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Math Science

Strings Link the Ultra-Cold With the Super-Hot 236

gabrlknght writes "Superstring theory claims the power to explain the universe, but critics say it can't be tested by experiment. Lately, though, string math has helped explain a couple of surprising experiments creating 'perfect liquids' at cosmic extremes of hot and cold. 'Both systems can be described as something like a shadow world sitting in a higher dimension. Strongly coupled particles are linked by ripples traveling through the extra dimension, says Steinberg, of Brookhaven. String math describing such ripples stems from an idea called the holographic principle, used by string theorists to describe certain kinds of black holes. A black hole's entropy depends on its surface area — as though all the information in its three-dimensional interior is stored on its two-dimensional surface. (The 'holographic' label is an allusion to ordinary holograms, where 3-D images are coated on a 2-D surface, like an emblem on a credit card.) The holographic principle has value because in some cases the math for a complex 3-D system (neglecting time) can be too hard to solve, but the equivalent 4-D math provides simpler equations to describe the same phenomena.'"
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Strings Link the Ultra-Cold With the Super-Hot

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  • string analogues (Score:3, Interesting)

    by rlseaman ( 1420667 ) on Tuesday April 14, 2009 @07:05PM (#27579323)

    "The point is that we have two different kinds of systems capturing the same kind of physics," says string theorist Clifford Johnson

    Back in the day it was commonplace to construct analogs of mechanical systems, for instance, using electronic components [vwh.net]. If the differential equations describing the two systems are similar, so will their solutions be.

    That the topic is string theory is also reminiscent of how soap works [elmhurst.edu]. Half of a soap molecule is soluble in water, the other half insoluble - thus bridging between wet and oily substances. Very yin and yang.

  • Re:Of course (Score:3, Interesting)

    by linzeal ( 197905 ) on Tuesday April 14, 2009 @07:10PM (#27579377) Homepage Journal
    String theory to me is like those search algorithms that you run into that are utterly unique yet confounding to parse but get the job done somehow and no one feels smart enough to question half the time. A modified standard model works for me, with some of the new phenomenologies [arxiv.org] emerging based on it.
  • Hang on (Score:2, Interesting)

    by Anonymous Coward on Tuesday April 14, 2009 @07:15PM (#27579453)
    Hang on a minute... "Similarly, the extra dimensions that strings require would probably be far too small to detect by available methods." What? I was under the impression a dimension was like a mathematical axis, i.e. infinite in two directions...? I keep seeing a lot of articles on this sort of low level physics and mathsy stuff, and I'm not sure if I'm not understanding it because it is too complicated, but I'm starting to think the reporters are dumbing everything down and trying to explain complicated topics using nontechnical language, just throwing in the odd keywords to sound clever. There seem to be two extremes - sciencey news articles written by reporters which try to give a general idea to people who don't have a clue (It's something to do with holography, dimensions, strings and is far too complicated for you), and sources like wikipedia, which you need to already know what it's telling you to understand (I'm not saying that is a bad thing, I'm saying wikipedia is not good for teaching things - which it isn't supposed to be, I think). Can't I have something inbetween?
  • by c6gunner ( 950153 ) on Tuesday April 14, 2009 @07:25PM (#27579595)

    The thing is, "God did it" doesn't give you any equations or principles. String theory, while it may turn out to be completely wrong, at least gives us something to test.

  • Re:string analogues (Score:4, Interesting)

    by DirtySouthAfrican ( 984664 ) on Tuesday April 14, 2009 @07:28PM (#27579629) Homepage
    Well this is closer to "universality", which is a concept in field theory and condensed matter physics, in which the "atomic" characteristics of a system are largely irrelevant to its macroscopic properties, save for specifying a few parameters like viscosity or resistivity. Unlike your differential equation example, the equations for both are very different and non-trivial. When you start enumerating differential equations starting from the simplest you can write down, the harmonic oscillator, heat equation, diffusion equation and so forth pop out right away. You'll be writing for a long time before 11D supergravity equations of motion pop out.
  • Predicts Everything (Score:3, Interesting)

    by DJ_Adequate ( 699393 ) on Tuesday April 14, 2009 @07:45PM (#27579819)

    I think the problem is that it is so complicated it predicts everything that can or could happen. So the math is interesting to apply after the fact--but you can't extract the real from the possible results through the math alone.

    Having to many points is the same as having none at all. And that's what String Theory in its current form seems to be.

  • by StevenMaurer ( 115071 ) on Tuesday April 14, 2009 @08:13PM (#27580217) Homepage

    ...all claiming that String theory is not testable.

    To these people, I'd like to point out that:
    1] Not being testable with current technology is not the same as not making any testable predictions. Technology advances, after all, and there are predictions that were made by Einstein that are still being tested today.

    2] It's flat out wrong [blorge.com] to say there is no work being done to test String theory. The LHC will begin to unlock a number of answers in this regard.

  • Actually, most physicists believe the LHC will fail to find the Higgs and in doing so give some hints as to why the Standard Model is broken.

    Most physicists are optimistic like that.

  • by serutan ( 259622 ) <snoopdoug AT geekazon DOT com> on Tuesday April 14, 2009 @11:27PM (#27581919) Homepage

    My non-technical mother in law is interested in string theory but she has no clue what it's about, except that everything in the universe is made out of tiny "strings" that go into another dimension. She is a retired grade school teacher and knows what atoms and subatomic particles are, and she understands the idea of a line having zero width and a plane having zero thickness. I'm trying to come up with an analogy that will get across the basic idea.

    Say the universe is two-dimensional, like the surface of a drum. No thickness, just a plane. Then say somebody outside of the universe pokes a needle through the drum head and pulls a piece of thread through it. The thread is one-dimensional, with no actual thickness, so the place where it goes through is just a point. Nobody who lived in the 2-dimensional surface could see the point because it has no thickness. But what if the thread vibrates like a guitar string... as it moves back and forth, the point where it goes through the drum also moves back and forth. The spot becomes a little line. If the string didn't vibrate exactly back and forth but kind of wandered around in a fuzzy pattern, the point would look like a hazy dot.

    Because the string vibrates so fast, the people in the plane of the drumhead would never perceive it as a point, but only as a blurry spot (assuming they could see things that small).

    That's what a subatomic particle is in our universe, except in 3 dimensions. Wherever a vibrating cosmic string passes through our universe, it forms a hazy dot-like pattern in space, which to us is a subatomic particle.

    I know this is far from exact, but does it give enough of the general idea?

  • by Tacvek ( 948259 ) on Tuesday April 14, 2009 @11:40PM (#27581999) Journal

    But that is no different than quite a bit of Math itself, where there is a lot built on certain very difficult unsolved problems. There are quite a few theorems where the only currently developed proof is conditional upon the validity of one of those major unsolved theorems. Perfectly normal.

  • Re:Of course (Score:3, Interesting)

    by CFTM ( 513264 ) on Wednesday April 15, 2009 @01:18PM (#27588089)

    Well, the only evidence we have on how long "prehistoric peoples" is found in our very limited fossil record. Every really old cave man we seem to find, typically is in his 30's or 40's.

    You can't conclusively say that they didn't live for hundreds of years, but given that our life spans have been growing over the past 100 years, and given that our limited fossil record suggests that these people did not live that long, I think you can safely assume based on the best available information that "prehistoric" humans did not live 100's of years.

    That would imply some serious devolution...

  • Re:Of course (Score:1, Interesting)

    by MinistryOfTruthiness ( 1396923 ) on Wednesday April 15, 2009 @03:04PM (#27589313) Homepage Journal

    Just out of curiosity, what would be the difference between skeletons that age at 1/5th the rate (for whatever reason) and lived to 200 years old versus those of people who lived for 40 years? I'm no aging expert, but there's one thing that's always puzzled me: Why can the body repair itself to almost new, most of its cells are constantly being replaced, and yet over time its ability to do so diminishes? Is it possible that this diminution could have happened slower at one point? Maybe only in certain sets of people? And is it possible that something genetic was introduced into the bloodlines that quickly reduced lifespan of the groups that could live that long?

    I honestly have no idea, but I don't think it's quite so cut and dry. As far as I know, we still don't really understand why "aging" happens, and last I heard, there were some who classify aging itself as a disease to be cured, rather than something inevitable.

    For instance, we know that cells have "self destruct" signals that tell it when to die. Could this have not existed at one point? Could evolution have reduced the frequency of cancers by killing us sooner? I've also heard there are "tails" on DNA ( I forget the name ) that get shorter each replication, and that this affects the cell's ability to repair itself or reproduce or something. Maybe that wasn't happening at one point?

    I suppose if anyone has a good answer, someone on this site will have heard it and can relate it. I'm not making any points, just curious.

10.0 times 0.1 is hardly ever 1.0.