Jim's Blog

xkcd.com is the ultimate geek cartoon. Getting the joke usually requires esoteric knowledge of some combination of science, maths, popular culture, and internet trivia.

In today’s cartoon, Zombie Feynman shows up, seeking to eat brains, but then again explains the essence of the scientific method. He then implies that string theorists have no brains. This is very funny to those of us familiar with today’s critique of string theory, and Feynman’s critique of Cargo Cult Science. If you read it and laugh, you get a smug glow from being part of a tiny elite who understand that string theorists have given up on any effort to relate string theory to empirical consequences, and that this means that they constitute cargo cult science.

I think the educational and psychological studies I mentioned are examples of what I would like to call cargo cult science. In the South Seas there is a cargo cult of people. During the war they saw airplanes with lots of good materials, and they want the same thing to happen now. So they’ve arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head to headphones and bars of bamboo sticking out like antennas – he’s the controller – and they wait for the airplanes to land. They’re doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn’t work. No airplanes land. So I call these things cargo cult science, because they follow all the apparent precepts and forms of scientific investigation, but they’re missing something essential, because the planes don’t land.

Now it behooves me, of course, to tell you what they’re missing. But it would be just about as difficult to explain to the South Sea islanders how they have to arrange things so that they get some wealth in their system.

The science of anthropogenic global warming looks like science, sounds like science, but it lacks key elements of science. The typical procedure is to gather a pile of data that would likely be affected by the the answer to the question at issue, but also affected by lots of other things, and then announce that due to wonderfully scientific statistics, they extracted the signal of the one thing that they were interested in, and eliminated the influence of all the other effects. Thus, for example Mann deduced that the Medieval climatic optimum did not exist from the fact that a few bristlecone pines were not doing too well during the Medieval climatic optimum.

Similarly the IPCC announced that the Urban heat island effect is very small, much smaller than decadal warming. They deduced this by analyzing a bunch of weather stations, some of which they arbitrarily designated as urban, and others of which they designated as rural. But even if these designations had been accurate, you could not possible deduce the size of the urban heat island effect from this data.

To measure the size of the urban heat island effect, buy a thermometer in your local hardware store. Attach a toilet roll around the bulb to shield the bulb from radiant heat, and attach the thermometer to your car. Then drive your car from the countryside through a small town and out to the countryside again. You will observe an urban heat island effect of several degrees, about five or ten times larger than the decadal warming. That is real science. What the IPCC does is cargo cult science.