In The One Percent Doctrine, journalist Ron Suskind reported Vice President Cheney as declaring that if there were even “a one percent chance” of a terrorist threat, “we have to treat it as a certainty in terms of our response.”

That policy promoted the security state, but it was bad science. (More)

Governing Science, Part I – Fear and Safety

This week Morning Feature considers Richard Muller’s Physics for Future Presidents: The Science Behind the Headlines, a primer on the science underlying political issues. Today we look at terrorism and safety. Tomorrow we consider what we know, and what we don’t, about global climate change. Saturday we conclude with climate and energy solutions based in physics rather than fear or fantasy.

Disclaimer: I am not a physicist. Dr. Muller is a professor of physics at Berkeley, and teaches a  course on this topic. This is a shorter version of his textbook, written for a general audience. Even so, there is far more material than I can cover in three essays, and any errors are my own.

Which is more dangerous: a gasoline bomb or a “dirty” bomb?

This question was on the first slide of a presentation I used this week with some high school classes, in discussing how the media shape the public dialogue. I explained that a gasoline bomb spreads fire at the target, while a “dirty” bomb spreads radioactive material at the target. The slide included this hint: “The answer involves physics.”

The topic then moved to the 51 Park Place Islamic Center and Imam Feisal Abdul Rauf, the leader of the community who proposed the center. On his biography slide, amidst other facts about his life, I noted that Imam Rauf earned both bachelor’s and master’s degrees in physics. I then summarized the accusations made against him in the media, before rebutting those accusations. Then I asked two questions:

  1. Could Imam Rauf be a terrorist?
  2. If so, what kind of weapon do you think he might use?

Fifty-six of the 72 students (77%) believed Imam Rauf might be a terrorist. And after students suggested a “dirty” bomb would be his preferred weapon, three quarters of the students agreed.

My next slide was titled: Confession – I set you up. All of the facts I’d presented in the first five slides were true, but I’d arranged the facts to point toward false conclusions. Imam Rauf is a Sufi Muslim, and as I told the class, “‘Sufi terrorist’ makes as much sense as ‘militant Quaker.'” And no one who knows about physics would build a “dirty” bomb.

But … it’s radioactive!

Yes, and so are you. All living organisms generate radioactive carbon – carbon-14 – as a byproduct of metabolism, and scientists can measure the age of dead organic material by the level of carbon-14 remaining. And there’s a lot of other radioactive stuff around us all the time. Radiation measurements at Three Mile Island puzzled scientists at first, as the readings were too high for the tiny amount released in the accident. They later found the readings were caused by radon gas from natural uranium deposits. The same is true in Denver, where the cancer rate is lower than the national average.

Radiation poisoning is a function of how much radioactive material you’re exposed to, how radioactive the material is, and how long you are exposed. Put a lot of radioactive material in a small package, such as while building a “dirty” bomb, and you will get a very high dose. Spread it over several city blocks, such as after the bomb explodes, and instruments might not even detect it over the background radiation that surrounds us all the time. The people who built the “dirty” bomb would have a very high risk of radiation poisoning. But anyone at the target not injured by the blast itself would have a very low risk of radiation poisoning.

Conversely, the attacks on 9/11 used gasoline bombs. The fully-fueled jets were giant, flying Molotov cocktails. The fires from the spilled jet fuel, not the impacts of the jets, destroyed the World Trade Center towers. In fact, that fuel released seven times more energy (1.8 kiloton yield) than the likely yield of a “suitcase nuke” (0.25 kiloton yield).

And that assumes terrorists could buy or build a “suitcase nuke,” both hugely unlikely. Uranium bombs are comparatively easy to build, but they require a form of uranium – U-235 – which is extraordinarily difficult to refine. Plutonium is easier to acquire, but plutonium bombs are astonishingly difficult to make work. And hydrogen bombs are even more difficult. Dr. Muller suggests the most effective defense against terrorists acquiring nuclear weapons is to have lots of undercover agents offering to buy or sell the materials … to reduce the likelihood that a real buyer can find a real seller, and to identify and arrest would-be buyers and sellers.

The scientists are not 100% certain….

Under the “One Percent Doctrine,” the Bush administration treated even the tiniest possibility of nuclear terrorism as if it were a certainty, and caused far more damage than Al Qaeda could have. Yet as we’ll see tomorrow, both the Bush administration and today’s conservatives ignore the 90% probability of human-caused climate change … because the scientists aren’t 100% certain.

But it’s not only conservatives. Many progressives reject nuclear power because scientists cannot be 100% certain there would be no meltdown like Chernobyl. Many also oppose nuclear waste storage at Yucca Mountain, because scientists cannot be 100% certain there would be no leakage. Yet the risk of a Chernobyl-like meltdown is minuscule in modern nuclear plants, and the total estimated cancer risk from that tragedy – for all of the affected areas in Europe – was less than the estimated risk from the uranium deposits near Denver. (Scientists don’t know why Denver’s cancer rate is lower than the national average.) Similarly, the risk of a leak from Yucca Mountain is far less than the risk of leaving the radioactive waste where it is now.

And as we’ll see tomorrow, the risks of nuclear power plants are far less than the risks of today’s commercially viable alternatives: oil and coal. Hype-driven news and other media lead us to very bad estimates of risk and safety. We both recoil from tiny risks and blithely accept much greater risks.

To make better policy, both we and our leaders must know the science behind the headlines.


Happy Thursday!