Beta
×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Manyfold Universe Theory

Roblimo posted more than 14 years ago | from the bleeding-edge-of-science dept.

233

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. :-)"

Sorry! There are no comments related to the filter you selected.

Not gonna happen. (1)

Psiren (6145) | more than 14 years ago | (#1519947)

Portable submillimeter wormhole generators and personal parallel universe transmitters suffer badly with tachyon fields and wierd energy like thingies. I thought everyone knew this. Mind you, you could try reversing the polarity. That fixes most things... ;)

I love preprints (2)

rde (17364) | more than 14 years ago | (#1519948)

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!

time and multidimensional space. (1)

splinter (94036) | more than 14 years ago | (#1519949)

I wonder how this theory meshes with the earlier reports that time doesnt exist. creativity is our way of making up for feeble, 3D perception.

Load of tosh. (2)

Anonymous Coward | more than 14 years ago | (#1519950)

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 [slashdot.org] " dealing with the grandfather paradox etc, its just as much crap but it has nicer formatting and pretty side bar.

Don't forget to adjust the... (1)

wynlyndd (5732) | more than 14 years ago | (#1519951)

...Heisenburg compensators. Always works for Jordi. Oh and if you can channel all of the energy through some kind of deflector dish for just one shot before overloading it, I think that will work too.

What's the beef? (2)

janne (100806) | more than 14 years ago | (#1519952)

Even the "ordinary" string theory has extra dimensions. They are just folded at a very small time scale (closer to 10^-40mm than 1mm). You can't use them for space or time travel any more than you can use the curled-up extra dimension of the water hose in your garden - it's still local even if it's an extra dimension.

What's the new thing with this brane theory? Is there more dimensions, or are the scales more macroscopic?

Why Bother (1)

They_Call_Me_Spanky (83478) | more than 14 years ago | (#1519953)

This stuff is so far out there. Ever seem "Brave New World" on ABC, it was on a few months back, ran about 5 shows.. They would try to explain things like this with music videos, songs and whatnot. Definately a Bill Nye for adults. jackchaos.com -The Freak Of Geeks

Tensor calculus (1)

Mr Crazy (116378) | more than 14 years ago | (#1519954)

Ok really, how many of you people out there understand what they are talking about in that paper? Is there anyone who knows of a good page about tensor calculus?

Re:Load of tosh. Bad url (1)

Anonymous Coward | more than 14 years ago | (#1519955)

See! it's all so frustraiting I cant even get the url right! "Time Paradox [exaflop.org] "

My first thought... (1)

EricWright (16803) | more than 14 years ago | (#1519956)

... was "what a bunch of crap! Who are these freaks?" Turns out these freaks are faculty members at respected institutions. Doesn't mean they are less freaky, but it is harder to dismiss offhand what they have been working on.

However, since this is in no way the type of astrophysics I am familiar with, I don't feel qualified to make many comments on the paper. I will just say that, after reading the introductory chapter, I find it hard to believe that they could have accurately done all the things they claimed to. (I forgot many of the details, but suffice it to say that they claimed to have solved just about every problem, up to and possibly including GUT!)

Anyway, I look forward to comments from those who actually have time to wade through the paper (it is 28 pages long after all).

Eric

Inconsistent gravity?? (2)

Gurlia (110988) | more than 14 years ago | (#1519957)

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??

Can someone explain this whole "first" thing? (1)

Anonymous Coward | more than 14 years ago | (#1519958)

I mean, is there some reason for people to sit and blast away "first post" whenever a new article is up at /.? I mean, do you get an award? The respect of your peers? A blowjob? I mean, what?

And to make matters worse, more than half of the "first post" posts are not actually first, but second or even 10th. You end up looking like complete and total morons. So why?

-Lost

Re:Not gonna happen. (1)

EngrBohn (5364) | more than 14 years ago | (#1519959)

you could try reversing the polarity
If that should fail, try tesselating a recursion matrix.
Christopher A. Bohn

Re:Tensor calculus (1)

hubie (108345) | more than 14 years ago | (#1519960)

A rather nice, inexpensive book is 'Tensor Calculus' by Synge and Schild. It is a Dover book.

Anti-matter (1)

HL (109017) | more than 14 years ago | (#1519961)

I'm no physisist, but from what I understand, the Big Bang must have produced a lot of anti-matter (as much as there is matter). If this were true, then all matter and anti-matter should have "vanished" into energy, unless the anti-matter was confined to some other place. Is this a possible explanation as to where the anti-matter went?

Re:Load of tosh. (1)

EngrBohn (5364) | more than 14 years ago | (#1519962)

Of course, if time runs backwards, we'd experience everything backwards, and we wouldn't realize time was running backwards while the universe contracted.
So, to our perception, time would be running forward and the universe would be expanding.
Like the Thermos-bottle question, how would you know?
Christopher A. Bohn

Hmm (4)

LordChaos (2432) | more than 14 years ago | (#1519963)

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.

Re:Can someone explain this whole "first" thing? (1)

Anonymous Coward | more than 14 years ago | (#1519964)

'First posts' are not always 'first posts' for two reasons. The slashdot server does not add your post imediately, I suspect something like a cron job collects them every minute or two and ads them the the list, so posts may have been made before you see it. Additionaly posts may have been made between you loading the page and pressing the 'submit' button. As for the award or respect of ones pears I doubt it. If anyone can provide posisitve information regarding the blowjob I may start trying for 'fist post' myself.

Re:Anti-matter (1)

rde (17364) | more than 14 years ago | (#1519965)

Prevailing theories state that it's possible in very rare cases for anti-matter to spontaneously turn into matter. Therefore 99.lotsof9s % of the universe annihilated, and what we see is a teeny fraction of what the universe started with.
Of course, it's only a theory, so who knows?

Why quote this preprint? (0)

Anonymous Coward | more than 14 years ago | (#1519966)

There are many significant articles from well-known researchers every month, yet this one finds its way to /., obviously because its speculative title and suggestive abstract. If you know a little bit about string theory (and all these brane world scenarios are based on stringy ideas) you also see the severe shortcomings of this approach - (almost) instantaneous proton decay for example. So its far less realistic than you can imagine, and an overly optimistic abstract wont change this.

The moral of the story: dont believe everything, especially not a preprint from a bunch of no-names that does not mention the problems of the own approach. If you want something significant read e.g. Wittens next paper.

(even better: dont believe anything :-)

Dennis Rodman??? (0)

Anonymous Coward | more than 14 years ago | (#1519967)

"Such parallel 3-D universes, or three-branes, might contain unusual forms of matter, possibly forming stars, planets and strange people -- all less than a millimeter away from the home brane of the sun, Earth and Dennis Rodman." Ok... now i'm really confused... why is Dennis one of the planets?????

Re:Load of tosh. (1)

CyberMandrake (110333) | more than 14 years ago | (#1519968)

The "science" in some ways took the place Religion used to have in people's mind. Unfortunatelly, most non-technical people tend to repeat the "scientific"(or "holy") words without thinking about them; so do the non-technical press, and so on.

Re:Inconsistent gravity?? (0)

Anonymous Coward | more than 14 years ago | (#1519969)

Their is an even bigger mistake than this, to quote the article "Since the early 1980s, many physicists had suspected that space contains more than the familiar three dimensions", even Mr Albert E. discusses dimensions beyond 3 (If I remember correctly relativivty required it), and people had been proposing the posibility since (or before) Newton's day.

Re:Inconsistent gravity?? (1)

Austenite (21871) | more than 14 years ago | (#1519970)

That would be because in the neighbouring branes the area of space that interacts with Earth is empty and/or has a uniform gravity field.

At random points a long way from here, there might be a black hole in a neighbouring brane that produces effects such as gravtational lenses.

At least that's my crackpot take on a crackpot theory :)

Re:Load of tosh. (0)

Anonymous Coward | more than 14 years ago | (#1519971)

Thats a good way of putting it. Couple the need of the public to read and believe strange stuff, the need of some 'scientists' to produce it and the willingless of the media to spread it about and we practicly have a cult thang going here.

Misgivings (2)

omarius (52253) | more than 14 years ago | (#1519972)

I'm not so sure about this.

'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

Re:Anti-matter (1)

hubie (108345) | more than 14 years ago | (#1519973)

There is a lot of speculation on this issue. One thought is that of course any matter and anti-matter that came together would annihilate into gamma rays. The rest of the stuff we see is either matter or anti-matter that coalesced with each other, so there would be matter galaxies and anti-matter galaxies. The problem is that we wouldn't be able to tell remotely whether a galaxy is matter or anti-matter because, for instance, an anti-molecule (made up of an anti-protons, neutrons, and positrons) has the same electron shell structure as a regular molecule, so from afar they would look the same. Also gravity acts the same on matter and anti-matter.

I've always been rather partial to this explanation because it is simple and satisfies my preference towards Occam's Razor.

Robin, forget the Star Trek analogies (1)

Anonymous Coward | more than 14 years ago | (#1519974)

Robin, forget the Star Trek analogies, what this news really means is we're one step closer to constructing our very own TARDISes. Just fold space back on itself a few times and you too can have an entire seemingly infinate universe that's bigger on the inside than on the outside.

Face it, the universe is exactly as it is portrayed in Doctor Who. Bill Gates is constructing an army of his genetic creations to exterminate all competition, and Britain is ahead of us in the space race.

Yeah, yeah ... (1)

Cally (10873) | more than 14 years ago | (#1519975)

... and we'll all be living on Mars next week.

Could someone with the time & qualifications to actually understand the paper briefly say what's different between this and 'traditional' string theory / M space etc etc ?


--

Re:Load of tosh. (1)

Sunstar (93424) | more than 14 years ago | (#1519976)

Are you saying that the current scientific community is a bunch of idiots, or are you saying that science is worthless? If you are saying the latter, then you are either refusing to see the truth or you ar an idiot; I have no proof which. Bashing the scientific community is OK, but in the future, be more specific whether you are bashing people or science.

The photon issue (0)

Anonymous Coward | more than 14 years ago | (#1519977)

The key issue here is that anti-matter would still emit and reflect photon's, x-rays etc.. This meens that galaxies out their could be anti-matter and their is no way of knowing (unless we try to land on a planet in one and get a nasty shock).

Re:Not gonna happen. (2)

jd (1658) | more than 14 years ago | (#1519978)

Care for a jelly baby?

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.

Be CAREFUL with that thing! (3)

the eric conspiracy (20178) | more than 14 years ago | (#1519979)

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.

Re:Robin, forget the Star Trek analogies (0)

Anonymous Coward | more than 14 years ago | (#1519980)

I though science was pretty much ok with a tardis like object that's bigger on the inside than the outside. Somebody who knows what they are talking about please respond.

Re:Misgivings (1)

Midnight Ryder (116189) | more than 14 years ago | (#1519981)

If what they propose is really the structure of the universe (ok, a multiverse I guess) then conservation of energy would apply across all of the various universes - not just to a single universe. In the way that they propose this, you are right. There are some serious problems with how things would end up interacting with each other. Of course there could be more too it - what if massive gravity fields automatically extend a massive object (a star, for instance) across multiple dimensions? The theory leaves a lot of unanswered questions, and for every answer, there's an entirely new set of questions to be asked.

Re:Robin, forget the Star Trek analogies (1)

jonas37377 (85847) | more than 14 years ago | (#1519982)

Ooooh. Thanks for the blast from the past! So that is where M$ is heading with it's "technology", Darlecks (sp?)...

EXTERMINATE!! EXTERMINATE!!

Re:Load of tosh. (0)

Anonymous Coward | more than 14 years ago | (#1519983)

I was bashing the scientific fringe, i'll try to be more specific in future. The reply from CyberMandrake puts it in better perspective, I was never good with words.

Re:What's the beef? (0)

Anonymous Coward | more than 14 years ago | (#1519984)

It's not about being right or wrong. Good quality science is about letting other peer review and letting other people check your work before it gets splashed all over press and /.
This kind of paper may be 100% accurate but if it is it will get lost among all the crap that gets posted in the same way.

Splitting the graviton... (2)

Otto (17870) | more than 14 years ago | (#1519985)

Is it just me or does this article read a bit like a Terry Pratchett novel? :-)

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." :-P

When some bright lad tries to split the graviton, I'm outta here.


---

Re:Misgivings (1)

Gid1 (23642) | more than 14 years ago | (#1519986)

But, if you could send matter into a parallel universe, wouldn't that violate the conservation of mass and energy?

Well, if dark matter is just matter in another brane, then the gravitational effects could presumably cause some weird perpetual motion effects.

I think if these guys are right then the conservation of mass and energy thing goes out the window as a nice approximation when you don't have a whopping great blob floating past you in another brane.

Anyway, the paper's blocked by our bloody proxy. Who names their webserver 'xxx' anyway?!?

Re:What's the beef? (3)

Otto (17870) | more than 14 years ago | (#1519987)

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. :-)


---

Re:Anti-matter (1)

spiralx (97066) | more than 14 years ago | (#1519988)

There is actually a very small difference in the behaviour of matter and anti-matter in some reactions and the theory is IIRC that for every 1 billion AM particles produced 1 billion and one matter particles were produced. So there were 1 billion M-AM annihilations leaving a single matter particle, giving rise to the observed ratio of approx. 1 billion photons to every baryon.

That would be handy. (1)

MattXVI (82494) | more than 14 years ago | (#1519989)

I am waiting for Star Trek-like devices: 'portable submillimeter wormhole generator' and 'personal parallel universe transmitter' to appear on the market. :-)"

If I get one, I'm zapping to a universe with no First Post DUDEZ!! and no Bill Shithook Clinton.

Re:Misgivings (1)

Salgak1 (20136) | more than 14 years ago | (#1519990)

Omarius asked:

"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?"

Depends. Is mass-energy conservation a function of each individual dimension / "brane", or a function of the "Manyfold" ??? If the latter, no problem. Assuming that the math checks and peer review passes the theory. . . interesting stuff, tho. . .

Manifolds (3)

Hard_Code (49548) | more than 14 years ago | (#1519991)

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.

http://www.physics.helsinki.fi/~matpitka/honey.h tml

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.

arXiv.org (OT Slightly) (1)

DanaL (66515) | more than 14 years ago | (#1519992)

I probably won't understand the Manyfold universe theory, but this was a great article anyway, in that it pointed me towards arXiv.org, which looks like a pretty cool and (currently browsing the comp sci section) interesting site.

Dana


Re:Load of tosh. (2)

turg (19864) | more than 14 years ago | (#1519993)

"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."

Well, that proves it then. Somewhere in that five minutes, the universe started contracting.
-
<SIG>
"I am not trying to prove that I am right... I am only trying to find out whether." -Bertolt Brecht

One big problem... (1)

frankie (91710) | more than 14 years ago | (#1519994)

This theory claims that there are arbitrarily many parallel universes, separated by micron distances along additional dimensions. While strong, weak & electromagnetic forces are confined to our layer, gravity works across all dimensions simultaneously. And THAT is a HUGE problem.

What happens when a parallel universe star passes close to (or directly across) an object in our universe? Gravity would ramp up to insane amounts with no visible cause. Stars would be thrown out of galactic orbit, or ripped apart by tidal forces. If a few ordinary stars (like our Sun) happened to line up, the combined gravity could form a black hole where none should exist.

The fact is, in all of our history of astronomy, we have not seen this happen. But with thousands/billions/googols of parallel branes, it should be a statistical certainty. We would have already seen gravitational interference in the objects of our solar system, a million times over.

The only solution, which the article briefly mentions, is that ALL of the other universes must have tremendously lower densities than ours. This strikes me as inelegant to the extreme. A much more likely solution is that this brane theory is flat out wrong.

Re:What's the beef? (1)

janne (100806) | more than 14 years ago | (#1519995)

What I was trying to say: preprints come out every day, and curled dimensions is nothing new. What is the new thing in this paper compared to all other preprints?

Reading the abstract :) cleared things a bit. It's not about curled dimensions but about a few parallel universes which interact only through gravity.

For everybody interested in strings and stuff like this: read the book Elegant universe [amazon.com] by Brian Greene. Another good one is Life of the cosmos [amazon.com] by Lee Smolin (you may read the first part and forget the crap about black holes and evolution at the end if you feel so). Penrose's Emperor's New Mind has a similar structure: good review of modern physics at the beginning, hard-to-swallow personal views later.

The gist of it. (4)

ruppel (82583) | more than 14 years ago | (#1519996)

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...

Re:Load of tosh. (4)

dingbat_hp (98241) | more than 14 years ago | (#1519997)

Just look at the expanding / contracting universe theory [...] after this was suggested the scientific community disregarded it and the original author retracted it.

Seems that you don't have much of a clue what "science" means.

Western science doesn't teach facts (as such), it teaches a method. The method (crudely stated) says that a bright idea gets written up, passed around a bit, and described as a "theory". No-one claims it's provably true. It's just there as a hypothetical idea, for discussion and debate. If, after some thought, an experiment is devised that can demonstrate it, then we might start to collect experimental proof that validates it. The best experiment is one that requires some outlandish and unexpected result, but a result that is predicted by this theory. If the experiment then produces that result as predicted, weird as it first sounded, then the majority of scientists start to believe in it.

If after some enormous period of time, a general concensus and a lack of contrary experimental evidence, then the theory may begin to be regarded as a "law of nature". Even then, no-one really claims that it's perfect or entirely accurate; after all Newton's Laws of Motion are demonstrably inaccurate for relativistic speeds, yet we still feel quite happy to build aircraft based on them, nor has anyone suggested they be re-phrased as "Newton's Wrong Theory of Stuff, Hey Isaac, you really like suck, man".

So where does that leave "expanding universe theory" ? Well, it leaves it just there; as a theory. What's your problem here ? No-one ever claimed it was right, just that it was one possible explanation of how things worked, that fitted what was known at the time. We look harder, we think harder, we get better ideas about it. As we've been looking at the universe for barely any time at all, from just the one pipsqueak little planet, then it's amazing we've worked out as much as we have done! Universes are complex critters and they don't come with instruction manuals -- why should we be able to work out how they operate ?

Re:What's the beef? (2)

janne (100806) | more than 14 years ago | (#1519998)

About those extra dimensions: they are curled up in the same sense as the surface of a tube is curled up. If you look at a long tube from a distance, you see only one dimension (which you would measure by 'length'). A closer look reveals another dimension with a different circle-like topology. The same thing can happen with 10 dimensions, 7 being microscopic - it's just harder to imagine and the number of possible ways to do it is very high. :)

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.

Black Holes & Time Warps... (1)

Guttata (35478) | more than 14 years ago | (#1519999)

An excellent book which deals with with some ideas of parallel universes and time warps, etc.. is the book Black Holes and Time Warps : Einstein's Outrageous Legacy by Kipp Thorne. It doesn't deal directly with things like the world being a brane, but it deals with a lot of things in a similiar vein.

But I thought one of the more interesting aspects of this book is how it describes the way certain findings became accepted - it makes me wonder what happens behind the scenes in articles like this one...

The forward by Stephen Hawking is very interesting, as well.

Re:Splitting the graviton... (1)

frankie (91710) | more than 14 years ago | (#1520000)

"Oh dear, I appear to have accidentally ripped the fabric of space-time. Damn." :-P When some bright lad tries to split the graviton, I'm outta here.

I hoped that someone would take that bait. Groups of protestors have tried to shut down various particle accelerators using that exact claim. "If they rip open space or make a black hole, it will destroy the world/universe!" BZZT.

Dr. Lykken is correct, a micro black hole would evaporate itself to x-rays in infinitesimal time. Furthermore, such events happen ALL THE TIME, out in space. Fusion reactions inside active stars, or plate tectonics on a neutron star, or cosmic rays striking our atmosphere, or thousands of other effects -- all of them release energy and produce particle events that are MUCH more powerful than anything our puny accelerators are capable of.

The earth, the sun, and the universe are still here just fine. It's NOT a problem.

Windows 98 was made by the Cardassian ... (0)

Anonymous Coward | more than 14 years ago | (#1520001)

... it just arrived on Earth thru the wormhole :)

Re:Manifolds (2)

Hard_Code (49548) | more than 14 years ago | (#1520002)

I think the book I read might have been:

http://www.amazon.com/exec/obidos/ASIN/082477437 X/qid=943023771/sr=1-122/102-5569579-46784 25

Re:Load of tosh. (2)

rde (17364) | more than 14 years ago | (#1520003)

In reality the entire scientific community is bunch of argumentative ego-maniacs
And slashdot is a bunch of anonymous cowards.

You're falling victim to the same problem as the reporters you cited; you've heard about a couple of egomaniacal scientists, and you assume that 'science teaches that they're all ego driven'.

If a bunch of moronic reporters or lazy scriptwriters invoke a theory that's outdated (or just plain wrong), don't blame the scientists. Which scientist do you blame when even Lisa Simpson thinks that the coriolis effect works on toilets?

Re:The photon issue (0)

Anonymous Coward | more than 14 years ago | (#1520004)

The key issue here is that anti-matter would still emit and reflect photon's, x-rays etc.. This meens that galaxies out their could be anti-matter and their is no way of knowing (unless we try to land on a planet in one and get a nasty shock).

Actually, there is a way to distinguish matter and anti-matter at a distance. Due to a breakdown in symmetry with respect to the weak nuclear force, their are differences in the branching ratios of some nuclear decay modes. However, I've not heard of any attempts to check for these differences in distant galaxies (via, for example, spectrascopic analysis of x-ray telescope data).

Re:Load of tosh. (1)

Barahir (109349) | more than 14 years ago | (#1520005)

"In reality the entire scientific community is bunch of argumentative ego-maniacs."

Okay, as I scientist (or one in training, at any rate), I can't let that slip.

There is a certain truth to the statement: scientists tend to be egotistical. On the other hand, as a community, I think we've earned the right to a ceratin amount of pride. We've accomplished a helluva lot, esp. in the last century or so. Sometimes the justified pride just gets out of control...

We are also very definitely argumentitive. But that's a Good Thing. That's how we get at the truth: if I propose some new theory of gravity, I fully expect every scientist who's able to try and beat the crap out of it, and try and prove it's garbage. If I'm right, the theory will survive and maybe I'll win a Nobel Prize. If I'm completely off base, then all those arguments will show it. And if I'm partly right (which is the most likely possibility), then the process will weed out the garbage and preserve the good parts.

Re:Load of tosh. (1)

Brett Viren (296) | more than 14 years ago | (#1520006)

In reality the entire scientific community is bunch of argumentative ego-maniacs (who will be first against the wall when the revolution comes)

While I agree somewhat with your first statement (I am part of this comunity so I know first hand), I think your second is childish and ignorant. With out this comunity of argumentative ego-maniacs you would not have been able to express your ``learned'' opinion in this /. forum.

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.

I see you have your priorities straight. Why don't you go watch TV, it has lots of pretty pictures for you. You'll like it.

Criminal Waste of Public Funds (0)

Anonymous Coward | more than 14 years ago | (#1520007)


This is simple thievery, no more and no less. It's a fantastically extravagant welfare system for incompetent academics. They sit on their asses and make up fairy tales all day! That's their religion: They believe that anything they say is true. They have appointed themselves God, and they proceed to "create the universe" in a new way every year. And all you stupid suckers outside their little academic "club" just eat it up, don't you? You believe anything you're told.

Well, they can't prove any of this garbage, for the simple reason that it's all fantasy. I say, enough! No more! The increasingly insane and bizarre myths generated by the pseudo-scientific establishment are all the proof we need that "big science" is utterly bankrupt, morally and intellectually. Every year it becomes increasingly obvious that so-called "science" cannot explain anything at all. The total collapse of the discredited evolutionary "theory" was the first big public wake-up call, but in physics it's been happening for decades as well. But these pseudo-scientific ayatollahs can't give up their funding! They wouldn't be running scams for a living if they were capable of doing productive work! They have no choice but to keep robbing us. So in their desperation and sick hate for the truth, they dream up more and more implausible "theories" which purport to dispense with God. They're like dishonest children who get caught lying: When you reveal their lies, they keep making up more lies off the cuff to explain the discrepancies in the first lie. When you point out how pathetic the second-order lies are, they proceed to invent the most fantastic lies of all to explain those. And so on, ad infinitum.

They think they're God, but they just can't do the job, can they?

The answer is simple: If the only way you can rid God's Creation of its Creator is to postulate a universe the size of an ant, then it's time to give up and face the Truth. They've always known the Truth, too. Their insane hatred and lies wouldn't be so vicious if they weren't motivated by the knowledge of their own failure.

centre of the universe. (1)

bob_jordan (39836) | more than 14 years ago | (#1520008)

If there are an equal number of parallel universes "above" us as there are "below" then all those pre-Copernicus scientists (the likes of Aristarchus of Samos not withstanding) would have been right in saying we are at the centre of the universe.

Maybe they were onto something. :-)

Bob.

Re:Hmm (2)

Hard_Code (49548) | more than 14 years ago | (#1520009)

Um, actually it is not a "wild theory". Topology is a long standing field of mathematics with a wealth of research. We have already concluded that our universe has more than just three dimensions, and that it is hyperbolically curved. Topology, and manifolds have been around for a long time and I am /surprised/ that anyone is actually /surprised/ by this. I thought a multidimensional universe was cool when I read about it way back in 1995.

Manifold not ManYfold (3)

Hard_Code (49548) | more than 14 years ago | (#1520010)

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.

"Creating Life", for example. (0)

Anonymous Coward | more than 14 years ago | (#1520011)


They think they're God, but they just can't do the job, can they?

You've hit the nail right on the head. The tenets of the evolution religion imply that humans can create life in the laboratory. If we can't do that, then the whole thing's a joke. Well, they tried and they failed. And they tried again, and they've been trying ever since. No dice.

What really pisses me off most isn't the mere fact that the money's being wasted, but that it's being wasted on what amounts to a STATE RELIGION, one in which I do not believe. I don't make these morons spend their money to support my religion, why should I pay for theirs?

Why this could permit superluminal communication (0)

Anonymous Coward | more than 14 years ago | (#1520012)

Click through and look at the paper. The author postulates that the entire viewable universe is folded, macroscopically. If we were two-dimensional, so that the universe were a big sheet of paper, he's saying that big sheet of paper is all crumbled up and folded over. So objects that appear to us to be a billion light-years away may actually be only a millimeter away in this fourth (spatial) dimension. These objects can interact gravitationally across the fourth dimension, and this is what dark matter is--matter on another fold.

Interesting quote: "The folded universe picture permits apparently superluminal communication between different segments of the brane through the bulk." He argues that this solves some problems in cosmology.

Re:centre of the universe. (2)

drudd (43032) | more than 14 years ago | (#1520013)

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

Re:Splitting the graviton... (0)

Anonymous Coward | more than 14 years ago | (#1520014)

The latest concern wasn't just black holes, the more likely was that a new matter composed just of strange quarks would be created, with a lower energy level than normal matter, forming a chain reaction quickly transforming the entire planet to strange matter. This possibility was raised by the physicists on the project, which is why people were worried. The conclusion was that cosmic rays of higher energies hit the earth already, so let's not worry.

But it does bring up an interesting scenario: an answer to the "Where are they?" question. It seems unlikely that we're the first spacefaring species in the galaxy, and chances are any other should be millions of years ahead of us. So why haven't they arrived already? Well, any species inquisitive enough to travel space will probably also build particle accelerators....

Re:One big problem... (0)

Anonymous Coward | more than 14 years ago | (#1520015)

Actually the theory explains a number of astronomical observations, which you'll discover if you read the paper.

Re:Dennis Rodman??? (1)

IHateEverybody (75727) | more than 14 years ago | (#1520016)


why is Dennis one of the planets?

He was visiting home.

Re:Hmm (1)

kevlar (13509) | more than 14 years ago | (#1520017)

Are you smoking crack? We have not concluded anything other than our known 3-Dimensions, and that Space and Time are actually Space-Time. This is pretty much another one of those baseless thoeries that have no physical proof, which is fine because thats why we have theories. However, entertaining this as anything but a theory that someone conjured up is simply not scientific, and you shouldn't consider yourself such if you do. Mathematics can show many things, like objects with N dimensions, that doesn't mean that they actually exist or that there is even a universe that exists with such. Just because someone has an explanation that talks about folds and an excuse for gravity does not overall prove a damn thing about the Universe, simply because there's no *proof*.

Neat view on the Universe. Thats all this is. Considering it to be anything but that is baseless.

Re:centre of the universe. (1)

bob_jordan (39836) | more than 14 years ago | (#1520018)

I see nothing in the article to suggest anything other then a finite number of branes but your idea is interesting. Of course if the universe is mobius then this is all academic since we are all at the centre.

As for my different uses of the word universe. I accept I used it in two different ways but I prefer to think that I used it as it is in some of the more questionable science fiction around at the moment, and as it was by the early greek philosophers.

My apologies for any misunderstanding. I'l make the smiley bigger next time.

Bob.

Re:"Creating Life", for example. (1)

Derek Pomery (2028) | more than 14 years ago | (#1520019)

I assume this is some sort of joke.
Evolution does not imply the creation of life in a laboratory.
Unless you're willing to wait a couple of billion years.
Evolution HAS been observed, however.
In fossil evidence.
In changes in DNA.
In observed speciation.
It is the basis for many predictions in current biology which HAVE been shown true.
It is used in medicine, biology, sociology, computer sciences, and geology.
The difference between it and a religion, is that evolution is science, tested science, observed science, proven science. You, on the other hand, are a nutcase.

why in fucking hell was this moderated up?!?! (0)

Anonymous Coward | more than 14 years ago | (#1520020)

jesus, slashdot has really gone to hell. the least relevant, least humorous, and least thoughtful comment is sitting right on top with the highest score? there are more insightful, and on-topic posts below. instead of blatantly satirizing (through ignorance) this theory, why not actually discuss the merits of it?

Re:Manifolds (1)

Genom (3868) | more than 14 years ago | (#1520021)

"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."

Okay - I'm assuming this just breaks down when you go below 3 dimensions, as the shadow of a 2d object would also be 2d. Since we don't have any 1d objects, we can't test those, but if a 2d object casts a 2d shadow, and a 3d object casts a 2d shadow, wouldn't it follow that the 4d object would also cast a 2d shadow?

Of course, the whole Evangelion thing built around the 4d-produces-3d-shadow thing was just way too cool (watch the anime - I think the ep is somewhere around the middle of the series)

Re:"Creating Life", for example. (1)

mmontour (2208) | more than 14 years ago | (#1520022)

There is only a tiny scrap of "religion" in science, and that basically amounts to the beliefs that (1) people exist, (2) stuff exists, and (3) people and stuff can interact. Just about everything else is derived from observations. If you question a particular bit of science, you can look up the chain of assumptions and experiments that lead to it, and test each one individually for validity. If a transcription error resulted in a textbook being printed with "F=Gm1m2/(r^3)" instead of "F=Gm1m2/(r^2)", the error would eventually be noticed and corrected, since the new version of the formula would be mathematically and experimentally incorrect. If a similar transcription error took place in the printing of a new Bible, it would from then on be the Word of the Lord(tm & amen).

Oddball theories like the big-bang CAN be tested, by observing things like the ratio of hydrogen, deuterium, and helium in distant galaxies (and many, many other such observations). They can't be fully tested, but even a partial check for internal consistency is very valuable and lets you reject many ideas that sound good but just don't describe our actual universe.

As for the failure to create life in the laboratory, that's mostly due to the mind-boggling complexity of organic systems. It is *NOT* due to the lack of any mystic "life force" (and to be fair, neither is it the lack of a Frankenstein-ish lightning bolt). We are capable of *affecting* life on a very subtle scale, such as adding or deleting limbs from developing embryos. We can insert missing genetic material into cells by customizing a virus (e.g. to treat cystic fibrosis). The list goes on and on.

Honestly, you can get a much bigger sense of awe and wonder about the universe from reading a molecular biology or embryology journal (or watching pictures from astronomical probes), than from reading a typical book of the Bible.

Carl Sagan has written a couple of very good books about the wonders of science. Scientific American is a very good, accessible magazine. John Gribbin has written a good introduction to quantum mechanics called "In Search of Schrodinger's Cat". Read them, and maybe you'll get a hint of why scientists are.

Why should you pay to support "their religion"? I don't personally think you should. I'd be perfectly happy to allow a tax-exemption category (proportional to the % of tax dollars that are actually spent on scientific research) for anyone who chose to live the rest of their life on an Amish-style farm away from antibiotics, computers, doctors (excluding faith healers), and preserved food (Pasteur was a scientist, after all...).

Re:Robin, forget the Star Trek analogies (1)

mmontour (2208) | more than 14 years ago | (#1520023)

I think that you can do this with the Alcubierre warp bubbles, but I can't find a link to a paper right now.

Sub milimeter? How "sub"? (1)

CyberMandrake (110333) | more than 14 years ago | (#1520024)

I heard about another(?) theory proposing the existence of many dimensions "confined" (or somehow "tied") within a Planck space (the amount of space measured by a Planck Constant, a very, very, very small number) (I heared about this space being some kind of "quantum of space") Is this new theory (many dimensions within sub-milimeters) related with the older (many dimensions within Planck space) ???

Shut up. (1)

Jogar the Barbarian (5830) | more than 14 years ago | (#1520025)

If you're gutsy enough to castigate an entire /. post without even addressing its merits, then you should be gutsy enough to login.

You sound vaguely like a believer. I'm one too, and frankly I think your rabid vitriol makes you, and anyone else who believes in God, sound like a chauvanistic Luddite.

Shut up.

--GAck

Re:Inconsistent gravity?? (1)

janne (100806) | more than 14 years ago | (#1520026)

Relativity assumes 3 spatial dimensions and one temporal. That's four, but still only three for the space.

Re:Manifold not ManYfold (1)

janne (100806) | more than 14 years ago | (#1520027)

Manifold is another word for curved space.

Re:time and multidimensional space. (0)

Anonymous Coward | more than 14 years ago | (#1520028)

Time exists. Not only that, TIME HAS INERTIA!!! :)

Re:Manifolds (1)

janne (100806) | more than 14 years ago | (#1520029)

Uncertainty in quantum mechanics is not related to extra dimensions. Uncertainty is something more fundamental, although it may have some relationship with the 'fabric' of space-time we don't know about yet.

The position of a particle along those extra dimensions is just a kind of state of the particle.. except that in quantum mechanics particles are waves, and the state is not about th e position (only) but about the frequency of the wave in the direction of those extra dimensions. Different vibrational states give rise to different kinds of particles.

(Or closely like that... this really goes below my knowledge.)

You fool nobody. (0)

Anonymous Coward | more than 14 years ago | (#1520030)


If you're gutsy enough to castigate an entire /. post without even addressing its merits

I had the guts and brains to address the fact that it has no merits. Take it or leave it.


You sound vaguely like a believer. I'm one too

"Believer", yeah, right. You don't get to pick and choose. It's all or nothing. If you reject any part of God's Law, you have rejected the whole.


. . . frankly I think your rabid vitriol makes you, and anyone else who believes in God, sound like a chauvanistic Luddite.

Here's where you display the "sick hatred of the truth" that I referred to in my post. I speak the simple plain truth, which is obvious to any honest, reasoning being -- and you start whining about "rabid vitriol". You can't defend yourself against the truth, so you respond with an infantile retort: "I know you are, but what am I!"

We both know exactly what you are. Don't waste your time lying about it.

Re:One big problem... (1)

janne (100806) | more than 14 years ago | (#1520031)

... and space is mostly empty anyway, so collisions in our neighbourhood would be extremely rare, and "all of our history of astronomy" is only less than 1/10^7:th part of the history of the universe.

Learn to spell! It's eezy...erm, easy! (0)

Anonymous Coward | more than 14 years ago | (#1520032)

Brain is spelled "BRAIN" not "BRANE". You know, you guys REALLY need a proofreader here.

Re:Manifolds (1)

maxume (22995) | more than 14 years ago | (#1520033)

I don't really know, but I would think that a 2d object would cast a 1d shadow, i.e. a line. You say that we don't have any 1d objects, but we don't have any real 2d objects either. Anyway, depending upon which dimension you take the circle would cast a shadow of two dots seperated by a varying distance up to the diameter of the circle, or it would be a line segment with the length of the diameter of the circle.

!=new theory... (1)

Evil-Cartman (107229) | more than 14 years ago | (#1520034)

...But it's very much like a story that many scientists are beginning to tell about the universe...

i do not believe that this theorey is entirely new stuff. not to say it is not cool, it most definetly is...

check out Frijtof (sp??) Capra's "The Tao of Physics" (if you don't know, and you wanna seem cool and knowledgeable, it's pronounced "DAO" ... whatever ... )
"Tao of Physics" was written in 1975-ish (i believe) and its underlying theory is that there is a narrowing of the rift between Eastern (and no, i don't mean Cambridge, MA) Mysticism/Religon and modern Physics.

One of the sources Capra quoted talks of a tower with many rooms, each room containing many towers exactly like the first, on and on and on, like two facing mirrors... the mansion metaphor struck me as being remarkably similar.

anyway, this is pretty cool stuff, although the article didn't go into as much depth as i would have liked to see... *sigh*

Props...



"Cogito ergo es... I think, therefore you is." -The King of the Moon's Head,

"stationary matter" travels thru time at speed c. (0)

Anonymous Coward | more than 14 years ago | (#1520035)

This was in Green's book "Superstring Theory and the quest for Ultimate Truth" (title may not be quire right) Anyway, all matter travels through a four dimensional space (time + 3 spatial) at the speed of light. This is why traveling through space at near c speeds slows time down for yourself. Your directing your speed of travel into the 3 spatial dimenstions and away from the time dimension. Consequently, "stationary " matter is still traveling at the speed of light. It's just traveling through time at that rate instead of through space. Wierd, huh?

Explain what mean here, please. (1)

Don Negro (1069) | more than 14 years ago | (#1520036)

The total collapse of the discredited evolutionary "theory" was the first big public wake-up call,

What events constituted the collapse of the theory of evolution?

I'm not trying to troll or start a flame war, I really am curious. The public perception of evolution as a theory often differs wildly from the rather conservative notions of the actual text of the theory as written by Darwin, and I've often noticed that observations and explanations which are claimed to discredit evolution are actually aimed at the perception rather than the theory itself.

I really hope you respond, because in recent years my parents - after encouraging my interests in science throughout my childhood and adolescence - have developed a fascination with creation science, but can't explain their precepts well due to a difference in the focus of their educations. I would really like to understand what they believe, and I have a feeling that understanding what you're saying here would help me understand them.

Don Negro

No! Read the article! (2)

Sheridan (11610) | more than 14 years ago | (#1520037)

Hard_Code wrote:
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.
No! Whilst manIfold *is* a standard mathematical term, the article *does* indeed mean manYfold. This term is defined by the authors on page three of the article.

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

Re: Learn to spell! It's eezy...erm, easy! (0)

Anonymous Coward | more than 14 years ago | (#1520038)

That's "Brane" as in P-Brane and M-Brane.
They're mathematical entities.
W e're talking physics here... You're allowed make up new words as you go along, since you're talking about new things.

Some context for this... (5)

zunger (17731) | more than 14 years ago | (#1520039)

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.

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 [lanl.gov] 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. :) is one thing. In some of the models effective FTL travel may be possible.

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.

Re:Manifolds books on Amazon (1)

23 (68042) | more than 14 years ago | (#1520040)

Is it also a shadow from the higher dimensional manifold we see, when -looking up your url, i.e.
this one [amazon.com] - they also recommend reading/buying on an auction the book "Enlarge and firm your
breasts by hypnosis tape"????

Of course, it does have to do with geometry.... :)

Roland

Re:"Creating Life", for example. (0)

Anonymous Coward | more than 14 years ago | (#1520041)

Actually, you can watch viruses and bacteria evolve in the laboratory - HIV being a particularly nasty example.

There is no God. All god does is provide a father figure for the sheep, so that priests can control them. Sure the false hope religion gives is comforting, but we must forsake God to realise our own power.


www.infidels.org [infidels.org]

Re:Manifold not ManYfold (0)

Anonymous Coward | more than 14 years ago | (#1520042)

Oy! Moderators! Any of you actually READ the abstract before +'ing this incorrect correction??? (which was at +3 informative when I wrote this)

We propose that our world is a brane folded many times inside the sub-millimeter extra dimensions. The folding produces many connected parallel branes or folds with identical microphysics - a Manyfold.

Re:You fool nobody. (0)

Anonymous Coward | more than 14 years ago | (#1520043)

THERE IS NO GOD.

Stop deluding yourself, and start to take responsibility for your own actions.

If you want to choose god over science, then go live in a commune without computers, electrical power, medical care, and all the other things which science has produced. Of course, you'd most likely be dead in infancy, since you wouldn't have vaccinations.


Go to www.infidels.org [inifidels.org] and read up on atheism.

Irreducible complexity. (0)

Anonymous Coward | more than 14 years ago | (#1520044)


It's as likely for pure random chance to generate a human being as it is for a strong wind to blow through a junkyard and produce a 747. Think about it: They want us to believe that of all conceivable configurations of matter, pure random chance led inexorably and inevitably to the human race. The odds against it are absolutely mind-boggling! According to their own hypotheses, it should have been equally likely for an intelligent race to have "evolved" from squids or birds -- or for no intelligent race to have "evolved" at all. But they conveniently forget this logic when they come to the undeniable fact that we do exist, and we do have our present form. They can't account for that.


What events constituted the collapse of the theory of evolution?

Every educated person in the United States has been aware for years that evolution holds no logical or factual water. It's been almost entirely abandoned by serious biologists. The mainstream media steadfastly refuse to report the facts, quite naturally, but I suggest that you drop by your local university and have a chat with the head of the biology department. You'll find that evolution is treated as an historical curiosity and is no longer taught. So-called "evolutionary biologists", who substitute undisciplined speculation for hard facts, are the only ones still clinging to the illusion.


in recent years my parents - after encouraging my interests in science throughout my childhood and adolescence - have developed a fascination with creation science

That's not surprising. They encouraged you to seek out the truth, and obviously they were sincere in that because they've continued to seek out the truth themselves. You're lucky to have parents like that.


The public perception of evolution as a theory often differs wildly from the rather conservative notions of the actual text of the theory as written by Darwin

Darwin himself admitted -- in so many words -- that he could not account for the development of the modern vertebrate eye. In other words, he admitted that his theory was nothing but an idle fantasy. It was the first canonical example of irreducible complexity, and ultimately that crack in the foundations of evolution religion went on to bring down the whole absurd edifice.

Re:Criminal Waste of Public Funds (1)

coslor (116451) | more than 14 years ago | (#1520045)

Anonymous Christian Coward states:
Every year it becomes increasingly obvious that so-called "science" cannot explain anything at all.
Obviously! It's amazing that people haven't realized this before! I mean, if these myths like "Quantum Physics" or "Molecular Biology" actually had predictive power and could be used in everyday life, we'd end with things like:
  • Computers with components that you could see them only with the best of microsopes
  • Human-engineered microbes and viruses that can actually change the DNA of living cells
  • Hydrogen bombs
  • Communication using coherent light through thin glass fibers
Come on, we don't see "Buck Rogers" things like that in our everyday world, do we? What? We do? Damn! Maybe these guys in their little "club" actually have something here. Well, your argument, as stated, seems to be a little thin. Perhaps you could back it up with a few clarifications:
  1. This God that you seem to have put forward as the Uncaused Cause: Where does He live? What is He made of? What are the physical laws that determine His abilities? How might we experimentally prove or disprove His existance and properties?
  2. Please give three examples of the "insane hatred" of mainstream scientific institutions. (I wasn't personally aware of it.) Please be specific and concrete.
The above information might make your post seem a little less vitriolic and a little more like rational discourse, which I'm sure was your intent all along.
Chris Coslor
coslor[at]sprynet.com

Uhhh . . . Hello? (0)

Anonymous Coward | more than 14 years ago | (#1520046)


There is no God. All god does is provide a father figure for the sheep, so that priests can control them. Sure the false hope religion gives is comforting, but we must forsake God to realise our own power.

You're as mindlessly dogmatic as the Creationist Troll is, but there's a difference: He's kidding.

You can't prove that God doesn't exist any more than he can prove that God does exist (or, even postulating the existence of a god, that his god is the right one.) So chill out.


I don't know what you mean by "our own power", but I have a weird and depressing suspicion that it has something to do with either Ayn Rand or Nietzsche. Ugh.

Load More Comments
Slashdot Login

Need an Account?

Forgot your password?