## The new glass bead game?

An interesting review of two recent books critical of ‘string theory’ – ‘The trouble with physics’ and ‘Not even wrong’ for amateur enthusiasts of science:

Aficionados claim that string theory provides the foundation for a Ã¢â‚¬Å“theory of everythingÃ¢â‚¬ÂÃ¢â‚¬â€a harmonious unification of all of fundamental physics. To the contrary, declare Lee Smolin, a physicist at CanadaÃ¢â‚¬â„¢s Perimeter Institute, and Peter Woit, a mathematician at Columbia University, string theory has thus far explained exactly nothing.

The essence of string theory is a literal assertion: Elementary Ã‚ÂparticlesÃ¢â‚¬â€Ã‚Âelectrons, photons, quarks, and their numerous Ã‚ÂcousinsÃ¢â‚¬â€Ã‚Âare not Ã‚ÂpointÃ‚Âlike objects but Ã¢â‚¬Å“stringsÃ¢â‚¬Â of energy forming tiny, wiggly loops. If a stringy loop vibrates one way, it manifests itself as an electron.

To put it very briefly, what turned interest in string theory from an oddball enthusiasm to a mainstream occupation was a twofold realization that came in 1984. ThatÃ¢â‚¬â„¢s when two of the early string pioneers, John Schwarz of Caltech and Michael Green … published a paper showing that just a handful of possible string theories were free of mathematical inconsistencies that plagued tradiÃ‚Âtional Ã‚Âparticle-Ã‚Âbased models, and also had sufficient capacity …to accomÃ‚Âmodate all the known elementary particles and their interactions. There was one little difficulty: The systems these theories described existed only in 10 Ã‚Âdimensions.

… that last point might seem to be a Ã‚Âdeal Ã‚Âbreaker, but so appealing were the other virtues of string theory that physicists found a solution. The Ã¢â‚¬Å“extraÃ¢â‚¬Â dimensions, they proposed, could be wrapped up so tight that we couldnÃ¢â‚¬â„¢t see them.

The review also has some interesting comments about the sociology of science and discovery:

The problem with string mania, Smolin concludes, is that it suits the wrong kind of mentality. He makes a nice distinction between scientific Ã‚ÂseersÃ¢â‚¬â€Ã‚Âpeople such as Einstein and Niels Bohr, his heroes, who deeply pondered the working of nature and were by no means brilliant Ã‚ÂmathematiciansÃ¢â‚¬â€Ã‚Âand craftspeople, who are enormously adept at intricate calculation but donÃ¢â‚¬â„¢t seem to think much about the larger meaning of their ingenious manipulations. Seers are always in short supply, and the technical demands of mastering string theory are such that Ã‚Âwould-Ã‚Âbe researchers of a more philosophical stripe can rarely meet the price of Ã‚Âentry

Jason, the scepticism about string theory sounds common sense to general public. I am no theoretical physicist, but one needs to know a bit more about theoretical physics to understand why such things appeal to these scientists. The main objective of theoretical physics is to build theories which will predict experimental laws and observations from the minimum number of fundamental axioms. That is why Einstein spent a third of his life trying to find a general field theory which would unify gravity, electromagnetic and nuclear forces, without success. A strange obsession for the greatest scientist of modern times, when we have good theories for each of these forces, isn’t it?

A suggestion that Einstein wasn’t good at maths is insane. His grasp of mathematics was outstanding (for a physicist), although perhaps less perfect than that of Poincare or Minkowski. But while the role of Einstein and Bohr is regognised more than that of Poincare, Minkowski or, say, Schroedinger, the role of the latter three as almost as essential.

Theoretical physicists are desparate to find the unifying theory and string theory is one attempt to get something in that regard. I agree that they have not been successful, and it may soon be abandoned. But it is the best they have at the moment.

BorisNovember 30, 2006 at 2:01 am

I’m with Boris, Einstein and Bohr were masterful mathematicians even though they talked down the role of mathematics in physics. I think they held to the view, as Smolin is suggesting, that good physical theories tend to be relatively uncomplicated.

I’m a bit bugged by the aforementioned article as it mixes up the opinions of Smolin and Wolf and throws in “common sense” objections which are objections to ideas in theoretical physics that aren’t explicitly tied to string theory. For instance, he takes a swipe at the dimensionality of a theory and the parallel universes concept however these things aren’t unique to string theory.

I’m in the school of theoretical physics that thinks that we don’t know enough yet to merge gravitational theories with quantum electrodynamics. We are a big school nowadays. I think in order to do this we are going to have to make a big intellectual leap which we aren’t ready to make.

mickNovember 30, 2006 at 2:18 am

“I think they held to the view, as Smolin is suggesting, that good physical theories tend to be relatively uncomplicated.”

Anyone who tries to study, say, general relativity, may not agree that this theory, arguably a good physical theory by any standards, is “relatively uncomplicated.”

I would formulate it in a slightly different way. I would say that they distinguished between mathematics as language of physics from mathematics as substitute for physics.

What can be reasonably claimed is that nearly all significant physical discoveries and breakthroughs have been made from physical intuition (with or without the use of serious math) and only later attained rigorous mathematical description. My favorite example is Bohr’s atom, which on the face of it looked absurd, but lay the foundation for Schrodinger’s wave mechanics. The other oddity was Dirac’s delta function, which later attained perfect sense in Shwartz’s and Sobolev’s distribution theory.

Mathematics by itself seldom leads to breakthroughs in physics.

BorisNovember 30, 2006 at 2:43 am

Boris – general relativity is relatively uncomplicated untill you get into the specifics. I agree with your point though, mathematics is more the language than the main game.

The Bohr’s atom example is a bit weird though. It’s way too simple and this simplicity leads to a whole lot of unphysicality (if there is such a word). The real breakthroughs in quantum mechanics came later once we had a better understanding of the mathematics, or rather the implications for a theory with that mathematical structure. For instance, Heisenberg’s famous uncertainty relations came about as a purely mathematical observation.

I think that there are plenty of examples of breakthroughs in physics that are a result of mathematical observations. It’s true that some of the biggest were a result of physical intuition, but there definitely exists a regime in which the two are totally blurred. One could argue that general relativity was a reult of mathematical breakthroughs and not of breakthroughs in physics.

mickNovember 30, 2006 at 3:43 am

“For instance, HeisenbergÃ¢â‚¬â„¢s famous uncertainty relations came about as a purely mathematical observation.”

Yes, an that was one thing Einstein was unable to accept.

“ItÃ¢â‚¬â„¢s true that some of the biggest were a result of physical intuition, but there definitely exists a regime in which the two are totally blurred.”

Yes, I agree.

“One could argue that general relativity was a reult of mathematical breakthroughs and not of breakthroughs in physics.”

Yes, you could. But I guess what I was trying to say is that you can’t take it too far… Or at least this is what these sceptics are saying about string theory etc.

BorisNovember 30, 2006 at 4:18 am

I think I’m not with the sceptics on this one Boris.

If it turns out that string theory provides a unified theory of everything ,then I presume then thats a fairly simple explanation for a theory of everything, even if it happens to be ridiculously complicated for anyone to understand. In this respect, I don’t see what is wrong with looking at increasingly complex versions of string theory.

I think also that, to some extent, people think that some of the old theories are more simple than they would have been at the time, since it is easy to pick up a book now exaplaining the concepts of many theories in general terms and a book going through all the maths. I can imagine how mind boggling it would have been to try and understand some of the theories at the time without nice textbooks and the like.

conradNovember 30, 2006 at 8:41 am

Boris

I don’t think the quote was saying Einstein was a poor mathematician or even an average one, merely that he wasn’t a brilliant one by the standards of professional mathematicians which is very high indeed. I recall that his relativity theory involved him getting an intensive course and a breakthrough in some area of algebra by some famous mathematician. He was short on the tools and needed to learn from this fellow how to use this particular tool before he could piece his theory together.

Jason SoonNovember 30, 2006 at 9:24 am

As I understand it the criticism levelled at string theory is at its core based on it not actually making any new predictions but so many people pursuing it as

theanswer to a grand unified theory.However complicated Quantum mechanics or GR may have seemed at the time, they were able to both existing unexplained phenomena and predict new as yet unknown phenomena which were later verified.

There is also a semantic issue in that it really should be String Hypothesis as calling it theory weakens the word theory in the way that creationists would like to do.

Steve EdneyNovember 30, 2006 at 9:36 am

Yeah its just what I’ve been telling you guys.

In Economics we need people with the soul of Shakespeare who can capture the wider understandings of the human action.

But until Mises made a comeback on the net, (and bringing with him the marvellous George Reisman and others) all we were getting was the tyrrany of the statisticians and Macromancers.

In Physics we need natural philosophers instead we are getting Rainman-type idiot-savant mathematicians who are trying to set up a priesthood.

In climate science, the subject involves so many different specialists to sort it out…… that what we need more then anything is honest and open debate……..

….. And specialists being open with their expertise and for the specialists to be trying to give up their knowledge readily to anyone who is trying to put the whole big picture together.

Instead we have these border-line communist fuckwits at Deltoid and realclimate.

GMBDecember 1, 2006 at 2:49 am