I see QED as a bit like stating the axioms of a mathematical theory. You can, in principle, derive the whole theory from the axioms, but in practice it takes generations of ingenuity to come up with the tools to do that. We take courses in mathematics not just to learn the axioms, but also, and primarily, to learn the vast library of tricks that let us do something useful with the axioms.
Similarly, I remember my first or second physics course, either mechanics or electromagnetism. The inside of the cover had, as I recall, all the “axioms”, the fundamental laws from which everything could be derived. Those fit inside the cover. But, just as in a mathematical subject, the main body of the subject was the library of tricks that let us actually make specific predictions from those fundamental laws.
Feynman, as I recall, was very up front in QED about what it did and did not contain. He was explicit about it not including the tricks that we would need to learn to apply the fundamental principles to real predictions about real situations.
However, I would not really call the book “vague” or even “hand-waving”, any more than I would call the inside cover of my physics textbook “hand-waving” or even “not physics”. It was seriously lacking, yes, admittedly so. But not at all in the way that, say, quantum mechanics popularizations typically are. Popularizations include neither the axioms (fundamental laws) of the theory, nor the tricks, but instead are filled with metaphor and impressionistic talk and not a small amount of pop philosophy. Not the same thing at all as QED (I mean QED the book, not the subject of quantum electrodynamics).
I see QED as a bit like stating the axioms of a mathematical theory. You can, in principle, derive the whole theory from the axioms, but in practice it takes generations of ingenuity to come up with the tools to do that. We take courses in mathematics not just to learn the axioms, but also, and primarily, to learn the vast library of tricks that let us do something useful with the axioms.
Similarly, I remember my first or second physics course, either mechanics or electromagnetism. The inside of the cover had, as I recall, all the “axioms”, the fundamental laws from which everything could be derived. Those fit inside the cover. But, just as in a mathematical subject, the main body of the subject was the library of tricks that let us actually make specific predictions from those fundamental laws.
Feynman, as I recall, was very up front in QED about what it did and did not contain. He was explicit about it not including the tricks that we would need to learn to apply the fundamental principles to real predictions about real situations.
However, I would not really call the book “vague” or even “hand-waving”, any more than I would call the inside cover of my physics textbook “hand-waving” or even “not physics”. It was seriously lacking, yes, admittedly so. But not at all in the way that, say, quantum mechanics popularizations typically are. Popularizations include neither the axioms (fundamental laws) of the theory, nor the tricks, but instead are filled with metaphor and impressionistic talk and not a small amount of pop philosophy. Not the same thing at all as QED (I mean QED the book, not the subject of quantum electrodynamics).