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String Theory Predicts Behavior of Superfluids
schrodingers_rabbit writes "Despite formidable odds, condensed matter physicists have made a breakthrough most thought impossible — finding a practical use for string theory. The initial breakthrough was made by physicist and cosmologist Juan Maldacena. His theory states that the known universe is only a 2D construct in anti-de-Sitter space, projected into 3 dimensions. This theory manages to model black holes and quantum theory congruently, a feat that has eluded scientists for decades; but it fails to correspond to the shape of space-time in the known universe. However, it does predict thermodynamic properties of black holes, including higher-dimensional viscosity — the equations for which elegantly and almost exactly calculate the behavior of quark-gluon plasma and other superfluids. According to Jan Zaanen at the University of Leiden, 'The theory is calculating precisely what we are seeing in experiments.' Unfortunately, the correspondence cannot prove or disprove string theory, although it is a positive step." Not an easy path to follow: one condensed matter theorist said, "It took two years and two 1000-page books of dense mathematics, but I learned string theory and got kind of enchanted by it. [When the string-theory related] thing began to... make predictions about high-temperature superconductors, my traditional mainstay, I was one of the few condensed matter physicists with the preparation to take it up."
That is to say, if you view that the proving of string theory to be true a positive step.
Is it just me or does String Theory really sound like someone is making it up as they go along. It's like: "we haven't a clue whats going on but reality's so wierd we've decided to pull a theory out of our ass!"
I'm always amazed that theoretical physicists can manipulate such immensely complex abstract objects in their heads and still be able to breathe and maintain bladder control. It really makes software engineering look like a piece of piss. Much respect.
I would also say that having worked with academic medics, chemists, mathematicians, computer scientists and biologists, physicists are almost always the coolest, most down to earth and least douchey scientists out there.
the known universe is only a 2D construct in anti-de-Sitter space, projected into 3 dimensions
Well if THAT'S all it is, I see no reason to upgrade my video card.
Rich And Stupid is not so bad as Working For Rich And Stupid.
String theory works because the math works. There isn't anything special about the string theorists' model of humming cosmic strings that makes it work. All particle behavior is explainable using mathematics.
What makes this interesting is that the model allowed for the construction of mathematical constructs that explain the behavior correctly. But it still doesn't say anything about the predictions that the model completely blows.
What String Theory has, more than anything else, is a great set of marketeers behind it. Michio Kaku is a smart and articulate guy. It's not the steak, it's the sizzle.
on page 642 of the second book, they divide by zero, so back to the drawing board.
one condensed matter theorist said, "It took two years and two 1000-page books of dense mathematics, but I learned string theory and got kind of enchanted by it.
Boy, long winter evenings must just fly.
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
I have a theory that there must be a joke in here somewhere about strings and superfluid!
Maybe something about David Carradine or Michael Hutchence?
The Maldacena duality can't be used to 'make predictions' with a string theory, its just a correspondence between a string theory and a conformal field theory. It's useful because sometimes calculations which are hard in a CFT can be made in the corresponding string theory which is sometimes easier (or vice versa). It cannot be used to support the physical validity of some string theory.
The main criticism of string theory is that it is too flexible. It can be contorted to generate any prediction, so it predicts nothing. This problem is not unique to physics; I saw it in economics too. Add more parameters to your model and you can fit historical data better, but your predictions of the future get worse. TFA seems to be just a string of examples of contorting string theory to fit past experimental results.
The holographic principle doesn't mean that the universe has only 2 spatial dimensions, but rather that the universe can be modeled using one less degree of freedom than our view of spacetime would imply. Again, these kinds of theories are not suggesting that our space is two-dimensional, rather they are saying that the 3 dimensions we observe are emergent from a lower-dimensional description. All of the 'information' in a given region of space can be described as being encoded in the surface of said region.
This remarkable, if bizarre, conclusion gains considerable support from the fact that black-hole entropy (and entropy is a measure of information content) is related only to the surface area of the black hole. So this is a case where we know with some confidence that we can indeed reduce all the information about a 3D region of space (the black hole) to an expression that only relies on 2 dimensions (the surface of the black hole). The holographic principle appears in numerous theories that imply that this holds generally for any region of space, not just black holes.
Now, whether you view this is 'just a mathematical trick' or 'a deep insight into the actual structure of the universe' is in some sense a matter of taste. (The same goes for all other physical theories: e.g. do electrons exist or are they just mathematically-useful constructs? How about photons? Gravity waves? Spacetime?) If you take the math seriously then this may mean that our universe is in some sense 'actually' 2-dimensional, with the three spatial dimensions we see being emergent instead of fundamental.
But in no case is the theory saying that there are not 3 spatial dimensions. The predictions it makes are for particles moving through a 3+1 spacetime.
I don't know, but I do have a theory how 7of9 would look in a string.
This is not the sig you're looking for.
Oh, I think you know the answer to that.
Is something burning?
Oh, it's my karma.
Everybody gives string theory a hard time because it hasn't made any predictions, and because it can't be tested. Give it some damn time. It took ages before anyone could make useful predictions with quantum mechanics, and it was shunned for a while too (even by Einstein) and now it's an essential part of our scientific understanding. We shouldn't be so quick to cast out string theory either. Some time, eventually, maybe very far down the road (and if it turns out to be right), it too could be as useful as quantum mechanics has become. I wish scientists would just open their damn minds for once.
I have left slashdot and am now on Soylent News. FUCK YOU DICE.
The major problem with String/F/D/Dn/S/Brane/M/Multiverse/Whatever's-next Theory is that every time someone finds a problem that doesn't fit with experiments/reality they just go and find an excuse and then modify the equations until it mathematically works out in that general direction. They don't start with the latest and greatest and modify that. They just pick their favourite Theory-of-the-day and add an extra dimension here, or there, twist it there, or subtract another infinite from both sides, because the formula is inconveniently looking incorrect at the moment. In other words, Just squish the Jello a little here and make it come out over there instead, until someone discovers 'the new mess' on the floor.
If a theory has no basis in fact (i.e. no physical reality that can be described) then it is just Math. Math is not reality. You can model anything with Math, and it doesn't even have to exist.
"Do you know string theory?"
"No, I'm a frayed knot."
"Omnis tuus capsa sunt inesse nos"
Spaghetti is tastier than string, and they could unify biology and physics with AdS/FSM spaces. How many dimensions has His Noodly Appendage?
As always....xkcd explains it best here.
Motorcycles, Robots, Space Gossip and More!
http://xkcd.com/171/
Your "intelligent variable" is just the long-discredited "hidden variable" interpretation dressed up with a bunch of hokum to explain away the Aspect Experiment. You can't close your eyes to the truth and stumble around in the dark, when a single photon will show you His Noodly Appendage!