QED

Rating:
Summary: Outstanding Penetrating Intro to QED
Review: Feynmann, one of the physicists who developed the theory of quantum electrodynamics, winning a Nobel Prize for doing so (with 2 others) had a unique skill at presenting the physical essence of a principle, without getting lost in mathematical formalizm. After all, the mathematical description of a concept is only one form of expression of the idea, albeit in precise terms. Feynmann's discussion of QED explains with great power the way that when one examines the action of particles in the real world, the classical deterministic description of the particle and what happens to it proves inaccurate. For instance, when a particle travels between two points, one cannot know its exact location and how it is moving. One can only describe the particle's movement in terms of probabilities. A classical description of the action of the particle would attribute a fixed path to its course. In quantum physics, one describes the probable path. There is a finite, however small, probability that at any given time in the questioned interval the particle may be found in any location in space. It's true path description allows the particle to travel by all possible paths, and the classical path is merely the one which is most probable. Feynmann explains this and related phenomena with compelling logic and power. He writings are a unique and essential explanation of modern quantum analysis. They are readily understood by non-physicist readers, requiring only a willingness to concentrate and open one's mind. This is a remarkable work.

Rating:
Summary: Geek book, but I'm not a geek
Review: I'm not really sure why I bought this book, or exactly why I read it cover to cover. I was strolling through the bookstore, and came across it, and the next thing you know I was at the checkout stand with it in my hand. I have a degree in business, not physics, math, or any other "physical" science degree. Just found it really interesting. Sick, huh?

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Summary: All of electromagnetism can be described simply; a triumph
Review: In introductory physics courses, whether in high school or college, one tends to be exposed to some of the rudiments of electromagnetism. Often it seems overly complex or badly organized: while all of classical electromagnetism can be put under the header of Maxwell's equations, the student learns that there are separate equations for resistance, capacitance, magnetic and electric fields in matter as opposed to vacuum, moving electric fields and static, and what is all this business about fields, anyway? The student is told of a world where electrons do indeed collide, the speed of light can slow in some media, and electric and magnetic fields are two different things.

In QED (quantum electrodynamics, a theory that was proposed independently by Feynman, Schwinger, and Tomanga, and which earned the Nobel Prize for all three in 1965) none of these mysteries exist. "Fields" don't act differently in matter, and electrons *don't* collide. The speed of light does not slow, and magnetic and electric fields are two aspects of the same relativistic effect (this is known generally to students above the freshman level, but unfortunately is either skimmed over or is untouched by an introductory course). How is all this made possible? Why, by simply understanding what electromagnetism really is, on the most fundamental level: the interactions between electrons, mediated by photons they pass between one another, emit or absorb, or pass back and forth between themselves and the nucleus. Indeed, all of electromagnetism can be generalized to tiny particles emitting and absorbing packets of light --- and this simplicity of thought, this generalization, is what led many people back then and now (including myself) to consider Richard Feynman one of the greatest minds physics has ever known.

This book is better if one has taken an introductory physics course in high school or elsewhere, but it is not necessary to have any prior physics or higher level math background. One just needs to have a good imagination to picture interactions on such a tiny and observationally unknowable scale.

Rating:
Summary: Entertaining and Informative
Review: A book on physics that is entertaining? Hard to believe, but during the reading of this book I not only got a grasp on some of the fundamental concepts of Quantum Electro Dynamics, but thoroughly enjoyed the way it was explained. Feynman is a master teacher. He has the ability to take complex concepts and boil them down so that even a physics dummy can understand them. It is obvious when reading the text how complete Feynman's understanding of the material is. You know how you can read a science book and not really get what the author is trying to explain? Sometimes that comes from your own lack of intelligence, but a lot of times it's because the author wasn't totally clear about what he was writing. In this book, you really get the underlying concepts becasue Feynman's understanding of the subject is so complete. I found myself absorbing some of the QED concepts almost by osmosis.
The book is composed of 4 lectures Feynman gave at UCLA in the mid 80's.
QED is about the interaction of light and matter. Feynman starts the explanation of QED by dealing with the partial reflection of light onto 2 surfaces of glass, and uses arrow diagrams to make the explanation easy to understand.
He uses the arrow diagrams in the other lectures which continue the discussion of QED's attempt to explain the interaction of photons with matter. The last lecture deals with subatomic particles and QED's relationship to the rest of physics.
The part of the book I enjoyed most was the 3rd lecture called "Electrons and Their Interactions" which explains how electrons go from point to point in space/time. He gets into the famous "Feynman Diagrams" showing how electrons and photons seem to travel backwards in time, and how photons can go faster or slower than the conventional speed of light. It's fascinating!
What's great about these lectures is their clarity and humor. The author doesn't take himself too seriously and as a result the book is a delight to read, as well as being enlightening.
Kudo's as well to the editor who distilled the material down to a manageable length of 152 pages.
Can a book on Quantum Electro Dynamics be really fun to read? This one is.

Rating:
Summary: A good book as an introduction to Physics dummies
Review: When I was a physics dummy as a freshman in college, I read this book and found it so interesting: I can understand the so-called "Quantum ElectroDynamics" without studying any advanced physics! Although there is no quantitive stuff in this book, it's really a good feeling to know the physics ideas. If you have some interest in Physics, just find this book and read it: the book will make you sure that you have talent in physics:)

Rating:
Summary: Great general introduction to QED..
Review: I read this book over the holidays and throughly enjoyed the experience. The text is a compilation of lectures for the general public on QED. The explanations of light and matter interactions are superb considering that there is no math to speak of in the text.

Do NOT expect this to be a easy read. The book does require concentration and some effort on the part of the reader. I found myself reading some of the chapters twice just to ensure that I understood the material.

I do have one cavil. I wish Dr. Feynman had included a reference section for "further reading". Perhaps one of his students will include the references in the next revised edition.

All in all a fine book that deserves your attention.

Rating:
Summary: Excellent Introductory to QED
Review: This is a great book for anyone who is slightly intrested in physics. This is the best book that I have ever read at relating the subject of the book to everyday life. While the book starts out quite simple, the end of the book gets more in depth, therefore, there is something in this book for everyone.

Rating:
Summary: great
Review: This is great book. It's rather startling, however, to see (further down the line) someone recommend this and David Deutsch's "The Fabric of Reality" in the same breath. It ought to be clear to anyone familiar with Richard Feynman's works, how adamant he was about the scientific method and how adverse he was to the sort of pseudo-scientific tricks played in "The Fabric of Reality". (See especially the last chapters of "The Character of Physical Law", "Surely You're Joking, Mr. Feynman", and "What Do You Care What Other People Think?".) The moral of this, I suppose, is that it is possible to read a book, and even to think you like it, and not understand a word of it. Very discouraging. Well, some people are capable of appreciating Richard Feynman, at least.

Rating:
Summary: Difficult But Worth It
Review: This book is not as well written as his book on physical laws, but is well worth the struggle. There will come that moment when you actually believe that you understand quantum theory. It won't last long, but then nothing does in this quantum world!

Rating:
Summary: QED demystified
Review: Whereas once I was blind, now I can see. Thank you Dr. Feynman!