Kernel
Turing is the figure who turns mathematical logic into the substrate of an industrial civilization. The 1936 paper defines the universal Turing machine. The Bletchley Park work breaks Enigma. The 1950 paper poses the question "can machines think?" — still the question being argued in every AI lab in 2026.
Contribution
The universal computing machine — the abstract framework every modern processor instantiates. The decision-problem proof. The Bombe. The Turing Test. The morphogenesis paper (1952) that founded mathematical biology and presaged today's neural-pattern-formation work.
Civilization-scale significance
The civilizational figure of computation. Every artificial-intelligence project is, ultimately, a Turing project. His 1954 chemical castration and probable suicide became, half a century later, the moral test case the British government failed and formally apologized for.