War, Code, and Logic
To understand Turing’s boldness, we must rewind a decade.
During World War II, the Nazis relied on the Enigma machine, a cipher device thought unbreakable. Messages were scrambled daily with billions of possible settings. Cracking it seemed impossible.
At Bletchley Park, Britain’s codebreaking hub, Turing led a small team tasked with breaking Enigma. He designed the Bombe machine, an electromechanical device that searched rapidly through cipher possibilities. With it, his team decoded thousands of German communications — including plans for U-boat attacks in the Atlantic.
Historians estimate Turing’s work shortened the war by at least two years. Winston Churchill later called the Bletchley team, “the geese that laid the golden eggs and never cackled.”
But Turing’s genius was not confined to wartime ingenuity. Even before the war, in 1936, he had published “On Computable Numbers”. In it, he introduced the idea of the Turing Machine — an abstract device with an infinite tape and a read/write head that could simulate any possible algorithm.
It was the first rigorous definition of computation. Every laptop, smartphone, or neural net we use today is, at some level, a realization of that theoretical machine.