All science is either physics or stamp collecting — attributed to Ernest Rutherford (many variations on this quote exist)

The biologist PZ Myers wrote a scathing criticism of a video by physicist Michio Kaku yesterday. (The transcript of the video is at the Big Think site.) To summarize: Kaku is making some very strong statements about evolution and how it relates to humans which are frankly incorrect. Kaku isn’t an idiot: he’s a string theorist (no job for the faint of heart), and I have his textbook on quantum field theory on my shelf which I refer to for my own research. However, it’s pretty obvious he doesn’t understand evolution very well, and Myers points out exactly where he goes wrong, then asks the question “Why do physicists think they are masters of all sciences?”

Obviously, Kaku is just one person. To complicate matters, he’s a TV personality as well as a professional scientist, and that can often lead people to feel they have something significant to say on any issue, whether they’re qualified to talk about it or not. On the other hand, Myers isn’t completely wrong in accusing physicists of being arrogant (even discounting physicists like Rutherford, quoted above), though we can argue over whether all physicists are as absurd as Kaku is being in the video.

Physics covers a wide range of phenomena, and in a certain sense it is the foundation of other sciences. However, that’s not the same thing as saying that it’s useful to use (say) quantum mechanics when talking about genetics, or assuming human societies will conform to equations from chaos theory. Things become even sticker when there is cross-fertilization (biophysics, mathematical models that describe phenomena in physics and biology, application of statistical physics to economics, etc.). Physics itself is a very broad field. I’m a gravitational physicist, but my job requires me to teach quantum mechanics, solid state physics, electrodynamics, thermal physics, optics, etc. etc. etc.—none of which are directly related to my area of expertise, though I’ve taken all the usual classes in them and feel competent to teach them. Maybe the very breadth of the field makes us susceptible to a false belief that we can automatically understand other fields, since we have to master so much already.

On this very blog, I probably flirt with making fundamental errors of biology in the defense of teaching evolution—my intentions are good, but I sincerely hope I’m not drifting into this same arrogance. The thing is, I don’t want to avoid writing about evolution. As I said in my previous post, those of us who care about science education have to stand up for all science education, and besides: there’s some really cool stuff out there that I want to share. I suppose the answer in the end is the usual one: humility. Qualify statements that aren’t certain, or better yet: check your facts with those who know before making statements in the first place.