Some thoughts on blowing up airplanes

So, unless you’ve been living under a rock lately, you probably already know that a bunch of British terrorists were recently arrested for plotting to blow up a bunch of airplanes bound for the US using explosives mixed together from various liquids smuggled aboard in drink bottles. In fact, even if you have been living under a rock, it’s still pretty tough to get away from all the “news” on the topic; and airlines are now banning any “liquids, gels, or creams” from being brought on board.

What you probably don’t know is that the entire plot is a load of crap that would not have worked even if the terrorists had boarded the plane.

See, here’s the thing.

Supposedly, the terrorists had planned to whip up a batch of triacetone triperoxide, a highly unstable compound that tends to go “bang” if you heat it, jar it, or look at it crosseyed. Now, this stuff is for real, and yes, it does go bang, and yes, you can mix it up from chemicals you can get fairly easily, like hydrogen peroxide and sulphuric acid. But it’s not just a question of mixing the chemicals together and making a bomb; it doesn’t work that way. physicsduck might be able to do it; a bunch of random religious fanatics without the brains to pick their noses, much less blow up a plane–not.

Synthesizing TATP takes several hours under carefully controlled conditions. If you mix it too fast, or too hot, it smells really bad and then blows up in your face, but not with very much force–you might injure yourself and if you’re remarkably clumsy you might even kill yourself, but you’re not going to bring down a plane. (Bringing down a plane is rather more difficult than people realize.) Creating enough TATP to actually blow up an airplane is not the kind of thing you can do in a makeshift lab or, say, an airplane bathroom.

That’s not the interesting part, though. Blind hysterical panic and hand-wringing over some largely illusory threat, followed by political pandering for power and stupid, pointless “security” measures that don’t actually make anyone any safer but do admirably at diverting attention from real weaknesses in airline security that’d be just too expensive to fix–none of that is interesting at all. What is interesting is triacetone triperoxide.

I like triacetone triperoxide. I like it for two reasons–first, because it belongs to a class of explosives called “entropic explosives;” and second, because it’s used to make a type of toy called a “whippersnapper”–a little twisted ball of paper about as big as your fingernail that goes bang when you throw it on the ground or step on it.

I used to buy boxes of whippersnappers when I was a kid. They’d come 25 little sperm-shaped paper snappers to a box, packaged in sawdust, and I would hide them in my sister’s room so that they’d bang when she walked into her closet or open her dresser drawer. (Yes, I was a very, very bad kid. When I got bored with that, I’d rig old-fashioned flashcubes to a battery using a variety of improvised triggers, so that there’d be this dazzling flash of light when she opened her jewelry box or otherwise least expected it…but I digress.) I haven’t seen any whippersnappers in stores in a long time, but I’m told they’re still available, only now they’re called “snap and pops” or something.

When TATP goes bang, it’s called an “entropy explosion.” I shit you not. It doesn’t explode by rapid oxidation like other explosives do, and it doesn’t produce any heat to speak of; the explosion is not vigorously exothermic, and it does not end up in an energy state that’s very much lower than the state it began in. Instead, the force of the explosion results from the very rapid (and sometimes spontaneous) decomposition of the solid to a gas. This decomposition doesn’t produce much heat, but it does liberate tremendous amounts of entropy.

Now, I have mixed feelings about entropy. But I do have to admit that the fact that you can actually make an entropy bomb is pretty damn cool.