Back when I was interested in theoretical physics (>15-20 years ago), String theory was the Hot Thing.

Imagine my surprise when, in a random browsing, I stumbled upon a science-themed blog "Not Even Wrong" written by Columbia University-associated Math professor Peter Woit where one of the comments by blog's owner stated (emphasis mine):

Many people thought the initial 1984 models for string theory unification were elegant, hardly anyone thinks that about the complicated mess you get out of a conjectural anthropic string theory multiverse.

“Enormous explanatory power” doesn’t really go with “can’t predict a single f—ing thing”….

Given that forming falsifiable predictions is the cornerstone of scientific method, the above quote sounded pretty damning to me.

QUESTION: Is it true that since 1980s, string theory - or at least parts of it associated with Anthropic principle have not made any (or any non-disproven) falsifiable predictions? Or was that comment somewhat hyperbolic?

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    I think it's a good question. I should research this, because at this particular time, I feel that the predictive capability of string theory is beyond our current technology. – Larian LeQuella Apr 23 '11 at 22:08
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    @Larian - Thanks! That would be my assumption based on what I read about String theory back in high school, but I've been out of touch with theoretical physics for waaaaay too long since then to have a proper enough clue. – user5341 Apr 23 '11 at 22:10
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    It has been already asked on physics actually :-) Let's see if we get good answers here (it's a hotly debated topic in physics). – Sklivvz Apr 23 '11 at 22:21
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    The underlying problem with string theory for the foreseeable future is that it is not one theory: it's a huge family of theories. If we knew which was the right one, you could use it to predict things, but we can't know until we can run tests that are very much beyond our current technology. So, there are pretty good odds that a string theory is a good description of the universe but this fact does us almost no good at all. – dmckee --- ex-moderator kitten Apr 23 '11 at 22:40
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    yeah I don't think we're going to get better answers here than what was already provided oh the physics SE that Sklivvs linked. I'm prepared to be surprised but they pretty much covered the gamut over there. – erikthebassist Apr 25 '11 at 12:43

I just read an article in Scientific American: "The Strangest Numbers in String Theory" by John C. Baez and John Huerta, where they state:

At this point we should emphasize that string theory and M-theory have as yet made no experimentally testable predictions. They are beautiful dreams - but so far only dreams. The universe we live in does not look 10- or 11- dimensional, and have not seen any symmetry between matter and force particles. David Gross, one of the world's leading experts on string theory, currently puts the odds of seeing some evidence for supersymmetry at CERN's Large hadron Collider at 50 percent. Skeptics say they are much less. Only time will tell.

So I think our initial thoughts are in line with major names in the field. And as the last four words say, only time will tell.

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    Predictions must come prior to experiments. If it doesn't make experimentally testable predictions, what is there a 50% chance we'll find? Is there a verifiable prediction that Gross guesses might be confirmed? If it's not confirmed, is there a chance it can falsified? That sentence reeks of bad science writing. – user792 Apr 26 '11 at 12:22
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    Supersymmetry is the prediction. Although I must admit that I don't know exactly what that prediction looks like experimentally. Seeing a force particle along with an elementary particle is the gist of supersymmetry as I recall. – Larian LeQuella Apr 26 '11 at 13:42
  • What I mean is, the paragraph contradicts itself. If string theory and M-theory have as yet made no experimentally testable predictions, what evidence has a 50% chance of showing up? – user792 Apr 26 '11 at 15:41
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    I have used this answer once before, but... Monty hall has the answer behind one door, and behind the other doors, goats.... – Monkey Tuesday Apr 26 '11 at 22:26
  • @JoeWreschnig The parameters that can be used to configure string theory include values whose predictions diverge from the standard model at conditions only slightly beyond current experimental results and values whose divergences occur at levels far beyond current experimental capabilities. – Dan Is Fiddling By Firelight Feb 16 '12 at 21:01

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