Brisy, brisy-- Turns out the word comes from French for "shatter," and refers to the rate of pressure increase when an explosive is set off. PETN is one example of a high-brisance explosive: it is not the most explosive, unit-for-unit, but the pressure wave ramps up very fast and leaves broken bits when it passes by.
It's what the shoe-bomber was trying to use. But it takes a hard push to set off, and for that, the idiot was using-- Um. Why make things easier for fools? Suffice to say there is a very explosive, very unstable substance that can be made from stuff you'd find under the sink, but don't; it's so poorly-behaved that even mad bombers speak ill of it.
For those of you who appreciate irony, ponder the happy, emphatic people on X: that ill-behaved explosive is also an unwanted by-product of MDMA synthesis. So, kid? Don't visit the lab! (Y'otta be nicer to your serotonin and dopamine levels anyway; gross fiddling with them is like trying to adjust a wristwatch with a sledgehammer.)
Clear down at the bottom of this heap of suck, fail and disappointment is a rotten little Easter egg: safrole. It's the reason you can't find real old-time sassafrass root at the grocers, the root being a source thereof: first, safrole makes rats break out in cancer, so FDA banned it along about 1980 (except you'll still find a bit in things like cinnamon, basil and black pepper) and second, it's a DEA List I chemical! So if you were planning to dig up some sassafrass root and brew your own? The Feds will save you a seat on the bus, right next to the enterprising, slender, dentally-challenged fellow who built his very own meth lab.
Geesh. I should'a run with the definition inferred from context. "Brisance!" It sure busted up a little corner of what I thought I knew.
T. R. MCELROY'S STREAMLINED TELEGRAPH KEYS
8 months ago