Via the Mathematical Tourist I came across this article on the Enigma machine. The short version of the story is that during World War Jr. the Germans were convinced that their code machine, known as Enigma, kept their military secrets safe. It didn’t, partly through the efforts of three Polish mathematicians and partly because of the British crypto-analysts working at Bletchley Park in England (any story that involves a machine called Enigma and a place called Bletchley Park is already off to a really good start). The story is often told as if the Polish mathematicians had spirited away a physical copy of the machine, but in fact what they had was a reasonable mathematical model of how the machine worked. This they gave to the British. Goodness ensued and Hitler was vanquished.
It’s an often told story, and I mention it here because I was so impressed with this page maintained by a Danish high school teacher named Erik Vestergaard. I consider this to be the best kind of amateur reporting, and the kind of thing that really distinguishes the Age of the Web. It’s got beautiful illustrations, lovely old photos, and deep colorful piles of mathematical detail that really tell you what happened. Vestergaard figured out how Enigma worked, and now he’s telling you. No editor, not even of a specialist book with a limited print run, would let you include all that detail. “Cut out all that boring permutation crap,” says the Editor, Mr. Book, “You’re killing your market!” But Mr. Web, the imperturbable Not-An-Editor, says “Leave it in!”
Mr. Web wins again.