The 1964 Messenger Lectures, Cornell University
-- pp57-58, Chapter 2, "The Relation of Mathematics to Physics"
-- p129, Chapter 6, "Probability and Uncertainty"
Most people who write books about computation starting at the level of assembly language would then work up from there; Feynman works down, covering lots of the fascinating nitty-gritty stuff that he, as a physicist, is interested in. So there is lots of material here that is rarely found in computing texts, and certainly even more rarely found in as accessible a form as this. And the lectures that are right down in the physics -- on thermodynamically reversible computation and quantum computing -- are some of today's hot topics: Feynman, as usual, was way ahead of his time.
This is a write-up of a series of lectures Feynman gave at CalTech in the mid 1980s, transcribed from tape recordings. So the chapters capture the flavour of the great man's lecturing style, and the informality of the spoken word. But although I am a great admirer of Feynman's, I don't think the change of medium works too well in this case. I'd love to hear these lectures, but when reading, I would prefer a deeper and more polished form.
Contents:
This slim book publishes for the fisrt time three of Feynman's public lectures, given in 1963.
In The Uncertainty of Science he talks about what makes science fun, and the contrast between scientific and unscientific reasoning. His real enthusiasm (if that is strong enough a word) for science shines through.
Then in The Uncertainty of Values, how important it is to adopt a doubtful, questioning approach. Although his example of the opposite is Russia (and particularly Lysenkoism), the sentiment in today's world is just as relevant:
The final lecture, This Unscientific Age, is less well-structured. Feynman himself admits that he got through all his material in the first two! It is more a sequence of small anecdotes of how unscientific our age is, and how dangerous that can be.
It is interesting to see how much is the same 40 years later, how many of his predictions have come true, and which ones have not. One of the few not so true is plentiful cheap fusion power. (One day, one day.) But most of the scientific predictions have panned out, especially that new advances, in space, in biology, will also cause new problems.
The result was the path integral approach, which satisfied – and transcended – its original motivation, and has enjoyed great success in renormalized quantum field theory, including the derivation of the ubiquitous Feynman diagrams for elementary particles. Path integrals have many other applications, including atomic, molecular, and nuclear scattering, statistical mechanics, quantum liquids and solids, Brownian motion, and noise theory. It also sheds new light on fundamental issues like the interpretation of quantum theory because of its new overall space-time viewpoint.
The present volume includes Feynman’s Princeton thesis, the related review article “Space-Time Approach to Non-Relativistic Quantum Mechanics” [Reviews of Modern Physics Vol. 20 (1948), pp. 367–387], Paul Dirac’s seminal paper “The Lagrangian in Quantum Mechanics” [Physikalische Zeitschrift der Sowjetunion, Band 3, Heft 1 (1933)], and an introduction by Laurie M Brown.