Until Now
TechnologyScience

The first computers

Turing defines computation, and wartime machines make it electronic.

When
Duration
9 years
Known to
± 1 year
Era
Industrial, Holocene

Turing's 1936 paper on computable numbers defines a universal machine and shows some problems have no algorithmic solution. Colossus, built at Bletchley Park from 1943 to break the Lorenz cipher, is the first programmable electronic digital computer; it was kept secret for decades and several were destroyed. ENIAC follows in 1945. Babbage and Lovelace had described the concept a century earlier without being able to build it.

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