I love Gödel, Escher, Bach, but GEB is over 800 discursive pages. Turing's Vision is a short translate of Turing's key paper "On Computable Numbers, with an Application to the Entscheidungsproblem". Turing paper conclusively proved a key result in mathematics, that some questions cannot be answered "yes" or "no", but will drift in infinite indeterminability. And second, his model of a simple machine with states and an infinite memory provided a conceptual design for the first universal computers as opposed to electro-mechanical calculating machines.

While no one programs pure Turing machines, instead working with friendly abstractions, the Turing machine is the strongest model of computation that we know how to build (stronger ones involve breaking the laws of physics). Bernhardt offers simple and elegantly explained proofs by contradiction to show the powers and limits of this class of machines. While the arguments are fuzzier than pure math demands, this is also a book that is almost thrilling in its readability, and it's a math book!