Is String Theory Really a Scientific Theory?

vk38 writes, "The New Yorker is running a story on whether String Theory is really a scientific theory or just an abstract exercise in math designed to churn out papers and Ph.Ds for the established academics. The article reviews two current books, by Lee Smolin and Peter Woit, laying out the case against string theory." From the article: "Dozens of string-theory conferences have been held, hundreds of new Ph.D.s have been minted, and thousands of papers have been written. Yet... not a single new testable prediction has been made, not a single theoretical puzzle has been solved. In fact, there is no theory so far — just a set of hunches and calculations suggesting that a theory might exist. And, even if it does, this theory will come in such a bewildering number of versions that it will be of no practical use: a Theory of Nothing... String theory has always had a few vocal skeptics... Sheldon Glashow, who won a Nobel Prize for making one of the last great advances in physics before the beginning of the string-theory era, has likened string theory to a 'new version of medieval theology,' and campaigned to keep string theorists out of his own department at Harvard. (He failed.)"

Comments

Re:Uh no

[808140]

Here's the problem though. GR and QM are both, relative to ST, extremely simple. And while ST may make the same predictions that GR and QM make, it does so in a far more complex way, without adding any extra information -- QM and GR are incompatible, but ST fails to resolve those incompatibilities in a testable way.

GR was more complex than Classical Newtonian Mechanics, but it was, essentially, a value-added theory: it explained a bunch of things that Classical Mechanics couldn't, all while remaining compatible with Classical Mechanics in places where Classical Mechanics made accurate predictions. Therefore, GR was taken to replace classical mechanics, despite the added complexity of the theory, because it was broader in scope, falsifiable, and provably more correct than the theory it replaced.

ST does not fit this mold. It is far, far, far, far more complex than either GR or QM, and makes no extra falsifiable predictions. It doesn't resolve the inconsistencies between the two. In other words, from a purely scientific perspective, it's just a hypothesis and not a particularly useful one at that.

Of course, I'm a mathematician by training and lots of interesting math has come out of ST, so for that I'm happy.

Re:Thanks for the troll submission

[k98sven]

It's not "FUD" in the least. Have you forgotten entirely what that term's origin and use is? Just because you disagree with a critical view doesn't make it a baseless propaganda effort. If it had been that, they wouldn't have bothered writing an entire book to presesnt their arguments. They wouldn't be presenting arguments to begin with!

There are reasons why string theory has failed to come up with any NEW predictions. For one thing, it's being constantly tweaked so that it is consistent with EXISTING experimentation. After all, why would you build a theory that you hope will become a GUT if it's not consistent with other proven theories?

This is why you don't get it: That is behaviour which is generally considered unscientific. If you need to keep modifying your theory to explain stuff, then it's not a scientific theory. It's an ad-hoc mess of empiricism of zero real value. The rules of the game are:
1) It must be testable (falsifiable)
2) You must provide new predictions
3) You must explain previous observations, observations not used in formulating the theory., and ideally, none at all.
4) You must do so using fewer postulates (assumptions) than the previous theory.

The other thing is that this is a theory... the fact that it (mathematically) treats particles as being a 1D string vibrating in n-dimensions doesn't actually mean that if you could see items smaller than the planck length, that you would actually see a vibrating string!! It's a mathematical representation... the math doesn't have to represent exactly what's happening as long as it can be used to describe what is happening.

The word you're looking for is "model". But how is this another thing? Our current understanding is a model as well. The question is whether it's a better model or not is still there and unanswered.

After all, modern chemistry is incredibly useful for predicting how atoms interact with eachother to form compounds... even though it's based off the idea that electrons orbit a nucleus like a tiny little planet orbitting a sun... that is precisely NOT what an electron does, but who cares, the math allows you to make determinations. It's the same with string theory.

You have no clue. Modern chemistry is not based on any such model. It's based entirely on the standard model of physics. There is not one, not one! molecular property that can be described in anything less than a fully quantum-mechanical treatment. All of chemistry is purely due to quantum-mechanical effects.

And string theory is not the same at all, even if you'd been right. String theory is an attempt at a more basic and general theory of quantum mechanics, in the same way as classical mechanics is a limiting case of quantum theory. It is not an approximation of quantum theory, and not intended to be one.

They're starting with a very simple, and very elegant premise (that all particles are periodic vibrations with different frequencies corresponding to different particles) and then building from there. Hell... start with that and just try and figure out how to represent the periodic table... that alone would be mind-boggling.

You don't get it. The periodic table is already entirely explained from QM, and has been for some time. There's no more reason to describe it in terms of string theory than to describe the motion of billiard balls in terms of quantum mechanics: It's unnecessary because it's already explained by classical mech, and we know classical mech is a subset of quantum mech.

In the case of string theory, all they need to do is show that QM is a subset of that theory. That's not hard and it is. It forms the basic premise of their work as well as the goal. The idea is that they're going to work from part of quantum theory and relativity and somehow arrive at the whole thing. Which parts the