Feynman Physics Quotes & Sayings

I want to build a billion tiny factories, models of each other, which are manufacturing simultaneously ... The principles of physics, as far as I can see, do not speak against the possibility of maneuvering things atom by atom. It is not an attempt to violate any laws; it is something, in principle, that can be done; but in practice, it has not been done because we are too big. — Richard Feynman

On the contrary, it's because somebody knows something about it that we can't talk about physics . It's the things that nobody knows anything about that we can discuss. We can talk about the weather; we can talk about social problems; we can talk about psychology; we can talk about international finance gold transfers we can't talk about, because those are understood so it's the subject that nobody knows anything about that we can all talk about! — Richard P. Feynman

Are you looking for the ultimate laws of physics? No, I'm not. I'm just looking to find out more about the world and if it turns out there is a simple ultimate law which explains everything, so be it; that would be very nice to discover. If it turns out it's like an onion with millions of layers and we're just sick and tired of looking at the layers, then that's the way it is ... My interest in science is to simply find out more about the world. — Richard Feynman

To do any important work in physics a very good mathematical ability and aptitude are required. Some work in applications can be done without this, but it will not be very inspired. If you must satisfy your "personal curiosity concerning the mysteries of nature" what will happen if these mysteries turn out to be laws expressed in mathematical terms (as they do turn out to be)? You cannot understand the physical world in any deep or satisfying way without using mathematical reasoning with facility. — Richard P. Feynman

Look, if you're going to insist that I've taught you something, I guess I should give you a final exam." "Really?" "One question." "Sure." "Go look at an electron microscope photograph of an atom, okay? Don't just glance at it. It is very important that you examine it very closely. Think about what it means." "Okay." "And then answer this question. Does it make your heart flutter?" "Does it make my heart flutter?" "Yes or no. It's a yes or no question. No equations allowed." "All right, I'll let you know." "Don't be dense. I don't need to know. You need to know. This exam is self-graded. And it's not the answer that counts, it's what you do with the information." We locked eyes. His younger face flashed in my mind. The energetic, smiling bongo drum player I had seen pictured in the front of his book, The Feynman Lectures on Physics. A question popped from my lips. — Anonymous

CURIOSITY DEMANDS THAT WE ASK QUESTIONS,
THAT WE TRY TO PUT THINGS TOGETHER AND TRY TO UNDERSTAND THIS MULTITUDE OF ASPECTS
AS PERHAPS RESULTING FROM THE ACTION OF A RELATIVELY SMALL NUMBER OF ELEMENTAL
THINGS AND FORCES ACTING IN AN INFINITE VARIETY OF COMBINATIONS — Richard Feynman

It is to be emphasized that no matter how many [amplitude] arrows we draw, add, or multiply, our objective is to calculate a single final arrow for the event . Mistakes are often made by physics students at first because they do not keep this important point in mind. They work for so long analyzing events involving a single photon that they begin to think that the arrow is somehow associated with the photon [rather than with the event]. — Richard P. Feynman

It is important to realize that in physics today, we have no knowledge of what energy is — Richard P. Feynman

Take this neat little equation here. It tells me all the ways an electron can make itself comfortable in or around an atom. That's the logic of it. The poetry of it is that the equation tells me how shiny gold is, how come rocks are hard, what makes grass green, and why you can't see the wind. And a million other things besides, about the way nature works. — Richard Feynman

A very great deal more truth can become known than can be proven. — Richard Feynman

Suppose we had some kind of device with particles moving with a certain definite symmetry, and suppose their movements were bilaterally symmetrical (fig. 20). Then, following the laws of physics, with all the movements and collisions, you could expect, and rightly, that if you look at the same picture later on it will still be bilaterally symmetrical. So there is a kind of conservation, the conservation of the symmetry character. This should be in the table, but it is not like a number that you measure, and we will discuss it in much more detail in the next lecture. The reason this is not very interesting in classical physics is because the times when there are such nicely symmetrical initial conditions are very rare, and it is therefore a not very important or practical conservation law. But — Richard Feynman

All theoretical chemistry is really physics; and all theoretical chemists know it. — Richard P. Feynman

We get the exciting result that the total energy of the universe is zero. Why this should be so is one of the great mysteries - and therefore one of the important questions of physics. After all, what would be the use of studying physics if the mysteries were not the most important things to investigate? — Richard P. Feynman

Atoms are very special: they like certain particular partners, certain particular directions, and so on. It is the job of physics to analyze why each one wants what it wants. — Richard P. Feynman

After reading the salary, I've decided that I must refuse. The reason I have to refuse a salary like that is I would be able to do what I've always wanted to do- -get a wonderful mistress, put her up in an apartment, buy her nice things.. With the salary you have offered, I could actually do that, and I know what would happen to me. I'd worry about her, what she's doing; I'd get into arguments when I come home, and so on. All this bother would make me uncomfortable and unhappy. I wouldn't be able to do physics well, and it would be a big mess! What I've always wanted to do would be bad for me, so I've decided that I can't accept your offer. — Richard Feynman

There was an interesting early relationship between physics and biology in which biology helped physics in the discovery of the conservation of energy, which was first demonstrated by Mayer in connection with the amount of heat taken in and given out by a living creature. — Richard Feynman

Physics isn't the most important thing. Love is. — Richard Feynman

I think nature's imagination Is so much greater than man's, she's never going to let us relax — Richard Feynman

When I bike to work int he fall, I see beauty in the trees tinged with red, orange and gold. But seeing these trees through the lens of physics reveals even more beauty, captured by the Feynman quote that opens this chapter. And the deeper I look, the more elegance I glimpse: we'll see in Chapter 3 how the trees ultimately come from stars, and we'll see in Chapter 8 how studying their building blocks suggests their existence in parallel universes. — Max Tegmark

Turbulence is the most important unsolved problem of classical physics. — Richard P. Feynman

Computer science is not as old as physics; it lags by a couple of hundred years. However, this does not mean that there is significantly less on the computer scientist's plate than on the physicist's: younger it may be, but it has had a far more intense upbringing! — Richard P. Feynman

If you want to win this argument with Dad, look in chapter two of the first book of the Feynman Lectures on Physics. There's a quote there about how philosophers say a great deal about what science absolutely requires, and it is all wrong, because the only rule in science is that the final arbiter is observation - that you just have to look at the world and report what you see. Um ... off the top of my head I can't think of where to find something about how it's an ideal of science to settle things by experiment instead of arguments - — Eliezer Yudkowsky

We're always, by the way, in fundamental physics, always trying to investigate those things in which we don't understand the conclusions. After we've checked them enough, we're okay. — Richard P. Feynman

We cannot do it in this way for two reasons. First, we do not yet know all the basic laws: there is an expanding frontier of ignorance. Second, the correct statement of the laws of physics involves some very unfamiliar ideas which require advanced mathematics for their description. Therefore, — Richard Feynman

All physics is rooted in the notion of law, the belief that we live in an ordered universe that can be understood by the application of rational reasoning. — Richard Feynman

If Feynman could see beauty as the inspiration for the theory of the rainbow, and if an electron could behave like a wave, and light like a particle, then the little contradiction of Leonard flitting among different subfields of physics, or even among varied careers, would not shake the universe. — Anonymous

I think equation guessing might be the best method to proceed to obtain the laws for the part of physics which is presently unknown. Yet, when I was much younger, I tried this equation guessing, and I have seen many students try this, but it is very easy to go off in wildly incorrect and impossible directions. — Richard P. Feynman

If all of mathematics disappeared, physics would be set back by exactly one week. — Richard P. Feynman

There was a Princess Somebody of Denmark sitting at a table with a number of people around her, and I saw an empty chair at their table and sat down.
She turned to me and said, "Oh! You're one of the Nobel-Prize-winners. In what field did you do your work?"
"In physics," I said.
"Oh. Well, nobody knows anything about that, so I guess we can't talk about it."
"On the contrary," I answered. "It's because somebody knows something about it that we can't talk about physics. It's the things that nobody knows anything about that we can discuss. We can talk about the weather; we can talk about social problems; we can talk about psychology; we can talk about international finance--gold transfers we can't talk about, because those are understood--so it's the subject that nobody knows anything about that we can all talk about!"
I don't know how they do it. There's a way of forming ice on the surface of the face, and she did it! — Richard Feynman

I decided to sell my drawings. However, I didn't want people to buy my drawings because the professor of physics isn't supposed to be able to draw - isn't that wonderful - so I made up a false name. — Richard P. Feynman

Until the advent of modern physics it was generally thought that all knowledge of the world could be obtained through direct observation, that things are what they seem, as perceived through our senses. But the spectacular success of modern physics, which is based upon concepts such as Feynman's that clash with everyday experience, has shown that that is not the case. The naive view of reality therefore is not compatible with modern physics. — Stephen Hawking

There is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics. — Richard P. Feynman

Discovering the laws of physics is like trying to put together the pieces of a jigsaw puzzle. We — Richard Feynman

Now that I am burned out and I'll never
accomplish anything, I've got this nice position at the university teaching
classes which I rather enjoy, and just like I read the Arabian Nights for
pleasure, I'm going to play with physics, whenever I want to, without
worrying about any importance whatsoever. — Richard Feynman

Einstein's gravitational theory, which is said to be the greatest single achievement of theoretical physics, resulted in beautiful relations connecting gravitational phenomena with the geometry of space; this was an exciting idea. — Richard P. Feynman

It is going to be necessary that everything that happens in a finite volume of space and time would have to be analyzable with a finite number of logical operations. The present theory of physics is not that way, apparently. It allows space to go down into infinitesimal distances, wavelengths to get infinitely great, terms to be summed in infinite order, and so forth; and therefore, if this proposition [that physics is computer-simulatable] is right, physical law is wrong. — Richard P. Feynman

We absolutely must leave room for doubt or there is no progress and there is no learning. There is no learning without having to pose a question. And a question requires doubt. People search for certainty. But there is no certainty. People are terrified - how can you live and not know? It is not odd at all. You only think you know, as a matter of fact. And most of your actions are based on incomplete knowledge and you really don't know what it is all about, or what the purpose of the world is, or know a great deal of other things. It is possible to live and not know. — Richard Feynman

Physics has a history of synthesizing many phenomena into a few theories. — Richard P. Feynman

What I am going to tell you about is what we teach our physics students in the third or fourth year of graduate school ... It is my task to convince you not to turn away because you don't understand it. You see my physics students don't understand it ... That is because I don't understand it. Nobody does. — Richard Feynman

As revealed by physics, the truth is so remarkable, so amazing! — Richard P. Feynman

I am a successful lecturer in physics for popular audiences. The real entertainment gimmick is the excitement, drama and mystery of the subject matter. People love to learn something, they are 'entertained' enormously by being allowed to understand a little bit of something they never understood before. One must have faith in the subject and in people's interest in it. — Richard P. Feynman

The correct statement of the laws of physics involves some very unfamiliar ideas which require advanced mathematics for their description. Therefore, one needs a considerable amount of preparatory training even to learn what the words mean. — Richard P. Feynman

We can deduce, often, from one part of physics like the law of gravitation, a principle which turns out to be much more valid than the derivation. — Richard P. Feynman

It was no secret joke that brought the smile and the sparkle in his eye, it was physics. — Feynman, Richard

Underneath so many of the phenomena we see every day are only three basic actions: one is described by the simple coupling number, j; the other two by functions-P(A to B) and E(A to B)- both of which are closely related. That's all there is to it, and from it all the rest of the laws of physics come. — Richard Feynman

Often one postulates that a priori, all states are equally probable. This is not true in the world as we see it. This world is not correctly described by the physics which assumes this postulate. — Richard P. Feynman

The drawing teacher has this problem of communicating how to draw by osmosis and not by instruction, while the physics teacher has the problem of always teaching techniques, rather than the spirit, of how to go about solving physical problems. — Richard P. Feynman

Professor Weyl,* the mathematician, gave an excellent definition of symmetry, which is that a thing is symmetrical if there is something that you can do to it so that after you have finished doing it it looks the same as it did before. That is the sense in which we say that the laws of physics are symmetrical; 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. It is this aspect of physical laws that is going to concern us in this lecture. — Richard Feynman

The reason Dick's physics was so hard for ordinary people to grasp was that he did not use equations. The usual theoretical physics was done since the time of Newton was to begin by writing down some equations and then to work hard calculating solutions of the equations. This was the way Hans and Oppy and Julian Schwinger did physics. Dick just wrote down the solutions out of his head without ever writing down the equations. He had a physical picture of the way things happen, and the picture gave him the solutions directly with a minimum of calculation. It was no wonder that people who had spent their lives solving equations were baffled by him. Their minds were analytical; his was pictorial. — Freeman Dyson

Physics is to math what sex is to masturbation. — Richard Feynman

Nature has a great simplicity and therefore a great beauty — Richard Feynman

If instead of arranging the atoms in some definite pattern, again and again repeated, on and on, or even forming little lumps of complexity like the odor of violets, we make an arrangement which is always different from place to place, with different kinds of atoms arranged in many ways, continually changing, not repeating, how much more marvelously is it possible that this thing might behave? Is it possible that that "thing" walking back and forth in front of you, talking to you, is a great glob of these atoms in a very complex arrangement, such that the sheer complexity of it staggers the imagination as to what it can do? When we say we are a pile of atoms, we do not mean we are merely a pile of atoms, because a pile of atoms which is not repeated from one to the other might well have the possibilities which you see before you in the mirror. — Richard Feynman

THE QUESTION IS, OF COURSE, IS IT GOING TO BE POSSIBLE TO AMALGAMATE EVERYTHING,
AND MERELY DISCOVER THAT THIS WORLD REPRESENTS DIFFERENT ASPECTS OF ONE THING? — Richard Feynman

There is a physical problem that is common to many fields, that is very old, and that has not been solved. It is not the problem of finding new fundamental particles, but something left over from a long time ago - over a hundred years. Nobody in physics has really been able to analyze it mathematically satisfactorily in spite of its importance to the sister sciences. It is the analysis of circulating or turbulent fluids. — Richard Feynman

It's because somebody knows something about it that we can't talk about physics. It's the things that nobody knows anything about we can discuss. — Richard P. Feynman

Have no respect whatsoever for authority; forget who said it and instead look what he starts with, where he ends up, and ask yourself, "Is it reasonable?" — Richard P. Feynman

Physics is to mathematics like sex is to masturbation. — Richard Feynman

When it came time for me to give my talk on the subject, I started off by drawing an outline of the cat and began to name the various muscles.
The other students in the class interrupt me: "We *know* all that!"
"Oh," I say, "you *do*? Then no *wonder* I can catch up with you so fast after you've had four years of biology." They had wasted all their time memorizing stuff like that, when it could be looked up in fifteen minutes. — Richard Feynman

As you know, a theory in physics is not useful unless it is able to predict underlined effects which we would otherwise expect. — Richard P. Feynman

We do not know what the rules of the game are; all we are allowed to do is to watch the playing. Of course, if we watch long enough, we may eventually catch on to a few of the rules. The rules of the game are what we mean by fundamental physics. — Richard P. Feynman

Experiment is the sole judge of scientific "truth." But what is the source of knowledge? Where do the laws that are to be tested come from? Experiment, itself, helps to produce these laws, in the sense that it gives us hints. But also needed is imagination to create from these hints the great generalizations - to guess at the wonderful, simple, but very strange patterns beneath them all, and then to experiment to check again whether we have made the right guess. This imagining process is so difficult that there is a division of labor in physics: there are theoretical physicists who imagine, deduce, and guess at new laws, but do not experiment; and then there are experimental physicists who experiment, imagine, deduce, and guess. — Richard Feynman

Physics is like sex: sure, it may give some practical results, but that's not why we do it. — Richard Feynman

The present situation in physics is as if we know chess, but we don't know one or two rules. — Richard P. Feynman

You might ask why we cannot teach physics by just giving the basic laws on page one and then showing how they work in all possible circumstances, as we do in Euclidean geometry, where we state the axioms and then make all sorts of deductions. (So, — Richard Feynman

For example, life itself is supposedly understandable in principle from the movements of atoms, and those atoms are made out of neutrons, protons and electrons. I must immediately say that when we state that we understand it in principle, we only mean that we think that, if we could figure everything out, we would find that there is nothing new in physics which needs to be discovered in order to understand the phenomena of life. Another — Richard Feynman

Everything is made of atoms. That is the key hypothesis. The most important hypothesis in all of biology, for example, is that everything that animals do, atoms do. In other words, there is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics. This — Richard Feynman

In physics the truth is rarely perfectly clear, and that is certainly universally the case in human affairs. Hence, what is not surrounded by uncertainty cannot be the truth. — Richard Feynman

It always seems odd to me that the fundamental laws of physics, when discovered, can appear in so many different forms that are not apparently identical at first, but, with a little mathematical fiddling, you can show the relationship. — Richard P. Feynman

The laws of physics could be like an onion, with new laws becoming operational as we probe new scales. We simply don't know! — Richard Feynman

So far as we know, all the fundamental laws of physics, like Newton's equations, are reversible. — Richard P. Feynman

There is no authority who decides what is a good idea. — Richard P. Feynman

It is odd, but on the infrequent occasions when I have been called upon in a formal place to play the bongo drums, the introducer never seems to find it necessary to mention that I also do theoretical physics. — Richard P. Feynman

From the point of view of basic physics, the most interesting phenomena are, of course, in the new places, the places where the rules do not work - not the places where they do work! That is the way in which we discover new rules. — Richard P. Feynman

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?' ... Nobody knows how it can be like that. — Richard P. Feynman

My faith in the expertise of physicists like Richard Feynman, for instance, permits me to endorse - and, if it comes to it, bet heavily on the truth of - a proposition that I don't understand. So far, my faith is not unlike religious faith, but I am not in the slightest bit motivated to go to my death rather than recant the formulas of physics. Watch: E doesn't equal mc2, it doesn't, it doesn't! I was lying, so there! — Daniel Dennett

It is the facts that matter, not the proofs. Physics can progress without the proofs, but we can't go on without the facts ... if the facts are right, then the proofs are a matter of playing around with the algebra correctly. — Richard P. Feynman

In its efforts to learn as much as possible about nature, modern physics has found that certain things can never be "known" with certainty. Much of our knowledge must always remain uncertain. The most we can know is in terms of probabilities. — Richard P. Feynman

Therefore psychologically we must keep all the theories in our heads, and every theoretical physicist who is any good knows six or seven different theoretical representations for exactly the same physics. — Richard P. Feynman

When I was a young man, Dirac was my hero. He made a breakthrough, a new method of doing physics. He had the courage to simply guess at the form of an equation, the equation we now call the Dirac equation, and to try to interpret it afterwards. — Richard P. Feynman