"It's only a (string) theory"

[HarryKeogh]

http://www.msnbc.msn.com/id/3217961/

But Krauss has an unconventional scientific take on the quest for the theory of everything "So far, it has explained absolutely nothing,"

In fact, Krauss wisecracked, "I might say one should call it the string hypothesis, because it's unfair to evolutionary theory for us to call it string theory — because that's one of the big problems, that the public doesn't understand what a theory means in science."

"There is not a single physical problem that we know of, that cannot be explained by anything else, that these explain," he said. "Nor do they make predictions yet of anything that has been seen."

Despite all that, he acknowledged that string theory is currently "the only game in town" when it comes to addressing the gaps in modern-day cosmology. And there may be hope is on the horizon: Krauss noted that Europe's Large Hadron Collider, the super-duper particle accelerator due to start operations in 2007, could conceivably provide evidence for the existence of large, spread-out extra dimensions.

so my question for the myriad number of people on this board that are better versed in science than myself is: Why is it called string theory anyway?

 

[Luke T.]

I have read a few books on QED. As a matter of fact, I am currently reading QED: The Strange Theory of Light and Matter by Richard Feynman right now. I read one once in a while just as a hobby.

None of the books I read have any hard maths in them. It's been almost 20 years since I took calculus and since I have never had cause to use it, I no longer know the difference between a differential equation and coffee grinds.

But my guess is that it is called a "theory" and not a "hypothesis" because it has been verified by a huge catalog of experiments.

 

[KingMerv00]

I am also unqualified in the math department. All of my understanding of string theory comes from layman's books.

I don't believe there are any experiments that can only be explained by little bits of vibrating "stuff". Assumptions such as these usually fall victim to Occam's Razor.

On the other hand, the mathematics are supposedly so elegant and are capable of deriving so many physical constants that some feel that strings must exist. Unfortunately, all of these "discoveries" are made after the fact.

Personally, I think hypothesis is a more accurate description.

 

[CurtC]

But my guess is that it is called a "theory" and not a "hypothesis" because it has been verified by a huge catalog of experiments.

No, that's the problem - String "Theory" has not been verified at all, and hoping that the LHC can observe something that ST would predict is really a long stretch. ST was supposed to be an elegant way that you could derive all those arbitrary things about physics from simple equations, like why the electron mass is what it is, why the charge has the value it does, on and on with all the different particles. In quantum mechanics, we know those values, but they seem pretty arbitrary, and we want an explanation of why the values are what they are. ST was supposed to provide that, but it's looking like ST is so flexible that possibly an infinite number of parameter sets could be derived from it. It seems to me that it is then therefore useless.

I believe it's called a "theory" because it provides a big-picture explanation of something, but agree that the word shouldn't be used until it's verified.

 

[SpaceFluffer]

String Theory is a scientific theory in that it is an extension to several models of physics that have stood up extremely well to experimental tests. However, String Theory itself has not made any experimental predictions, save for ones which we are unlikely to be able to test in the next few hundred years, nor has it explained any observations.

It is still a 'theory' because it is not based on guesswork, but on the study of many different well-understood models and the construction of a natural extension to them. That is, a theory doesn't have to be based on experimental evidence for it to not be a guess!

 

[DrMatt]

So in other words, you're saying it's a mathematically elegant summarization of existing theories. What gets exciting is when it IS tested, and something testable is found in the realm where all that elegance differs with the old clunky arbitrary QM... just for instance. Not that experiments support a bifurcation of hypotheses other than "This hypothesis either stands-- or it doesn't".

 

[bagtaggar]

String Theory is a theory because it makes predictions.

We just don't have the capacity to test those predictions yet.

The "big crunch" theory is still a theory; it had all the componants of a theory. Its core prediction however has so far failed in cosmology.

It would be a hypothesis if it didn't make any predictions.

 

[CurtC]

String Theory is a theory because it makes predictions.

We just don't have the capacity to test those predictions yet.

We don't even have the capability to figure out what its predictions are yet. The math is too hard. Any fitting of the theory to real results has been done only by making lots of assumptions, and knowing the goal of which results you want to derive ahead of time. Getting ST to make predictions of experiments that haven't yet been performed is not going to happen anytime soon.

 

[Cecil]

The Large Hadron Collider, scheduled to come online in 2007, is expected to be able to experimentally test some of the predictions of string theory (such as supersymmetry - the theory that every particle has a counterpart). String theory seems to require some form of supersymmetry, and the LHC will be able to reach energies that would produce some supersymmetric particles if they exist. This isn't necessarily indicative that string theory is correct, but it would be supporting evidence.

It'll also be able to do unrelated, yet exceedingly cool things, like detect the existence of a Higgs boson.

 

[CurtC]

But the idea of supersymmetry has been around longer than String Theory. I keep being the wet blanket here, but I just don't see why String Theory is so exciting to everyone, other than the little fact that it's the only viable candidate we have right now for a TOE.

 

[KingMerv00]

... other than the little fact that it's the only viable candidate we have right now for a TOE.

Doesn't this answer your own question? Anytime you come up with an idea that could explain everything, people take notice. Sure it may just be a pipe dream but the very idea that humans are capable of coming close to the fabric of reality is exciting.