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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.


( 19 comments — Leave a comment )
(Deleted comment)
Aug. 18th, 2006 01:28 am (UTC)
Well, I do believe you're correct. I had always thought those things were TATP, but I've done a bit of research, and I think you're right; they're likely silver fulminate instead.

Damn, you've just robbed me of part of my childhood... *sniff*
Aug. 18th, 2006 02:14 am (UTC)
Is mercury fulminate more or less explosive than silver fulminate?

. . . and what is the chemical difference between silver fulminate and fulminating silver, anyway?

Jeez. I _knew_ I shouldn't have slept through inorganic chem in college. . .
Aug. 19th, 2006 02:41 pm (UTC)
Silver fulminate and fulminating silver have slightly different chemical structures; an oxygen is moved. Silver fulminate is


It's white. Fulminating silver is black, and has the formula


They both go bang if you look at them funny. I don't know anything about mercury fulminate, though. Mercury scares me.
Aug. 18th, 2006 02:03 am (UTC)
Interesting term- "entropic explosive". To my way of thinking, all explosions are entropic, neh?
Aug. 19th, 2006 02:43 pm (UTC)
Well, yeah. But an entropic explosive doesn't 'explode' in the traditional sense of the word; it doesn't combine with oxygen and release energy as the oxidation moves the reactants to a lower energy state. It just changes form, because there's so much strain on the chemical bonds that they tend to disintegrate. The 'bang' is the result of the atoms moving rapidly from a low-probability state to a high-probability state, increasing disorder without releasing heat.
Aug. 18th, 2006 02:25 am (UTC)
I remember those little guys. They were about the size of an English pea. We'd throw them down and they'd pop. Lot's of fun.

Thanks for this post. It makes sense and I agree with you that it is pretty hard to bring down an airplane. One of my instructors showed us pictures of the Twin Otter he landed safely after a shoulder launched IR missle took out one of his engines. I'm guessing they'd do more damage if they shorted out a laptop battery. Oops, shouldn't give anybody ideas.
Aug. 19th, 2006 04:08 am (UTC)
Atom Pearls
In the 1950's, when I was about 10 years old, I used to buy Atom Pearls at Snyder's Magic Shop, just a block from the Terminal Tower at the center of Cleveland. They were pea sized, gold colored, and packed in a circular box full of saw dust. When you threw them down on a hard surface or stepped on them, you got a nice bang.

The terminal tower was the station for both the New York Central railroad and one of the country's finest examples of light rail, the Cleveland Rapid transit. The Terminal tower had long ramps that went up several stories from the commercial mall to the street. When a train came in these ramps were crowded with people. We used to wait for a train to unload its passengers, then we would role Atom Pearls down the ramps and watch as people stepped on them. What fun!

May. 9th, 2010 04:38 pm (UTC)
Re: Atom Pearls
FYI, Sadly, they haven't made Atom Pearls for about half a century. There exists a product called Sprite Bombs that comes close. They're gray pea-sized orbs, not covered in a gold shell, and are a bit like a de-fanged version. They come in a blister pack (like certain kinds of gum or pills), and make sparks when they explode. Better than "bang snaps (http://en.wikipedia.org/wiki/Bang_snaps)," but not as explosive as Atom Pearls.
Aug. 19th, 2006 03:21 pm (UTC)
"One of my instructors showed us pictures of the Twin Otter he landed safely after a shoulder launched IR missle took out one of his engines."

Wow. I'm kind of glad I don't have any stories like that...
Aug. 18th, 2006 03:52 am (UTC)
We have some of them. I think they are in my desk, but definitely somewhere in the house. I love those things.
Aug. 18th, 2006 04:04 am (UTC)
Figured I'd better comment seeing as I'm mentioned, lol.

Yes, you can still get them. If any of you are in the MI area and would like some let me know, I have a supplier and I can get them by the thousands.

Also (and NO I'm not telling you how, do your own damn research) you can (relatively) easily make a liquid contact low-order explosive that is rather stable as a liquid, but when it dries/crystalizes it gets interesting.

In my mispent youth we poured the contents of a gallon jug of this throughout the hallways of my junior high. Imagine walking through a room carpeted with snap-n-pops, that was the effect.

Lasted for a couple days too :)

Nowadays you'd do time for something like that, back then I just got a week's detention (which I got out of when I offered to make a batch for the History teacher).

And it doesn't matter if you like entropy or not, you'd better get used to it. It's the way of the future!


Wishing you all a fun time until the heat-death of the universe...

Dr.Duck the Physics Phreak
Aug. 19th, 2006 02:45 pm (UTC)
There are all kinds of low-order explosives you can mix up relatively easily that'll go bang when they dry--I remember a friend of mine playing with ammonium triiodide a long time ago--but the real question is, can you make enough of them on board an airplane to bring down the plane? I'm very, very skeptical about that...
Aug. 19th, 2006 02:50 pm (UTC)
There are SUCH easier ways to bring down an airplane.

You don't need an explosion, just walk on board with a cup of mercury.

ANYONE can explode a plane, only a scientist can dissolve one.

Beware of Arab Meterologists....
Aug. 18th, 2006 02:53 pm (UTC)
Explosives aside...
There is a lot more that indicates this "plot" was a bunch of hooey.


seems to me that messing about with tricky explosives mixing, while potentially spectacular, is a lot less sure than just using plain old highly flammable liquids and a match... a couple litres of pure alcohol or gasoline dumped on the floor and set alight? not my idea of a good flight. The "authorities" are feeding the fear ruled public silly hollywood scenarios, because they are scary!!! Are you afraid? Then vote for the war-mongers, they have guns, they will keep you safe!

Aug. 18th, 2006 08:28 pm (UTC)
Re: Explosives aside...
Holy crap! That site is a bunch of liberals all telling each other they're right and patting each other on the back while condemning anything even vaguely republican.

I think I need to go boil my brain...I feel soiled just reading it!
Aug. 18th, 2006 05:47 pm (UTC)
I have my own theory...
They are trying to save money for the airlines to use for their security checks by preventing those that want to drink on the planes from being able to bring any kind of liquid on the plane... so they have to pay high prices for water, alcohol etc.... you know, trapped and really thirsty on a long plane ride?

it's their secret plan you know...
Aug. 19th, 2006 03:01 pm (UTC)
Wow, that seems like an awfully...convoluted way to go about it... :)
Aug. 19th, 2006 03:13 pm (UTC)
I figure it's less depressing to think up imaginary scenarios than to think about our current presidency and etc...
*quietly in self-delusion land*
Aug. 20th, 2006 03:18 pm (UTC)
"Sir, I'm going to have to take this bottle of water away from you since it might be a liquid explosive, and I'm going to have to mix it with all of these other bottles of possibly liquid explosive, and I'm going to have to dump them all in this trash can... together. Nevermind that the plot specifically mentions mixing chemicals and/or nitroglycerin... which explodes if handled too roughly." --from Xopl dot com
( 19 comments — Leave a comment )