O'Reilly logo

The Annotated Turing: A Guided Tour Through Alan Turing's Historic Paper on Computability and the Turing Machine by Charles Petzold

Stay ahead with the world's most comprehensive technology and business learning platform.

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, tutorials, and more.

Start Free Trial

No credit card required

6  Addition and Multiplication

As early as May 1935 Alan Turing had considered attending Princeton University, and had applied for a visiting Fellowship.1 A year later, when he discovered that Princeton mathematics professor Alonzo Church had also published a paper on the Entscheidungsproblem, Turing “decided quite definitely”2 that he wanted to go there.

Max Newman helped. In the same letter in which Newman informed Church of Turing's work (page 62), he also pleaded for help in getting Turing a scholarship:

I should mention that Turing's work is entirely independent: he has been working without any supervision or criticism from anyone. This makes it all the more important that he should come into contact as soon as possible with the leading workers on this line, so that he should not develop into a confirmed solitary.3

The tendency to work alone without outside influences was actually one of Turing's big problems. Earlier in his life, Turing had reinvented the binomial theory and developed his own notation for calculus. In attacking the Entscheidungsproblem, perhaps it was best that he wasn't familiar with the earlier work of Church and his colleagues, or he might not have developed such an interesting solution. In general, however, knowing what's going on in the rest of the world is essential, and for the field of mathematical logic, Princeton was the place to be. Turing failed to get the Procter Fellowship he applied for, but he was able to get by on his King's College fellowship. ...

With Safari, you learn the way you learn best. Get unlimited access to videos, live online training, learning paths, books, interactive tutorials, and more.

Start Free Trial

No credit card required