The Character of Physical Law

by Richard P. Feynman, Alan Sleath (foreword), Dale R. Corson (introduction)

In these Messenger Lectures, originally delivered at Cornell University and recorded for television by the BBC, Richard Feynman offers an overview of selected physical laws and gathers their common features into one broad principle of invariance. Rather than an essay on the most significant achievements in modern science, The Character of Physical Law is a statement of what is most remarkable in nature. Feynman's enlightened approach, his wit, and his enthusiasm make this a memorable exposition of the scientist's craft. The Law of Gravitation is the author's principal example. Relating the details of its discovery and stressing its mathematical character, he uses it to demonstrate the essential interaction of mathematics and physics. He views mathematics as the key to any system of scientific laws, suggesting that if it were possible to fill out the structure of scientific theory completely, the result would be an integrated set of mathematical axioms. The principles of conservation, symmetry, and time-irreversibility are then considered in relation to developments in classical and modern physics, and in his final lecture Feynman develops his own analysis of the process and future of scientific discovery.

Genres: Science, Physics, Nonfiction, Philosophy, Audiobook, Popular Science, Mathematics

174 pages, Paperback

First published January 1, 1964

About the author

Richard 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 Ричард Фейнман

Reviews

[Manny · Rating 4 out of 5]

As I progressed through this excellent little book, I began to feel that the style was somehow familiar from another genre. Mozart? Perhaps e.e. cummings? But my subconscious, while granting that I wasn't totally off-base, informed me that it had a chess analogy in mind.

I had never thought about it before, but I am suddenly rather taken with the idea of comparing great physics writers with great chess players. Penrose reminds me of Tal, trusting his astonishing visual intuition to steer him through mind-bogglingly complicated thickets of mathematical formulae. Einstein is Botvinnik, an iron logician who formulates his strategy at the beginning of the game and ruthlessly implements it to what seems like an inevitable conclusion. Newton is Fischer: not quite sane, he nevertheless plays perfectly without anyone being able to see where he finds the brilliant ideas. Dirac is Alekhine, producing a miraculous mating attack out of nowhere.

And Feynman? Well, he can't be anyone except Capablanca. The deceptive effortlessness and simplicity of his moves, explained in a voice evidently more often used for seducing beautiful women...
___________________________________

I have been thinking about this remarkable book ever since I finished it a few days ago, and I feel I should say more. But it's difficult. Feynman is, of course, telling you interesting things about science, but the reason people love him is not so much the content, but the style. You read him, and you believe for a moment that you understand how this unique person saw the world.

Is it an illusion? I really don't know. His voice is so immediate and personal. He says in a matter-of-fact way that we understand these things over here quite well, these other things a bit, and the matters in this last group not at all. He tells you how you question Nature to learn a new fundamental law as though it were the simplest thing in the world. At the same time, he warns that we are at a very unusual and exciting point in history, and that soon it will no longer be possible for people to have these experiences. He is utterly convincing.

I just read William James's Varieties of Religious Experience, and I couldn't help thinking: is Feynman what James would call a mystic? If anyone had made the suggestion to him, I am sure he would have laughed at them. He hated all forms of pretentiousness, and his book never uses a long word when a short one will do. He evidently felt that formal philosophy was a waste of time. He didn't think he was doing anything special, and that anyone could understand the physical world as he did if only they would try a little.

Of course, that's the kind of thing mystics often say.

[brian · Rating 4 out of 5]

all the great early-20th century physicists came up with this l. ron hubbardish conceit to invent a pornucopia of whackadoo sci-fi theories and sell 'em to the public as hard 'reality'… the solvay conference - where they came up with the first round of bullshit - was a blast! they eliminated absolute time, described light as particle & wave, defined space as 'curved', played with cats which were simultaneously dead and alive, came up with a slew of random constants, and - just as Area 51 info is passed on to every american prez ('except for the black guy! we can't seriously tell state secrets to the black guy, can we?!?!') - every new generation a select group of dreamers and thinkers are told of the great joke-slash-conspiracy and allowed to add on a bit. double slit experiment? multiverses? string theory? hadron collider? sure. have fun. just kick some of that grant money our way, sister.

the gossip is that feynman wanted to blow the whole thing wide open and one can see the first cracks in lecture #6 'Probability and Uncertainty' -- in imploring his listener to just shut up and accept what feynman says, our humble lecturer is just begging to be called out on the bullshit:


"It will be difficult. But the difficulty really is psychological and exists in the perpetual torment that results from your saying to yourself, 'But how can it be like that?' which is a reflection of uncontrolled but utterly vain desire to see it in terms of something familiar. I will not describe it in terms of an analogy with something familiar; I will simply describe it. There was a time when the newspapers said that only twelve men understood the theory of relativitiy. I do not believe there ever was such a time. There might have been a time when only one man did, because he was the only guy who caught on, before he wrote his paper. But after people read the paper a lot of people understood the theory of relativity in some way or other, certainly more than twelve. On the other hand, i think I can safely say that nobody understands quantum mechanics. So do not take the lecture too seriously, feeling that you really have to understand in terms of some model what I am going to describe,  but just relax and enjoy it. I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possibly avoid it, 'But how can it be like that?', because you will get 'down the drain', into a blind alley from which nobody has yet escaped. Nobody knows how it can be like that.' 

feynman contracted two forms of rare cancer and died.
hmmm….

[Robert · Rating 5 out of 5]

This is a fantastic little book for which we have to thank the BBC: They decided to film these lectures and subsequently publish transcripts of them, at a time before Feynman had turned into a one-man industry and every one of Feynman`s students`first-draft lecture notes became as diamond dust.

The title tells one enough about the contents; if you have any interest in the topic you should read this book. It is almost but not completely non-mathematical. If you can cope with the algebra contained within F=GMm/R - well, that's as hard as it gets.

The aspect of the book that particularly interested me this time around is in Chapter two (and reprised somewhat in the final lecture). Feynman takes the above given equation, which expresses Newton's Law of Universal Gravitation and says - that's all very well, but you can express it in another way that's to do with how something called a potential varies locally - and if you do it will always give exactly the same answer! And, not content with that, you can express it another way that is to do with finding the minimum of a certain thing called the Action. (Technically it doesn't have to be a minimum, just somewhere where the tangent to the graph of the Action would be horizontal.) Done this way, the answers always come out the same as the other two ways! What's the point of that? Three ways to say the same thing!

But here's the interesting, indeed profound thing: when it came to understanding quantum mechanics (which doesn't deal with gravity) it was found that both potentials and a principle of minimum (stationary, strictly) Action were needed. So the different ways of expressing Newton's gravity law turned out profoundly useful in understanding a different set of phenomena, namely the nuclear forces and electromagnetism.

So if you are involved in trying to understand fundamental physics it would probably be healthy to actively search for different mathematical methods of expressing the laws as we understand them now!

Incidently, I doubt you will ever come across a more accessible introduction to the essential mystery of quantum mechanics (the photon/electron double slit experiment) than that given in this lecture, in which Feynman gave his famous quote, "...I think I can safely say nobody understands quantum mechanics."

[Roy Lotz · Rating 4 out of 5]

It is impossible, by the way, by picking one of anything to pick one that is not atypical in some sense. That is the wonder of the world.

I would probably be giving this little book five stars if I wasn't already familiar with much of it from reading Feynman's Six Easy Pieces and Six Not-So-Easy Pieces. There's a good deal of overlap in the material, and Feynman even uses several of the same examples and analogies. It seems he was so often explaining these things that he developed a method. I must admit I'm glad to see this, as it humanized the man a little in my eyes. The idea that he could just extemporize these things made me feel like I might as well bottle my brain in formaldehyde, and donate it to some med students for their instruction, because I wasn't using it for anything.

What was new for me, however, was Chapter 2, "The Relation of Mathematics to Physics." It is extraordinary how Feynman is able to make such sophisticated philosophical points with such plain language, and with such apparent scorn for all philosophizing. Really, Feynman didn't dislike philosophy, he disliked bad philosophy.

So what is the relationship of mathematics to physics? This is a difficult question, one that can apparently be probed through thought alone. Since physical laws seem only expressible in a mathematical language, and since mathematicians have many times developed the tools necessary for physicists, often a hundred of years before they were needed, it seems there is a deep connection between these two. Maybe they are ultimately the same thing? Maybe we could do physics like mathematicians do math, with axioms and proofs?

Not so, says Feynman, and he offers one simple argument. In physics, we can often express the same thing in many different ways. We can talk about gravity as a field, with Newton's laws, or with the least action principal. Which is right? There's no way to tell. Maybe, he says, when we have all the laws figured out, we can do physics by pure deduction. But now that we're still in the process of guessing new laws, it's good to have multiple ways to formulate them, for one formulation might be very useful in the future. He gives as an example the ways that Newton's laws were useful to Maxwell, even though gravity and electro-magnetism did not appear to have a deep connection. The same sorts of relationships are found in apparently unrelated phenomena, thus preventing us from using purely deductive reasoning.

Well, I'm quickly reaching the end of my scant knowledge, so I'd better end this review. I'll only add that, if you know any young physics students, do the universe a favor and get them this book. The cosmos will thank you.

[Christopher Wilson · Rating 5 out of 5]

I once had a friend that I was tutoring in physics explain to me that this was her intro physics "textbook". Amazingly, though I was studying physics, I hadn't really been introduced to Richard Feynman in any real way. That Saturday, I sat down with a cup of coffee in my small rooming house kitchen and started reading this book. Feynman is a magician of explanation. On every page I read, Feynman took some concept that I was familiar with and tugged it apart, then with a sly turn deftly snapped it back together in a new form. The explanation that he produced this way was simpler, better, and it was as if he'd dropped that concept to its ground state. A puff of needless complication floats away and he hands you back a pearl of an idea. That's what reading this is like.

[إيمان · Rating 4 out of 5]

يعد ريتشارد فاينمان بلا ريب واحد من أعظم فيزيائيي القرن العشرين إن لم يكن واحد من الأعظم على الإطلاق. كانت له عدَة اسهامات في مجال فيزياء الجسيمات, الميوعة الفائقة, ميكانيكا الكم و الكهروديناميكا الكميَة. و عن أبحاثه حول الأخيرة تحصَل على جائزة نوبل للفيزياء سنة 1965 بالتشارك مع تشينيتشيرو توموناغا و جوليان شفينغر. و قد كان أيضا واحدا من العلماء المشاركين في مشروع مانهاتن إبان الحرب العالمية الثانية
ترك فينمان إرثا بيداغوجيا لا يضاهيه فيه أحد من حيث مكانته لدى متعلمي الفيزياء رغم وجود إستثناءات قليلة لعلَ أبرزها والتر لوين, حيث تشكل "محاضرات فينمان في الفيزياء" ,و هي سلسلة من المحاضرات التي ألقاها مطلع ستينات القرن الماضي, إلى اليوم واحدا من أهم مراجع طلاَب المرحلة الأولى من الجامعية. و يعود سرَ شهرتها خاصَة إلى الطَريقة التي انتهجها في التفسير و التحليل منطلقا في كل مرَة من الظاهرة ليفسَر القاعدة الرياضية (عكس ما يحصل عندنا) إضافة إلى الروح المرحة التي غلبت على هذه المحاضرات, هادفا بذلك إلى إرساء طريقة صحيحة لفهم الفيزياء بعيدا كلَ البعد عن التعلَم
بالغيب (rote learning)
التلقين و غيرها من طرق التعليم التي عارضها بشدَة,
يعدَ هذا الكتاب الذي بين يدينا أيضا ( خصائص القانون الفيزيائي) واحد من أهم مؤلفاته و يضم كذلك سلسلة من المحاضرات (عددها سبعة) قام من خلالها بشرح الخاصيات المشتركة للقواعد الفيزيائية من خلال تفسير الطريقة التي اكتشفت ب��ا, مكانة الرياضيات من الفيزياء و الفرق الجوهري بين العلمين و قوانين الحفظ و التناظر. كما تطرَق إلى القوانين "الجديدة" من خلال حديثه عن الماضي و المستقبل و علاقة ذلك بالكيفية التي تحدث بها الأشياء و أيضا من خلال تناوله لقانون الإحتمالات الذي يحكم العالم الكمي (شرحه لهذا الفصل من أروع الشروحات التي مررت بها في هذا الموضوع حيث يعدَ مقدمة رائعة حتى لغير أصحاب الإختصاص). ختم فينمان محاضراته هذه بتفاؤل غريب حول إقتراب انتهاء اكتشاف كلَما يتعلَق بقوانين الفيزياء و الطبيعة, ربما عكس من خلاله
اعتقادا سائدا في تلك الحقبة أن نظرية كلَ شيء باتت مسألة و قت. (طبعا نحن إلى يومنا هذا بعيدون جدا عن ذلك و ربما إبتعدنا أكثر.) ...ما شدَ انتباهي إلى جانب سلاسة الطَرح و الفهم العميق لصاحبه, "النزعة الفلسفية" التي تخلَلت هذا الكتاب حيث أكَد الفيزيائي الشهير في كلَ مرَة على قصور العلم عن الفهم الكامل للعالم سواء من خلال إنقسام العلوم إلى فيزياء بيولوجيا و غيرها أو من خلال التأكيد بأن قوانين الفيزياء و إن قدَمت وصفا لما يجري حولنا من ظواهر فإنها لا يمكن أن تقدَم صورة مطابقة لها أو فهما لسببيتها (كما هو شأن ميكانيكا الكمَ) ...ختاما استمعت حقا بما ورد في هذه المحاضرات خاصة في فصلها
السادس ... لا تنسو واضعي المناهج و الأساتذة الذي لا يقدمون مجهودا كبيرا في الشرح مما لا يصلح من دعائكم (مزحة)... و إلى لقاء قريب بإذن الله سيد فاينمان
:)
تمت
17/09/2017

[Zanna · Rating 4 out of 5]

It is commonplace to praise Feynman for describing fiendishly difficult concepts in friendly vernacular and intuitive analogies, for example, his wet towels metaphor for the second law of thermodynamics communicates its content, import, and the sad desperation physicists have felt about it unforgettably. But what matters as much is that he is never sloppy, he never allows an analogy to carry away substance or overstep its explanatory limits. I have read other accounts of the double-slit experiments aimed at the layperson that sound like hocus pocus, but Feynman explains the Heisenberg Uncertainty Principle so that it makes the sort of sense that would have GCSE students (or my grandmother, even) nodding sagely, at the same time as he reveals the ostensibly juiceless statistical view of the universe as jubilant poetry, silver trumpets and redemption: even in the mind of god there is no fate...

[Jim · Rating 3 out of 5]

Somewhat dated since this was first published in the mid 60s, it's still a fairly decent primer on some basic physics. I'd heard Feynman was renowned for his ability to explain complex topics in simple language. I found that true to a large extent, although sometimes I got confused. It's one reason I can't recommend the audiobook. There are a lot of diagrams & while I didn't need the early ones, about midway through they became critical.

Table of Contents
1   The Law of Gravitation, an example of Physical Law
2   The Relation of Mathematics to Physics
3   The Great Conservation Principles
4   Symmetry in Physical Law
5   The Distinction of Past and Future
6   Probability and Uncertainty – the Quantum Mechanical view
of Nature
7   Seeking New Laws

Interesting, but nothing really new & there are better, more up to date books/lectures available now. I can't think of a single book off hand, but Science Matters: Achieving Scientific Literacy & Astrophysics for People in a Hurry would cover all the subjects & then some.

[Flarne · Rating 5 out of 5]

*4.75*
« What we are looking at when we see the moons is not how they are now but how they were the time ago it took the light to get there »

I realize how lucky I am when, the fruit of so many years, of centuries of research, of thousands of lives agglomerated in these discoveries by geniuses of times gone by, have been able to be translated from complex mathematics to the benefit of any mathematically untrained audience in such a small book that I was able to read in less than 3 days.

Less than 3 days is the time that took me to have access to this gold mine in such a playful, stimulating, clear way, for someone who has not done physical sciences since high school (5 years).

Having read Einstein’s book on relativity, I’ve noticed he even explained Einstein theory in a way with more clearness to me.

IVe found myself returning to this review each time I need to remind myself of physics’ solid base and for that, it’s among my favorite non fiction book. It is an essential for beginners in my opinion.

The following review is going to be a non-linear lump of my notes!

Two electrons repel each other inversely as the square of the distance due to electricity
and they attract each other inversely as the square of the distance due to gravitation (actually tous Les corps)

-Planets are not only attracted by the sun but also they pull on each other a little , only a little.
-

Einstein said that: x cannot occur instantaneously.
==> all masses fall, light has energy, and energy is equivalent to mass. So light falls and it means that light going near the sun is deflected.



Using The Quantum Theory of Gravity (how does gravity look on a small scale) in order to correct Newton’s laws.

No laws are exact, we have to put the quantum theory in.

Quantum physics is something imperceptible by the eyes in our everyday basis; the author managed to chronicle with such vividness how atoms behave and give them shape, going from abstract to something much more transparent and clear in any reader’s mind.

The only possible way in which a person moving and a person standing still could measure the speed to be the same was that their sense of time and their sense of space are not the same, that the clocks inside the space ship are ticking at a different speed from those on the ground and so forth.

Two balls attracting, has to be expanded ten million xxx times to become the solar system.

Nature uses only the longest threads to weave her patterns (of the same law).

It is possible to tell that the earth is rotating by a pendulum or by a gyroscope without looking at the stars.

It is possible to tell that we are going around at uniform angular velocity on the earth without looking outside, because the laws of physics are not unchanged by such a motion.

The symmetry of laws, makes us aware of the fact that we cannot tell whose view is correct; when I talk about everything that is happening in the world ‘now’, that does not mean anything. We cannot agree what ‘now’ means at a distance.

If you are moving along at a uniform velocity in a straight line, then the things that happen that appear to you as simultaneous are not the same events as appear simultaneous to me, even though we are passing each other on.

Two events which from one point of view seem to be simultaneous, at the same time (t), from another point of view can seem to be at different time (t’). A generalization of the two-dimensional rotation was therefore made into space and time, so that time was added to space to make a four-dimensional world.

Real space has the characteristic that its existence is independent of the particular point of view, and that looked at from different points of view a certain amount of ‘forward-backward’ can get mixed up with ‘left-right’.

Similarly, a certain amount of time ‘future-past’ can get mixed up with a certain amount of space.

Space and time must be completely interlocked. Hence the necessity for a four-dimensional space-time.



The interrelationships between energy :

Elastic and chemical energy both have the same origins, the forces between the atoms.
When the atoms rearrange themselves in a new pattern some energy is changed, and if that quantity changes it means that some other quantity has to change.


For Ie, if we burn something , the chemical energy changes , and we find heat where we did not have heat before

The interactions (of the 2 energy up there) are always a combination of the electrical energy and the kinetic energy, (quantum mechanical this time).

-

The connection of symmetry laws to conservation laws comes from quantum mechanics.

The case that rotation in space does not make any difference comes out as the conversation of angular momentum.










Past And Future

Physicists believe that most of the ordinary phenomena in the world, which are produced by atomic motions, are according to laws which can be completely reversed.

So they sought to look further to find the explanation of the irreversibility.

the Earth’s rotation on its axis is slightly slowing down. It is due to tidal friction, and you can see that friction is something which is obviously irreversible.

If I take a heavy weight on the floor, and push it, it will slide and stop. If I stand and wait, it does not suddenly start up and speed up and come into my hand. So the frictional effect seems to be irreversible.

But a frictional effect is the result of the enormous complexity of the interactions of the weight with the wood, the jiggling of the atoms inside. The organized motion of the weight is changed into disorganized, irregular wiggle-waggles of the atoms in the wood. So therefore, we should look at the thing more closely.

Atoms of different kinds in perpetual irregular motions get mixed up and that is why the water becomes more or less uniformly blue. (it was an experience in the book)


The laws of molecular collision are reversible; but in his experience blending blue and white water; the different atoms through all the collisions made seemed not to be.

If you start with a thing that is separated and make irregular changes, it does get more uniform.

But if it starts uniform and you make irregular changes, it does not get separated. It could get separated. It is not against the laws of physics that the molecules bounce around so that they separate. It is just unlikely. It would never happen in a million years. And that is the answer.

“Things are irreversible only in a sense that going one way is likely, but going the other way, although it is possible according to the laws of physics, would not happen in a million years.”

It is just ridiculous to expect that if you sit there long enough the jiggling of the atoms will separate a uniform mixture of ink and water into ink on one side and water on the other.

The actual objects with which we work have not only four or five blues and whites. They have four or five million, million, million, million, which are all going to get separated like this.

And so the apparent irreversibility of nature does not come from the irreversibility of the fundamental physical laws; it comes from the characteristic that if you start with an ordered system, and have the irregularities of nature, the bouncing of molecules, then the thing goes one way.



--
One of the rules of the world is that the thing goes from an ordered condition to a disordered. all on one side and all on the other, or they are mixed up – and that is ordered and disordered.

When we look at any ordinary situation, which is only partly ordered, we can conclude that it probably came from one which was more ordered.

The phenomena of nature will go one way as long as they are out of equilibrium, as long as one side is quieter than the other, or one side is bluer than the other. (or the towels example,


The towel has the same ease of removing water from it as you have, so when you touch yourself with the towel, as much water comes off the towel on to you as comes from you to the towel.

It does not mean there is the same amount of water in the towel as there is on you – a big towel will have more water in it than a little towel – but they have the same dampness. When things get to the same dampness then there is nothing you can do any longer.)

Now the water is like the energy, because the total amount of water is not changing.

In the same way if you imagine a part of the world that is closed, and wait long enough, in the accidents of the world the energy, like the water, will be distributed over all of the parts evenly until there is nothing left of one-way-ness, nothing left of the real interest of the world as we experience it.


See how he presents clearly how physical laws intertwines, each needing and re-affirming each other; utilizing everyday examples that we can all understand such as the dampness of water, in order to re-affirm **both** the law of conservation of energy in the world and the order - disorder universal law.



--
Quantum Mechanical, The description of the actual behaviour of particles on a small scale.

Electrons behave in this respect in exactly the same way as photons; they are both screwy, but in exactly the same way.

The electron behaves sometimes like a particle and sometimes like a wave. It behaves in two different ways at the same time.

Explaining us why it’s impossible to predict the fucture because it is impossible to predict in any way, from any information ahead of time, through which hole the thing will go, or which hole it will be seen behind. That, it is not our lack of knowledge in physical laws that prevent us from accurately predict the future. Nature herself does not even know which way the electron is going to go.





CONCLUSION:

I love this book because it unlocked my passions in so many different physics topics despite my shortcomings since I have not studied neither physics nor math since 5 years now.

It’s such a well-crafted work that motivated me to read more and more on physics and for that, I am forever grateful.

Making us more aware to the behavior of objects in motion, with each other, all the recurrent forces that apply to most things and their effects. Exposing us to how nature, as a matter of fact, seems to be so designed that the most important things in the real world appear to be a kind of complicated accidental result of a lot of laws.

“What we need is imagination. We have to find a new view of the world that has to agree with everything that is known, but disagree in its predictions somewhere, otherwise it is not interesting. And in that disagreement it must agree with nature »

« The age in which we live is the age in which we are discovering the fundamental laws of nature, and that day will never come again. It is very
exciting, it is marvellous »


You can just feel his genuine passion and joy in physics through these last words, it’s so contagious

[Ami Iida · Rating 4 out of 5]

the author explained "Foundation of quantum mechanics and Physics".
He treated many interesting physics and quantum mechanics examples.
I have a lot of harvest from the book. (^ ^)V

[Kunal Sen · Rating 5 out of 5]

It is so very rare to come across someone who understands something with such clarity that leaves you stunned and in awe, and perhaps a little dwarfed. It is even rarer to find someone with such clarity to communicate the same clear understanding to another person. This book is exactly that. I have not come across another piece of writing that is clearer than Feynman's understanding of the basic principles of Physics, his deep understanding of the scientific method, and above all, what is the meaning of understanding anything.

While reading this series of lectures from more than 50 years ago, I had to constantly wonder will I ever have the satisfaction of understanding anything to this depth. I don't think so, and that is the greatest tragedy of most of us. We will never be able to claim that we truly understood something. There are only a few people who ever lived who can enjoy this feeling of seeing into a messy, opaque sphere and seeing through it to its center and understanding the elegant mechanism that makes it tick. The rest of us will only penetrate the first few layers, but then our vision gets fuzzy, confused by the less important details.

This is where science and arts come together. Scientists see through one part of the sphere, artists through another, writers through yet another. Perhaps Dostoyevski had a similar clear view through his part of the sphere and could see the deepest truths behind human nature. Perhaps Picasso could see through physical forms. The ultimate goal of any thinking person can only be the desire to see through and make some sense of it all.

There are many open questions that Feynman was pondering in these essays, and many of them got solved. Some were resolved during his lifetime, others after he died. For all curious people, this must be the ultimate detective story. The story keeps unfolding, but we all know that we will die before the book is over.

[Mientras Leo · Rating 4 out of 5]

Fantástico ensayo de divulgación.

[Deepak Raja Nadarajan · Rating 5 out of 5]

The best of the Feynman lectures I have ever read. The lectures cover the most important physical laws that we know of with more focus on what the laws and equations mean in real life and how we can make sense of them. We know Feynman's ability to simplify complex scientific concepts. In these lectures, he gets poetic in quite a few passages. My favourite line being:

"Nature's imagination far surpasses our own"

[Mohamed al-Jamri · Rating 4 out of 5]

This is a short and easy to understand book. It is beneficial mostly to those new to popular science books. Feynman talks about the following topics: What are the laws of nature and how are they discovered. The story of the Law of Gravity up to Einstein, and that of the law of conservation of energy. The uncertainty and universality of the laws of nature. The flow of time, order and disorder (entropy). Levels of complexity. Quantum mechanics and uncertainty principle. And falsifiability.

[Jeremy · Rating 5 out of 5]

This is not a book about the content of physics, but the practice of physics. What is it physicists do and how do they think? Feynman's explanation here is unmatched in its clarity and accessibility.

[Peter Tillman]

Alan Lightman mentions this book in his review of Gleick's Feynman bio, https://www.nybooks.com/articles/1992... (free copy online)
"In his brilliant little book "The Character of Physical Law" he places great value on seeking different formulations of the same physical law, even if they are exactly equivalent mathematically, because different versions bring to mind different mental pictures and thus help in making discoveries. “Psychologically they are different because they are completely unequivalent when you are trying to guess new laws.”

Lightman's 'review' is really a small biography of Feynman, and a small history of physics in his time. An excerpt:
".... in the strange quantum world subatomic particles are constantly appearing out of nothing and then disappearing again. Each particle, such as the electron, surrounds itself with a cloud of other, ghost-like particles, called “virtual particles,” which fleetingly come into existence and then slip away into oblivion. Electrons interact with the ghost-like particles around them, and those interactions alter the properties of the electron, such as its mass and electrical charge. In reality, the physicists found, there are no isolated electrons. The quantum ghosts are everywhere. Their shadows have been seen in experiments. When physicists in the late 1930s and early 1940s tried to modify the quantum theory of Schrödinger, Heisenberg, and Dirac so as to accurately describe particle interactions, they ran into technical difficulties with the ghosts. Once the ghosts began popping up in the mathematics, the equations couldn’t be solved."
His article is not to be missed, if you are interested in Feynman and/or 20th C. physics. Kudos to the NYRB for making it freely available!

One more bit:
"In February 1988, after a gruesome series of illnesses and complications from cancer, Feynman entered the UCLA Medical Center for the last time. He was sixty-nine. Across the city, on a corner of his blackboard, he had written in chalk, “What I cannot create I do not understand.” As he lay in his hospital bed, with his strength ebbing, Feynman whispered his last words: “I’d hate to die twice. It’s so boring.”

1964 book, long out of print. None of our libraries has a copy. What to do? Used copy?
And maybe I should re-read Gleick's biography?

[Rosemary Standeven · Rating 4 out of 5]

This was an interesting book, but sadly for me – it was in the wrong format. I listened to it, and had a lot of difficulty taking in some of the concepts. Not a problem with the content, nor the explanations. Just that I struggle to process things that I hear, rather than see in black and white on a page. Luckily, the audiobook was accompanied by a pdf containing pages of the hardcopy book which contained diagrams. Those sections I found easier, as I could go back over them.
My other ‘problem’, was that the author kept apologising for the difficult maths that was often required to understand the physics. Well, I have no problem with the maths – equations are great – just can’t relate them to the actual physics/real world. I am very much a pure mathematician.
On the positive side, a number of major laws of physics were discussed – how they were discovered and adapted, what they mean, and possible future investigations they could
Feynman stresses that science cannot explain everything. Every potential law can be disproved, if empirical evidence contradicts it, but it is seldom possible to fully prove a law. Science keeps making and analysing educated guesses that best fit the available information.
At some stage I would like to get a hardcopy of this book, and really take my time with it.

[Gia Jgarkava · Rating 4 out of 5]

"სამეცნიერო პოპულარული"-დან მეცნიერება აქ უფრო მეტია, ვიდრე პოპი :) მეგონა უფრო ემსგავსებოდა სხვა მეცნიერების წიგნებს, თუმცა სხვებისგან განსხვავებით სათაური ზუსტად ასახავს შინაარსს - ეს არის ლექციების სერია ზუსტად ფიზიკური კანონების ხასიათზე. ანუ, თუ საგანის "კოსმოსში" მარტო კოსმოსი არაა და ჰოკინგის "დროს მოკლე ისტორიაში" საკმაოდ ცოტა ისტორიაა, აქ ზუსტად ისაა რაც სათაურში. ოღონდ აქცენტი ამ ლექციებში უფრო მეცნიერების ფილოსოფიაზეა და არა იმდენად თვითონ ფიზიკურ კანონებზე. ფეიმანის ასე სრული წიგნი აქამდე არ მქონდა წაკითხული და დავრწმუნდი რომ წასაკითხია კიდე სხვა რამეებიც, ძალიან ჭკვიანი, მაგარი და საყვარელი ადამიანი ჩანს ❤️

[Robert Kosara · Rating 4 out of 5]

Clearly my favorite Feynman book, because it’s actually about physics. The lectures are very well done, cover a lot of ground, and go into just the right level of depth. It’s also interesting to see him talk so much about the limitations of physics and what do and can know.

[Jerry · Rating 5 out of 5]

If it disagrees with experiment it is wrong. In that simple statement is the key to science… We never are definitely right, we can only be sure we are wrong.

This is a semi-transcript of a lecture series that Feynman gave at Cornell University. Semi-transcript because “The lectures were not given from a prepared manuscript” and “The chapters in this book are reports of talks which were presented”. Comparing it with video of what I think was one of the lectures, it comes very close. “They have been checked for scientific accuracy by Professor Feynman,” according to the introduction.

The lectures are about the character of physical law, that is, what kinds of things show up in the laws of physics, their symmetries and conservations.

It is easy to understand how an object can be symmetrical, but how can a physical law have a symmetry? Of course it cannot, but physicists delight themselves by using ordinary words for other things.

Feynman here uses symmetry in both the relatively normal word—how the different laws can often appear to be mirrors of each other—and the physics sense:

that there are things we can do to the physical laws, or to our way of representing the physical laws, which make no difference, and leave everything unchanged in its effects.

There are also nice descriptions of how relativity affects these laws, such as that the conservation of charge is “local”, that is, it is independent of the movement of particles.

He emphasizes throughout the necessity of experimentation, and of definite predictions that can be measured.

It is a small section only of natural phenomena that one gets from direct experience. It is only through refined measurements and careful experimentation that we can have a wider vision.

This is a small book that will definitely benefit from re-reading, because not only is it easily understandable on the surface, there are critical insights that ought to become more clear after thinking about them and re-reading the text.

The book does not have an index, sadly, which means you can’t look up in the back later to quickly find where he talks about symmetry, or locality, or strangeness.

It looks like the full lecture series is available on video.

Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry.

[Brian Clegg · Rating 3 out of 5]

This was a late discovery for me amongst Richard Feynman's books, and it's something of an oddity. Like all the books with his name on, this wasn't a case of Feynman sitting down to write a book; he never wrote a single book - in this case it's a transcription of a set of lectures Feynman gave at Cornell University which were broadcast in the UK by the BBC.

What the great physicist sets out to do is to explore the nature of physical laws. Where this works best (and he would probably have hated this suggestion) is where he was at his most philosophical. In the first lecture he explored just what was meant by physical laws and this is genuinely interesting stuff, especially as it's something we rarely give much thought to.

After that he goes on to cover specific areas, with lectures on gravity, maths, conservation, symmetry, the arrow of time and probability, before pulling things together in a final lecture on the search for new laws. For me these chapters don't work quite as well in book form, partly because we miss the visual aspects of Feynman's talks, and partly because they are perhaps a little too summary for the topics covered. The other slight problem with specifics is that inevitably some of the content (from the 1960s) is quite dated - particularly in the 'new laws' section, where he covers particle physics at a point before quarks and when the particle zoo seemed out of control. It's interesting from a historical perspective of what the understanding was like at the time, but it's not an ideal way to find out about particle physics.

Overall, an essential if you want to have a complete picture of Feynman's output, and fascinating in that opening chapter, but not the best of the Feynman books.

[Daniel Bensen · Rating 4 out of 5]

God damn I love reading Feynman. When other physicists proclaim, he clarifies. When others offer up half-baked metaphors, he gives us thoughts experiments that are both helpful and funny. How precisely could we determine a bowling ball's velocity and position by bouncing ping-pong balls of it? What would an Aztec astrologer say to Galileo? What if mysteries in physics never run out, but new discoveries get harder and harder to make? In that last case, Feynman would consider himself very lucky to be born when he was.

[Amirreza · Rating 5 out of 5]

A splendid story of the phyical laws of nature written by the best physics teacher of all times, Richard Feynman. He tells the theories of physics in the layman's language, making them easy to comprehend.

[Mustafa Acungil · Rating 5 out of 5]

Bazen bir kitaba 5 üzerinden 6 yıldız vermek istediğim olur.
Bu kitaba 5 üzerinden 7 yıldız vermek istiyorum.
Özel olarak fiziksel yasaların ve daha genel olarak bilim yaklaşımının özünü kavramak için daha iyi bir kitap hayal edemiyorum.

Kitaptan fizik öğrenmeyi beklemeyin. Fiziğin ve bilimin yaklaşımını, yaklaşımının nasıl olması gerektiğini öğrenmek için ise mükemmel.

[Matthew Royal · Rating 4 out of 5]

Much better than other, more biographical works of his. Guess I never thought of Physics as such a scattershot patchwork of guesses before. He does a good job democratizing it, emphasizing that ideas can come from anywhere, and their value comes only from their agreement with experiment data.

[Raph Cc · Rating 4 out of 5]

Intéressant mais parfois trop compliqué

[Abdulhafedh · Rating 4 out of 5]

“We are very lucky to be living in an age where we are still making discoveries. It’s an age that will never come again” - Richard P. Feynman.

[Salma · Rating 4 out of 5]

this irritated me

[Blake · Rating 4 out of 5]

An insightful overview of how the laws of physics are discovered, utilized, and changed, as well as commentary on how nature yields beautiful simplicity.

[David · Rating 5 out of 5]

I read this transcript of lectures and watched some of them on YouTube as well. The first few are good reviews about gravity and basic physics concepts, but the interesting bits are about the nature of the laws themselves: how they were discovered and how science works in practice. I was surprised to learn first that the axiomatic approach that grounds mathematics isn't the most effective way to approach physics and that (relatedly) physicists often guess at the right explanations and only later figure out why they're so.

I found especially interesting that Feynman explicitly values the practice of generalizing an observation beyond the realm in which it was observed. He makes a good case why this is critical for science. On the other hand, I've often felt that in some domains (especially software), people's tendency to generalize from their own experiences to everybody else's is a major impediment to real progress. I think these are pretty different cases, because science is trying to make predictions, but it's a thought-provoking point.