July 10th, 2008

reading, activism, writing

Book #24: The Annotated Turing, by Charles Petzold

Wouldn't you like to know the outcome of your actions before you decide what to do? Looking into the future, you could see if biting that apple was a good idea or something completely different and unexpected.

However, there's no way through it but to do it.

Well mathematicians and computer programmers have the same problem. British mathematician, Alan Turing, proved that there is no way a computer can be designed with the correct set of instructions (program) so as to be able to determine if any other program will work properly. The program in question must be run -- come what may.

By proving that to be true, he also proved that there was no set of instructions or number of actions that could analyze a mathematical formula and see if it's going to work (or be decidable) except doing the math.

It sounds simple, and my husband Charles Petzold almost makes it seem simple in his new book The Annotated Turing: A Guided Tour through Alan Turing's Historic Paper of Computability and the Turing Machine.

You like that sly disclosure? Here is another one. I haven't ever read a mathematical paper. I haven't thought much about math since I took my last class in it in 1977. Although I did receive a Math/Science Regent's Diploma from Clinton Central School in 1978, I did so without taking either subject my senior year.

Did I understand Charles' book? Yes. I read it carefully and I think I got the first eleven chapters. Please don't quiz me, but I seemed to follow the basic idea. I tried to ask him few questions as I read. I will admit that I've been listening to him talk about the book for the last nine years though. I will admit to being overwhelmed in the chapters on mathematical logic. They were words and numbers on a page.

However, if anyone out there is a computer programmer or a math whiz, take a look at the book. Alan Turing's paper, "On Computable Numbers, with an Application to the Entscheidungsproblem," was historic for many reasons. He solved one of Hilbert's famous problems. He imagined a machine that could do what all computers do these days. And he showed the limitations of computers and software before they existed.

Charles is a great guide in this endeavor. Impress your professors, read it this summer and dazzle them this fall.