Feynman Science Quotes & Sayings

In fact, the science of thermodynamics began with an analysis, by the great engineer Sadi Carnot, of the problem of how to build the best and most efficient engine, and this constitutes one of the few famous cases in which engineering has contributed to fundamental physical theory. Another example that comes to mind is the more recent analysis of information theory by Claude Shannon. These two analyses, incidentally, turn out to be closely related. — Richard P. Feynman

A philosopher once said, "It is necessary for the very existence of science that the same conditions always produce the same results." Well, they don't! — Richard 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

Science is a way to teach how something gets to be known, what is not known, to what extent things are known (for nothing is known absolutely), how to handle doubt and uncertainty, what the rules of evidence are, how to think about things so that judgments can be made, how to distinguish truth from fraud, and from show. — Richard P. Feynman

It doesn't make a difference how beautiful your guess is. It doesn't make a difference how smart you are, who made the guess, or what his name is. If it disagrees with experiment, it's wrong. — Richard Feynman

Psychoanalysis is not a science: it is at best a medical process, and perhaps even more like witch-doctoring. — Richard Feynman

It is interesting that this thoroughness, which is a virtue, is often misunderstood. When someone says a thing has been done scientifically, often all he means is that it has been done thoroughly. I have heard people talk of the "scientific" extermination of the Jews in Germany. There was nothing scientific about it. It was only thorough. There was no question of making observations and then checking them in order to determine something. In that sense, there were "scientific" exterminations of people in Roman times and in other periods when science was not so far developed as it is today and not much attention was paid to observation. In such cases, people should say "thorough" or "thoroughgoing," instead of "scientific. — Richard Feynman

My father had the spirit and integrity of a scientist, but he was a salesman. I remember asking him the question "How can a man of integrity be a salesman?"
He said to me, "Frankly, many salesmen in the business are not straightforward
they think it's a better way to sell. But I've tried being straightforward, and I find it has its advantages. In fact, I wouldn't do it any other way. If the customer thinks at all, he'll realize he has had some bad experience with another salesman, but hasn't had that kind of experience with you. So in the end, several customers will stay with you for a long time and appreciate it. — Richard Feynman

But the real glory of science is that we can find a way of thinking such that the law is evident. — Richard P. Feynman

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

Progress in science comes when experiments contradict theory. — Richard P. Feynman

Theorists write all the popular books on science: Heinz Pagels, Frank Wilczek, Stephen Hawking, Richard Feynman, et al. And why not? They have all that spare time. — Leon M. Lederman

If I say [electrons] behave like particles I give the wrong impression; also if I say they behave like waves. They behave in their own inimitable way, which technically could be called a quantum mechanical way. They behave in a way that is like nothing that you have seen before. — Richard P. Feynman

"Half genius and half buffoon," Freeman Dyson ... wrote ... [Richard] Feynman struck him as uproariously American-unbuttoned and burning with physical energy. It took him a while to realize how obsessively his new friend was tunneling into the very bedrock of modern science. — James Gleick

That is the logical tight-rope on which we have to walk if we wish to interpret nature. — Richard P. Feynman

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

Unless a thing can be defined by measurement, it has no place in a theory. And since an accurate value of the momentum of a localized particle cannot be defined by measurement it therefore has no place in the theory. — Richard P. Feynman

The whole question of imagination in science is often misunderstood by people in other disciplines ... They overlook the fact that whatever we are allowed to imagine in science must be consistent with everything else we know. — Richard P. Feynman

We decided that 'trivial' means 'proved'. So we joked with the mathematicians: We have a new theorem- that mathematicians can prove only trivial theorems, because every theorem that's proved is trivial. — 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

Science is of value because it can produce something. — Richard P. Feynman

I think we should teach them [the people] wonders and that the purpose of knowledge is to appreciate wonders even more. — Richard Feynman

I've always been very one-sided about science, and when I was younger, I concentrated almost all my effort on it. — Richard P. Feynman

I do believe that there is a conflict between science and religion ... the spirit or attitude toward the facts is different in religion from what it is in science. The uncertainty that is necessary in order to appreciate nature is not easily correlated with the feeling of certainty in faith. — 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

Tell your son to stop trying to fill your head with science - for to fill your heart with love is enough. — Richard Feynman

Science is a process for learning about nature in which competing ideas about how the world works are measured against observations. — Richard P. Feynman

First you guess. Don't laugh, this is the most important step. Then you compute the consequences. Compare the consequences to experience. If it disagrees with experience, the guess is wrong. In that simple statement is the key to science. It doesn't matter how beautiful your guess is or how smart you are or what your name is. If it disagrees with experience, it's wrong. That's all there is to it. — 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

Is science of any value? I think a power to do something is of value. Whether the result is a good thing or a bad thing depends on how it is used, but the power is a value. — Richard P. Feynman

Philosophers have said before that one of the fundamental requisites of science is that whenever you set up the same conditions, the same thing must happen. This is simply not true, it is not a fundamental condition of science. — Richard Feynman

[When a young person loses faith in his religion because he begins to study science and its methodology] it isn't that [through the obtaining of real knowledge that] he knows it all, but he suddenly realizes that he doesn't know it all. — Richard P. Feynman

Doubt is clearly a value in science. It is important to doubt and that the doubt is not a fearful thing, but a thing of great value. — Richard P. Feynman

There are all kinds of interesting questions that come from a knowledge of science, which only adds to the excitement and mystery and awe of a flower. — 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

We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress. — Richard Feynman

I now know that there is a happy abundance of science writers who pen the most lucid and thrilling prose - Timothy Ferris, Richard Fortey and Tim Flannery are three that jump out from a single station of the alphabet (and that's not even to mention the late but godlike Richard Feynman) - but, sadly, none of them wrote any textbook I ever used. — Bill Bryson

Science is what we have learned about how to keep from fooling ourselves. — Richard Feynman

To guess what to keep and what to throw away takes considerable skill. Actually it is probably merely a matter of luck, but it looks as if it takes considerable skill. — Richard P. Feynman

Science is a way of trying not to fool yourself. — Richard P. Feynman

It is necessary for the very existence of science that minds exist which do not allow that nature must satisfy some preconceived conditions. — Richard P. Feynman

It doesn't seem to me that this fantastically marvelous universe, this tremendous range of time and space and different kinds of animals, and all the different planets, and all these atoms with all their motions, and so on, all this complicated thing can merely be a stage so that God can watch human beings struggle for good and evil - which is the view that religion has. The stage is too big for the drama. — Richard Feynman

I love only nature, and I hate mathematicians. — Richard P. Feynman

I learned very early the difference between knowing the name of something and knowing something. — Richard Feynman

[Quantum mechanics] describes nature as absurd from the point of view of common sense. And yet it fully agrees with experiment. So I hope you can accept nature as She is - absurd. — Richard Feynman

The only way to have real success in science, the field I'm familiar with, is to describe the evidence very carefully without regard to the way you feel it should be. If you have a theory , you must try to explain what's good and what's bad about it equally. In science, you learn a kind of standard integrity and honesty . — Richard P. Feynman

We find that the statements of science are not of what is true and what is not true, but statements of what is known with different degrees of certainty: "It is very much more likely that so and so is true than that it is not true". — Richard P. Feynman

You know, the most amazing thing happened to me tonight ... I saw a car with the license plate ARW 357. Can you imagine? Of all the millions of license plates in the state, what was the chance that I would see that particular one tonight? Amazing! — Richard Feynman

Feynman once said, 'Science is imagination in a straitjacket.' It is ironic that in the case of quantum mechanics, the people without the straitjackets are generally the nuts. — Lawrence M. Krauss

Philosophy of science is about as useful to scientists as ornithology is to birds. — Richard Feynman

If someone were to propose that the planets go around the sun because all planet matter has a kind of tendency for movement, a kind of motility, let us call it an 'oomph,' this theory could explain a number of other phenomena as well. So this is a good theory, is it not? No. It is nowhere near as good as the proposition that the planets move around the sun under the influence of a central force which varies exactly inversely as the square of the distance from the center. The second theory is better because it is so specific; it is so obviously unlikely to be the result of chance. It is so definite that the barest error in the movement can show that it is wrong; but the planets could wobble all over the place, and, according to the first theory, you could say, 'Well, that is the funny behavior of the 'oomph. — Richard Feynman

What I got out of that story was something still very new to me: I understood at last what art is really for, at least in certain respects. It gives somebody, individually, pleasure. You can make something that somebody likes so much that they're depressed, or they're happy, on account of that damn thing you made! In science, it's sort of general and large: You don't know the individuals who have appreciated it directly. I understood that to sell a drawing is not to make money, but to be sure that it's in the home of someone who really wants it; someone who would feel bad if they didn't have it. This was interesting. — Richard Feynman

Science is the belief in the ignorance of experts. — 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

The ideas associated with the problems of the development of science, as far as I can see by looking around me, are not of the kind that everyone appreciates. — Richard P. Feynman

If you thought that science was certain - well, that is just an error on your part. — Richard Feynman

We are at the very beginning of time for the human race. It is not unreasonable that we grapple with problems. But there are tens of thousands of years in the future. Our responsibility is to do what we can, learn what we can, improve the solutions, and pass them on. — Richard Feynman

Philosophers say a great deal about what is absolutely necessary for science, and it is always, so far as one can see, rather naive, and probably wrong. — Richard Feynman

For instance, the scientific article may say, 'The radioactive phosphorus content of the cerebrum of the rat decreases to one- half in a period of two weeks.' Now what does that mean?
It means that phosphorus that is in the brain of a rat - and also in mine, and yours - is not the same phosphorus as it was two weeks ago. It means the atoms that are in the brain are being replaced: the ones that were there before have gone away.
So what is this mind of ours: what are these atoms with consciousness? Last week's potatoes! They now can remember what was going on in my mind a year ago - a mind which has long ago been replaced. To note that the thing I call my individuality is only a pattern or dance, that is what it means when one discovers how long it takes for the atoms of the brain to be replaced by other atoms. The atoms come into my brain, dance a dance, and then go out - there are always new atoms, but always doing the same dance, remembering what the dance was yesterday. — Richard Feynman

Science is like sex: sometimes something useful comes out, but that is not the reason we are doing it. — Richard Feynman

What is the fundamental hypothesis of science, the fundamental philosophy? We stated it in the first chapter: the sole test of the validity of any idea is experiment ... If we are told that the same experiment will always produce the same result, that is all very well, but if when we try it, it does not, then it does not. We just have to take what we see, and then formulate all the rest of our ideas in terms of our actual experience. — Richard P. Feynman

[Doubt] is not a new idea; this is the idea of the age of reason. This is the philosophy that guided the men who made the democracy that we live under. The idea that no one really knew how to run a government led to the idea that we should arrange a system by which new ideas could be developed, tried out, and tossed out if necessary, with more new ideas bought in - a trial-and-error system. This method was a result of the fact that science was already showing itself to be a successful venture at the end of the eighteenth century. Even then it was clear to socially minded people that the openness of possibilities was an opportunity, and that doubt and discussion were essential to progress into the unknown. If we want to solve a problem that we have never solved before, we must leave the door to the unknown ajar ... doubt is not to be feared, but welcomed and discussed. — 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

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

If science is to progress, what we need is the ability to experiment, honesty in reporting results - the results must be reported without somebody saying what they would like the results to have been - and finally - an important thing - the intelligence to interpret the results. — Richard P. Feynman

I happen to know this, and I happen to know that, and maybe I know that;and I work everything out from there. Tomorrow I may forgot that this is true, but remember that something else is true, so I can reconstruct it all again. I am never quite sure of where I am supposed to begin or where I am supposed to end. I just remember enough all the time so that as the memory fades and some of the pieces fall out I can put the thing back together again every day — Richard Feynman

So I started to think: "How can that happen?" ... So the guy says, "What are you doing? You come fix the radio, but you're only walking back and forth!" I say, "I'm thinking! — Richard Feynman

Although it is uncertain, it is necessary to make science useful. Science is only useful if it tells you about some experiment that has not been done; it is not good if it only tells you what just went on. — Richard P. Feynman

The principle of science, the definition, almost, is the following: The test of all knowledge is experiment. 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. — Richard P. Feynman

This is not very important what I'm doing. I'm just proving something. — Richard P. 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

The Feynman quip is not without a philosopher's tu quoque: "most scientists tend to understand little more about science than fish about hydrodynamics" (Lakatos 1978:62 n.2). — Robert Nola

So my antagonist said, "Is it impossible that there are flying saucers? Can you prove that it's impossible?" "No", I said, "I can't prove it's impossible. It's just very unlikely". At that he said, "You are very unscientific. If you can't prove it impossible then how can you say that it's unlikely?" But that is the way that is scientific. It is scientific only to say what is more likely and what less likely, and not to be proving all the time the possible and impossible. — 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

It is not unscientific to make a guess, although many people who are not in science think it is. — Richard P. Feynman

The exception proves that the rule is wrong. That is the principle of science. If there is an exception to any rule, and if it can be proved by observation, that rule is wrong. — Richard Feynman

Science is uncertain. — Richard P. 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

If one cannot see gravitation acting here, he has no soul. — Richard Feynman

You can know the name of a bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird ... So let's look at the bird and see what it's doing
that's what counts. — Richard Feynman

To every man is given the key to the gates of heaven. The same key opens the gates of hell.
And so it is with science. — Richard Feynman

Once you start doubting, just like you're supposed to doubt, you ask me if the science is true. You say no, we don't know what's true, we're trying to find out and everything is possibly wrong. — Richard Feynman

Scientists are explorers. Philosophers are tourists. — Richard P. Feynman

I would rather have questions that can't be answered than answers that can't be questioned. — Richard Feynman

There are thousands of years in the past, and there is an unknown amount of time in the future. There are all kinds of opportunities, and there are all kinds of dangers. — Richard Feynman

The most obvious characteristic of science is its application: the fact that, as a consequence of science, one has a power to do things. And the effect this power has had need hardly be mentioned. The whole industrial revolution would almost have been impossible without the development of science. — Richard P. Feynman

'Conservation' (the conservation law) means this ... that there is a number, which you can calculate, at one moment-and as nature undergoes its multitude of changes, this number doesn't change. That is, if you calculate again, this quantity, it'll be the same as it was before. An example is the conservation of energy: there's a quantity that you can calculate according to a certain rule, and it comes out the same answer after, no matter what happens, happens. — Richard P. Feynman

The trouble with playing a trick on a highly intelligent man like Mr. Teller is that the time it takes him to figure out from the moment that he sees there is something wrong till he understands exactly what happened is too damn small to give you any pleasure! — Richard Feynman

It is surprising that people do not believe that there is imagination in science. It is a very interesting kind of imagination, unlike that of the artist. The great difficulty is in trying to imagine something that you have never seen, that is consistent in every detail with what has already been seen, and that is different from what has been thought of; furthermore, it must be definite and not a vague proposition. That is indeed difficult. — Richard Feynman

This is the key of modern science and is the beginning of the true understanding of nature . This idea . That to look at the things, to record the details, and to hope that in the information thus obtained, may lie a clue to one or another of a possible theoretical interpretation. — Richard P. Feynman

I think the educational and psychological studies I mentioned are examples of what I would like to call cargo cult science. In the South Seas there is a cargo cult of people. During the war they saw airplanes land with lots of good materials, and they want the same thing to happen now. So they've arranged to make things like runways, to put fires along the sides of the runways, to make a wooden hut for a man to sit in, with two wooden pieces on his head like headphones and bars of bamboo sticking out like antennas - he's the controller - and they wait for the airplanes to land. They're doing everything right. The form is perfect. It looks exactly the way it looked before. But it doesn't work. No airplanes land. So I call these things cargo cult science, because they follow all the apparent precepts and forms of scientific investigation, but they're missing something essential, because the planes don't land. — Richard Feynman

We have been led to imagine all sorts of things infinitely more marvelous than the imagining of poets and dreamers of the past. It shows that the imagination of nature is far, far greater than the imagination of man. For instance, how much more remarkable it is for us all to be stuck-half of us upside down-by a mysterious attraction, to a spinning ball that has been swinging in space for billions of years, than to be carried on the back of an elephant supported on a tortoise swimming in a bottomless sea. — Richard Feynman

In general, we look for a new law by the following process: First we guess it; then we compute the consequences of the guess to see what would be implied if this law that we guessed is right; then we compare the result of the computation to nature, with experiment or experience, compare it directly with observation, to see if it works. If it disagrees with experiment, it is wrong. In that simple statement is the key to science. It does not make any difference how beautiful your guess is, it does not make any difference how smart you are, who made the guess, or what his name is - if it disagrees with experiment, it is wrong. — Richard Feynman

I believe, therefore, that although it is not the case today, that there may some day come a time, I should hope, when it will fully appreciated that the power of governments should be limited; that governments ought not to be empowered to decide the validity of scientific theories, that this is a ridiculous thing for them to try to do; that they are not to decide the description of history or of economic theory or of philosophy. — Richard 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

I have no responsibility to live up to what others expect of me. That's their mistake, not my failing. — Richard Feynman

The first principle is that you must not fool yourself and you are the easiest person to fool. — Richard Feynman

By the time Carl was four, Feynman was actively lobbying against a first-grade science book proposed for California schools. It began with pictures of a mechanical wind-up dog, a real dog, and a motorcycle, and for each the same question: "What makes it move?" The proposed answer - "Energy makes it move" - enraged him. That — James Gleick

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

If we will only allow that, as we progress, we remain unsure, we will leave opportunities for alternatives. — Richard P. Feynman