New Calculations May Lead To a Test For String Theory

dexmachina writes "A team of theoreticians, led by a group from Imperial College London, has released calculations that show string theory makes specific, testable predictions about the behaviour of quantum entangled particles. Professor Mike Duff, lead author of the study from the Department of Theoretical Physics at Imperial College London, commented, 'This will not be proof that string theory is the right "theory of everything" that is being sought by cosmologists and particle physicists. However, it will be very important to theoreticians because it will demonstrate whether or not string theory works, even if its application is in an unexpected and unrelated area of physics.' In other words, string theory may finally have shed its critics' most common complaint: unfalsifiability. However, given the second most common complaint, I can't help but wonder: which string theory?" Update: 09/03 23:34 GMT by S : Columbia University's Peter Woit, author of the Not Even Wrong blog, says these claims are overblown, and adds that a number of string theorists said as much to Wired.

Comments

Well...

[Korbinus]

That's a good news for Dr. Leonard Leakey Hofstadter...

Oops

[dexmachina]

It seems I may have jumped the gun on this one. My bad for being such an easy mark of sensationalist pop science headlines.

Re:Oops

[maxwell demon]

Indeed, it's worse. While I don't know much about string theory, I do work in the field of entanglement. And there's no way you could experimentally test this classification, for the simple reason that it's a classification. It may be a more or less useful classification, but you cannot experimentally test whether a classification is right (apart from that an reasonable entanglement classification has to be SLOCC invariant, which this classification is, but of course the others are as well). Trying to experimentally test if a classification is right is like doing an experiment on whether classifying a fruit on its color or on its size is more correct. What you can do is to evaluate the usefulness of a classification (i.e. does it tell you something interesting about the state, like what you can do with it; in the fruit example, you might find that classifying fruits on nutrition value may generally be more useful than classifying on water content).

Physicist speaking

[JohnFluxx]

As a physicist, I do get a bit annoyed at the constant attacks on string theory in public media.

Let me just state a few points please:

  * We have Quantum Mechanics for the realm of the very small
  * We have General Relativity for the realm of the very heavy
  * Both of these theories fit observational data and work very well
  * The two theories contradict each other in the case of very heavy and very small object (e.g. tiny black holes)

So, we need a new theory that gives the same predictions at QM and GR in the realms that we can measure them. This is where string theory etc comes in. But we do not yet have experimental data for very heavy and very small objects. If you want to complain about string theory not being testable, then accept that your same complaint is going to apply to EVERY grand-unified-theory that we know of.

Conclusion
=========

If you complain at string theory, then PLEASE state what you are proposing. What is the use in complaining when you have no alternative? The main scientific proponents against String Theory also just happen to have their own pet theories (e.g Quantum Loop Gravity) which are in an even worse situation.

If you complain about string theory taking so long, then what do you expect? It has taken 16 years just to do a single experiment (The LHC).

The only way we can make String Theory etc testable is by further research. If you dislike, please propose a better solution rather than just complaining.

TL;DR - People complain at string without proposing anything better.

Re:And when it fails this test too

[guyminuslife]

God is love. You believe in love, don't you? So there must be God, because there is love.

Obviously, it follows that love created the world in six days. Then love created a flood that destroyed just about fucking everyone, because you don't fuck with love, love is a sociopath.

Re:And when it fails this test too

[Anonymous Coward]

Just for the record: Gödel did not proof math to be not consistent. He showed two things:

1. That in every axiomatic system strong enough to capture aithmetic there necessarily are true sentences that can be expressed with the means of the system but cannot be deduced from the axioms (he presented a method to construct such sentences).

2. You cannot deduce a system's consistency from the axioms of such a system. (Which is something completely different from prooving that math is not consistent).

Then don't call it a theory, ya know?

[Moraelin]

Actually, it seems to me like we don't call those grand-unified things a proper scientific theory either. As long as there are no testable predictions, and it fails Occam's Razor, it's not a theory, plain and simple. It's a hypothesis.

Yes, there is a name for a theory which hasn't yet been tested: hypothesis.

And really, as someone who's gotten tired of hearing Young Earth Creationists go "well, evolution is just a theory" and having to explain to them "yeah, but theory in science doesn't mean what you think. It means it already made testable predictions and is the best we have"... it's getting annoying to see that a whole bunch of physicists are actually using it exactly as the YECs and conspiracy theorists think: as just an untested and untestable supposition, which may or may not actually hold any water at all.

Yes, I realize that calling it a "theory" is more science-y sounding and good for your funding. But it devalues the whole idea of science for everyone. If we accept that some untested and untestable calculation is just as worthy of being called a "theory" with a straight face as GR or electromagnetism just because it's the pet supposition of some physicist, then basically why wouldn't Behe's pencils-up-the-nose ID idiocies be a "theory" too? I mean Behe _is_ a professor of biochemistry.

Call it the String Hypothesis, and you'd see a lot less complaints, basically.

Re:And when it fails this test too

[Haxamanish]

Well, propositional logic can be proven to be consistent (there are no contradictions) AND complete (all true propositions can be proven out of the axioms), so can first order predicate logic (in the PhD dissertation of Gödel, 1929).

To construct arithmetic out of logic, we however need second order predicate logic. Gödel (1930, published 1931) showed that axiomatic systems in second order logic are either incomplete (true non-provable sentences can be constructed) OR they are inconsistent (containing contradictions).