Physics for Future Presidents by Richard Muller

Every time I mention the idea of teaching physics to a wider audience than just physics majors, somebody brings up Richard Muller’s course, “Physics for Future Presidents,” at Berkeley. So, I was pleased to find out that he has turned the course into a book, also titled Physics for Future Presidents, with the subtitle “The Science Behind the Headlines.” I was going to try to cadge a free copy from his publisher, but our default local Borders is closing, and they were offering deep discounts on all their stock, so I just bought a copy.

The book is framed as a sort of memo to somebody who will eventually become President, and walks through the science involved in a bunch of high-profile subjects that the President will potentially need to make decisions about– terrorism, energy, nukes, space, and global warming. The main text is almost completely math-free (he does do some calculations in footnotes), but it lays out the basic physics involved in the various scenarios in a very clear and compelling way.

By way of example, here’s his discussion of the threat of a terrorist “dirty bomb” similar to what Jose Padilla wanted to build:

I’ll assume the same amount of radioactive material as in the Goiania incident: 1400 curies of cesium-137. Radiation damage is measured in a unit called the rem, and if you stand 1 yard from such a cesium source, you’ll absorb 450 rem in less than an hour. This dose of radiation is 50% higher than the LD50 (which stands for lethal dose 50%) for cesium-137, meaning that, untreated, you’ll have greater than a 50% chance of dying in the next few months from that exposure.

To try to enhance the damage, let’s use explosives to spread our 1400 curies over a larger area– say, a neighborhood 1 mile square. The result will be a radioactivity of 0.5 millicurie per square yard, and a careful calculation shows that if you are in this area, then after an hour of exposure your exposure will be 0.005 rem, 5 millirem. That’s a tiny amount, far below the threshold for radiation illness (100 rem), so you won’t get sick at all. If you stay in the area, even after a month your dose will be only 4 rem, still way below the threshold for radiation sickness. There will be no dead bodies whatsoever, unless someone is killed by the explosion itself. I suspect this is why al-Qaeda instructed Jose Padilla to abandon the dirty-bomb concept and try to plan a natural-gas explosion instead. True, low levels of radioactivity can induce cancer, but that takes years. I suspect that al-Qaeda doesn’t just want to brag about the number of premature cancers that will be induced by their attack. They need their followers to see photos of bodies.

Muller then goes on to calculate the increased cancer risk, and shows that it is insignificant. For this reason, he advises the hypothetical future President that dirty bombs are not worth worrying about as a terrorist threat.

He does similar analyses for most of the issues he discusses– working through order-of-magnitude numbers to show that many threats are oversold, and many strongly hyped technologies can’t live up to their more extravagant publicity. The arguments he presents are clear, simple, and compelling, though I can’t help wondering if they would play as well for people who are not mathematically inclined. His calculations regarding cancer risks due to various nuclear scenarios are certainly convincing to me, but these are emotionally charged subjects, and I’m not sure a few back-of-the-envelope calculations will carry as much weight with the innumerate.

He makes some attempt to maintain a neutral tone in most of the issues, but he slips occasionally. At one point, he offers a weak apology for lapsing into outright advocacy for nuclear fission as a (partial) solution for energy problems, and he gets a little testy when talking about excessively dramatic claims made regarding the IPCC’s findings on climate (he was apparently a reviewer for the IPCC report, and doesn’t think too highly of Al Gore’s exaggerations of some of the findings for An Inconvenient Truth). He’s also a little more enthusiastic about “clean coal” technology than the online consensus– it’d be interesting to hear what some of ScienceBlogs’s more environmentally inclined bloggers think of Muller’s analysis.

Overall, his conclusions are surprisingly upbeat– terrorism is less of a threat than you might think, we can find solutions to our energy needs, and global warming (or at least CO2 emissions) can be addressed relatively easily. I can’t claim any great expertise in any of these fields, but I find his back-of-the-envelope estimates fairly convincing. Of course, making any of this work politically is another issue entirely…

This was an excellent book, all in all. There are a few places where it reads a little like a textbook (several of the sections end with what are obviously discussion questions), and a couple of typos here and there. My biggest complaint is that there’s no mention in the introduction about the footnotes– these are sprinkled through the text, and initially looked like they were just citations of sources. In fact, the footnotes often contain calculational details, along with some wonderfully witty asides. They deserve to be advertised in the introductory material.

Of course, I’m not exactly in the target demographic for this book. It looks great to me, but I’d be interested to hear what people with no science background think of it.