On this day in history

In 987, French king Louis V died under mysterious circumstances. Only 20 years old, he was described by the learned as Louis qui nihil fecit (Louis the do-nothing) and by the vulgar as Louis le Fainéant (Louis the lazy). He was the last of the Carolingians, the great dynasty founded by Charles the Hammer and best known for Charlemagne. It's unknown whether, like the Merovingian boy king Sigebert, he wept in his saddle; it's a cold certain fact that his line was replaced Hugh Capet. This new Capetian dynasty would rule France through Louis XVI and the Revolution, and then come back for a couple small bites at the apple, ending in 1848 with Louis-Philippe. Spain's king Juan Carlos is a distant descendant of Capet, continuing the dynasty. That's some run.

It was another ill-omened day in 1650 when James Graham, Marquess of Montrose was led to the scaffold. Originally a Covenanter (resisting the authority of bishops from the Church of England), Montrose became one of King James' Charles' greatest soldiers during the English Civil War. James Charles, of course, had his head taken off by Cromwell. Montrose, ever the King's Man, tried to invade Scotland for the exiled Charles II. He failed, and was hanged for his efforts, but leaves us his great legacy - his toast:

He either fears his fate too much,
Or his desserts are small,
Who dares not put it to the touch,
To win or lose it all.

Not for nothing is he known in Scotland simply as the Great Montrose.

But even as inspiring a legacy as Montrose's wasn't enough to change the bad luck associated with May 21. In 1946, a Plutonium experiment at the Los Alamos National Laboratory went horribly wrong. One of the problems with the World War II Atomic Bombs was that a large amount of fissile material was needed. The experiment was investigating whether by reflecting emitted neutrons back into the Plutonium, the efficiency of the device could be increased (and less material needed). The experiment used two hollow half spheres of Beryllium, surrounding what became known as the "Demon Core" - a sub-critical sphere of Plutonium (an amount too small to form a "Critical" - explosive - mass).

Well, it turns out that Beryllium was just a dandy reflector of neutrons, and the sub-critical mass scooted almost all the way over to "critical", which is a Very Bad Thing Indeed when you have eight nuclear physicists in the experiment room. Quick thinking by Louis Slotin pulled the spheres apart, but he got a fatal dose of radiation poisoning for his trouble, lingering nine days before shuffling off to join Louis V and the Great Montrose, perhaps to bitch about what a lousy day May 21 is.

Hope your day goes better.

UPDATE 21 May 2010 09:34: Bob in the comments points out that it was king Charles, not king James. Obviously, this is an ill-omened day.