Not Even Wrong

A commenter points out that the Edge web-site has put up John Horgan’s recent New York Times Op-Ed piece about science and common sense, together with some quite hostile responses to it. I’ve already explained what I think about Horgan’s piece, and I agree with some of the points of his critics, but I think their reaction to his quite accurate point that string theory is untestable is pretty remarkable.

John McCarthy, a computer scientists, writes the following bizarre paragraph:

“When Horgan says that string theory is untestable, he is ignoring even the popular science writing about string theory. This literature tells us that the current untestability of string theory is regarded by the string theorists as a blemish they hope to fix.”

Ignoring the peculiar characterization of the untestability of a theory as a “blemish” rather than a serious problem, does this make any sense to anyone? McCarthy seems to be trying to make the argument that one isn’t allowed to point out a problem with a scientific theory if the scientists involved agree it is a problem and say they wish they could do something about it.

McCarthy at least has figured out that string theory is currently untestable, unlike Lenny Susskind, who invokes the heavy artillery of big names to (seem to) claim that it is:

“Finally I must take exception to Horgan’s claim that “no conceivable experiment can confirm the theories [string theory and cosmological eternal inflation] as most proponents reluctantly acknowledge.” Here I speak from first hand knowledge. Many, if not all, of the most distinguished theoretical physicists in the world — Steven Weinberg, Edward Witten, John Schwarz, Joseph Polchinski, Nathan Seiberg, Juan Maldacena, David Gross, Savas Dimopoulos, Andrei Linde, Renata Kallosh, among many others, most certainly acknowledge no such thing. These physicists are full of ideas about how to test modern concepts — from superstrings in the sky to supersymmetry in the lab.”

First of all, his parenthetical elaboration “[string theory and cosmological eternal inflation]” isn’t quite right, Horgan never said anything about “cosmological eternal inflation”, although he did criticize as untestable claims for the existence of “parallel universes”. Susskind attacks Horgan’s claim that string theory is untestable by claiming that he and lots of illustrious physicists have ideas about how to test “superstrings in the sky to supersymmetry in the lab”. Note that Horgan never said anything about supersymmetry not being testable. The “superstrings in the sky” presumably refer to Polchinski’s claims that in some of the infinite variety of possible string theory scenarios there are cosmic strings that might be observable. I fail to see how this counts as a “test” of string theory, since if, as is likely, astronomers don’t see these things, that in no way shows that string theory is wrong.

After this piece of intellectual dishonesty, Susskind ends with the favorite tactic of string theorists on the losing side of an argument, the ad hominem attack:

“Instead of dyspeptically railing against what he plainly does not understand, Horgan would do better to take a few courses in algebra, calculus, quantum mechanics, and string theory.”

Today’s New York Times contains an Op-Ed piece by science writer John Horgan entitled In Defense of Common Sense. In it, Horgan takes an iconoclastic view of this year’s many celebrations of the 100th anniversary of Einstein’s great work of 1905, writing “In the midst of all this hoopla, I feel compelled to deplore one aspect of Einstein’s legacy: the widespread belief that science and common sense are incompatible.”

Horgan stirred up controversy in 1996 with the publication of his book The End of Science, where he claimed that most of the big discoveries in science have been made, forcing scientists to instead engage in what he calls “ironic science”. By this he means science done in a “speculative post-empirical mode”, something more like literary criticism, where claims are made that can never be shown to be right or wrong. While he saw this phenomenon taking place in many different areas of science, theoretical physics was where he had his strongest argument, pointing to controversies over the interpretation of quantum mechanics which seem to never be resolvable by experiment, and especially to string theory, which he describes in a later book as “science fiction in mathematical form.” Publication of his book made him rather unpopular in the science community and ultimately led to his leaving his position as an editor at Scientific American. At the time I thought he somewhat overstated his case, especially in trying to see the same pattern in a wide range of different sciences, but he had the insight and courage to put his finger on something very important that was going on in physics. Since 1973, the field has been a victim of its own success, suffering greatly from the fact that the Standard Model is just so good that it has been impossible to find experimental results that disagree with it, as well as impossible to find any convincing improvement on the model that would address any of the issues it leaves open. Horgan’s critique of string theory was forceful and on target, although to me his depiction of Witten seemed unnecessarily personally unkind.

I have mixed feelings about this latest piece of his, both strongly agreeing and strongly disagreeing with his defense of “common sense”. This comes down to what one means by “common sense”. One aspect of common sense is basically the standard scientific method and the norms traditionally used by scientists to evaluate what is good science and what isn’t. The sub-headline on Horgan’s piece “Beware of scientific theories that can’t be tested” involves this aspect. It’s just common sense to be skeptical of people who are making grandiose and radical claims unless they’ve got some good evidence for them, and string theory violates this notion of common sense. But I’m afraid Horgan conflates this kind of common sense with a different kind of “common sense”, the common sense about how the physical world behaves that is built into us based on the evolution of our species and our growing up in an enviroment where we interact with the world on a very specific scale of distances. This kind of common sense may not help us at all to understand how nature behaves at the atomic scale, near a black hole, etc., instead quantum mechanics and relativity are required, and these are subjects that don’t fit well with our notions of “common sense”, in the second of the two meanings. But even if they were initially counter-intuitive, both quantum mechanics and relativity were based on a wide range of detailed experimental evidence, something that overcame people’s qualms about whether they were violating “common sense”. Absent this kind of evidence, string theory is a very different story….

On a completely different topic, Lubos Motl has a posting about amazon.com censoring any criticism of a certain crackpot physics book. He’s started a contest, grand prize $3.00, which people may want to participate in.

Update: Lubos seems to have trouble telling apart John Horgan and John Hagelin….

The KITP program on Mathematical Structures in String Theory has a new weblog associated with it where Andrew Neitzke has been posting summaries of the talks given there. The idea of having such weblogs attached to programs like the one at the KITP seems to be an excellent one, it will be interesting to see how it works out.

Pierre Cartier has written a short biographical article about the remarkable French mathematician Jean Dieudonné. Cartier estimates that Dieudonné wrote about 80,000 pages of mathematics over the course of his career. He was a driving force behind Bourbaki, often taking on the bulk of the writing tasks. With Alexandre Grothendieck he co-wrote EGA, the huge foundational text on algebraic geometry (some people note that, considering the French meaning of his name, this text could be described as “God-given”).

A new institute devoted to theoretical particle physics has been organized, the Galileo Galilei Institute for Theoretical Physics, which will be located in Florence. The purpose of the institute is to organize advanced workshops, the first of which will take place next spring. There will also be an inaugural conference next month. The institute is clearly modeled after the KITP in Santa Barbara, and its web-site design looks very familiar…

A group called Thales and Friends, based in Greece and sponsored by MSRI, has organized a recent conference about Mathematics and Narrative that took place last month on Mykonos. Their web-site has abstracts of the talks and some other interesting material.

Update: There’s an article about this in the Independent.

The KITP in Santa Barbara, a few steps from the beach, is running a semester long program on Mathematical Structures in String Theory that started this past week. Some of the talks are already on-line.

On the other coast, as part of the Simons Workshop at Stony Brook, Witten will be giving a talk at Smith Point beach on “Gauge theory and the Geometric Langlands Program”. This sounds like it might be very interesting and mercifully off the main topic of the workshop, which seems to be swamps not beaches.

I’ve never really understood how Wikipedia works, especially how it protects itself from getting filled with nonsense. The entry about the Bogdanovs has evidently recently been the subject of repeated attempts by the Bogdanovs to modify it, one can follow the history here. This sort of thing seems to be enough of a problem that steps are being taken to prevent this kind of abuse.