Wolfram's 2-state 3-symbol Turing Machine

Wolfram's 2-state 3-symbol Turing Machine

In his book A New Kind of Science, Stephen Wolfram described a universal 2-state 5-color Turing machine, and conjectured that a particular 2-state 3-color Turing machine (hereinafter (2,3) Turing machine) might be universal as well.

On May 14, 2007, Wolfram announced a $25,000 prize to be won by the first person to prove or disprove the universality of the (2,3) Turing machine. According to Wolfram, the purpose of the prize was to encourage research to help answer foundational questions associated with the structure of what he calls the "computational universe". On 24 October 2007, it was announced that the prize had been won by Alex Smith, a student in electronics and computing at the University of Birmingham.