Turing's Cathedral

Google Tech Talks April, 9 2008 ABSTRACT New Light on the Dawn of Digital Computing, 1945-1958 The digital universe consists of two kinds of bits: differences in space and differences in time. Digital computers translate between these two forms of information--structure and sequence--according to definite rules. Sixty-three years ago, at the Institute for Advanced Study in Princeton, NJ, John von Neumann and a small group of nonconformists launched a project to do this at electronic speed. The resulting architecture and coding has descended directly to almost all computers now in use. Von Neumann succeeded in jump-starting the computer revolution by bringing engineers into the den of the mathematicians, rather than by bringing mathematicians into a den of engineers. The stored-program computer, as conceived by Alan Turing and delivered by John von Neumann, broke the distinction between numbers that *mean* things and numbers that *do* things. Our universe would never be the same. With a mere 5 kilobytes of random access memory, von Neumann and colleagues tackled previously intractable problems ranging from thermonuclear explosions, stellar evolution, and long-range weather forecasting to cellular automata, genetic coding, and the origins of life. Programs were small enough to be completely debugged, but hardware could not be counted on to perform consistently from one kilocycle to the next. This situation is now reversed. Speaker: George Dyson