Physical reality of string theory demonstrated

July 6, 2009

String theory has come under fire in recent years. Promises have been made that have not been lived up to. Leiden (The Netherlands) theoretical physicists have now for the first time used string theory to describe a physical phenomenon. Their discovery has been reported in Science Express.

'This is superb. I have never experienced such euphoria.' Jan Zaanen makes no attempt to hide his enthusiasm. Together with Mihailo Cubrovic and Koenraad Schalm, he has successfully managed to shed light on a previously unexplained natural phenomeon using the mathematics of .

can form a special kind of state, a so-called quantum critical state, that plays a role in high-temperature super-conductivity. Super-conductivity at high temperatures has long been a 'hot issue' in physics. In super-conductivity, discovered by Heike Kamerlingh Onnes in Leiden, electrons can zoom through a material without meeting any resistance. In the first instance, this only seemed possible at very low temperatures close to absolute zero, but more and more examples are coming up where it also occurs at higher temperatures. So far, nobody has managed to explain high temperature super-conductivity. Zaanen: 'It has always been assumed that once you understand this quantum-critical state, you can also understand high temperature super-conductivity. But, although the experiments produced a lot of information, we hadn't the faintest idea of how to describe this phenomenon.' String theory now offers a solution.

This is the first time that a calculation based on string theory has been published in Science, even though the theory is widely known. 'There have always been a lot of expectations surrounding string theory,' Zaanen explains, having himself studied the theory to satisfy his own curiosity. 'String theory is often seen as a child of that aims to devise a revolutionary and comprehensive theory, a kind of 'theory of everything'. Ten years ago, researchers even said: 'Give us two weeks and we'll be able to tell you where the big bang came from. The problem of string theory was that, in spite of its excellent maths, it was never able to make a concrete link with the physical reality - the world around us.'

But now, Zaanen, together with his colleagues Cubrovic and Schalm, are trying to change this situation, by applying string theory to a phenomenon that physicists, including Zaanen, have for the past fifteen years been unable to explain: the quantum-critical state of electrons. This special state occurs in a material just before it becomes super-conductive at high temperature. Zaanen describes the quantum-critical state as a 'quantum soup', whereby the electrons form a collective independent of distances, where the electrons exhibit the same behaviour at small quantum mechanical scale or at macroscopic human scale.

Because of Zaanen's interest in string theory, he and string theoreticist Koenraad Schalm soon became acquainted after Schalm's arrival in Leiden. Zaanen had an unsolved problem and Schalm was an expert in the field of string theory. Their common interest brought them together, and they decided to work jointly on the research. They used the aspect of string theory known as AdS/CFT correspondence. This allows situations in a large relativistic world to be translated into a description at minuscule quantum physics level. This correspondence bridges the gap between these two different worlds. By applying the correspondence to the situation where a black hole vibrates when an electron falls into it, they arrived at the description of electrons that move in and out of a quantum-critical state.

After days and nights of hard grind, it was a puzzle that fitted. 'We hadn't expected it to work so well,' says a delighted Zaanen. 'The maths was a perfect fit; it was superb. When we saw the calculations, at first we could hardly believe it, but it was right.' Gateway to more

Although the mystery of high temperature super-conductivity isn't fully resolved, the findings do show that major problems in physics can be addressed using string theory. And this is just the start, Zaanen believes. 'AdS/CFT correspondence now explains things that colleagues who have been beavering away for ages were unable to resolve, in spite of their enormous efforts. There are a lot of things that can be done with it. We don't fully understand it yet, but I see it as a gateway to much more.' The fact that Science was keen to publish this discovery early confirms this.

More information: String Theory, Quantum Phase Transitions, and the Emergent Fermi Liquid Mihailo Cubrovic, Jan Zaanen, and Koenraad Schalm Published online July 2 2009; 10.1126/science.1174962 ( Research Articles)

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Source: Leiden University

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5 / 5 (8) Jul 06, 2009
Wow. I wonder if this is actually as revolutionary as it sounds.
5 / 5 (7) Jul 06, 2009
Now we'll have to wait and see if this just a math thing or an indication that string theory works. But its new and a change!
2.2 / 5 (25) Jul 06, 2009
String theory is too elegant not to be true. God wouldn't do something like that to us.
3 / 5 (1) Jul 06, 2009
Hmm. First off, even if I'm a poor student of science history, I believe string theory described physics at its conception, for QCD phenomena. It was just that a year or so after they could make the same predictions from QCD itself. And certainly string theory has been said to predict black hole entropy as much as other models and so on.

Also, I don't think the use in describing an emergent phenomena is evidence for strings themselves any more than emergent chemistry is evidence for quarks. If anything, this article will be used as another one of those mythical "promises made that have not been lived up to".
not rated yet Jul 06, 2009
@BobSage - That's what they say about Garrett Lisi's ToE, based on Lie E8 geometry, and yet they aren't congruent.

Time to hedge my bets!
3.3 / 5 (9) Jul 06, 2009
String theory is too elegant not to be true. God wouldn't do something like that to us.

4.7 / 5 (10) Jul 06, 2009
The likelihood of string theory producing a perfect mathematical description of this complex phenomenon by pure accident is probably pretty small. This is the first strong (if indirect) evidence I've seen for string theory. But indirect evidence counts. Just as we observe black holes indirectly through their effect on surrounding matter and light, we can also observe string theory indirectly through its derivative formulas. Quarks are also never observed directly (so far as I know); their existence is typically inferred from the behavior of the hadrons that contain them. It will take a long time before strings are observed directly, if ever. If string theory correctly predicts phenomena better than any other theory, then it will be used whether or not strings have been directly observed.
5 / 5 (5) Jul 06, 2009
If string theory helps predict the recipe for a stable room temperature superconductor, then that would be pretty persuasive.
4.8 / 5 (5) Jul 06, 2009
Simple math does not a reality make. Newton's formula for gravitation is elegant & simple. Yet Einstein showed how it's far more complicated than that.

This is the first thing that string theory can resolve that defies other explanations. But that doesn't make string theory true, only possible. More cases like this, however, will really bolster its standing as the right way to go.

Of course, now we have to ask: WHICH string theory is the right one?
4.2 / 5 (5) Jul 06, 2009
This is not "string theory - theory of everything" it is mathematics developed for string theory applied to some problem from a different field.

Just as successfully using metric tensor to solve economic problem does not give support to general relativity so this result does nothing to support string theory as a fundamental theory of all interactions.
4.4 / 5 (7) Jul 06, 2009
These authors did not show the physical reality of string theory. They applied string theory methods to a condensed matter system, which is not saying that string theory is a correct unified theory of quantum mechanics and gravity. What they did is use AdS/CFT correspondence to attempt to describe quantum critical points in condensed matter. As far as I know, no predictions of this theory have been proven correct, and it appears to be mostly boasting from the authors.
2.3 / 5 (4) Jul 06, 2009
String theory is too elegant not to be true. God wouldn't do something like that to us.

So science is based on elegance?
3 / 5 (5) Jul 06, 2009
Physical reality of string theory demonstrated

I don't see anything in this article indicating that string theory made a prediction which was then experimentally proven.

Anyway, didn't 3 papers get printed last month showing that separating time and space allowed them to get rid of string theory?
1.8 / 5 (5) Jul 06, 2009
I believe the technical name for this breakthrough is called Fraud. It may also be know as B.S. It's very exciting and warrants additional investigation by the people who spent good grant money to pay for this fraud.
4.8 / 5 (4) Jul 07, 2009
11 dimensions is rather complex and lacks elegance and is as convenient as religion when one has no ability to test the existence of strings. String theory is so broad it would be difficult to find a problem that it couldn't explain. But mathematical trickery is far from real physics. An approximation here and there to obtain a result is about as far as the trickery goes in real physics.
4.7 / 5 (6) Jul 07, 2009
What makes this unsurprising is that string theory is tuneable. You can make it predict anything you want because you get to choose what the shape of space is before you start. Its not one theory, its an infinite number of theories. And often the maths is just ridiculously hard.

So its amazing that they could actually get a solution. If it works for other phenomena they've got to explain WHY it works.
5 / 5 (3) Jul 07, 2009
This is not "string theory - theory of everything" it is mathematics developed for string theory applied to some problem from a different field.

Tell that to John Nash.
4 / 5 (4) Jul 07, 2009
The theories that are most elegant are the ones that are intuitive. Obtuse and arcane theories not grounded in reality can hardly ever be described as elegant even if the math adds up. When you start to go beyond 4 dimensions, it becomes so counter-intuitive that it is downright ugly.
1 / 5 (1) Jul 07, 2009
1 plus 1=4
1.4 / 5 (5) Jul 07, 2009
11 dimensions is rather complex and lacks elegance and is as convenient as religion when one has no ability to test the existence of strings. String theory is so broad it would be difficult to find a problem that it couldn't explain. But mathematical trickery is far from real physics. An approximation here and there to obtain a result is about as far as the trickery goes in real physics.

Very good points that are always ignored by string dreamers...

Personally I also find it difficult to believe in quarks and nuclear forces as long as their existences have never been demonstrated.
1 / 5 (2) Jul 07, 2009

1 / 5 (1) Jul 07, 2009
String theory is too elegant not to be true. God wouldn't do something like that to us.

No! She certainly would not!
3.3 / 5 (10) Jul 07, 2009
..String theory is too elegant not to be true...
This just illustrates, how silly and religious is understanding of physical theories by common layman people. Can someone explain, what is so elegant in string theory? You're just repeating Brian Greene mantra like taoist monks...
Jul 07, 2009
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3.4 / 5 (9) Jul 08, 2009
Nothing is more elegant than a knowledge system based on nothing else but falsifiability.

Unfortunately The String Hypothesis doesn't appear to be falsifiable due the exceptionally large number of String Theories that are possible.

So it sure isn't based on falsifiability,

1.7 / 5 (6) Jul 08, 2009
This is just because one of string postulates (Lorentz invariance from special relativity, on which string theory is based) contradicts with postulate of hidden dimensions. From model of surface water waves spreading follows clearly, hidden dimensions should manifest just by violation of Lorentz invariance: the dispersion of surface wave is caused/affected by spreading of energy through underwater: if underwater (dimension) would dissapear, the spreading of surface wave would fill relativity exactly.

Due the redundancy o postulates string theory is behaving like loose table: the contradicting terms are making noise and singularities in equations, which leads to landscape of 10E 500 possible solutions and lost of predictability and falsifiability.

Analogous problem is in fact relevant even for loop quantum gravity and all formal theories, based on well minded, but blind combinations of relativity and quantum mechanics, because postulates of these theories aren't compatible each other. String theory is just one of simplest examples.
1.6 / 5 (7) Jul 08, 2009
..for StringTheory I assume less time of development until it "really flies" and will deliver falsifiable predictions...
Every combination of relativity and quantum mechanics would give better predictable power, then relativity or quantum mechanics itself. The only question is, if blind combination of existing theories is the most effective (and cheapest..) way, how to understand reality.

Aether Wave theory explains strings as a foamy density fluctuations of hypothetical dense gas, which is forming vacuum. While in superconductors electrons are heavilly compressed near holes by Coulomb forces, they behave in simmilar way, like particles on the boundary of black hole and they forms foamy fluctuations of density, we can use some string theory concepts for their description.

But string theory wasn't designed for such purposes, it was supposed to describe electron itself. While string theory failed this target apparently from obvious reasons (by AWT particles are formed by whole clouds of strings and membranes of vacuum foam, not by isolated stringy loops, as string theorists believe), the tendency to model superconductivity by AdS/CFT correspondence is just an attempt to make the best of a bad job. We should realize, how string theorists are frustrated after forty years of ST development, while still having no real physical system to describe...

AWT explains superconductivity in much more illustrative way - and if someone is interested about exact numbers here, he can simply solve classical quantum equations of large compressed particle system on computer - here's no need to integrate another abstract theory into formal description of superconductivity phenomena.
1.8 / 5 (8) Jul 08, 2009
... I'm not in a position to be able to pretend that I know everything..
me too, but the claim "we hadn't the faintest idea of how to describe this phenomenon" isn't correct at all, because some of us have such idea already for long time. It's just string theorists, who are pretending whole years, they're rescuers of physics.

The HT superconductivity is conceptually quite simple phenomenon and no working knowledge of string theory is required for its understanding at all. String theorists shouldn't forget it when pretending, they can provide the only description of this phenomena, explanation the less.

From AWT follows, every dense cloud of compressed electrons should exhibit a superconductivity, so we should rather think about ways, how to prepare such cloud without using of expensive diamond layers and other ultrahard materials. It's rather engineering problem - how to compress slippery electrons into flat channels. It means, how to create superfluid analogy of vacuum just from charged matter? Virtually everybody can propose the right trick by now!
not rated yet Jul 09, 2009
i thought i was crazy....

ill pat my dog just forget reading any of this

not rated yet Jul 09, 2009

Where is time in this formula? is the speed of gravity infinite?
So this is phenomology.
And I believe string theory is phenomology as is religion. We still don't know what to do with time.

But as long as we can use all theory to go forward I can live with it though.

5 / 5 (1) Jul 10, 2009
If the shoe fits, wear it.
2.3 / 5 (3) Jul 10, 2009
Sorry, but it's like saying: "We used fractions in a string theory equations and statistics can be calculated with fractions. Therefore you can calculate statistics with string theory calculations." I'm still waiting for a real evidence thou.
not rated yet Jul 10, 2009
I think the title of this article is quite mesleading...
Jul 10, 2009
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Jul 10, 2009
This comment has been removed by a moderator.
not rated yet Jul 10, 2009
Check the article for excellent maths.
not rated yet Jul 10, 2009
String theory is too elegant not to be true. God wouldn't do something like that to us.

So science is based on elegance?

Science IS elegance.

Nothing is more elegant than a knowledge system based on nothing else but falsifiability.

Yeah, if they actually followed that ideal!!!!
not rated yet Jul 11, 2009
I want to see the proof for the exsistence of your god.
4 / 5 (1) Jul 11, 2009
Scientists have been using the word 'elegant' to describe things for decades. Almost as annoying as 'robust'. Sorry, but to me it's old.

Funny how scientists are still called scientists today, you'd think we'd have a more modern name for them.

And math, come on people, can't we come up with something that's not so old, like numberology, or plusandminusism? 'Math' is just so... old school.

Maybe the fact that science IS elegant has something to do with the fact that scientists, who study science, keep using the word. I wonder how often farmers use the word Season in their daily work since farming started.

When scientists start using the word 'righteous' ALL THE TIME, then I'll start getting annoyed.
2.3 / 5 (3) Jul 11, 2009
I want to see the proof for the exsistence of your god.

I have proof that he exists. Children...behold...I am your master!
not rated yet Jul 12, 2009
I am hungry, what about the string bean theory?
1 / 5 (2) Jul 13, 2009
General Relativity and Quantum Mechanics can never be unified without the help of an Integral Paradigm that describes the nature of consciousness integrally.

In fact space is infinite dimensional while Time is teleological.
1 / 5 (2) Jul 13, 2009
Hey, everybody, lets not get heated. If the maths was a perfect fit, well then that's good enough for me.
1 / 5 (4) Jul 13, 2009
OK, so for example epicycle model of solar system gives perfect fit because of number of adjustable parameters... Why not to use it, after then?
1 / 5 (2) Jul 16, 2009
I already knew how HTSs work: superconductors. (They're infrared filters.)

And black holes are bullshit: http://blogs.disc...eighty/. (last comment)

I don't like superstrings:

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