What else Turing did

The movie The Imitation Game focused on how mathematician Alan Turing broke the German “Enigma” code, a major contribution to the Allied victory in World War II.   Those interested in artificial intelligence talk about the “Turing test,” the goal of making it impossible to tell whether a machine or a human being is responding to questions.  But  Turing’s most enduring contribution is not known so much.  He wrote a paper about 0’s and 1’s and computable numbers that basically invented the concept of software.

From Joel Achenbach,  What ‘The Imitation Game’ didn’t tell you about Turing’s greatest triumph – The Washington Post:

Turing’s greatest breakthrough wasn’t mechanical, but theoretical — that 1936 paper that Dyson was talking about. “On Computable Numbers,” written in England, was published in the proceedings of the London Mathematical Society after Turing arrived at Princeton, where he would spend two academic years earning a Ph.D.

Amid the paper’s thicket of equations and mathematical theories lay a powerful idea: that it would be possible to build a machine that could compute anything that a human could compute. Turing was addressing a question of logic, but in the process he clearly described a real machine that someone could build, one that would use 0s and 1s for computation.

And here we are.

“He invented the idea of software, essentially,” Dyson says. “It’s software that’s really the important invention. We had computers before. They were mechanical devices. What we never had before was software. That’s the essential discontinuity: That a machine would actually decide what to do by itself.”

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