Disclaimer: I have probably spent more time with Quantum Field Theory As Simply As Possible (QFTASAP) than most as I was a lay reader providing commentary to Dr. Zee as he was writing it. I came to know Dr. Zee after he responded to some questions I had while going through another of his books, Group Theory in a Nutshell for Physicists. We’ve corresponded for years about math, physics, medicine, biology and life both turning out to be grumpy old Princeton Alums (1960 and 1966). If this makes me a friend of his despite never having met and living on opposite coasts — and if this precludes this review appearing on Amazon, so be it.

Should you buy the book? It depends on two things: (1) your ability and (2) your background. Dr. Zee spends a lot of time in the preface describing the rather diverse collection of people he is writing for. “I am particularly solicitous of the young, the future physicists of the world. .. delighted beyond words if some college students, or even a few high school students are inspired by this book .. “

**Addendum 1** **In retirement, I met one such high school student whil auditing an abstract algebra course at a local college. He was simultaneously doing his German homework while listening to the lecture with one ear. He did not go on in physics but did get a double summa in math and physics at an Ivy League university (not Princeton despite my attempts to get him to go there).**

I fall into another class of reader for QFTASAP which the author mentions, “scientists, engineers, medical doctors, lawyers and other professionals . … Quite a few are brave enough to tackle my textbooks. I applaud these older readers, and address them as I write.”

So you need to know the background I bring to the book to put what I say in perspective. I am a retired neurologist. I did two years of graduate work in chemistry ’60 – ’62 before going to medical school. All grad students in chemistry back then took quantum mechanics, solving the Schrodinger equation to see where atomic (and molecular orbitals) come from.

At my 50th reunion, I met a classmate I didn’t know as an undergraduate, Jim Hartle, a world class relativist still writing papers with Hawking, so I decided to try and learn relativity so I’d have something intelligent to say to him if we met at another reunion. I studied his book on Gravitation (and Dr. Zee’s). Unfortunately COVID19 has stopped my attendance at reunions. To even begin to understand gravitation (which is what general relativity is about), you must first study special relativity. So my background was perfect for QFTASAP, as quantum field theory (QFT) tries to merge special (not general) relativity and quantum mechanics.

Do not despair if you have neither background as Dr. Zee starts the book explaining both in the first 99 pages or so. His style is very informal, with jokes, historical asides, and blinding clarity. As a retired MD I can’t speak to how accurate any of it is, but the publisher notes that his textbooks have been used at MIT and Cal Tech, which is good enough for me.

So quantum mechanics and special relativity gets you to base camp for the intellectual ascent to QFT — which takes the rest of the book (to page 342). If this sounds daunting, remember thAt physics majors and physics grad student’s QFT courses last a year (according to Dr. Zee). So read a little bit at a time.

The big leap (for me) was essentially abandoning the idea of force and thinking about action (which was totally unfamiliar). Much of the math, as a result is rather unfamiliar, and even if you took calculus, the integrals you will meet look like nothing you’ve ever seen.

e.g. d^4x e psibar (x) gamma^mu psi(x) A_mu(x) all under the integral sign

Fortunately, on p. 154 Dr. Zee says “I have to pause to teach you how to read this hieroglyphic.” This is very typical of his informal and friendly teaching style.

QFTASAP contains all sorts of gems which deepened my understanding of stuff I’d studied before. For example, Dr. Zee shows how special relativity demolishes the notion of simultaneity, then he goes even farther and explains how this implies the existence of antiparticles. Once you get integrals like the above under your belt, he gives a coherent explanation of where and how the idea of the expanding universe comes from and how it looks mathematically.

There is much, much more: gauge theory, Yang Mills, the standard model of particle physics etc. etc.

To a Princetonian, some of the asides are fascinating. One in particular tells you why you or your kid should want to go there (spoiler alert — not to meet the scion of a wealthy family, or an heiress, not to form connections which will help you in your career). He mentions that there was an evening seminar for physics majors given by a young faculty member (33) about recent discoveries in physics. In 1964 the same young prof (James Cronin) said that he had discovered something exiting — in 1980 he got the Nobel for it. For my part, it was John Wheeler (he of the black hole, wormholes etc) teaching premeds and engineers (not future physicists) freshman physics and bringing in Neils Bohr to talk to us. So go to Princeton for the incredible education you will get, and the way Princeton exposes their undergraduates to their very best faculty.

**Addendum #2 — As a Princeton chemistry major, my undergraduate adviser was Paul Schleyer , Princeton ’52, Harvard PhD ’56. We spent a lot of time together in his lab, and would sometimes go out for pizza after finishing up in the lab of an evening. For what working with him was like please see — https://luysii.wordpress.com/2014/12/15/paul-schleyer-1930-2014-a-remembrance/ and https://luysii.wordpress.com/2014/12/14/paul-schleyer-1930-2014-r-i-p/**

**Contrast this with Harvard where I did chemistry graduate work from ’60 – ’62. None of the 7 people who were in the department back then who later won the Nobel prize later (Woodward, Corey, Hoffmann, +4 more) did any undergraduate teaching. I did most of the personal teaching the Harvard undergrads got — 6 hours a week as a teaching assistant in the organic chemistry lab. I may have been good, but I was nowhere as good as I would be if I stayed in the field for 8 more years. I thought the Harvard students were basically cheated. **

I guess every review should have a quibble, and I do; but it’s with the publisher, not Dr. Zee. The whole book is one mass of related concepts and is filled with forward and backward references to text, figures and diagrams. Having a page to go to instead of Chapter III, 1 or figure IV.3.2 would make reading much easier. Only the publisher could do this once the entire text has been laid out.

One further point. QFTASAP clarified for me the differences between the (substantial) difficulties of medicine and the (substantial) difficulties of theoretical physics. When learning medicine you are exposed to thousands of unrelated (because we don’t understand what lies behind them) facts. That’s OK because you don’t need to remember all of them. Ask the smartest internist you know to name the 12 cranial nerves or the 8 bones of the wrist. The facts of theoretical physics are far fewer, but you must remember, internalize and use them — that’s why QFTASAP contains all these forward and backward references.

There is a ton more to say about the book and I plan to write more as I go through the book again. If interested, just Google Chemiotics II now and then. QFTASAP is definitely worth reading more than once.