As an amusing follow-up to Friday’s post, have a look at this lengthy op-ed from McGill University physicist Jim Cline, in The Ottawa Citizen. Here’s an excerpt:
Why is it that string theory has become such a favoured paradigm? Have theoretical physicists deluded themselves? Have they been pressured by social forces to blind themselves to other possible theories? Is there a behind-the-scenes string-theory conspiracy that is propping up a pseudoscientific house of cards?
We could ask a similar question about cars. Let’s suppose, for the sake of argument, that Hondas have been the most popular car on the market for the past 10 years. This is a source of great consternation to General Motors. Strangely, though, nobody has been writing books about how the North American public has been hoodwinked or brainwashed or pressured into thinking that Hondas are better than GM vehicles.
Somehow it is accepted that the public has enough common sense to form a correct opinion based on its collective experience.
True, some will be influenced by factors unrelated to the intrinsic quality of the car. But as a society we like to think that the free-market system will ultimately lead to the triumph of better cars over mediocre ones.
Although not so familiar to the general public, and comprising a much smaller number of participants, the economy of theoretical physics is not so different from the car business. Physicists choose which theory they are going to “buy” based on many considerations. After weighing the pros and cons of the different theoretical frameworks competing for their attention, they decide which ones seem most promising — which ones are worth investing (perhaps gambling!) years of hard work on, in the hope that they will provide the right description for experimental breakthroughs that we are anticipating, to shed light on the new physics we are so eager to discover.
I lack the technical expertise to fully assess the various claims and counterclaims regarding string theory. So I don’t have strong feelings one way or the other. But the paragraph above captures part of the reason I tend to be more suspicious of the string theory critics than of the string theorists themselves.
Which is not to say the critics don’t have some good points to make. Mathematician Peter Woit, of Columbia Univeristy, offers this reply to Cline. Woit begins:
The Ottawa Citizen today has an Op-Ed by string cosmologist Jim Cline, headlined The Big Idea That Won’t Die, with a subtitle “The fact that string theory is suddenly under attack only underscores its success as a path to a unified description of nature.” There’s a lot that it outrageous about this piece, beginning with the subtitle. Normally scientists don’t start going on about the success of their theories until they have some experimental evidence for them.
Most outrageous are Cline’s claims that Smolin’s book and mine are written in a “defamatory style”, and are “slandering” string theory. Since he gives no evidence for either of these claims, there’s not much to say about them except that they’re defamatory and slanderous.
Cline makes the standard claim that string theory should be accepted since it has legitimately triumphed in the marketplace of ideas, while clearly being rather upset about the success that critics of string theory have recently been having in this same marketplace. Somehow, overhyping string theory is a legitimate marketplace activity, pointing out its problems is not.
He makes many of the by now standard bogus claims about supposed predictions and tests of string theory. At some point I suppose I should write a FAQ about these, since the string theory hype machine keeps promoting these things in a less than honest way to a public that is not well-equipped to see through the hype. Here’s a pretty complete list of the bogus “predictions.”
From here Woit discusses in detail some of the predictions Cline attributes to string theory. Well worth reading.