Turing's Cathedral: The Origins of the Digital Universe

by George Dyson

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.

Turing’s model of universal computation was one-dimensional: a string of symbols encoded on a tape. Von Neumann’s implementation of Turing’s model was two-dimensional: the address matrix underlying all computers in use today.

The landscape is now three-dimensional, yet the entire Internet can still be viewed as a common tape shared by a multitude of Turing’s Universal Machines.