Science is hard, let’s go shopping!

There’s a debate going on over at The Edge about the role of common sense in science, especially physics and cognitive science. John Horgan is the science journalist who started the debate with a NYT op-ed:

[String theory and the idea of parallel universes] are preposterous, but that’s not my problem with them. My problem is that no conceivable experiment can confirm the theories, as most proponents reluctantly acknowledge. The strings (or membranes, or whatever) are too small to be discerned by any buildable instrument, and the parallel universes are too distant. Common sense thus persuades me that these avenues of speculation will turn out to be dead ends.

Common sense — and a little historical perspective — makes me equally skeptical of grand unified theories of the human mind. After a half-century of observing myself and my fellow humans — not to mention watching lots of TV and movies — I’ve concluded that as individuals we’re pretty complex, variable, unpredictable creatures, whose personalities can be affected by a vast range of factors. I’m thus leery of hypotheses that trace some important aspect of our behavior to a single cause.

He later responds to comments with:

The question that I raised — and that all these respondents have studiously avoided — is what we should do when presented with theories such as psychoanalysis or string theory, which are not only counterintuitive but also lacking in evidence. Common sense tells me that in these cases common sense can come in handy.

As I see it, Horgan is mistaking lack of differentiation for lack of evidence. Unlike the so-called theory of Intelligent Design, String Theory and the Parallel Universes interpretation of quantum physics have a great deal of predictive power and evidence behind them. The problem is that (currently) this is the exact same set of evidence that supports quantum theory in general, so there’s no way to say that one interpretation is better than the other. However, if we found evidence that our understanding of quantum theory was fundamentally wrong, the other two theories would also be out the window.

Horgan is also wrong about why these theories are so non-sensical. The reason is not, as he implies, that scientists mistake preposterousness for profundity, nor is it that they just like making fun of English majors like himself. As Stanford professor Susskind points out in the debate, the reason these theories violate our common sense is that the world violates our common sense as soon as we look outside of our comfort zone. No theory that fits the experimental evidence will satisfy our common-sense understanding because the evidence itself fails to do so.

(Props to Mind Hacks for the link.)