How do you measure nuclear warhead yield?
How do you measure nuclear warhead yield? This is something I learned at the USENIX Conference in January that I've been meaning to post here, but have managed to forget about until now. While chatting with some network acquaintances at the hotel bar (all the important discussion occurs at the bar, of course, preferably well past midnight), a friend who does sysadmin work at Los Alamos National Labs told us a marvelously funny story about how the fun folks at LANL measure yield from nuclear detonations. After all, they have to experiment, I guess, and one has to learn how much bang-for-the-Mbuck one is getting. The solution at LANL (note that this is now an 8-week-old memory, details may be somewhat inaccurate): Find a Qbus-based PDP-11 (e.g., 11/73) "which you no longer love." Install a DEQNA ethernet controller card in the backplane. Park the box at/near/over the hole. Connect a cable to the DEQNA and drop it down into the hole. DEQNAs have a TDR (time domain reflectometer) built right into the controller. TDR is useful for finding cable shorts and, in general, learning the length of one's ethernet cable. Before detonation, begin having the PDP-11 repeatedly exercise the DEQNA's TDR, recording and transmitting the length determined to some other (presumably distant :-) site. Detonate. As the beastie blows things to smithereens all around itself, the cable will be rapidly eaten away. TDR readings from the DEQNA will show a drastically reducing cable length. The speed with which the cable, ah, degenerates will correlate very closely with warhead yield. Just think, your tax dollars at work, ridding the world of PDP-11s... -Karl Kleinpaste PS- No, I'm not kidding. Not a word of it.