Feynman was a master of science communication. What a book! Confusing at points even for a physicist, but generally enjoyable. A must read for anyone interested in nature and Quantum mechanics.

I still don't understand quantum mechanics, but I don't understand a bit less now! Feynman is a truly legendary communicator, explaining complicated and "tricky" theories in surprising and understandable ways without compromising the integrity of the theory.

The way that concepts are slowly layered on was very helpful, explaining how the theory arrived at each new detail and how experiments agreed or pointed to gaps to be filled, and in many cases, how those gaps were filled.

Not an easy read, but very rewarding to get to the end with the standard model of particle physics filled out (for his time).

Feynman shows what the mathematics in quantum electro dynamics do without actually doing them. A pretty smart and convenient way to give a notion about what happens there. If you want to understand the fundamentals of most of physics and all of chemistry as an amateur it is a really good read. In the end I even understood the standard model better then ever before, although that is only featured on the last 20 pages.

I read this primarily because it was the first copy of a Feynman work I could get my hands on, not because it was a work on quantum electrodynamics. Instead, I read it primarily as a study in style and the clear expression of ideas, and on this front I wasn't disappointed. Widely praised for the clarity of his style, it felt effortless and welcoming, even to those — like me — who only have a vague knowledge of the outline of the theory. I came away thinking: "why isn't writing in the humanities like this?"

I confess that I began to get a bit hazy on the theory half-way through the second of the four lectures, and I found the specifics of the third lecture challenging. What I enjoyed about the book, though, was the sense that if I wanted to, I could re-read those sections, think about it, and I would be able to get a good handle of the complexities. I didn't feel that those sections were out of my reach, only that I needed to invest more time in grasping them.

3.5, especially liked the last chapter that gave an overview of particle physics (though a bit outdated nowadays)

This weekend just passed my flatmate's boyfriend was visiting. Being the inquisitive sort, at one point he asked me if I could explain the main results of my PhD thesis to him in terms he would understand. To my eternal shame my knee-jerk response was "No." But a few moments later I was to be found scrawling on a napkin, explaining rational points on curves, density arguments, counting functions, and concluding by using the word "generalise" far more times in one sentence than I was comfortable with.

He seemed to follow my haphazard ramblings which is always enough to leave one chuffed. It's no secret to the science community that its biggest failing is an inability to communicate with and engage the public. The more esoteric the science, the trickier it is to convey it in terms that are both accurate and interesting. And, outside of pure mathematics, it doesn't get a great deal more esoteric than quantum mecahnics. So Richard Feynman's QED is laudable for, if nothing else, being about as understandable as is possible with this subject. There were times that the text lost me, but after giving it some thought I realised in each case that it was because I was expecting the quantum world to make sense, and to paraphrase my old Physics teacher: if quantum mechanics starts making sense, then you've stopped understanding it.

Feynman's abilities as a scientific orator are pretty well known—one of my favourite videos on Youtube is a two-and-a-half minute video of Feynman sitting in a chair explaining how a train stays on the tracks. Seriously. Feynman's writing skills are apparently just as good, but I've not read any of his other books and this one is actually the edited transcriptions of four of his lectures, so his speaking prowess proves more useful here. And as if being fascinating, self-deprecating, and witty wasn't enough, he also manages to be quite touching. The lectures were the inaugural set in a series dedicated to Alix Mautner, an English major and long time friend of Feynman to whom the physicist had promised to explain quantum electrodynamics in terms she could understand. Sadly she died before he managed to do so, but the lectures here are, as he says, the ones he prepared for Alex, but that he could no longer give just to her.

Having already studied some classical optics, reading about the quantum side of light was akin to eating only half a cookie--at first sweet and satisfying ("Hey, that explains the distance minimizing stuff!"), but not quite filling.

Alas, that's the nature of science popularization. If you omit math, the heart is gone, and you have to make do with the leftover shell. Feynman does the best job of leaving behind some substance that I've ever seen in such a book.

Excellent pedagogy, and some great quotes.

I haven't written my rating for a book in a time, but my experience in QED this week was interesting enough to discuss publicly. As the young graduate physicist, the most fun challenge of the book ended up moving metaphoric language onto things that (to a young graduate physicist) are conceptually simple while describing mathematics that (still to a young graduate physicist - gonna get down on that renormalization this fall) are mostly foreign. I knew enough to get paused by the actual mechanics of "clockworks" in the "arrows" defining amplitudes, but in general haven't treated sums of probability amplitudes in a way that makes them as intuitive as they so clearly were for Feynman - I was definitely not the intended audience for QED, which initially obscured what some of the metaphors were doing.

Regardless, this was a beautifully and concisely presented set of lectures on an incredible topic, and after a bit of mediation, still holds as a great way to introduce any quantum field theory or solidify it for _any learner._ The final chapter was as brilliant an explanation as it was a solid history. Non-fiction rarely makes one smile and laugh, especially on something so esoteric.

Friends, sorry to fill my feed with only physics books this summer; I've got the qualifying exam and triple research duty this summer, so I'm only reading physics, the pretty and the gritty.

Wonderful,Feynman is a genius of popularization,without a mathematical expression has achieved the goal of give the rigurous quantum electrodinamics fundaments of geometric and physical optics,is to say,refraction,refraction index,reflexion, difraction ,converging lenses,classic Fermats principle of minimun time in path light and so on.

He uses arrows to represent complex numbers in complex plane,with its modules and phases and uses sums and products of histories in the propagation of the photon as sums and products of this arrows to obtain the final amplitude.
Also he explains the bizarre and incomprehensible behavior of the photon as it explores all ways each one with it own phase and in the sum the major contribution is of similar to classical path of mínimum time.
Also the strange property of a photon or electron that in the doublé slit experiment is able of have interference with itself.

In the next chapter,explains his diagrams,how to calculate each piece,the propagation piece and the vertex piece,also the radiative serie of corrections,succesful in explanation of the magnetic moment of the electron and also with a diagram explains very well as a positrón can be viewed as a electron going backwards in time.

In the last chapter explains the only ugly aspect of the theory,the problem of the infinities and the renormalization solution,ends with a brief account of the standard model.

He also makes a deep reflection in the sense that the complex amplitudes has no physical meaning and that the deep work of the theory is incomprehensible,the idea is that we dont know the true working of reality,only knows the model we make,the reality has a behavior as the model predicts but no more,our model is a simulation of reality and we only can know that simulation.

A masterpiece of science popularization,strongly recomended to those that want to have a taste of the deep conceps and strangeness of the quantum world reality

Inspired by "Oppenheimer" I finally got around to reading this; it's been in my library since the 1990s at least. Feynman was of course a very engaging writer when anecdotalizing but science is a different matter. These texts are adapted from lectures expressly designed to explain the head-swimming stuff to lay persons. But the best way to approach it is to believe Feynman when he says the theory will indeed be all but incomprehensible to lay persons, because in fact it's only slightly more comprehensible to the scientists who developed and continue to research it. Stiff, with a lit of graphs. I read it while lolling at the public pool, a rather apt place because watching light reflected on water is a good illustration of how, as the book explains, light behaves as both particle and wave.

Solita divulgazione di classe di Feynman, non solo un premio nobel per la fisica, pure un grande scrittore, s� perch� esistono pure i saggi, le raccolte di articoli, i trattati, i manuali, le enciclopedie eccetera. (su anobii si tende a trascurare la scrittura non fiction, suo uso principale). L'elettrodinamica quantistica, intrinsecamente probabilistica e legata alla lunghezza d'onda, viene spiegata meravigliosamente bene con pochi semplici attrezzi grafici, (*) quasi intuitivi, che conducono a un edificio teorico su una natura non solo pi� bizzarra di quanto immaginiamo, ma pure di quanto possiamo immaginare. Partiti da un catalogo sterminato di fenomeni, dopo secoli si arriva invece a scoprire che in natura ne avvengono ben pochi differenti, � la loro quantit� e frequenza e combinazione a generare l'universo. Pi� o meno, l'universo sembra uno strumento musicale, con poche note e poche regole milioni di ore di musica. Edificio teorico che - tolta la gravit� ed i fenomeni intranucleari - spiega il resto del mondo, non � tutto ma perbacco, quanto a scoperta di "principi unificatori", non mi vengono in mente altri testi che spieghino meglio di questo, come mai la filosofia, di fatto, oggi si chiami soprattutto fisica. Manca un aggancio comprensibile all'inclito pubblico sul perch� detta teoria si chiami, "quantistica". Il problema degli infiniti � comprensibile solo a chi sia ben pi� di un novizio in materia. Eccede di speranze inoltre nella parte finale, dove l'excursus � rapido e i mezzi esplicativi scarsini. Obiettivamente era per� difficile far di meglio, visto che non ho notizia di altri testi parimenti, anche se qualche paginetta di raccordo - magari scritta da un Rubbia o un Regge, avrebbe giovato. (*) ci� non ne sminuisce la potenza. In un mondo di bottiglie, Feynman invent� un cavatappi. Aggeggio semplice e funzionale, ma indispensabile. Colonna sonora: E.C. from the cradle

This is the last of the books I bought in 2021 that are less than 200 pages long. So I can finally move on to books in the 400 page range.

This is the first Feynman I have ever read and I don't know if I will read him again. I found his style frustrating and I got irritated with the writing, wishing he would just get to the point or at least lead with the point he was trying to make.

I would be halfway through a lecture and realize, oh this is about the wave- particle duality or this is about the uncertainty principle. And I just feel that if someone is new to the topic this style of writing is not going to be in the least bit helpful.

-2 stars for annoying me