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QED: The Strange Theory of Light and Matter
Famous the world over for the creative brilliance of his insights into the physical world, Nobel Prize-winning physicist Richard Feynman also possessed an extraordinary talent for explaining difficult concepts to the nonscientist. QED--the edited version of four lectures on quantum electrodynamics that Feynman gave to the general public at UCLA as part of the Alix G. Mautner Memorial Lecture series--is perhaps the best example of his ability to communicate both the substance and the spirit of science to the layperson.
The focus, as the title suggests, is quantum electrodynamics (QED), the part of the quantum theory of fields that describes the interactions of the quanta of the electromagnetic field-light, X rays, gamma rays--with matter and those of charged particles with one another. By extending the formalism developed by Dirac in 1933, which related quantum and classical descriptions of the motion of particles, Feynman revolutionized the quantum mechanical understanding of the nature of particles and waves. And, by incorporating his own readily visualizable formulation of quantum mechanics, Feynman created a diagrammatic version of QED that made calculations much simpler and also provided visual insights into the mechanisms of quantum electrodynamic processes.
In this book, using everyday language, spatial concepts, visualizations, and his renowned "Feynman diagrams" instead of advanced mathematics, Feynman successfully provides a definitive introduction to QED for a lay readership without any distortion of the basic science. Characterized by Feynman's famously original clarity and humor, this popular book on QED has not been equaled since its publication.
The focus, as the title suggests, is quantum electrodynamics (QED), the part of the quantum theory of fields that describes the interactions of the quanta of the electromagnetic field-light, X rays, gamma rays--with matter and those of charged particles with one another. By extending the formalism developed by Dirac in 1933, which related quantum and classical descriptions of the motion of particles, Feynman revolutionized the quantum mechanical understanding of the nature of particles and waves. And, by incorporating his own readily visualizable formulation of quantum mechanics, Feynman created a diagrammatic version of QED that made calculations much simpler and also provided visual insights into the mechanisms of quantum electrodynamic processes.
In this book, using everyday language, spatial concepts, visualizations, and his renowned "Feynman diagrams" instead of advanced mathematics, Feynman successfully provides a definitive introduction to QED for a lay readership without any distortion of the basic science. Characterized by Feynman's famously original clarity and humor, this popular book on QED has not been equaled since its publication.
176 pages, Paperback
First published January 1, 1985
1,416 people are currently reading
31.3k people want to read
About the author
Richard P. Feynman
243听books6,449听followersRichard Phillips Feynman was an American physicist known for the path integral formulation of quantum mechanics, the theory of quantum electrodynamics and the physics of the superfluidity of supercooled liquid helium, as well as work in particle physics (he proposed the parton model). For his contributions to the development of quantum electrodynamics, Feynman was a joint recipient of the Nobel Prize in Physics in 1965, together with Julian Schwinger and Sin-Itiro Tomonaga. Feynman developed a widely used pictorial representation scheme for the mathematical expressions governing the behavior of subatomic particles, which later became known as Feynman diagrams. During his lifetime and after his death, Feynman became one of the most publicly known scientists in the world.
He assisted in the development of the atomic bomb and was a member of the panel that investigated the Space Shuttle Challenger disaster. In addition to his work in theoretical physics, Feynman has been credited with pioneering the field of quantum computing, and introducing the concept of nanotechnology (creation of devices at the molecular scale). He held the Richard Chace Tolman professorship in theoretical physics at Caltech.
-wikipedia
See 袪懈褔邪褉写 肖械泄薪屑邪薪
He assisted in the development of the atomic bomb and was a member of the panel that investigated the Space Shuttle Challenger disaster. In addition to his work in theoretical physics, Feynman has been credited with pioneering the field of quantum computing, and introducing the concept of nanotechnology (creation of devices at the molecular scale). He held the Richard Chace Tolman professorship in theoretical physics at Caltech.
-wikipedia
See 袪懈褔邪褉写 肖械泄薪屑邪薪
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Displaying 1 - 30 of 689 reviews
September 23, 2014
Sometimes, it's too late, but that makes you do it better. You probably imagine that this book is a physics text. Well, it is, but that that's not what it really is. Really, it's a love letter to a dead woman. Feynman says in his introduction that his friend Alix Mautner had always wanted him to explain quantum electrodynamics to her so that she could understand it, and he'd never gotten around to doing that. Now it was too late. But, somehow, you can see that that only made him want to do it, not just well (he did everything well), but perfectly. If the book was perfect, that would make up for its appearing after Alix was no longer around to read it. It may seem like an odd formula, but it worked for Dante, and it also worked for Feynman.
The rest of this review is available elsewhere (the location cannot be given for 欧宝娱乐 policy reasons)
The rest of this review is available elsewhere (the location cannot be given for 欧宝娱乐 policy reasons)
September 11, 2021
Imagine having such a powerfully visual thought process that when you look at complex electrodynamic interactions at the quantum level and all the tedious, long equations that need to be solved to compute the probability of their occurence, you think "Actually, you know what? It's all a bunch of arrows going in and coming out. Some arrows are straight, some of them are wiggly, some of them even travel backwards in time, but they're all arrows nonetheless." Imagine starting with a toy model of this, sketching various quirky almost arts-y diagrams and immeasurably simplifying quantum electrodynamics for generations of physics students to come. Can you? I definitely can't.
Of course this is brilliant, but what stands out and I daresay even more, is the elegance of Feynman's simple writing. There are no grand words here, no pompous pretensions of technical terms but no false modesty either. There are arrows and there are simple everyday words. Reading this book is like a revelation, of understanding how deeply exquisite and how deceptively complex nature is. You also understand how it's all a problem with semantics, we don't have the language to understand nature. But Feynman here has quirky pictures and that makes him a physicist like no other.
This is a must read, if only to feel the satisfaction that you don't need to be a theoretical physicist to understand nature at its simplest. All you need is a pencil, a paper and minimal drawing skills. And every once in a while you need a brilliant theoretical physicist to guide you. Thankfully, we have Feynman.
Of course this is brilliant, but what stands out and I daresay even more, is the elegance of Feynman's simple writing. There are no grand words here, no pompous pretensions of technical terms but no false modesty either. There are arrows and there are simple everyday words. Reading this book is like a revelation, of understanding how deeply exquisite and how deceptively complex nature is. You also understand how it's all a problem with semantics, we don't have the language to understand nature. But Feynman here has quirky pictures and that makes him a physicist like no other.
This is a must read, if only to feel the satisfaction that you don't need to be a theoretical physicist to understand nature at its simplest. All you need is a pencil, a paper and minimal drawing skills. And every once in a while you need a brilliant theoretical physicist to guide you. Thankfully, we have Feynman.
August 16, 2017
My reaction upon finishing this book:
(Any excuse for a Breaking Bad reference.)
Seriously, though, this is one of the best pop science books I鈥檝e yet encountered. I read Surely You're Joking, Mr. Feynman!: Adventures of a Curious Character last year, and was thoroughly impressed by Feynman鈥檚 animated personality and his passion for physics. Now I find myself even more impressed by his exceptional teaching ability. QED: The Strange Theory of Light and Matter is a collection of 4 lectures he gave to the general public on the subject of quantum electrodynamics. The book is intended for laypeople, is written in very accessible language, and provides 鈥淔eynman diagrams鈥� instead of advanced mathematical formulae. A rather lengthy summary of these fascinating lectures follows. If you don鈥檛 want any spoilers, or whatever you want to call them, then skip ahead to the final paragraph.
The first lecture deals with photons, and how light behaves like particles. This is discussed in detail w.r.t. the partial reflection of monochrome light by glass. There鈥檚 already some fascinating shit right here, let me tell you! See, physicists can鈥檛 predict which photons will get reflected and which will pass through the glass. All they can tell you is the overall probability that it will happen. In other words, 鈥渋dentical photons are always coming down in the same direction to the same piece of glass,鈥� and this somehow winds up 鈥減roducing different results鈥� each time. Who knew that 鈥減artial reflection by a single surface鈥� was a 鈥渄eep mystery and a difficult problem鈥�?! Bizarre.
Feynman then teaches us how to calculate the probability of photons bouncing off either the front or the back surface of sheets of glass of varying thickness. The lecture concludes with a discussion of iridescence (the colors produced by the reflection of white light by two surfaces). Neat-o.
In the second lecture, Feynman uses QED to explain why, when light reflects off a mirror, the angle of incidence is equal to the angle of reflection. This is weirder than you might assume. (Actually, 鈥渨eirder than you鈥檇 assume鈥� sums up the entire book remarkably well!) The phenomenon discussed here is also the basis for diffraction gratings. Then he covers how light travels from air into water, and what causes mirages.
Feynman goes on to explain why light appears to travel in straight lines. Incredibly, it behaves as such only when you give it enough wiggle room, so to speak. For 鈥渨hen you try to squeeze light [or restrict its path] too much to make sure it鈥檚 going in only a straight line, it refuses to cooperate and begins to spread out.鈥� This is not altogether dissimilar to the behavior of surly teenagers. Perhaps we can reasonably refer to them as 鈥渓ittle rays of sunshine鈥� in an unironic fashion from now on! :D Bad joke, sorry. Anyway, the manner in which focusing lenses work is next revealed, and the lecture concludes with how quantum theory calculates the probability of compound events.
The third lecture introduces electrons, which behave similarly to photons: somewhat like waves, somewhat like particles. (Feynman jokes about 鈥渨补惫颈肠濒别蝉,鈥� a term I actually love to death, and will enthusiastically champion from now on!) We learn of the three basic actions from which all the phenomena of light and electrons arise: 1) photons rollicking about, 2) electrons rollicking about, and 3) electrons emitting or absorbing photons. As per the first item, we learn that 鈥渓ight doesn鈥檛 go only at the speed of light.鈥� So yeah, that happens. It鈥檚 anarchy, I tell you! Madness! And the third action is even stranger. Hint: time travel may or may not be involved. Oh, you beautiful, depraved little positrons, you.
Next, Feynman covers how electrons behave in atoms. He re-examines the partial reflection of light from glass in far greater detail than he did earlier, and we can now see why the former simplification was in fact warranted. (We previously treated light as reflecting from the 鈥渇ront鈥� and 鈥漛ack鈥� surfaces of a sheet of glass, as opposed to what light actually does, which is to be scattered by the electrons inside the glass.) This scattering is also the reason light appears to move more slowly in glass or water than it does in a vacuum or in air. Also of interest is how lasers work: photons tend to go to the same point in space-time. (These lunatics are predisposed to travel in packs!) It turns out the reverse is true for electrons. Their aversion to one another is known as the 鈥淓xclusion Principle,鈥� and helps explain chemical properties of atoms.
Before finishing the lecture by discussing polarization, Feynman examines the complexity of the magnetic moments of electrons. This is fairly bananas, even considering the fact that the entire book is pretty much out to lunch. Here is what can happen: an 鈥渆lectron goes along for a while and suddenly emits a photon; then (horrors!) it absorbs its own photon. Perhaps there鈥檚 something 鈥榠mmoral鈥� about that, but the electron does it!鈥� (You really have to love his sense of humor.) I鈥檝e included some Feynman diagrams which depict this wanton immorality:
The fourth and final lecture deals with some problems associated with quantum theory. It also looks at the relation of QED to the rest of physics, and includes a discussion of fundamental particles such as quarks and gluons, to name but a couple.
Overall, this short book is packed full of mind-blowing information. I really appreciated all of the helpful diagrams that illustrate the very peculiar concepts under discussion. Also, Feynman is an excellent teacher. I just loved his occasional bursts of exuberance and humor. His enthusiasm for his subject is irresistible, his subject itself truly extraordinary.
(Any excuse for a Breaking Bad reference.)
Seriously, though, this is one of the best pop science books I鈥檝e yet encountered. I read Surely You're Joking, Mr. Feynman!: Adventures of a Curious Character last year, and was thoroughly impressed by Feynman鈥檚 animated personality and his passion for physics. Now I find myself even more impressed by his exceptional teaching ability. QED: The Strange Theory of Light and Matter is a collection of 4 lectures he gave to the general public on the subject of quantum electrodynamics. The book is intended for laypeople, is written in very accessible language, and provides 鈥淔eynman diagrams鈥� instead of advanced mathematical formulae. A rather lengthy summary of these fascinating lectures follows. If you don鈥檛 want any spoilers, or whatever you want to call them, then skip ahead to the final paragraph.
The first lecture deals with photons, and how light behaves like particles. This is discussed in detail w.r.t. the partial reflection of monochrome light by glass. There鈥檚 already some fascinating shit right here, let me tell you! See, physicists can鈥檛 predict which photons will get reflected and which will pass through the glass. All they can tell you is the overall probability that it will happen. In other words, 鈥渋dentical photons are always coming down in the same direction to the same piece of glass,鈥� and this somehow winds up 鈥減roducing different results鈥� each time. Who knew that 鈥減artial reflection by a single surface鈥� was a 鈥渄eep mystery and a difficult problem鈥�?! Bizarre.
Feynman then teaches us how to calculate the probability of photons bouncing off either the front or the back surface of sheets of glass of varying thickness. The lecture concludes with a discussion of iridescence (the colors produced by the reflection of white light by two surfaces). Neat-o.
In the second lecture, Feynman uses QED to explain why, when light reflects off a mirror, the angle of incidence is equal to the angle of reflection. This is weirder than you might assume. (Actually, 鈥渨eirder than you鈥檇 assume鈥� sums up the entire book remarkably well!) The phenomenon discussed here is also the basis for diffraction gratings. Then he covers how light travels from air into water, and what causes mirages.
Feynman goes on to explain why light appears to travel in straight lines. Incredibly, it behaves as such only when you give it enough wiggle room, so to speak. For 鈥渨hen you try to squeeze light [or restrict its path] too much to make sure it鈥檚 going in only a straight line, it refuses to cooperate and begins to spread out.鈥� This is not altogether dissimilar to the behavior of surly teenagers. Perhaps we can reasonably refer to them as 鈥渓ittle rays of sunshine鈥� in an unironic fashion from now on! :D Bad joke, sorry. Anyway, the manner in which focusing lenses work is next revealed, and the lecture concludes with how quantum theory calculates the probability of compound events.
The third lecture introduces electrons, which behave similarly to photons: somewhat like waves, somewhat like particles. (Feynman jokes about 鈥渨补惫颈肠濒别蝉,鈥� a term I actually love to death, and will enthusiastically champion from now on!) We learn of the three basic actions from which all the phenomena of light and electrons arise: 1) photons rollicking about, 2) electrons rollicking about, and 3) electrons emitting or absorbing photons. As per the first item, we learn that 鈥渓ight doesn鈥檛 go only at the speed of light.鈥� So yeah, that happens. It鈥檚 anarchy, I tell you! Madness! And the third action is even stranger. Hint: time travel may or may not be involved. Oh, you beautiful, depraved little positrons, you.
Next, Feynman covers how electrons behave in atoms. He re-examines the partial reflection of light from glass in far greater detail than he did earlier, and we can now see why the former simplification was in fact warranted. (We previously treated light as reflecting from the 鈥渇ront鈥� and 鈥漛ack鈥� surfaces of a sheet of glass, as opposed to what light actually does, which is to be scattered by the electrons inside the glass.) This scattering is also the reason light appears to move more slowly in glass or water than it does in a vacuum or in air. Also of interest is how lasers work: photons tend to go to the same point in space-time. (These lunatics are predisposed to travel in packs!) It turns out the reverse is true for electrons. Their aversion to one another is known as the 鈥淓xclusion Principle,鈥� and helps explain chemical properties of atoms.
Before finishing the lecture by discussing polarization, Feynman examines the complexity of the magnetic moments of electrons. This is fairly bananas, even considering the fact that the entire book is pretty much out to lunch. Here is what can happen: an 鈥渆lectron goes along for a while and suddenly emits a photon; then (horrors!) it absorbs its own photon. Perhaps there鈥檚 something 鈥榠mmoral鈥� about that, but the electron does it!鈥� (You really have to love his sense of humor.) I鈥檝e included some Feynman diagrams which depict this wanton immorality:
The fourth and final lecture deals with some problems associated with quantum theory. It also looks at the relation of QED to the rest of physics, and includes a discussion of fundamental particles such as quarks and gluons, to name but a couple.
Overall, this short book is packed full of mind-blowing information. I really appreciated all of the helpful diagrams that illustrate the very peculiar concepts under discussion. Also, Feynman is an excellent teacher. I just loved his occasional bursts of exuberance and humor. His enthusiasm for his subject is irresistible, his subject itself truly extraordinary.
June 29, 2015
I love this area of physics and I think it鈥檚 wonderful: it is called quantum electrodynamics, or QED for short.
I love this book and I think it鈥檚 wonderful: it is called QED: The Strange Theory of Light and Matter, or QED for short.
I feel as though I鈥檝e been searching for this book for a long time, and now I鈥檝e finally found it. In scarcely 150 pages, Feynman takes you inside the logic of this famously obscure subject. What was before unintelligible is breezy in Feynman鈥檚 hands. What had before seemed impossible and bizarre of the physical world鈥攑articles behaving like waves, going back in time, eluding measurement鈥攊s, in Feynman鈥檚 presentation, just Nature being goofy.
So here鈥檚 the mystery. Newton proposed, in his Opticks, that light is corpuscular, or comes in little packets like raindrops. But it was later observed that light can interfere with itself, so it must be a wave. (For a while, English physicists were loath to admit that Newton could be wrong.) Then experimenters ran into trouble again when they discovered that if you take an extremely dim light and aim it at a detector, you don鈥檛 get one continuous signal, but a series of beeps and pauses like Morse code. So it appears that light comes in packets after all. But wait! In certain circumstances, if you shoot these particles one-by-one, you get an interference pattern like a wave. So light was both a particle and a wave? How was that possible?
Feynman begins by saying that this question鈥擧ow is this possible?鈥攊sn鈥檛 the right one to ask. Physics is an experimental science, so its task is to come up with a theory that will make predictions that agree with experiments, not to resolve philosophical paradoxes. In this book, that鈥檚 just what he does: he explains what physicists are doing when they are making these predictions. To do this, he must delve into the math. But he does not wish to explain how his graduate students do it (which wouldn鈥檛 be feasible in a book of this size, anyway), but to explain what is going on behind the scenes when they do these calculations. It鈥檚 like teaching children to add with pebbles rather than on paper.
Feynman begins by telling us that, in quantum physics, we calculate probabilities, not certainties. That鈥檚 a bit disappointing, but that鈥檚 the way nature is. So when a physicist is calculating the probability that a photon will pass through or reflect off a pane of glass, they use 鈥減robability amplitudes,鈥� which can sometimes reinforce and sometimes cancel one another. With this method, we can predict how many photons out of 100 will reflect, and how many will pass through. Not only that, but we can also deduce the wavelike properties of photons interacting with electrons to astounding levels of accuracy鈥攕o accurate that if you were measuring the distance from New York to Los Angeles, the uncertainty would be equivalent to the width of a hair. So as far as scientific theories go, QED is pretty dang good.
But what are 鈥減robability amplitudes鈥� in reality? It seems a bit cheap at first, like Feynman merely found a clever way to talk about particles as waves without having to use the word 鈥渨ave.鈥� Feynman describes how to calculate the answer by picturing the particle as having a little clock hand that spins extremely fast, giving you an angle. In the end, two arrows (the amplitudes) are added up, the result is squared, and there鈥檚 your answer鈥攁 percentage. But what is really going on down there when the photon is traveling from the light source to the detector? What is happening before our measurements? Surely, there are no clock-hands attached to the particles. What's the mechanism behind all this?
Of course, this is the kind of questioning that Feynman discourages. In his words:
So this framework of amplitudes has no experimental doubt about it: you can have all the philosophical worries you want as to what the amplitudes mean (if, indeed, they mean anything at all), but because physics is an experimental science and the framework agrees with experiment, it鈥檚 good enough for us so far.
So, really, there鈥檚 no way of knowing what鈥檚 going on before the particle is detected, since it is, in principle, undetectable. And in science, only things that can be measured are real. All of the stuff used to obtain the answer is just an intellectual apparatus, a tool for calculation.
Yet it鈥檚 hard to be as content with this as Feynman. If you wanted to learn how a car works, you鈥檇 want to know what鈥檚 going on in the engine, the transmission, the steering and braking. If somebody told you, 鈥淚t works by turning the key and stepping on the gas,鈥� you鈥檇 feel like you were cheated. But this is what we must do in QED. Nature doesn鈥檛 allow us to look under the hood. We can step on the gas and the thing moves; we can come up with an equation that helps us predict how fast the car will go depending on how much we press on the pedal. But what makes it go? Who knows? As Feynman said:
It is my task to convince you not to turn away because you don鈥檛 understand it. You see, my physics students don鈥檛 understand it either. That is because I don鈥檛 understand it. Nobody does.
January 1, 2022
This book contains four lectures given by Nobel Prize winning physicist Richard Feynman at UCLA in 1983. Feynman was a leader in the path integral formulation of quantum electrodynamics (QED) for which he won a Nobel prize. These lectures are intended for the non-scientist, but are best suited to those with a deep interest in the subject and the patience to wrestle with some complex ideas. The introduction to the 2006 edition puts this book of lectures halfway between a popular science book and a textbook. QED is a quantum field theory that describes the interaction of light and matter. To explain this, Feynman begins with the partial reflection of light by glass. Feynman shows us how to determine the probability of each photon being reflected. Rather than take us through complex numbers and integral calculus, he uses a system of arrows. The arrows鈥� length and direction are summed to provide an answer. While this seems straightforward at first, each ensuing example is more complicated requiring more steps. Along the way we learn about the strange world of photons and electrons and how QED is able to describe their interaction. At the end Feynman gives his takes on related subjects such as quantum chromodynamics. His well noted irreverent manner comes through in all the lectures. Feynman uses plain language that can be entertaining, at times flippant and self-deprecating. Feynman鈥檚 arrows accompanied by many illustrations and his famous diagrams make a difficult subject more accessible, but I did not find this to be a light read. Without prior familiarity with the topic, I would have been lost. But I was fascinated by his approach that uniquely complimented other books I have read about quantum field theory.
July 23, 2022
Although a bit more conceptually demanding, technically trying and theoretically abstract than some of his other, more widely-read pop-science books (I鈥檓 thinking primarily of the bestselling 鈥�Six Pieces鈥� duet published in the 1950s鈥攁 titularly symmetrical though somewhat uncreatively named duology, comprised of the now-classic tomes, 鈥�Six Easy-, and 鈥�Six Not-So-Easy Pieces鈥�), 鈥�QED: The Strange Theory of Light and Matter鈥� is still an engaging and elegant expostulation of some of the most thorny and mind-bending theories of the twentieth century鈥攁nd which still challenge the brightest minds of the twenty-first鈥攑unctuated by Feynman鈥檚 characteristic exuberance, creative outside-of-the-box thinking, and pure, childlike wonder at the mysteries of Nature that always come across so clearly in his prose. Feynman鈥檚 unabashed aim of educating the broader public; his very un-professorial tone; his interspersed jokes and common touch; surmounted by his folksy, metaphor-rich explanations may bother the more fastidious and advanced (not to say snooty!) reader who may be looking for and expecting something closer to a post-graduate level seminar from this eternally-adolescent Nobel laureate, but the fact that a minuscule portion of the physics contemporary to Feynman鈥檚 writing of 鈥�QED鈥� (and, in case you鈥檙e wondering, the acronym in the book鈥檚 title stands for Quantum Electrodynamics鈥攄别蹿颈苍颈迟别濒测 not for 鈥渜uod erat demonstrandum,鈥� the better-known, slightly arrogant mic-drop Latin phrase shouted gleefully upon pummeling one鈥檚 interlocutor in scientific or philosophical argument) really isn鈥檛 much of a strike against the book鈥攅specially for anyone interested not only in science, but also in the history (and to a lesser extent the epistemology) of science. 鈥�QED鈥� is a unique time-capsule of a book written by one of the most unique and influential geniuses of the 20th century. And of course, it鈥檚 also a typically entertaining, informative, and adept piece of Feynmanian explication. As Feynman himself once said, he didn鈥檛 believe that he could have fully absorbed and understood a theory until he was able to effectively explain it to a class of undergraduates (Feynman is chock-full of these sorts of casually brilliant and insightful maxims).
The most salient point of all, though, is the inherent value in reading a book like 鈥�QED鈥�. I found the experience both deeply fascinating and profoundly informative, which has been my reaction to everything else I鈥檝e ever read by Feynman. And I expect that reading this book will enhance most anyone鈥檚 overall understanding not only of 20th, but 21st century physics鈥攊n particular quantum electrodynamics. It generously imparts to the reader both the complexity and the innate beauty of our extraordinary cosmos; of the still-mysterious and hotly debated significance of the preternatural success of mathematics, and the superhuman ability it imparts to human scientists who wish to define and delimit, and then structure of the cosmos鈥攖o successfully predict the far future, as well as retrodict the distant past; of the epiphanic simplicity and intellectually harmonious perspective that only a mind like Feynman鈥檚 (even decades after his death) can still offer any reader with a curious and open mind.
The most salient point of all, though, is the inherent value in reading a book like 鈥�QED鈥�. I found the experience both deeply fascinating and profoundly informative, which has been my reaction to everything else I鈥檝e ever read by Feynman. And I expect that reading this book will enhance most anyone鈥檚 overall understanding not only of 20th, but 21st century physics鈥攊n particular quantum electrodynamics. It generously imparts to the reader both the complexity and the innate beauty of our extraordinary cosmos; of the still-mysterious and hotly debated significance of the preternatural success of mathematics, and the superhuman ability it imparts to human scientists who wish to define and delimit, and then structure of the cosmos鈥攖o successfully predict the far future, as well as retrodict the distant past; of the epiphanic simplicity and intellectually harmonious perspective that only a mind like Feynman鈥檚 (even decades after his death) can still offer any reader with a curious and open mind.
This entire review has been hidden because of spoilers.
November 30, 2015
I took this photo when I was about half way through the book. It shows a picture of a CD [click to enlarge]. It's been illuminated by an ordinary office lamp and the flashlight from my camera. I knew about this "rainbow" effect for a long time, but I didn't know exactly how it is created. This book gives some answers.
To write a successful book like QED (short for Quantum Electro-Dynamics) two prerequisites are required: 1) The author must know a great deal about the subject matter, and 2) He must love his work. Only then it is possible to explain the theory of QED to laypersons like me. Richard Feynman obviously fulfilled both of these conditions. For one he virtually "invented" Quantum Electro-Dynamics (and received the Nobel Prize for physics for it in 1940) and secondly you can clearly sense his deep affection for the nature of objects and processes in the realm of the very very very small things, that is the quantum world.
Instead of bothering the reader with mathematical formulas like this...
...Feynman developed a rather ingenious way of explaining the interaction of light particles (photons) and electrons (and later other particles too) using diagrams like this:
All those little arrows are of the utmost importance because they represent what is called "probability amplitudes" for an event. The longer the arrow the more likely the event. In fact all we have to do鈥搃n theory鈥搃s to draw all possible little arrows on a piece of paper to explain almost any phenomenon concerning light that we can observe in nature. Don't ask me why that is. In fact even Richard Feynman couldn't answer the "why", only the "how". That's the charming thing about quantum theory. It has to be pointed out that this way of dealing with quantum effects is not a deviation from the truth (as far as anyone knows the truth). Other popular science books make things too easy and thereby achieve simplicity only for the price of a somewhat distorted truth. Not so here!
But don't think that this drawing of arrows (and then later in the book what is called the "Feynman diagrams") is very simple. There are quite some things to consider, and the text is pretty dense. Anthony Zee, a Chinese American physicist, wrote in his introduction to QED:
[...] you must mull over each sentence carefully and try hard to understand what Feynman is saying before moving on. Otherwise, I guarantee that you will be hopelessly lost. It is the physics that is bizarre, not the presentation.I have to agree to that. Whenever I came to a point where Feynman lost me I skipped back a few pages and read it again....and again, until I made sense of it (as much sense as was possible for me). I think I understood the majority of this book, I just haven't internalized it. Not yet anyway. Maybe I have to read the whole book again after a couple of weeks. Until then I keep a quantum of solace that we (the humankind) are by now advanced enough to understand what make these cool "rainbow things" on CDs.
I highly recommend this book to anyone interested in the very foundation of what makes the world work the way it does.
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May 22, 2021
It's amazing what Feynman is attempting here. He tries to fully explain quantum electrodynamics to people with no background in physics. I am not sure he succeeds, I will have to check it by giving this book to someone who fears the subject.
Even for people like myself, who have been trained in physics, these lectures are useful. The way Feynman clearly communicates the concepts while not diving into mathematics is brilliant. I think these lectures are must read material for aspiring physicists. They show the big picture which is often buried in mathematical detail and remains inaccessible for many students.
Even for people like myself, who have been trained in physics, these lectures are useful. The way Feynman clearly communicates the concepts while not diving into mathematics is brilliant. I think these lectures are must read material for aspiring physicists. They show the big picture which is often buried in mathematical detail and remains inaccessible for many students.
September 15, 2020
兀乇亘毓丞 賲丨丕囟乇丕鬲 兀賱賯丕賴丕 賮賷賳賲丕賳 賮賷 賳賷賵夭賷賱丕賳丿丕 賯氐丿 廿賷氐丕賱 賲賮丕賴賷賲 丕賱賰賴乇賵丿賷賳丕賲賷賰丕 丕賱賰賲賷丞 賱睾賷乇 丕賱賲禺鬲氐賷賳. 賵 賯丿 鬲賲鬲 胤亘丕毓丞 賴匕賴 丕賱賲丨丕囟乇丕鬲 賰賴丿賷丞 賱乇賵丨 "兀賱賷賰爻 賲丕賵鬲賳乇" 丕賱鬲賷 賰丕賳鬲 賲鬲賷賲丞 亘丕賱賳馗乇賷丞 丕賱賰賲賷丞 賵 丕賱鬲賷 賰丕賳鬲 鬲胤賱亘 賲賳賴 鬲賮爻賷乇賴丕 賱賴丕 賱賰賳 丕賱賯丿乇 卮丕亍 兀賳 鬲乇丨賱 賯亘賱 兀賳 賷賳賮匕 胤賱亘賴丕. 賷賳胤賱賯 賮賷賳賲丕賳 賲賳 丕賱鬲爻丕丐賱 毓賳 馗丕賴乇丞 丕賱廿賳毓賰丕爻 丕賱噩夭卅賷 賱賷鬲賳丕賵賱 賮賷 丕賱賲丨丕囟乇丞 丕賱孬丕賳賷丞 丕賱胤亘賷毓丞 丕賱廿丨鬲賲丕賱賷丞 賱丨乇賰丕鬲 丕賱廿賱賰鬲乇賵賳丕鬲 賵 毓賱丕賯丞 匕賱賰 亘丕賱廿賳毓賰丕爻 孬賲 賱賷鬲毓賲賯 兀賰孬乇 賮賷 丕賱賮賰乇丞 賵 賷卮乇丨 胤乇賷賯丞 鬲賮丕毓賱 丕賱賮賵鬲賵賳丕鬲 賲毓 丕賱賰鬲乇賵賳丕鬲 丕賱賲丕丿丞 賵 賲丕 賷鬲亘毓 匕賱賰 賲賳 禺氐丕卅氐 賴匕賴 丕賱賳馗乇賷丞 丕賱鬲賷 賰丕賳 兀丨丿 乇賵丕丿賴丕 丕賱賳馗乇賷賷賳 (賳丕賱 噩丕卅夭丞 賳賵亘賱 乇賮賯丞 噩賵賱賷丕賳 卮賮賷賳噩乇 賵爻賷賳 鬲賵賲賵賳丕噩丕 亘爻亘亘 廿爻賴丕賲丕鬲賴 賮賷賴丕).
賵 賮賷 丨丕賱 賱賲 鬲噩毓賱賰 丕賱賲賮丕賴賷賲 丕賱賲賵噩賵丿丞 賮賷 丕賱賲丨丕囟乇丞 丕賱孬丕賱孬丞 兀賵 賲丕 爻亘賯賴丕 (兀賯賵賱 匕賱賰 賵 兀賳丕 丕賱賲鬲毓賵丿丞 毓賱賶 賲賷賰丕賳賷賰丕 丕賱賰賲) 鬲毓丿賱 噩賱爻鬲賰 兀賰孬乇 賲賳 賲乇丞 賵 鬲丨丿賯 賮賷 丕賱賮乇丕睾 賲卮丿賵賴丕 賲賳 爻丨乇 賲丕 賯乇兀鬲貙 賮廿賳 丕賱賲丨丕囟乇丞 丕賱乇丕亘毓丞 亘賰賱 鬲兀賰賷丿 賱丕 鬲禺賱賵 賲賳 丕賱賲鬲毓丞 丕賱賲毓乇賮賷丞 賮賮賷賴丕 亘丕賱廿囟丕賮丞 廿賱賶 賳賯丕卅氐 丕賱賰賴乇賵丿賷賳丕賲賷賰丕 丕賱賰賲賷丞 丨鬲賶 賱丨馗丞 廿賱賯丕亍 丕賱賲丨丕囟乇鬲貙 賲賯丿賲丞 乇丕卅毓丞 爻賴賱丞 賵 亘爻賷胤丞 賱賲噩丕賱 兀乇丕賴 賵 賷乇丕賴 丕賱賰孬賷乇賵賳 賲孬賱賷 丕賱兀賰孬乇 鬲毓賯賷丿丕 賮賷 丕賱賮賷夭賷丕亍 丕賱丨丿賷孬丞 賵 丕賱丨丿賷孬 賴賳丕 毓賳 賮賷夭賷丕亍 丕賱噩夭卅賷丕鬲.
賷亘賴乇賳賷 賮賷賳賲丕賳 賲乇丞 兀禺乇賶 亘賯丿乇鬲賴 丕賱賰亘賷乇丞 毓賱賶 廿賷氐丕賱 丕賱賲賮丕賴賷賲 丕賱賮賷夭賷丕卅賷丞 丿賵賳 丕賱毓賵丿丞 廿賱賶 丕賱乇賷丕囟賷丕鬲 賲丕 禺賱丕 亘毓囟 丕賱兀賲孬賱丞 丕賱囟乇賵乇賷丞 賵 丕賱鬲賷 賱丕 鬲鬲胤賱亘 丕賱賰孬賷乇 賲賳 丕賱賲毓乇賮丞 丕賱乇賷丕囟賷丞. 胤亘毓丕 兀賷 卮禺氐 丿乇爻 丕賱賮賷夭賷丕亍 賮賷 毓丕賱賲賳丕 丕賱毓乇亘賷 爻賷毓乇賮 兀賳 丕賱廿賳胤賱丕賯 睾丕賱亘丕 賷賰賵賳 賲賳 丕賱賯丕毓丿丞 丕賱乇賷丕囟賷丞 賱賱鬲賮爻賷乇...卮禺氐賷丕 賱丕 賷賲賰賳 兀賳 兀噩丿 鬲賮爻賷乇丕 睾賷乇 賰賵賳 丕賱兀爻鬲丕匕 睾賷乇 賲賱賲 亘丕賱賲賮賴賵賲 兀氐賱丕 賵 兀賳 賵丕囟毓 丕賱賲賳賴噩 賱丕 賷賴丿賮 廿賱賶 禺賱賯 噩賷賱 賲賮賰乇 賵 兀賳 賲丨丕囟乇丕鬲賳丕 丕賱噩丕賲毓賷丞 賮賷 睾丕賱亘賴丕 噩賵賮丕亍 鬲禺賱賵 賲賳 丕賱毓賲賯 丕賱賲毓乇賮賷...禺賲爻 賳噩賲丕鬲 賵 兀乇睾亘 丨賯丕 賮賷 廿囟丕賮丞 爻丕丿爻丞 賱賵 賰丕賳 匕賱賰 賲賲賰賳丕 ...廿賱賶 賱賯丕亍 丌禺乇 爻賷丿 賮賷賳賲丕賳
14/09/2020
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April 14, 2012You could call me a science groupie. I put on Cosmos while I clean the house, snatch up Michio Kaku's books like they won't be there tomorrow, know all the words to every Symphony of Science song ever, and follow Neil deGrasse Tyson on Twitter--but that doesn't mean I know the first thing about real science. I couldn't solve a linear algebraic equation even if the world depended on it (sorry, world). Instead, I revere famous physicists from afar while most women my age drool over movie stars like What's-His-Face. You know the one. That really hott one.
Anyway. Richard Feynman is definitely in the top five on my list of favorite physicists. (Yep, I have a list. Expect nothing less from a girl who named her cat Sagan.) I love Feynman's sense of humor and his whimsical world-view. He may be gone, but he's not forgotten. So when I had a stupid question about light, I figured it was high time I read his book on the subject. My stupid question goes like this: Why is it that, when you turn off a light, the room immediately goes dark? Where does the light go? Why doesn't it bounce around the room for a bit before dispersing? If light is everywhere, why is the universe so dark?
Well, this book didn't really help me answer those questions. If Feynman taught me anything here, it's that light is the honey badger of particles: it does what it wants, and leaves tiny arrows in its wake. Or something. I'm not sure.
Anyway. Richard Feynman is definitely in the top five on my list of favorite physicists. (Yep, I have a list. Expect nothing less from a girl who named her cat Sagan.) I love Feynman's sense of humor and his whimsical world-view. He may be gone, but he's not forgotten. So when I had a stupid question about light, I figured it was high time I read his book on the subject. My stupid question goes like this: Why is it that, when you turn off a light, the room immediately goes dark? Where does the light go? Why doesn't it bounce around the room for a bit before dispersing? If light is everywhere, why is the universe so dark?
Well, this book didn't really help me answer those questions. If Feynman taught me anything here, it's that light is the honey badger of particles: it does what it wants, and leaves tiny arrows in its wake. Or something. I'm not sure.
November 19, 2016
Richard Feynman's friend Alix had asked him to explain Quantum Electrodynamics (the titular QED) to her in a way a layman could understand many times. Heartbreakingly, it wasn't until her death that he actually found the time to write a series of four lectures that would do just that. This book is a (slightly edited) transcript of those four lectures.
Feynman writes for the layman without ever being condescending and his famous sense of humour shines through. He makes this subject both approachable and fascinating. I've studied much of the content before in physics classes and other books but Feynman has made me look at it in a different way. In fact, I can safely say that this book has significantly changed the way I think about reality.
If that's not worth five stars, nothing is. If you've not read this book before, do yourself a favour and give it a bash.
Feynman writes for the layman without ever being condescending and his famous sense of humour shines through. He makes this subject both approachable and fascinating. I've studied much of the content before in physics classes and other books but Feynman has made me look at it in a different way. In fact, I can safely say that this book has significantly changed the way I think about reality.
If that's not worth five stars, nothing is. If you've not read this book before, do yourself a favour and give it a bash.
April 10, 2017
QED: The Strange Theory of Light and Matter is an outstanding book on a subject that is often overlooked or glossed-over in many popular physics books. Feynman does a deep dive on Quantum Electrodynamics: a theory that deals not only with the various interactions between light and matter, but which can be applied to every area of physics with the exception of gravitation and nuclear physics.
The theory of QED is fascinating, both in its explanatory power and its elegance. Using only a handful of conceptual tools, and working with just two fundamental particles - the photon and electron - it can describe phenomena as varied as reflection and refraction of light, changes in the speed of light through different mediums, quantum interference, lenses (I found the application of QED to this seemingly mundane property of glass to be particularly mind-blowing), and even suggests how all the diverse properties of the elements arise from only three basic actions performed by these two fundamental particles.
To say that this book changed the way I see the world is only a slight overstatement - it has certainly opened my eyes. QED is an absolute must-read for anyone with an interest in physics. Feynman takes great pains to present the theory in a clear and logical way, and while the subject is challenging, it is utterly comprehensible from cover to cover. This is by far the best popular science book I've read in a long time - I cannot recommend it highly enough.
The theory of QED is fascinating, both in its explanatory power and its elegance. Using only a handful of conceptual tools, and working with just two fundamental particles - the photon and electron - it can describe phenomena as varied as reflection and refraction of light, changes in the speed of light through different mediums, quantum interference, lenses (I found the application of QED to this seemingly mundane property of glass to be particularly mind-blowing), and even suggests how all the diverse properties of the elements arise from only three basic actions performed by these two fundamental particles.
To say that this book changed the way I see the world is only a slight overstatement - it has certainly opened my eyes. QED is an absolute must-read for anyone with an interest in physics. Feynman takes great pains to present the theory in a clear and logical way, and while the subject is challenging, it is utterly comprehensible from cover to cover. This is by far the best popular science book I've read in a long time - I cannot recommend it highly enough.
May 31, 2016
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 m铆nimum time.
Also the strange property of a photon or electron that in the doubl茅 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 positr贸n 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
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 m铆nimum time.
Also the strange property of a photon or electron that in the doubl茅 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 positr贸n 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
July 25, 2020
In the beginning of QED, Richard Feynman says that people are always asking physicists about the new findings of a grand unified theory. He feels they should also be asked about known and confirmed theories instead of undercooked and partially analyzed ones. So he decides to speak about the 鈥渨ell dissected and marvelous鈥� theory of QED. The theory describes the interactions between photos and electrons, space-time and probabilities, among others.
The book is based on four conferences given by Richard Feynman in the 1980s. These were done in memory of a friend of his who had passed away, Alix Mautner. She had a career in english literature but was curious about physics and often asked him about quantum mechanics. He never had the chance to explain her the theory of quantum electrodynamics (QED), for which he was awarded a Nobel prize (alongside Schwinger and Tomonoga), and which he described as 鈥渢he jewel of physics鈥�.
It鈥檚 remarkable how much content there is in this book, having only 150 pages or so. The explanations are easy, illustrated with a great amount of examples and figures, and may seem too simple at times, until Feynman shows the grand picture and demonstrates how brilliant physics is. He had the ability to make topics which could be seen as too complex become accessible.
I was delighted to read this book, as there aren鈥檛 many books for non-physicists that mention QED. Feynman鈥檚 mix of humour and humility just improves the experience.
This is a wonderful book and one couldn鈥檛 ask for a better teacher than Feynman. He reminds us that physics can be fun and inspiring.
The book is based on four conferences given by Richard Feynman in the 1980s. These were done in memory of a friend of his who had passed away, Alix Mautner. She had a career in english literature but was curious about physics and often asked him about quantum mechanics. He never had the chance to explain her the theory of quantum electrodynamics (QED), for which he was awarded a Nobel prize (alongside Schwinger and Tomonoga), and which he described as 鈥渢he jewel of physics鈥�.
It鈥檚 remarkable how much content there is in this book, having only 150 pages or so. The explanations are easy, illustrated with a great amount of examples and figures, and may seem too simple at times, until Feynman shows the grand picture and demonstrates how brilliant physics is. He had the ability to make topics which could be seen as too complex become accessible.
I was delighted to read this book, as there aren鈥檛 many books for non-physicists that mention QED. Feynman鈥檚 mix of humour and humility just improves the experience.
This is a wonderful book and one couldn鈥檛 ask for a better teacher than Feynman. He reminds us that physics can be fun and inspiring.
August 8, 2016
Ce livre propose de vulgariser la th茅orie scientifique la plus exacte dont nous disposons avec laquelle il est possible de mod茅liser la lumi猫re, la mati猫re et leurs interactions r茅ciproques, 脿 savoir la m茅canique quantique. D茅velopp茅e au cours du si猫cle pr茅c茅dent, elle se fonde sur des principes qui brusquent le sens commun, comme la dualit茅 onde-corpuscule ou le principe de superposition, car il n'est plus possible de s'aider d'analogies 脿 partir de notre exp茅rience pour en rendre compte sans prendre le risque de commettre des erreurs, et seul la ma卯trise de l'outil math茅matique en rend compte fid猫lement. C'est donc une gageure que d'expliquer ces m茅canismes avec l'aide de petits sch茅mas et dessins, tels que l'entreprend l'auteur.
Il s'y emploie cependant, illustrant par exemple des ph茅nom猫nes aussi familiers que la r茅flexion de la lumi猫re dans un miroir, sa r茅fraction dans l'eau ou le verre, ou encore le fait qu'une partie est transmise et une autre r茅fl茅chie. On aborde 茅galement la cause des magnifiques irisations diapr茅es qui ornent la surface des bulles de savons, les ailes des papillons ou la face lisibles des compact-disc. Tout est ramen茅 au calcul d'une somme de probabilit茅s repr茅sent茅e ing茅nieusement par de petites fl猫ches mises bout-脿-bout. Pour autant, je ne suis pas certain qu'il parvienne 脿 rendre tout aussi clair qu'il le souhaite. La dur茅e n茅cessairement limit茅e des expos茅s dont ces textes sont la transcriptions ne permettent pas d'en 茅clairer toutes les subtilit茅s.
L'humour et la modestie avec laquelle l'auteur traite le sujet rend la lecture agr茅able, mais il me semble qu'en d茅pit des immenses efforts d茅ploy茅s par l'auteur pour rendre son sujet accessible, l'essentiel restera obscur pour le plus grand nombre, 脿 moins de nourrir un int茅r锚t particuli猫rement fort pour le sujet. J'ai n茅anmoins beaucoup appr茅ci茅 que ce livre aiguise ma curiosit茅, et exerce mon 茅merveillement pour la beaut茅 de la Nature.
July 12, 2017
Throughout the years of reading both popular and less-popular science, I鈥檝e kind of steered clear of Richard Feynman. The main reason is that what others describe as a 鈥渓arger than life persona鈥� I tend to describe as really bloody annoying, what with his bongos and womanizing and oh-so-clever quips where he always gets the upper hand with the old and rusty physics establishment. Having now fought my way through QED, I can see that this may have been a mistake. My annoyance with his autobiographical works has kept me away from some truly gorgeous scientific writing.
The thing is, I鈥檓 not sure if it is even possible to explain quantum mechanics properly without all the higher math, but if it is possible, this is likely the only proper way 鈥� with a lot of 鈥渢his is how it is, and don鈥檛 ask why, because even we, physicists, do not know鈥�, and a lot of weird and unexpected analogies, such as his substitution of 鈥渓ittle clock hands鈥� for the harmonic oscillator that pops up every which way in QM. The only problem I had was that knowing the 鈥減roper鈥� theory it took me a while to fully intuitively accept and adopt his 鈥渢iny clocks running鈥� description and match it with the complex numbers/oscillators he is describing in this roundabout fashion. However, once that clicked into place, his descriptions of simple everyday phenomena, such as reflection and diffraction, the two-slit experiment, and later on the interaction of electrons and photons, really popped off of the page and sort of 鈥渂roadened the groove鈥� wherein all the counter-intuitiveness of QM is trying to get a foothold in my brain.
The thing is, I鈥檓 not sure if it is even possible to explain quantum mechanics properly without all the higher math, but if it is possible, this is likely the only proper way 鈥� with a lot of 鈥渢his is how it is, and don鈥檛 ask why, because even we, physicists, do not know鈥�, and a lot of weird and unexpected analogies, such as his substitution of 鈥渓ittle clock hands鈥� for the harmonic oscillator that pops up every which way in QM. The only problem I had was that knowing the 鈥減roper鈥� theory it took me a while to fully intuitively accept and adopt his 鈥渢iny clocks running鈥� description and match it with the complex numbers/oscillators he is describing in this roundabout fashion. However, once that clicked into place, his descriptions of simple everyday phenomena, such as reflection and diffraction, the two-slit experiment, and later on the interaction of electrons and photons, really popped off of the page and sort of 鈥渂roadened the groove鈥� wherein all the counter-intuitiveness of QM is trying to get a foothold in my brain.
March 29, 2016
In this series of short lectures, Feynman reduces (except for gravity and radioactivity) the whole of the universe to quantum electrodynamics or QED.* QED involves the relationship between photons (light) and electrons (matter), or quantum phenomena, the interaction of which (electrons emit/give up and absorb/get photons/particles of light) creates all of the atoms and elements in the universe.
Feynman uses light鈥檚 refraction to illustrate the relationship between electrons and photons. To understand light, one has to lose 鈥渃ommon sense,鈥� he says. Light does strange things. We understand light not as specifically identified photon movement but in terms of probability. 鈥淚 am not going to explain how the photons actually 鈥榙ecide鈥� whether to bounce back or go through [an opening]; that is not known,鈥� he writes, and then adds, 鈥�(Probably the question has no meaning.)鈥� Light seeks the fastest (shortest) route in its movement from A to B, but it borrows or uses paths that are adjacent. When light moves through a small opening, it also spreads out. In this regard, he writes that 鈥渓ight doesn鈥檛 really travel only in a straight line; it 鈥榮mells鈥� the neighboring paths around it and uses a small core of nearby space.鈥滶lectron movement is strange as well. Electrons jump from one path to another and positive electrons (positrons) go backward in time. The book quickly gets technical. It is filled with Feynman diagrams and I can鈥檛 say I grasped much.
Feynman is describing quantum phenomena but describing is different than understanding. 鈥淲hile I am describing to you how Nature works,鈥� he writes, 鈥測ou won鈥檛 understand why Nature works that way.鈥� 鈥淢y physics students don鈥檛 understand it鈥�.That is because I don鈥檛 understand it. Nobody does.鈥� This makes his quote above, 鈥淧robably the question has no meaning,鈥� particularly interesting as Feynman seems to be saying that, in the end, we can only describe how nature works, but not why it works the way it does. By extension, is Feynman saying that there are no ultimate explanations (e.g., God, Deist design) for the cosmos and how it operates, and that Nature just Is?
*鈥淭he theory describes all the phenomena of the physical world except the gravitational effect, the thing that holds you in your seats,..and radioactive phenomena.鈥� QED is 鈥渁 horrible name,鈥� Feynman concedes. The theory also describes what goes on inside the nucleus itself, which are the quarks and gluons, and involve some 400 (and counting) subparticles.
Feynman uses light鈥檚 refraction to illustrate the relationship between electrons and photons. To understand light, one has to lose 鈥渃ommon sense,鈥� he says. Light does strange things. We understand light not as specifically identified photon movement but in terms of probability. 鈥淚 am not going to explain how the photons actually 鈥榙ecide鈥� whether to bounce back or go through [an opening]; that is not known,鈥� he writes, and then adds, 鈥�(Probably the question has no meaning.)鈥� Light seeks the fastest (shortest) route in its movement from A to B, but it borrows or uses paths that are adjacent. When light moves through a small opening, it also spreads out. In this regard, he writes that 鈥渓ight doesn鈥檛 really travel only in a straight line; it 鈥榮mells鈥� the neighboring paths around it and uses a small core of nearby space.鈥滶lectron movement is strange as well. Electrons jump from one path to another and positive electrons (positrons) go backward in time. The book quickly gets technical. It is filled with Feynman diagrams and I can鈥檛 say I grasped much.
Feynman is describing quantum phenomena but describing is different than understanding. 鈥淲hile I am describing to you how Nature works,鈥� he writes, 鈥測ou won鈥檛 understand why Nature works that way.鈥� 鈥淢y physics students don鈥檛 understand it鈥�.That is because I don鈥檛 understand it. Nobody does.鈥� This makes his quote above, 鈥淧robably the question has no meaning,鈥� particularly interesting as Feynman seems to be saying that, in the end, we can only describe how nature works, but not why it works the way it does. By extension, is Feynman saying that there are no ultimate explanations (e.g., God, Deist design) for the cosmos and how it operates, and that Nature just Is?
*鈥淭he theory describes all the phenomena of the physical world except the gravitational effect, the thing that holds you in your seats,..and radioactive phenomena.鈥� QED is 鈥渁 horrible name,鈥� Feynman concedes. The theory also describes what goes on inside the nucleus itself, which are the quarks and gluons, and involve some 400 (and counting) subparticles.
February 17, 2019
That's my position: I'm going to explain to you what the physicists are doing when they are predicting how Nature will behave, but I'm not going to teach you any tricks so you can do it efficiently.
Starting from the idea of photons as particles of light, Feynman develops a nontechnical, easily understandable theory of basic quantum electrodynamics, or QED. He uses it to give modern explanations of everyday phenomena such as reflection and refraction, before delving into the basic of electron-photon interactions (the so-called Feynman diagrams) which underly all phenomena except gravity and nuclear physics. No maths is involved, though he uses pictures creatively. In the final lecture, he talks about the experimental aspects and the cutting-edge developments of his time (gluons, quarks, chromodynamics etc).
If all sciences were so well explained in so few words with so much good will and humour, the ideas and intuition behind humanity's greatest achievements would be accessible to a much wider audience.
September 17, 2018
Richard Feynman, m谩s all谩 de haber sido uno de los mejores f铆sicos del siglo XX, y de haber sido premiado con un Nobel por esto, fue un excelente profesor; y el mundo lo conoce muy bien por esto.
Este libro es otra gran muestra de ello; es el compendio de una serie de conferencias que estaban destinadas para explicar F铆sica Cu谩ntica a la esposa de un amigo suyo (que, por supuesto, no era f铆sica), as铆 que es una obra excelente para introducirse o incluso para profundizar en el mundo de las part铆culas subat贸micas. Las conferencias se enfocan especialmente en los fotones y en los electrones, y en como siguiendo tres simples reglas logran explicar pr谩cticamente todos los sucesos que ocurren a tal escala; y para hacerlo, recurre nada y nada menos que al "simple" proceso a trav茅s del cual la luz atraviesa un cristal.
Una lectura para CUALQUIERA que quiera conocer un poco (m谩s) sobre lo que para muchos parece estar fuera de alcance: la F铆sica Cu谩ntica.
Este libro es otra gran muestra de ello; es el compendio de una serie de conferencias que estaban destinadas para explicar F铆sica Cu谩ntica a la esposa de un amigo suyo (que, por supuesto, no era f铆sica), as铆 que es una obra excelente para introducirse o incluso para profundizar en el mundo de las part铆culas subat贸micas. Las conferencias se enfocan especialmente en los fotones y en los electrones, y en como siguiendo tres simples reglas logran explicar pr谩cticamente todos los sucesos que ocurren a tal escala; y para hacerlo, recurre nada y nada menos que al "simple" proceso a trav茅s del cual la luz atraviesa un cristal.
Una lectura para CUALQUIERA que quiera conocer un poco (m谩s) sobre lo que para muchos parece estar fuera de alcance: la F铆sica Cu谩ntica.
July 11, 2017
銆丆hapter 3; electrons and their interaction will be a clue to solve all the phenomena for the universe.
It's the absolutely essential reading physics book for everyone .
It's the absolutely essential reading physics book for everyone .
February 19, 2022
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
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
January 24, 2010
It's all arrows, man. All about arrows. Physics is not a subject I have a terribly good grasp on mainly because my eyes glaze over at the sight of advanced mathematical equations, however Feynman is a pretty great at making the complex subjects of particle physics and quantum mechanics intelligible to the layest of laypersons. Fortunately I also read this with able-minded people who translated the math into clearer ideas which of course opened things up to broader philosophical speculation--something I am pretty good with. The introduction to the book is also worth reading by itself at the very least.
"I think I can safely say that nobody understands quantum mechanics."
-Richard Feynman
He was also a very funny and clever man who left behind , for instance:
"A poet once said, 'The whole universe is in a glass of wine.' We will probably never know in what sense he meant it, for poets do not write to be understood. But it is true that if we look at a glass of wine closely enough we see the entire universe. There are the things of physics: the twisting liquid which evaporates depending on the wind and weather, the reflection in the glass; and our imagination adds atoms. The glass is a distillation of the earth's rocks, and in its composition we see the secrets of the universe's age, and the evolution of stars. What strange array of chemicals are in the wine? How did they come to be? There are the ferments, the enzymes, the substrates, and the products. There in wine is found the great generalization; all life is fermentation. Nobody can discover the chemistry of wine without discovering, as did Louis Pasteur, the cause of much disease. How vivid is the claret, pressing its existence into the consciousness that watches it! If our small minds, for some convenience, divide this glass of wine, this universe, into parts -- physics, biology, geology, astronomy, psychology, and so on -- remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for. Let it give us one more final pleasure; drink it and forget it all!"
"I think I can safely say that nobody understands quantum mechanics."
-Richard Feynman
He was also a very funny and clever man who left behind , for instance:
"A poet once said, 'The whole universe is in a glass of wine.' We will probably never know in what sense he meant it, for poets do not write to be understood. But it is true that if we look at a glass of wine closely enough we see the entire universe. There are the things of physics: the twisting liquid which evaporates depending on the wind and weather, the reflection in the glass; and our imagination adds atoms. The glass is a distillation of the earth's rocks, and in its composition we see the secrets of the universe's age, and the evolution of stars. What strange array of chemicals are in the wine? How did they come to be? There are the ferments, the enzymes, the substrates, and the products. There in wine is found the great generalization; all life is fermentation. Nobody can discover the chemistry of wine without discovering, as did Louis Pasteur, the cause of much disease. How vivid is the claret, pressing its existence into the consciousness that watches it! If our small minds, for some convenience, divide this glass of wine, this universe, into parts -- physics, biology, geology, astronomy, psychology, and so on -- remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for. Let it give us one more final pleasure; drink it and forget it all!"
August 22, 2018
I've never seen something like this before! It explains the way quantum electrodynamics actually works (not just analogies), but without assuming any physics or math background. I would have been skeptical if the author were anyone other than Richard Feynman, but it's super well done. With my limited physics background, I found the explanations super clear, at least in the beginning.
Some of my favorite parts: I learned that light doesn't always travel in a straight line or at the speed of light, but I also learned why paths where it doesn't won't be observed at macroscopic scales. I learned why puddles of oil make rainbows and what a diffraction grating is. And I learned why when light reflects off or travels through a piece of glass, we can treat it as only interacting with the two surfaces of the glass, even though actually it interacts with all the electrons inside.
Towards the end, the explanations became less complete and didn't make as much sense to me. For example, Feynman says that in a hydrogen atom, "by exchanging photons, the proton keeps the electron nearby", but he didn't explain how exchanging photons would make it more likely that the electron stays near. Overall, though, this was well worth reading.
Some of my favorite parts: I learned that light doesn't always travel in a straight line or at the speed of light, but I also learned why paths where it doesn't won't be observed at macroscopic scales. I learned why puddles of oil make rainbows and what a diffraction grating is. And I learned why when light reflects off or travels through a piece of glass, we can treat it as only interacting with the two surfaces of the glass, even though actually it interacts with all the electrons inside.
Towards the end, the explanations became less complete and didn't make as much sense to me. For example, Feynman says that in a hydrogen atom, "by exchanging photons, the proton keeps the electron nearby", but he didn't explain how exchanging photons would make it more likely that the electron stays near. Overall, though, this was well worth reading.
January 18, 2013
I visited my brother a long time ago, when he was working on his Ph.D. in Physics. He tossed a small, innocuous-looking book to me and said, "Read this - its a complete brain-f**k. I've been hooked ever since. QED is, by far, the best piece of non-fiction I have ever read. It takes a long time for me to work though the concepts, and, as Feynman points out, nobody (including me) (especially me) truly understands Quantum Electrodynamics. But to begin with adding 'damned little arrows' and take that to an all-encompassing description of atomic theory, accurate to ten decimal places, in about 120 pages, so the likes of me can follow along, is the purest of genius. Bravo!
October 19, 2015
Its a subject that got glazed over when I was in Engineering and after that, a wiki entry that I frequented whenever I had questions. Feynman targets this book to, well, everyone. He holds your hand and shows how things work. Its a slow step by step process and if you invest some time, its highly rewarding and quite refreshing to be taught physics by a man who is long dead but doesn't really feel so when you read his words. You get transposed to his classroom as he explains basic concepts and the paradox surrounding the most natural thing in this world: light.
Its a re-read which I enjoyed and will get on to re-reading some of his other famous lectures.
Its a re-read which I enjoyed and will get on to re-reading some of his other famous lectures.
February 11, 2022
些械 芯写薪邪 泻薪懈卸泻邪 胁 褟泻褨泄 褟 (谐褍屑邪薪褨褌邪褉褨泄) 锌褉芯斜褍褦 褕芯褋褜 蟹褉芯蟹褍屑褨褌懈 胁 泻胁邪薪褌芯胁褨泄 褎褨蟹懈褑褨. 袉 芯褌 褋泻邪卸褍 褔械褋薪芯, 锌褉懈 褌芯屑褍, 褖芯 褋泻邪蟹邪褌懈 褖芯 "蟹褉芯蟹褍屑褨胁" 斜褍谢芯 斜 写褍卸械 谐芯谢芯褋薪芯, 褑褟 泻薪懈卸泻邪 薪邪褋锌褉邪胁写褨 薪邪斜谢懈蟹懈谢邪 写芯 褉芯蟹褍屑褨薪薪褟. 袛褍卸械 泻褉褍褌芯 褉芯蟹卸芯胁邪薪芯 蟹胁褨写泻懈 胁蟹邪谐邪谢褨 胁蟹褟谢邪褋褜 褌械芯褉褨褟 (薪邪 锌褉芯褋褌芯屑褍 械褋锌械褉懈屑械薪褌褨 蟹 胁褨写斜懈褌褌褟屑 褋胁褨褌谢邪), 褟泻邪 屑邪褌械屑邪褌懈泻邪 谢械卸懈褌褜 锌褨写 薪械褞 (褦 锌褉芯褋褌褨 褎芯褉屑褍谢懈), 褟泻 褑械 胁褋械 锌芯褌褨屑 械泻褋锌械褉懈屑械薪褌邪谢褜薪芯 锌褨写褌胁械褉写卸褍胁邪谢芯褋褜 褨 谐芯谢芯胁薪械 - 胁 锌褉邪胁懈谢褜薪懈褏 屑褨褋褑褟褏 锌芯胁褌芯褉褞褦褌褜褋褟 褖芯 "褌邪泻, 褑械 褦 薪械蟹褉芯蟹褍屑褨谢芯 褨 薪械谢芯谐褨褔薪芯 褨 薪械 褋锌褨胁褋褌邪胁谢褟褦褌褜褋褟 蟹 谢芯谐褨泻芯褞 褎褨蟹懈泻懈 薪芯褉屑邪谢褜薪懈褏 胁械谢懈褔懈薪, 褌褍褌 锌褉邪胁懈谢邪 褨薪褕褨".
孝芯褔薪芯 薪械 褋泻邪卸褍 褖芯 谢械谐泻芯 褔懈褌邪褦褌褜褋褟 - 屑褨褋褑褟屑懈 锌褉褟屑 写褍卸械 褋泻谢邪写薪芯 褨 薪械蟹褉芯蟹褍屑褨谢芯, 邪谢械 蟹邪谐邪谢褜薪邪 泻邪褉褌懈薪邪 褋锌褉懈泄屑邪褦褌褜褋褟 褟泻芯褋褜 褑褨谢褨褋薪褨褕械. 袛褍卸械 褋锌芯写芯斜邪胁褋褟 芯褋褌邪薪薪褨泄 褉芯蟹写褨谢 (谢械泻褑褨褟) 锌褉芯 褨薪褕褨 锌褉芯斜谢械屑懈 褨 褋褍屑褨卸薪褨 褌械芯褉褨褩. 袙懈泻谢邪写械薪芯 褌褉芯褕泻懈 锌芯胁械褉褏薪械胁褨褕械 邪谢械 写褍卸械 褑褨泻邪胁芯. 袧邪褉械褕褌褨, 褏褌芯褋褜 薪芯褉屑邪谢褜薪芯 锌芯褟褋薪懈胁 褋褍斜邪褌芯屑薪褨 褔邪褋褌懈薪泻懈 (褩褏 屑邪褋褍,蟹邪褉褟写, "锌芯泻芯谢褨薪薪褟") 褨 褟泻 褑械 胁褋械 锌褉邪褑褞褦.
袙褋械 褑械 蟹写芯斜褉械薪芯 褏芯褉芯褕懈屑 褋邪屑芯褉褨薪褨褔薪懈屑 褨 "蟹邪写褉芯褌褋褜泻懈屑" 谐褍屑芯褉芯屑.
孝芯褔薪芯 薪械 褋泻邪卸褍 褖芯 谢械谐泻芯 褔懈褌邪褦褌褜褋褟 - 屑褨褋褑褟屑懈 锌褉褟屑 写褍卸械 褋泻谢邪写薪芯 褨 薪械蟹褉芯蟹褍屑褨谢芯, 邪谢械 蟹邪谐邪谢褜薪邪 泻邪褉褌懈薪邪 褋锌褉懈泄屑邪褦褌褜褋褟 褟泻芯褋褜 褑褨谢褨褋薪褨褕械. 袛褍卸械 褋锌芯写芯斜邪胁褋褟 芯褋褌邪薪薪褨泄 褉芯蟹写褨谢 (谢械泻褑褨褟) 锌褉芯 褨薪褕褨 锌褉芯斜谢械屑懈 褨 褋褍屑褨卸薪褨 褌械芯褉褨褩. 袙懈泻谢邪写械薪芯 褌褉芯褕泻懈 锌芯胁械褉褏薪械胁褨褕械 邪谢械 写褍卸械 褑褨泻邪胁芯. 袧邪褉械褕褌褨, 褏褌芯褋褜 薪芯褉屑邪谢褜薪芯 锌芯褟褋薪懈胁 褋褍斜邪褌芯屑薪褨 褔邪褋褌懈薪泻懈 (褩褏 屑邪褋褍,蟹邪褉褟写, "锌芯泻芯谢褨薪薪褟") 褨 褟泻 褑械 胁褋械 锌褉邪褑褞褦.
袙褋械 褑械 蟹写芯斜褉械薪芯 褏芯褉芯褕懈屑 褋邪屑芯褉褨薪褨褔薪懈屑 褨 "蟹邪写褉芯褌褋褜泻懈屑" 谐褍屑芯褉芯屑.
March 25, 2024
The quantum world is wild and I don鈥檛 understand it. Feynman assures me that is ok because nobody understands it.
March 4, 2012
Esta es una de las muchas incursiones que hizo el gran en el terreno de la divulgaci贸n cient铆fica. En realidad 茅l no escribi贸 ninguno de sus libros de divulgaci贸n cient铆fica, sino que se adaptaron de sus ciclos de conferencias de divulgaci贸n, que, ah铆 s铆, Feynman preparaba a conciencia. Este libro surge de una serie de cuatro conferencias que dio Feynman en (que en ingl茅s no se dice ucla sino u-c-l-a, iusielei, dato CPI para viajeros por tierras californianas).
La , adem谩s de asustar con su nombre chulo y mol贸n, es la parte de la f铆sica que se encarga de estudiar las interacciones entre la luz y la materia (o, m谩s concretamente, entre los fotones y los electrones). Es, abreviando, la teor铆a del electromagnetismo pero en versi贸n cu谩ntica. La electrodin谩mica cu谩ntica no entra en las reacciones nucleares o intra-nucleares. Feynman contribuy贸 decisivamente al desarrollo de esta teor铆a, motivo por el que recibi贸 su premio Nobel de 1965.
Feynman logra la haza帽a de hacer algo m谩s comprensible la mec谩nica cu谩ntica a partir de unas pocas situaciones bastante simples. Cuando iluminamos un cristal de frente, dependiendo del grosor del cristal, se refleja m谩s o menos luz, en valores que oscilan desde el 4% al 16%. El resto de la luz atraviesa el cristal (t茅cnicamente un es otra cosa y una ventana es un vidrio). Feynman reconstruye los mecanismos b谩sicos de la teor铆a cu谩ntica a partir de la explicaci贸n de este fen贸meno.
Despu茅s, otra pregunta simple. 驴Por qu茅 la luz, al rebotar en un espejo, sale reflejada con el mismo 谩ngulo con el que lleg贸? Esta simple pregunta sirve para plantear toda la teor铆a de integrales de caminos de Feynman, que explica un mont贸n de fen贸menos cotidianos. Cuando un electr贸n va de A a B rebotando en un espejo, seg煤n el modelo de la Electrodin谩mica cu谩ntica, no sigue un camino sino muchos (de hecho, todos los posibles). Para cada camino hay asociada una probabilidad y una fase, concepto crucial que Feynman explica como un maestro que fue. La suma de todos los caminos nos da el camino m谩s probable, que resulta ser, oh sorpresa, la reflexi贸n cl谩sica en la que el 谩ngulo de entrada es igual al 谩ngulo de salida.
El rayo de luz rebotando en un espejo, base de la construcci贸n de las integrales de caminos de Feynman.
Finalmente, Feynman da el salto y nos habla de las interacciones entre part铆culas, de la y usa profusamente sus diagramas (los famosos ), utilizando bastantes conceptos expuestos en los dos primeros cap铆tulos (las dos primeras charlas).
Diagramas de Feynman. Aunque parezcan complicados Feynman los hace simples.
El libro no es complicado en el sentido de que no tiene f贸rmulas ni desarrollos matem谩ticos. Feynman presupone una audiencia sin formaci贸n pero con capacidad de aprender y razonar. Comienza explicando c贸mo sumar dos flechas (vectores) y c贸mo sumar dos n煤meros (tiempos), y a partir de ah铆 tira para adelante. Sin embargo, tampoco es un libro de entretenimiento y pasar el rato. Hay conceptos que deben ser pensados un par de veces antes de seguir, y les recomiendo que no pasen a la siguiente cuesti贸n sin entender la anterior.
Al acabar, uno tiene la sensaci贸n de que bajo el cap贸 de las charlas de Feynman hay un incre铆ble y complicad铆simo mundo, cosa que es cierta, pero que uno ha aprendido los rudimentos b谩sicos del funcionamiento de la luz y la materia, cosa que tambi茅n es cierta. Feynman era un gran divulgador, y lo demuestra.
Mi nota: excepcional.
May 16, 2012
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鈥攐ne of my favourite videos on Youtube is a two-and-a-half minute video of Feynman sitting in a chair explaining . 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.
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鈥攐ne of my favourite videos on Youtube is a two-and-a-half minute video of Feynman sitting in a chair explaining . 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.
August 11, 2012
I think this is my favorite science book. This was in large part due to having Feynman's real voice in my head, as I've heard him often in recorded lectures and documentaries.
The book is transcription of a few lectures Feynman gave on Quantum Electrodynamics (QED), a branch of quantum theory he and Dirac developed. Feynman introduces a few simple rules on how electrons and photons behave (which appear to be easy-to-digest analogs for vector calculus) and then off he goes, explaining the theory and how it describes an enormous amount of phenomena, such as the uncertainty principle, the how lenses and mirages physically work, how light scattering creates particles that travel backwards in time (via an antiparticle), why electrons stay in their orbits, lasers (exclusion principle). The only concept which I felt didn't come across quite so clearly was his discussion of spin.
Once he is satisfied with the level of detail he gave to explaining QED, Feynman quickly runs through the rest of the menagerie of sub atomic particles, doing little more than listing them and noting that the toolkit from QED is useful in describing the interaction of quarks and gluons.
The book is transcription of a few lectures Feynman gave on Quantum Electrodynamics (QED), a branch of quantum theory he and Dirac developed. Feynman introduces a few simple rules on how electrons and photons behave (which appear to be easy-to-digest analogs for vector calculus) and then off he goes, explaining the theory and how it describes an enormous amount of phenomena, such as the uncertainty principle, the how lenses and mirages physically work, how light scattering creates particles that travel backwards in time (via an antiparticle), why electrons stay in their orbits, lasers (exclusion principle). The only concept which I felt didn't come across quite so clearly was his discussion of spin.
Once he is satisfied with the level of detail he gave to explaining QED, Feynman quickly runs through the rest of the menagerie of sub atomic particles, doing little more than listing them and noting that the toolkit from QED is useful in describing the interaction of quarks and gluons.
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