If we accept the premise that the naughty Nigerian on Flight 253 had 80 grams of pentaerythritol tetranitrate sewn into his underwear, it follows that the energy released by its efficient explosion could, at most, have amounted to one or two megajoules. That’s roughly the heat of combustion of a jelly doughnut.
If that much energy were released instantaneously, the 80 gram fireball in the villain’s briefs would have reduced his midriff to hamburger. But that didn’t happen. Instead, Umar Farouk Abdulmutallab got a firecracker-sized bang and some richly deserved second-degree burns. Which means the explosion of the powdery un-plasticized charge did not propagate. (One presumes that the bomb’s designer incorrectly hoped the first bit would set off the rest.)
But even if it had worked correctly, the energy released would have been distributed through the expansion of 80 grams of hot gas. Think of it as an air bag gone wild, or a shrapnel-free hand grenade, driven by what amounts to rather less than a 10th of a cubic meter of air at room temperature. The radius of explosive destruction would have extended to a meter or so at most.
Had the detonating dervish hugged the metal wall of the wide body jet, he might have punched a foot wide hole in it, and the resulting explosive decompression could have brought about another Lockerbie. In response, the Transportation Security Administration (TSA) has banned late-flight restroom access. But even if the device had gone off in a restroom, the resulting closed-door thunder box explosion—though guaranteed to make hash of the bomber and anyone or anything directly across the aisle—would have been unlikely to rupture the hull several meters away (the shattering effect of an expanding, and thus cooling, explosion is an inverse-radius-squared sort of thing).
So why was the bomber packing so modest an explosive charge? My guess is that anything upwards of 100 grams invites detection nowadays by any number of security devices, not all of which civilians need to know about. Good thing, too. If al-Qaeda’s idea of an existential threat is a befuddled young man with three ounces of not-so-high explosives sewn into his underwear, weapons of mass destruction aren’t what they used to be.
Still, reflecting on the cold utilitarian calculus of how may lifetimes are being wasted standing in line, or how many lives may be lost to deep thrombosis per zillion immobile passenger miles if the TSA nincompoops are given free rein, I counsel an immediate escalation of the Global War on Terror.
Why begrudge Gen. Stanley McChrystal 40,000 extra pairs of hands to deal with the life-shattering daily threat of IED’s and car bombs in Afghanistan, when we have 100,000 men and women in uniform—or at least TSA blazers— trained at the taxpayer’s expense in the dark arts of explosive detection standing guard at the nation’s airports against a threat that has proven largely psychological?
The threat that merits constant vigilance is not an 80 gram explosive charge, but a jumbo jet that morphs into an 80 ton flying bomb. Why not deputize the top 10 percent of the Department of Homeland Security’s (DHS) standby army as air marshals to help deter a repeat of the 9-11 hijackings, and send the remainder abroad as America’s Foreign Transportation Security Legion?
Or we could just let DHS Director Janet Napolitano and her lot take their chances, and we’ll take ours. Outside of landing a blockbuster bomb in Osama bin Laden’s lap, what better way to ruin his happy new year than by resolutely ignoring the shoddy antics of his hapless minions? At the end of the day, airline passengers still have al-Qaeda’s mile high club outnumbered a million to one, and if we just say no to airport paranoia, the odds of perishing in the air will still remain about as low as those of going up in flames with the Christmas pudding.
Defiance is a dish best served cold, and in this case the right technology for detecting small explosive charges has been on open offer since 2007 in the form of a terahertz bomb detection scanner.
As with medical imaging, the sensitivity and resolution of this technology is rising almost as fast as Moore’s Law. If only the smart folks at DHS had used their powers of intrusion to inflict this sort of transparency on wannabe bombers years ago.
Russell Seitz, formerly of Harvard’s Center For International Affairs, is now a Fellow in Harvard's Department of Physics.