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….
