Friday, November 7, 2008

Physics for Future Presidents

This blog has remained free of politics throughout the fall's presidential election. Having no intention of injecting partisanship now that the voting is over, I nevertheless would like to find a way to celebrate the election with you all. My solution: write a post about Richard Muller's recently published book Physics for Future Presidents: The Science Behind the Headlines. I checked out a copy from the Rochester Hills Public Library and started reading it. Those of you familiar with the 4th Edition of Intermediate Physics for Medicine and Biology won't be surprised that I focused on the aspects of Physics for Future Presidents that have biomedical relevance.

I came to the book a skeptic, as I imagined it would be a very elementary, watered down presentation of physics. But after reading it, I came away with a positive impression of the work. It really does capture much of the physics that world leaders will need to know in the 21st century. The introduction begins

"Are you intimidated by physics? Are you mystified by global warming, spy satellites, ICBMs, ABMs, fission, and fusion? Do you think all nukes, those in bombs and those in power plants, are basically the same? Are you perplexed by claims that we are running out of fossil fuels when there are counterclaims that we are not? Are you confused by the ongoing debate over global warming, when some prestigious scientists say that the debate is over? Are you baffled, bewildered, and befuddled by physics and high technology?

If so, then you are not ready to be a world leader. World leaders must understand these issues. The moment when you are being told that a terrorist left a dirty bomb hidden in midtown Manhattan is not a good time to have to telephone your local science advisor to find out how bad that situation really is. Nor is it a good time simply to assume the worst, to decide that all government resources must now be pulled off other projects to address this new emergency. You have to know enough to act wisely, quickly, proportionately."
About one-fourth of the book deals with issues related to nuclear physics (in section III, titled "Nukes"). Particularly relevant to readers of Intermediate Physics for Medicine and Biology is the chapter "Radioactivity and Death". It discusses the biological effects of radiation (using the old fashioned unit of rem instead of the more modern Sievert). I particularly liked its discussion of the "linear hypothesis," which states that there is no threshold for biological effects of low-dose radiation, a topic Hobbie and I discuss in our Chapter 16. Muller writes
"The government asked the National Academy of Sciences to review the question [of the threshold for radiation effects], and they published a report in 2006. They examined all the papers that argued for a threshold effect and concluded that the evidence was not sufficiently compelling to change the policy [of assuming no threshold]. So the US government continues to derive its laws according to the linear hypothesis.

Future presidents should note that that was a policy decision, not a scientific one. Many people have argued that the effects of the policy are not just health, but other central aspects of national policy. Much of the fear of nuclear power, for example, comes from the projections of the number of people who will die of cancer from low levels of radiation. If the policy results in consequences that hurt people in other ways (everything from evacuating their homes to fighting in a war), then the linear hypothesis is no longer the conservative choice. This is policy, not science--at least not yet."
Other medical physics topics the book addresses with this clear, if qualitative, tone are the risk posed by environmental radioactivity, the safety of storing nuclear waste, anthrax attacks ("It turns out that the spread of the spores, and their failure to kill more people, is more related to physics than biology"), and the danger of microwave radiation produced by cell phones ("Much of the fear of microwaves undoubtedly comes from the fact that they share the name radiation with the other, far more dangerous forms, such as gamma radiation. The fear that some people have shown toward such cell phone radiation finds its origin not in physics, but in linguistics"). In fact, I would say that much of the book deals with risk analysis, and the impact physics has on estimating risk.

Muller teaches a class based on the book at Berkeley. Videos of his lectures are posted on his class website. The San Francisco Chronicle has an article about his book and lectures, and says that "self-starting students in 35 states and 43 countries have been watching the 90-minute Physics for Future Presidents talks he gives every Tuesday and Thursday morning to a packed lecture hall of 300 undergrads on campus."

I believe that readers of Intermediate Physics for Medicine and Biology--future scientists and engineers--must be able to express many concepts that Muller explores quantitatively through mathematics. Yet, I see his point that future presidents require a qualitative, rather than quantitative, understanding of physics. In any event, I welcome our new president by suggesting that one of the first book he reads (after the 4th Edition of Intermediate Physics for Medicine and Biology, of course!) is Physics for Future Presidents.

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