Quantum Field Theory, as Simply as Possible

Quantum Field Theory- As Simple as possible is a very readable book given the complexity of the subject matter. The subject of quantum field theory is extremely difficult and reading this is not nearly sufficient to read the author's textbook on QFT but it does start to give the interested reader a picture of how to think about the subject in more sophisticated terms than is expected of most nonfiction science books. This book fills a middle ground of giving a real flavor of the subject while keeping it at a level that is of the 1st or 2nd year undergraduate physics student. This is a bit of a narrow audience but for such an audience the book is motivational.Having read the author's other non-textbook on gravity, I must say this is much much better. That book to me seemed hastily put together and was quite disappointing whereas this I found much more illuminating. The book starts with basic concepts and moves up, introducing matter and fields and the use of the Lagrangian to determine the equations of motion. The author describes QED first then gets into QCD, the coverage of the weak interaction I have to say is quite confusing but the author tries to communicate about a very complex subject without completely losing the reader. For background, I did not study physics but have learned a fair amount of basic undergraduate physics on my own and started to learn the very basics of QED. In this process, which has been very difficult, taking certain concepts at face value, like what the vertices of Feynman diagrams represent was fine but never made me feel like I really had any depth of understanding on what was going on. This book has cleared up some intuition which was very difficult for me to find elsewhere. Like virtual particle exchange taking place with spacelike separation makes the time ordering ambiguous; this is finally made the diagram of positron going backward in time less bizarre. Overall I found the first 3/4 very readable and the last parts of the book were tougher, I certainly got something out of it and much more so than gravity. I feel a little more prepared to read the author's actual QFT textbook, though much of it is well out of reach.All in all for me the book has been a minor bridge for understanding the subject a little better than trying to read a textbook. It is not superficial but it is not intended to teach QFT either, merely prepare the reader for what the subject is about and how it emerged and the tools used to examine it. It is a strange book in that it is written for a physics student but a physics student who is still a while away from being able to learn the subject and as such it is motivational for a small number of people. It is probably approachable for an interested person but I suspect much will be lost on them as well, so I rate the book but also realize I am probably a narrow audience.

Zee’s “semi-popular” introduction to QFT is definitely a five-star book if you have the right level of background knowledge of physics, and I am giving it five-stars because I’m right in what I think is Zee’s target audience. I’m a retiree who was a physics major 45 years ago, but whose career was in an unrelated field and who also did not take a course in QFT when I was in school. If you weren’t a physics major, you can get all the background you need by viewing and carefully following Leonard Susskind’s “theoretical minimum” video lectures, which consist of about half a dozen series of ten two-hour lectures each. These lectures presuppose some knowledge of elementary calculus.What I think you need to extract from Susskind’s lectures or an equivalent to maximally enjoy and understand the knowledge embedded in Zee’s book (and I presume the “theoretical minimum” book series that I have not read but that I believe follows Susskind’s lectures would also suffice) is 1) at least some understanding of the Lagrangian formulation of classical mechanics, 2) comfort with special relativity and classical field theory, 3) exposure to undergraduate-level non-relativistic quantum mechanics, and 4) a hint of how gauge theories work. Nevertheless to be fair, Zee offers a well-articulated introduction to all these things in his book, although at a level that’s barely mathematical (and most of what math he offers is put into chapter endnotes), and my prejudice here is that a mathematical introduction to these concepts is what is really needed for good comprehension of the QFT concepts that are based on them.The point is that if you do already have these prerequisites you are more likely to be able to read between the lines in Zee’s book in a way that lets you learn more of what you need to put you in a position to take the next step and actually read a textbook on QFT, which is something that I, and probably many people in the target audience for this book, would like to be able to do but who have been too intimidated by the jump to a real QFT textbook like Zee’s own Quantum Field Theory in a Nutshell. Textbooks like these assume a strong math background and tend to skip steps in derivations.Yet even though I know I am going to need a refresher in things like contour integration to tackle a real QFT textbook, I believe I will now have much more of a shot at success when reading such a textbook after reading this new popularization of Zee’s. For example, thanks to his new book I now understand better the relationship of QFT path integrals to the Schrödinger and Heisenberg pictures in QM, I now see the underlying quantum-mechanical basis that explains why the Lagrangian works in classical mechanics, I now better understand what mass amounts to in the context of the theory, and also better understand the role of the Dirac equation, the differences between real and virtual particles, why and where perturbation theory is required, and many other things. So Zee’s book has inspired me to giving a real textbook (probably “Quantum Field Theory for the Gifted Amateur” rather than Zee’s more difficult “Nutshell”) a shot.So Zee’s new book was an ideal read for me. Those who have actually studied real QFT would likely find it trivial. What is less clear to me is how little physics or math background you could have and yet still enjoy this book. You certainly don’t need to know how to do an integral, but those who have no sense of what an integral is, or even a complex exponential, would probably get a little lost. Nevertheless, I strongly commend Zee for addressing a largely unoccupied segment that lies between between typical popularizations and textbooks.

This is well beyond basic physics or calculus. We were able to intuit a good deal of what the author was delivering and gained a better understanding of a subject that is considerably above our pay grade. That being said, unless you’re willing to reread passages several times and look up other sources and opinions you will probably find this work daunting. But if, like us, you enjoy a true challenge ( think technical rock climbing in Yosemite) this is a key to one of the doors to the future!

Well documented and referenced. Not a dry read and holds your interest. May require reading the book twice for a full understanding. Notes at the end of the chapters are valuable resources.

This book contains the best explanations of several key physics questions that I have ever read. Explanations that make the question intuitively clear to the reader without requiring a lot of complex math, but explanations that are rigorously accurate. Even though I took physics as an undergrad, after reading Zee I came away with much deeper understanding of special relativity, why c is a constant, and how to derive E=mc^2. And to top it off, Zee has a very droll sense of humor which infuses every chapter. It's just a fun book to read if you want to understand the last 100 years of physics.