Richard Feynman

We scientists are clever — too clever — are you not satisfied? Is four square miles in one bomb not enough? Men are still thinking. Just tell us how big you want it!

— Richard Feynman

PrinciplesAll mass is interaction.

— Richard Feynman

I had too much stuff. My machines came from too far away.

— Richard Feynman

The theoretical broadening which comes from having many humanities subjects on the campus is offset by the general dopiness of the people who study these things.

— Richard 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

Hell, if I could explain it to the average person, it wouldn't have been worth the Nobel prize.

— Richard Feynman

We have a habit in writing articles published in scientific journals to make the work as finished as possible, to cover all the tracks, to not worry about the blind alleys or to describe how you had the wrong idea first, and so on. So there isn't any place to publish, in a dignified manner, what you actually did in order to get to do the work.

— Richard Feynman

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

— Richard Feynman

The chance is high that the truth lies in the fashionable direction. But, on the off-chance that it is in another direction — a direction obvious from an unfashionable view of field theory — who will find it? Only someone who has sacrificed himself by teaching himself quantum electrodynamics from a peculiar and unfashionable point of view; one that he may have to invent for himself.

— Richard Feynman

Do not read so much, look about you and think of what you see there.

— Richard Feynman

Science is the belief in the ignorance of experts.

— Richard Feynman

I, therefore, did learn a lesson: The female mind is capable of understanding analytic geometry. Those people who have for years been insisting (in the face of all obvious evidence to the contrary) that the male and female are equally capable of rational thought may have something. The difficulty may just be that we have never yet discovered a way to communicate with the female mind. If it is done in the right way, you may be able to get something out of it.

— Richard Feynman

Energy is a very subtle concept. It is very, very difficult to get right.

— Richard Feynman

Science alone of all the subjects contains within itself the lesson of the danger of belief in the infallibility of the greatest teachers of the preceding generation.

— Richard Feynman

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

— Richard Feynman

We are not to tell nature what she’s gotta be. … She's always got better imagination than we have.

— Richard Feynman

Tell your son to stop trying to fill your head with science — for to fill your heart with love is enough!

— Richard Feynman

Nature isn't classical, dammit, and if you want to make a simulation of nature, you'd better make it quantum mechanical, and by golly it's a wonderful problem, because it doesn't look so easy.

— Richard Feynman

I took this stuff I got out of your [O-ring] seal and I put it in ice water, and I discovered that when you put some pressure on it for a while and then undo it it doesn't stretch back. It stays the same dimension. In other words, for a few seconds at least, and more seconds than that, there is no resilience in this particular material when it is at a temperature of 32 degrees. I believe that has some significance for our problem.

— Richard Feynman

The Quantum Universe has a quotation from me in every chapter — but it's a damn good book anyway.

— Richard Feynman

There are 10 stars in the galaxy. That used to be a huge number. But it's only a hundred billion. It's less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers.

— Richard Feynman

I'd hate to die twice. It's so boring.

— Richard Feynman

This dying is boring.

— Richard Feynman

What I cannot create, I do not understand.Know how to solve every problem that has been solved.

— Richard Feynman

You know, the most amazing thing happened to me tonight. I was coming here, on the way to the lecture, and I came in through the parking lot. And you won't believe what happened. 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

[I call myself] an atheist. Agnostic for me would be trying to weasel out and sound a little nicer than I am about this.

— Richard Feynman

Einstein was a giant. His head was in the clouds, but his feet were on the ground. But those of us who are not that tall have to choose!

— Richard Feynman

Physics is to mathematics what sex is to masturbation.

— Richard Feynman

I believe that a scientist looking at nonscientific problems is just as dumb as the next guy — and when he talks about a nonscientific matter, he will sound as naive as anyone untrained in the matter.

— Richard Feynman

The imagination of nature is far, far greater than the imagination of man.

— Richard Feynman

Is no one inspired by our present picture of the universe? This value of science remains unsung by singers, you are reduced to hearing not a song or poem, but an evening lecture about it. This is not yet a scientific age.

— Richard Feynman

If we take everything into account — not only what the ancients knew, but all of what we know today that they didn't know — then I think that we must frankly admit that we do not know.

— Richard Feynman

Each piece, or part, of the whole of nature is always merely an approximation to the complete truth, or the complete truth so far as we know it. In fact, everything we know is only some kind of approximation, because we know that we do not know all the laws as yet. Therefore, things must be learned only to be unlearned again or, more likely, to be corrected. … The test of all knowledge is experiment. Experiment is the sole judge of scientific “truth”.

— Richard Feynman

If an apple is magnified to the size of the earth, then the atoms in the apple are approximately the size of the original apple.

— Richard Feynman

It is important to realize that in physics today, we have no knowledge what energy is. We do not have a picture that energy comes in little blobs of a definite amount. It is not that way.

— Richard Feynman

We cannot define anything precisely. If we attempt to, we get into that paralysis of thought that comes to philosophers, who sit opposite each other, one saying to the other, "You don't know what you are talking about!". The second one says, "What do you mean by know? What do you mean by talking? What do you mean by you?"

— Richard Feynman

So, ultimately, in order to understand nature it may be necessary to have a deeper understanding of mathematical relationships. But the real reason is that the subject is enjoyable, and although we humans cut nature up in different ways, and we have different courses in different departments, such compartmentalization is really artificial, and we should take our intellectual pleasures where we find them.

— Richard Feynman

So far as we know, all the fundamental laws of physics, like Newton’s equations, are reversible.

— Richard Feynman

From a long view of the history of mankind — seen from, say, ten thousand years from now — there can be little doubt that the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics. The American Civil War will pale into provincial insignificance in comparison with this important scientific event of the same decade.

— Richard Feynman

The same equations have the same solutions

— Richard Feynman

It requires a much higher degree of imagination to understand the electromagnetic field than to understand invisible angels. … I speak of the fields and wave my arms and you may imagine that I can see them … [but] I cannot really make a picture that is even nearly like the true waves.

— Richard Feynman

Whenever you see a sweeping statement that a tremendous amount can come from a very small number of assumptions, you always find that it is false. There are usually a large number of implied assumptions that are far from obvious if you think about them sufficiently carefully.

— Richard Feynman

The "paradox" is only a conflict between reality and your feeling of what reality "ought to be."

— Richard Feynman

I hope … that you will find someday that, after all, it isn’t as horrible as it looks.

— Richard Feynman

Perhaps you will not only have some appreciation of this culture; it is even possible that you may want to join in the greatest adventure that the human mind has ever begun.

— Richard Feynman

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 Feynman

A person talks in such generalities that everyone can understand him and it's considered to be some deep philosophy. However, I would like to be very rather more special and I would like to be understood in an honest way, rather than in a vague way.

— 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 Feynman

The next question was — what makes planets go around the sun? At the time of Kepler some people answered this problem by saying that there were angels behind them beating their wings and pushing the planets around an orbit. As you will see, the answer is not very far from the truth. The only difference is that the angels sit in a different direction and their wings push inward.

— Richard Feynman

It is impossible, by the way, when picking one example of anything, to avoid picking one which is atypical in some sense.

— Richard Feynman

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

— Richard Feynman

To those who do not know mathematics it is difficult to get across a real feeling as to the beauty, the deepest beauty, of nature. … If you want to learn about nature, to appreciate nature, it is necessary to understand the language that she speaks in.

— Richard Feynman

Mathematics is not just a language. Mathematics is a language plus reasoning. It's like a language plus logic. Mathematics is a tool for reasoning. It's, in fact, a big collection of the results of some person's careful thought and reasoning. By mathematics, it is possible to connect one statement to another.

— Richard Feynman

Now we have a problem. 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. This doesn't happen in mathematics, that the theorems come out in places where they're not supposed to be!

— Richard Feynman

So in order to understand the physics one must always have a neat balance and contain in his head all of the various propositions and their interelationships because the laws often extend beyond the range of their deductions. This will only have no importance when all the laws are known.

— Richard Feynman

For those who want some proof that physicists are human, the proof is in the idiocy of all the different units which they use for measuring energy.

— Richard Feynman

Our imagination is stretched to the utmost, not, as in fiction, to imagine things which are not really there, but just to comprehend those things which are there.

— Richard Feynman

I think I can safely say that nobody understands quantum mechanics.

— Richard Feynman

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.

— Richard Feynman

Nature's imagination far surpasses our own.

— Richard 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 Feynman

People are always asking for the latest developments in the unification of this theory with that theory, and they don't give us a chance to tell them anything about what we know pretty well. They always want to know the things we don't know.

— Richard Feynman

Will you understand what I'm going to tell you? … No, you're not going to be able to understand it. … That is because I don't understand it. Nobody does.

— Richard Feynman

While I am describing to you how Nature works, you won't understand why Nature works that way. But you see, nobody understands that.

— Richard Feynman

The theory of quantum electrodynamics describes Nature as absurd from the point of view of common sense. And it agrees fully with experiment. So I hope you accept Nature as She is — absurd.

— Richard Feynman

The scale of light can be described by numbers — called the frequency — and as the numbers get higher, the light goes from red to blue to ultraviolet. We can't see ultraviolet light, but it can affect photographic plates. It's still light — only the number is different.

— Richard Feynman

Light is something like raindrops — each little lump of light is called a photon — and if the light is all one color, all the "raindrops" are the same.

— Richard Feynman

Every instrument that has been designed to be sensitive enough to detect weak light has always ended up discovering that the same thing: light is made of particles.

— Richard Feynman

When a photon comes down, it interacts with electrons throughout the glass, not just on the surface. The photon and electrons do some kind of dance, the net result of which is the same as if the photon hit only on the surface.

— Richard Feynman

You will have to brace yourselves for this — not because it is difficult to understand, but because it is absolutely ridiculous: All we do is draw little arrows on a piece of paper — that’s all!

— 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 Feynman

Why are the theories of physics so similar in their structure?

— Richard Feynman

There were certain things I didn't like, such as tipping. I thought we should be paid more, and not have to have any tips. But when I proposed that to the boss, I got nothing but laughter. She told everybody, "Richard doesn't want his tips, hee, hee, hee; he doesn't want his tips, ha, ha, ha." The world is full of this kind of dumb smart-alec who doesn't understand anything.

— Richard Feynman

I don't know what's the matter with people: they don't learn by understanding; they learn by some other way — by rote or something. Their knowledge is so fragile!

— Richard Feynman

The electron is a theory we use; it is so useful in understanding the way nature works that we can almost call it real.

— Richard Feynman

[John] von Neumann gave me an interesting idea: that you don't have to be responsible for the world that you're in. So I have developed a very powerful sense of social irresponsibility as a result of von Neumann's advice. It's made me a very happy man ever since. But it was von Neumann who put the seed in that grew into my active irresponsibility!

— Richard Feynman

And this is medicine?

— Richard Feynman

One time I was in the men's room of the bar and there was a guy at the urinal. He was kind of drunk, and said to me in a mean-sounding voice, "I don't like your face. I think I'll push it in."I was scared green. I replied in an equally mean voice, "Get out of my way, or I'll pee right through ya!"

— Richard Feynman

I have to understand the world, you see.

— Richard Feynman

Since then I never pay attention to anything by "experts". I calculate everything myself.

— Richard Feynman

I'll never make that mistake again, reading the experts' opinions. Of course, you only live one life, and you make all your mistakes, and learn what not to do, and that's the end of you.

— Richard Feynman

This conference was worse than a Rorschach test: There's a meaningless inkblot, and the others ask you what you think you see, but when you tell them, they start arguing with you!

— 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 Feynman

If we are to replace standard numerical probability usage with engineering judgment, why do we find such an enormous disparity between the management estimate and the judgment of the engineers? It would appear that, for whatever purpose, be it for internal or external consumption, the management of NASA exaggerates the reliability of its product, to the point of fantasy.

— Richard Feynman

There was no way, without full understanding, that one could have confidence that conditions the next time might not produce erosion three times more severe than the time before. Nevertheless, officials fooled themselves into thinking they had such understanding and confidence, in spite of the peculiar variations from case to case. A mathematical model was made to calculate erosion. This was a model based not on physical understanding but on empirical curve fitting.

— Richard Feynman

You can know the name of that bird in all the languages of the world, but when you're finished, you'll know absolutely nothing whatever about the bird. You'll only know about humans in different places, and what they call the bird. … I learned very early the difference between knowing the name of something and knowing something.

— Richard Feynman

My mother … had a wonderful sense of humor, and I learned from her that the highest forms of understanding we can achieve are laughter and human compassion.

— Richard Feynman

Doubting the great Descartes … was a reaction I learned from my father: 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 Feynman

The real question of government versus private enterprise is argued on too philosophical and abstract a basis. Theoretically, planning may be good. But nobody has ever figured out the cause of government stupidity — and until they do (and find the cure), all ideal plans will fall into quicksand.

— 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 Feynman

The most important thing I found out from [my father] is that if you asked any question and pursued it deeply enough, then at the end there was a glorious discovery of a general and beautiful kind.

— Richard Feynman

I don't like honors. … I've already got the prize: the prize is the pleasure of finding the thing out, the kick in the discovery, the observation that other people use it. Those are the real things.

— Richard Feynman

Jiry, don't worry about anything. Go out and have a good time.

— Richard Feynman

Some people say, "How can you live without knowing?" I do not know what they mean. I always live without knowing. That is easy. How you get to know is what I want to know.

— Richard Feynman

Looking back at the worst times, it always seems that they were times in which there were people who believed with absolute faith and absolute dogmatism in something. And they were so serious in this matter that they insisted that the rest of the world agree with them. And then they would do things that were directly inconsistent with their own beliefs in order to maintain that what they said was true.

— Richard Feynman

It is in the admission of ignorance and the admission of uncertainty that there is a hope for the continuous motion of human beings in some direction that doesn't get confined, permanently blocked, as it has so many times before in various periods in the history of man.

— Richard Feynman

The fact that you are not sure means that it is possible that there is another way someday.

— Richard Feynman

The first one has to do with whether a man knows what he is talking about, whether what he says has some basis or not. And my trick that I use is very easy. If you ask him intelligent questions — that is, penetrating, interested, honest, frank, direct questions on the subject, and no trick questions — then he quickly gets stuck. It is like a child asking naive questions. If you ask naive but relevant questions, then almost immediately the person doesn't know the answer, if he is an honest man.

— Richard Feynman

Anyway, I have to argue about flying saucers on the beach with people, you know. And I was interested in this: they keep arguing that it is possible. And that's true. It is possible. They do not appreciate that the problem is not to demonstrate whether it's possible or not but whether it's going on or not.

— Richard Feynman

If the professors of English will complain to me that the students who come to the universities, after all those years of study, still cannot spell "friend," I say to them that something's the matter with the way you spell friend.

— Richard Feynman

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

— Richard Feynman

I don't know anything, but I do know that everything is interesting if you go into it deeply enough.

— Richard Feynman