TURING’S BOMBE; HOLMES MEETS HARRY NILE 

TALK ABOUT SERENDIPITY: November 30 marks publication of Alan Turing’s 1936 paper “On Computable Numbers, with Application to the Entscheidungsproblem.” The November 2023 issue of BBC HISTORY recounts this idea of a first digital computer. And just recently, a SiriusXM “Radio Classics” sleuth encounters the world’s first consulting detective—in WWII England!

Here are tidbits on these related events gleaned from a variety of sources.

“No” to Hilbert’s Decision Problem. As described by Wikipedia, “In mathematics and computer science, the Entscheidungsproblem (German for ‘decision problem’) is a challenge posed by David Hilbert and Wilhelm Ackermann in 1928. The problem asks for an algorithm that considers, as input, a statement and answers ‘yes’ or ‘no’ according to whether the statement is universally valid, i.e., valid in every structure satisfying the axioms.”

Alan Mathison Turing, OBE, FRS, 1912–1954. English mathematician, computer pioneer, cryptanalyst, philosopher.

Turing’s 1936 paper was one of two proving that no such algorithm was possible. The other was Alonzo Church‘s concept of “effective calculability” based on his λ-calculus. Both are involved with Kurt Gödel’s Incompleteness Theorems.

Turing’s “Universal Machine.” As noted by BBC, “In 1936, Turing published a paper that is now recognised as the foundation of computer science. Turing analysed what it meant for a human to follow a definite method or procedure to perform a task. For this purpose, he invented the idea of a ‘Universal Machine’ that could decode and perform any set of instructions.”

The Bombe Breaks Enigma. Wikipedia says, “The Bombe was an electro-mechanical device used by British cryptologists to help decipher German Enigma-machine-encrypted secret messages during World War II.” Indeed, Wikipedia’s detailed descriptions of the Bombe and Enigma remind me of the kid saying “This book tells me more about whales than I want to know.” (This, I confess, from a mathematician, though recall that my Ph.D. involves dynamical systems theory, what I’ve called “differential equations without the dirty bits.”)

There’s no lack of dirty bits in Enigma machine encryption and decryption, but here are two key points: It is a self-inverse machine; that is, it substitutes letters reciprocally: If A gets replaced by R, then R is transformed into A. And, inherent to its operation, a letter cannot be enciphered into itself. These two features proved to be Enigma’s Achilles Heel with Bletchley Park’s Bombe helping.

War Comes to Harry Nile. My first mention of Jim French’s ’40s–’50s radio sleuth was here at SimanaitisSays in “Harry Nile, Seattle P.I.” Nile’s wartime activities (he’s turned down for military service) focus on security matters. And in the “Fifteen Years Later” episode, first broadcast April 10, 2011, the time is June 1944: “Following the events of Chapter 3, ‘D-Day Minus One,’ Harry is still in England waiting to get a flight home. However, he isn’t bored. He manages to get himself involved with murder, treason and a former ‘girl’ detective. Oh yeah, he also meets an aged consulting detective, a reformed, for the duration, gentleman thief, and a nut job who says he is a seeker of the strange and unusual.”

Sherlockian Fun. All in good fun, especially the encounters with the aged consulting detective (whose bee-keeping has provided a magic elixir of Royal Jelly).

One quip is about Basil Rathbone’s “funny haircut” in portraying you-know-who. And upon meeting Bletchley Park’s “Old Man,” Nile remarks, “a character in a movie I just watched looked just like you.” 

The “former ‘girl’ detective” is Hilary Caine (another of Jim French’s sleuths). She reminiscences about a previous wartime spy boss named Fleming having established “a strong bond.” She also explains the inside joke of the Golf, Cheese, and Chess Society: Bletchley Park’s official name was the Government Code and Cypher School.

The “nut job” prattles on about Martians (whom do you suppose gave Nazis those rockets?) 

The “Fifteen Years Later” title has Nile returning to England in 1959 for a funeral (the Old Man’s). Hilary Caine is there too and explains that the funeral is a faux one: What with movies and all, the Old Man just wanted some privacy (but “he’s always ready to help England when he’s needed.”)

What a nice thought. ds 

© Dennis Simanaitis, SimanaitisSays.com, 2023