The Speculist

Actually, even if String Theory never really generates a theory with accurate and novel physical predictions nor achieves the formal rigor of mathematics, it still is quite interesting from the mathematical point of view. It has implications for differential geometry and topology. For example, the construction of several classes of topological invariants (things which don't change under transformations of the space in a continuous way). And some slick structures, eg, exactly six 10-dimensional distinct models of superstrings (string theory plus supersymmetry between boson and fermion objects) that in turn are special cases of an 11-dimensional theory ("M theory").

Also, I dimly recall some types of perturbation of particular differential geometry objects lead to string theories.

My take is that most of the effort in modern superstring theory is merely in understanding the mathematics of the structure of the theory. They are a long ways off from a genuine application of the theory to the real world unless experimentalists can jump to experimenting at the Planck scale where these theories would apply.

One of the objections raised in the story is the dependence of the theory on which local minimum (lowest energy state in the neighborhood) it resides in. Ie, the theory, if it applies to the real world, is probably at our scale trapped in some dip in what is called the "energy landscape".

The idea is that you have something similar to a surface in 3-dimensions with ripples and low lying pits. Left to its own devices, a very small marble with a minor amount of energy could be trapped in one of these pits. If you were to attempt to extrapolate the entire surface from the behavior of the marble in that pit, you might get the idea that the entire surface must be some sort of parabola centered at the pit since the little bit you could see looked like that. Your impression of the surface would be greatly dependent on where the marble was and how much energy it had.

In our case, a genuine model of everything might be highly dependent on the Anthropic Principle. Ie, the pit we happen to be in is one that would support life, and more generally generates the physical laws we observe. At some point, the Anthropic Principle does intrude. After all, it's doubtful that there's a simple theory of existence that explains the innumerable conincidences that lead up to us discussing this subject here. But the question is are basic physical constants similarly dependent? Generally it's undesirable from a theory viewpoint because that's an extremely hard (assuming that you can at some point generate another local minimum somehow and observe it). And predictions of the theory can be iffy merely because you might have too much flexibility in the theory to ever make a firm prediction.

On the other hand, future theories down the road may end up being special cases of string theories or vice versa, much as newtonian mechanics is a special case of both special and general relativity as well as some variants of quantum mechanics.

String theories had at most a thirty years' history. Why are its detractors so hasty in predicting its doom? In history there were well known hypotheses which never delivered the predicted results and yet these have not faced the onslaught of critics such as those faced by string theories. Why? Let me describe using two historically famous cases:

(i) Erastosthene (276-196BC) - A sieve for prime numbers?

A Greek mathematician named Erastosthenes of Cyrene (276-194 B.C.) discovered a clever technique called the "Sieve of Erastoshthenes," for finding all primes below a given integers n.

Erastosthenes had wrongfully labelled his technique as "Sieve of Prime Numbers" when in actual fact the technique should be labelled as sieves for composite numbers. This inappropriate description had misled number theorists in their endless search of the holy grail ... a formula for predicting prime numbers. Up to this moment of writing, no one has succeeded in developing such a globally accurate formula. So Erastosthenes had led number theorists in a wild-goose-chase for more than twenty two centuries!

(ii) Riemann's hypothesis

Riemann's hypothesis predicts that there are deep connections between zeroes on the critical line and the distribution of primes but for more than a centuary this problem still remains unsolved. The problem is that no one could prove that all the infinitude of zeroes will lie on the critical line.

Compared to the above two examples, why are we fussing over a trivial thirty year period in string theories? Time has changed. In Erastosthene's and Riemann's time, there was no Internet. So detractors would have difficulties airing their views. In fact the global formula for predicting prime numbers was successfully developed by the author using QNT which exploited quantum superpositions in its derivation. Unwittingly, Erastosthenes had discovered prematurely superposition algorithm used in quantum mechanics. Please visit: http://home.pacific.net.sg/~topchoice/index.html under the heading:

Predicint The Prime Sequence

Compared to the above two examples, why are we fussing over a trivial thirty year period in string theories? Time has changed. In Erastosthene's and Riemann's time, there was no Internet. In fact the global formula for predicting prime numbers was successfully developed by the author using Quantum Number Theory (QNT)which exploited quantum superpositions in its derivation. Unwittingly, Erastosthenes had discovered prematurely superposition algorithm used in quantum mechanics which only materialized in early 20th centuary. My opinion is that String theories had dropped into the 20th centuary when its birth should have been scheduled for the 22nd centuary. Do not harass these poor string theorists, give them time. Maybe a breakthrough could be imminent!

Huen from Singapore