The Annotated Turing

I've always been curious about the reverence and mystery with which Turing machines get mentioned, and if you want to say you've read the words from the man himself, this is the only way I'd suggest doing it.

The Annotated Turing is precisely as advertised, a walk through the very paper Turing wrote for his thesis, errors and all. While I would have never been able to climb that mountain without a serious amount of background information, here we get the guidance of Mr. Petzold, our sherpa of mathematics, and what excellent guidance it is.

While I could not bring myself to understand the full complexities of the paper, The Annotated Turing takes it step by step, passage by passage and provides illuminating background and context, as well as clarifying Turing's intent and straight up fixing a decent number of typographical errors.

I feel like I need another read of this to understand how the minutiae of the machines translates into the overall findings of the paper, the creation/discovery of a conceptual computer that is not only programmable but is a generalized computer and one that can solve any problem solvable by a computer. A wonderful and informative book, written with obvious love for the subject.

This is one of those books that is so deep that I doubt anyone can read it cover to cover without having to go back and puzzle over the contents of some of the chapters. It is intended as a commentary on Turing's paper which, in some ways, due to the notation Turing uses, is more difficult to understand than it needs to be. Petzold plows through this giving several lines of commentary and examples to each line of Turing's paper.

Petzold demonstrates his knowledge of computing and mathematics and has obviously read and understood the mathematical papers that form the backdrop and purpose of Turing's paper and he refers to them knowledgeably.

No book on Turing can avoid the tragic story of his short life and Petzold covers this in a sensitive way intertwining both the depth of the mathematical theory and historical background in a seamless way.

I'm reminded of Bill Gates review of Knuth's work: "If you think you're a really good programmer . . . read (Knuth's) Art of Computer Programming . . . You should definitely send me a résumé if you can read the whole thing.". This book is, along with Godel, Escher, Bach in the same category.

This book is of the level of advance Computer Science Degree and should define Petzold's legacy more than all of the seminal Windows programming books that he has written over the last 20 years.