FEBRUARY 5, 2005
You Never Know What Could Hit You
I’ve reached 10.8 mph on the treadmill, a new personal record for (stationary) land speed, and am experiencing runner’s high tinged with anxiety. Underfoot, the rubber belt is damp and slippery, and I don’t need to know the annual number of exercise equipment injuries (nearly 40,000, as it happens) to fear a nasty fall. Back in Brooklyn, I like to jog in the park, and things can be dicey there, too. On a run last fall, I suddenly heard a desperate “Watch out!” from behind me. Jumping aside, I narrowly missed being trampled by a galloping horse, the man atop it pulling helplessly at the reins. Horse trampling is so 1850. Who knew to worry about the danger in contemporary New York? Risk pros have a name for a hazard like this: “A black swan is an outlier, an event that lies beyond the realm of normal expectations,” wrote Nassim Nicholas Taleb, the author of Fooled by Randomness, in a 2004 op-ed piece for the New York Times. A black swan is particularly troubling, he argued, because “its very unexpectedness helps create the conditions for it to occur.”
Hoping to avoid nasty surprises, credible scientists speculate considerably about black swans. The most far-out of these risks are, as Wilson and Crouch put it, “predictable by very well verified physical theories but involve events which have never been observed and probably never will be observed.” For example, on Long Island, the Brookhaven National Laboratory operates a particle accelerator with the potential to seriously screw up my afternoon run. In theory, it could generate quarks that would reassemble themselves into a “strangelet,” which would in turn absorb matter until the entire planet was transformed into a hyperdense sphere 100 meters across. It sounds like sci-fi. Nevertheless, Brookhaven’s director took the threat seriously enough to have physicists study the scenario before allowing the accelerator to begin operating in 2000.
The strange-matter event and a host of other doomsday scenarios—greatly accelerated global warming; the engulfing of the world by self-replicating nanobots (the so-called gray-goo
problem); the engulfing of the world by self-replicating nano-organisms (green goo); severe bioterrorism—are detailed in Richard Posner’s Catastrophe: Risk and Response. Posner, a U.S. Court of Appeals judge and a lecturer at the University of Chicago Law School, argues that we should think more about these low-probability, high-consequence risks. “The probable costs of the catastrophic risks, when compared with the probable costs of efforts to minimize them, indicate that we are not doing enough,” he writes.