to experimentaly test it. On the other hand this idea has been around for a couple of years now so it can't be totally crappy. I hope you remember some high school physics. You may remember that the gravitational force and the electromagnetic force both grow weaker with the inverse square of the distance ~G*r^-2 with G the constant of the relevant force. If you know Math or have done universtiy physics you know that this law is because the space is three-dimensional and this is just the way a wave dissipates in three dimensions. Now imagine that as you go to smaller and smaller distances, say between two particles, the space suddenly has more dimensions so the wave gets to dissipate at a faster rate. Since the interaction remains the same the coupling constant G must change in response. The coupling constant of gravity relates to the Plank scale so you end up changing that and voila by adding some extra dimensions the "Desert" dissapears and everybody is happy. Exept for the experimantalists since you can't verify this theory yet...
This analogy helps, but mathematically you can describe the tube as a curved two-dimensional object without the third dimension. It is just easier to understand untuitively if you think it embedded into a third dimension.
Then you refer to orthogonality (being at right angles). It's a matter of parametrization, i.e. setting up the coordinate axes.
Um, it's manifold not manYfold. A manifold is another term for dimension or "membrane". E.g. Our universe is a manifold of X dimensions.
It's 10 PM. Do you know if you're un-American?
Not really. Consider the case where there are an infinite number of parallel universes.
Then there are an infinite number "above" and "below" and no one universe is at the "center."
Besides, you are using the word universe in two different ways, one to describe the set of "parallel universes" and another describing an object which is in parallel with other similar objects.
Doug
Venn ist das nurnstuck git und Slotermeyer? Ya! Beigerhund das oder die Flipperwaldt gersput!
Essentially, they refer to a brane (which is in itself a manifold) which is "kinked" within a higher dimensional space within which some (e.g gravitational) interactions propagate whilst others (e.g. electromagnetic) are confined to propagation within the brane itself.
Imagine the universe is 1-dimensional (and composed of Crap ASCII Art (TM)). The the Manifold would be a 1d line within 2d, e.g.
---------X-------------------------------Y----
(exciting, huh?... bear with me...)
with all interactions between points X and Y taking place within the 1d line, oblivious of the extra (up-down)dimension.
The manYfold concept would take the above and turn it into the following:-
---------X--------------\
-----------Y------------/
where, although most (i.e. electromagnetic etc.) interactions still have to go all the way along the line and back between X and Y (regardless of the bend of which they are oblivious), gravitational interactions "know" about the extra up-down dimension (referred to in the article as the "bulk") and interact over the now much shorter distance between X and Y, bypassing the normal space distance along the line, leading to things which seem distant in space (but nearby in the "bulk") having much more gravitational influence than they would otherwise.
On a very related note to this concept, I seem to remember something similar being touted about a particular Superstring Theory (E8xE8) where one ends up with 2 independent universes coupled only by gravity. Whilst this is not the same (in the manybrane paper the two universes are actually spatially distant parts of the same one) it does have common features. Of course, it is a long time since I heard about E8xE8 and I may be misremembering.
On a less related (but again similar) note, Richard Feynman and John Wheeler once postulated that all electrons in the universe were in fact the same electron wrapped back and forth (where it appears as an anti-electron) between the beginning and end points of the universe, thus accounting for the fact that every electron in the universe appears absolutely identical.
--
"I am not a nut-bag." -- Millroy the Magician
There's actually been a lot of fuss about what's called "large extra dimensions" recently. The original problem was that the energy scale associated with gravity is about 10^19 GeV (1GeV = the energy an electron would get going through a potential gap of 10^9 V = approximately the mass of a proton) while the energy scale associated with all the other forces of nature is only 10^3 GeV. This is really bad because it means that (for instance) particles would get gravitational fields surrounding them that give them masses on the order of 10^19 GeV, which would turn everything in sight into a black hole.
:) is one thing. In some of the models effective FTL travel may be possible.
This problem can be solved in a number of ways - notably supersymmetry, which causes those giant gravitational fields to cancel out. But there's one other odd problem to deal with, which are "extra dimensions." Basically string theory requires that the universe is actually 10-dimensional, and the other 6 dimensions are simply wrapped up very tightly. (Mental picture: If you wrap up a sheet of paper (which is 2-dimensional) into a very tight tube and look at it from far away, it looks 1-dimensional. Unless you're scanning it on distance scales comparable to the radius of the tube.) The problem is that you have to somehow wrap up these 6 dimensions on a really small distance scale (the length scale of gravity, about 10^-42 cm) and keep the other 4 really big. (the size of the universe) This again happens because the energy scale of gravity is big.
So about a year ago, Nima Arkani-Hamed, Savas Dimopoulos, Gia Dvali and John March-Russell had an interesting thought: We don't *know* that gravity really behaves like anything in particular at length scales below about a millimeter. (The current limit of experiment is about 0.8mm) So they noticed that the following setup gives the right answers too:
* We live in a universe with however many "extra" (small, rolled-up) dimensions, but these are rolled up with radii on the order of somewhere between 1fm (10^-15m, the size of a nucleus) to 0.1mm. (The range of sizes is because there are several different models)
* In this loosely rolled-up world, there are these 4-dimensional objects called "branes" floating around.
Then several amazing things happen. First of all, all matter particles (electrons, quarks, people) are bound to the surface of the brane and can't leave it. So are all the non-gravity force particles. (Photons, gluons, etc.) This just follows from the physical properties of branes in string theory, and it means that as far as anything but gravity is concerned, the universe is 4-dimensional and we won't see the extra dimensions.
Second, gravity completely ignores the brane (except insofar as there's matter, and therefore sources of gravity, there) and flies around freely in all of the dimensions. But because some of them are rolled up, what happens is that at long distances (bigger than the radius) all the gravity gets "squeezed" along the extra dimensions and gravity behaves like ordinary 4-dimensional gravity. At short distances, this changes -- for instance, the 1/r^2 force of gravity becomes something like 1/r^4.
But the real magic is, if the fundamental energy scale of gravity was 10^3 GeV, (the same as the scale for everything else) the distortion of gravity by the rolling up of space would make it seem like the scale was 10^19 GeV to any observer looking at distance scales bigger than the radius!
So the bonus of the Large Extra Dimensions (LED) scenario is, everything has the same energy scale, and it only seems that gravity has this high energy scale because we're looking at too long a distance. And all of the problems of a high energy scale indeed go away.
Of course, you can ask what the hell any of this has to do with reality. The thing is that all of this is consistent with all experiments to date and explains several tricky points. More importantly, it is experimentally testable; part of the testing happens in tabletop experiments (groups at Stanford and at NIST in Boulder are working on measuring gravity at distances down to about 10^-6 m) and part of it in accelerators. The final tests (thumbs up or thumbs down) will come from experiments at the LHC accelerator in Geneva, which should (knock on wood) be up to spin around 2004/5. Final results should take a few more years after the machine comes on-line.
But disclaimer: At this point this entire scenario is conjecture. People are already working out "observational experiments" to check these models -- for instance, whether these are consistent with the known spectrum of cosmic rays -- which are strong experimental constraints. But until the final experiments happen we can't be certain, one way or the other.
Also, since the original paper came out there have been several modified versions of the conjecture, which differ essentially in technical (but very important) points. The Randall-Sundrum model is especially important, and today's model looks to join the list of candidates.
So what does this mean for us? First of all, if it's right then the underlying scale of gravity is only 10^3 GeV, which is definitely accessible with the next generation (LHC) of accelerators. This means we can start to directly monkey around with the processes associated with black hole formation and the origins of the universe. Apart from completely changing physics (by making quantum gravity experiments practical) this is one of those things that creates more applications than we know what to do with. Making small black holes (and no, they wouldn't eat up the planet.
But possibly the most interesting thing is that there's no reason at all for our brane -- the one that our universe lives on -- is the only one. In fact, the most reasonable model suggests that there is some unbelievable number of branes floating out there, maybe 10^24 of them. It's not clear that the laws of physics would be the same on all of them -- e.g. the speed of light may be different, or the charge of the electron, or whatever -- but if the scenario turns out to be true, it is possible (though difficult) to communicate between two different worlds.
And for my money, that's the neatest thing of all.
The fact that you disbelieve what they are working on doesn't make it any less useful. This paper is a hypothetical description, but it actually contains items that are testable. Somebody will work out a way to test them, and our knowledge base will get larger. All whether you like it or not.
Rather than screaming and stomping your feet about how outraged you are, why don't you show us where they are wrong? (And just so you know, waving the christian bible around won't constitute acceptable evidence. It's already got too many problems.)
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
Can anyone join this thread, or do you need a degree in surrealism? :) Seriously, I believe Slashdot works in a connected space, so who or what are you two AC's replying to?
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
WTF?! I don't know what Amazon is suggesting for you, but when I click my link (and the same one you provide) i get:
The Shape of Space : How to Visualize Surfaces and Three-Dimensional Manifolds
(Monographs and Textbooks in Pure and Applied Mathematics, Vol 96)
It's 10 PM. Do you know if you're un-American?
Darwin himself admitted -- in so many words -- that he could not account for the development of the modern vertebrate eye.
So? Modern biology has progressed far beyond what Darwin ever thought. Just because Darwin didn't explaing the eye doesn't mean it was explained later by someone else. Try this for starters.
In other words, he admitted that his theory was nothing but an idle fantasy.
Bullcrap. He did nothing of the sort, except admit his own limits. As much as you'd like to believe otherwise.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
On the contrary - it's been observed, in plants and fish.
You can't breed a dog into a lizard, which is what the fantasy of MACRO-evolution (so-called "Darwinism") explicitly claims to be the case.
Strawman alert. Where was this explicit claim made?
A truly and literally honest "scientist" will simply admit that he knows absolutely nothing at all, that his wild guess is as good as the next, and that neither of them is worth a bucket of warm spit.
An odd statement, made in a world where the process of science has given us antibiotics, microelectrons, and space probes to the outer planets.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
No, it hasn't.
See? I can make unsupported assertions, too. If you want us to accept your statements, you'll have to provide something other than lip flapping. Where has this demonstration taken place? (Please don't reference the ICR. Everything they say has been shot down like a cheap clay pidgeon.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
Okay, okay, you CAN have your coordinate axes any way you please, but they're still at right angles to one another. It's just a matter of remapping the axes however you want.
So, yes, you can curve your dimensions. But it's easier (for most applications) not to think of them that way. I could use spherical coordinates to describe how to build a building, but I don't because it's not very useful. It's easier to do with rectangular dimensions.
Now, as to a real dimension being curled, lets use your tube analogy. Can one traverse around the tube (in one dimension, mind), ending up back where you started? Sure. Can you do that in reality? Well, that depends on whether the universe is closed or not. I have yet to see a satisfactory answer either way on that issue.
---
- Give a man a fire and he's warm for a day, but set him on fire and he's warm for the rest of his life.
Does that make my result a miracle? Hardly. I was going to get some result. Same way with the Earth. Given what we know about biochemisty, it was pretty likely that something biological would happen. Four billion years ago, given all the random factors the odds that it would be us were astronomical, but after the fact it's not remarkable (other than for sentimental reasons) that it turned out to be us.
Hard as it may be for devout beleivers (who usually want to go backwards in time for their authoritative statements) to understand, we've learned a few things since Chuck Darwin's time. You might try this, for example.Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
These things sound with an interesting similarity to some SF and paranormal stories. While most of these things go too much over fantasy there is a point that humans cannot imagine things completely out of this world. So are these "fantasies" a mirror of what the human mind may presume out of its own reality? Are dreams a middle term between "our" world and this "parallel" part of reality? :)
:)
What about travelling between worlds? Frankly this theory does not sound like StarTrek. It sounds much more like Zelazny's "9 Princes of Amber". There are several worlds. They are the result of the intersection between two "original" ones. So there are several Earths. Each one differs from the other by its distance to each of the "original" worlds. Funny but, somehow, certain human myths exactly reflect this nature.
While this is the world of phantasies and dreams there is a point that still theory seems to pass by. The fact that, the other possible "world", may be not like ours. Not only by events or biology but by its inner nature. Physics and its constants may be a little different from ours. Even its geometry may be quite different from ours. Maybe somehow that "other" dimension may be felt stronger than in our world...
Interesting is the Universe has such a nature. So don't get scared if you suddenly see your mirror image with a grey skin. It's just you
In other words, you are willing to stand up and make hysterical pronouncements, but when called upon to support your position, you hide behind ad hominem and run away. I'm not surprised.
As far as "damned" goes, that necessitates the existence of a god as specified in the christian bible, for which the evidence is thin at best. I'm not worried.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
I have.
Prove it.
I don't have to. You won't stand behind any of your statements. I'm just adopting the same tactic.
...phil
...phil
"For a list of the ways which technology has failed to improve our quality of life, press 3."
I guess you didn't get the coin-flip example I posted. Let's try another one. Say someone comes up to you and says "I'm going to win the lottery! I can feel it in my bones!" You'd think he was wacky - it would be be a "wildly improbably accident" were he to win. And in fact, before the drawing we could say that about any of the participants.
But yet, if you sum up all those small probabilities, you get unity. Someone will win.
And if you summed up the small probabilities of all the possible courses that Earth could have taken 4.5 billion years ago - the dead and sterile planets, the ones where life never got beyond the blue-green algae, or where the dinosaurs never died out, or where rodents instead of primates got the big brains and opposable thumbs, or where Hilter won WWII, and our own improbable situation...sum them all up, and you get unity. One of them became the reality we observe today. There's no more need to invoke supernatural beings to explain it than to explain the lottery.
Tom Swiss | the infamous tms | my blog
You cannot wash away blood with blood
The problem with special relativity is that it only works for sublight speeds in three dimensions. Dimensions higher than our trusty dusty 3rd would have the ability to link two points in 3 dimensional space as if they were ten feet away since distance is something lower dimensions have problems with. In the right higher dimension you could occupy every point of 3 dimensional space at the same instant and therefore be moving faster than light. Or so it goes.
I'm a loner Dottie, a Rebel.
Actually, we've never had experimental or observational evidence to determine if antimatter is affected by gravity in the same way as matter.
Standard theories generally have antimatter inherently less common than matter, asymetric weak force interactions, and both matter and antimatter affected by gravity in the same way. But none of those three items has a heck of a lot of observation to back it up.