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.

It is the fact that the electrons cannot all get on top of each other that makes tables and everything else solid.

If all of this, all the life of a stream of water, can be nothing but a pile of atoms, how much more is possible?

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.

Some things that satisfy the rules of algebra can be interesting to mathematicians even though they don’t always represent a real situation.

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.

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.

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.

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

No one really understands quantum mechanics.

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.

Physicists like to think that all you have to do is say, these are the conditions, now what happens next?

I don’t believe in honors, it bothers me, honors bother, honors is epaulettes, honors is uniforms. My papa brought me up this way. I can’t stand it, it hurts me.

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.

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.

The game I play is a very interesting one. It’s imagination, in a tight straightjacket.

To decide upon the answer is not scientific. In order to make progress, one must leave the door to the unknown ajar ajar only.

Every object is a mixture of lots of things, so we can deal with it only as a series of approximations and idealizations.

With quantum physics, who needs drugs?

I’ve found out since that such people don’t know what they’re doing, and get insulted when you make some suggestion or criticism.

In fact the total amount that a physicist knows is very little. He has only to remember the rules to get him from one place to another and he is all right.

Religion gives inspiration to act well. Not only that, it gives inspiration to the arts and to many other activities of human beings.

The things that mattered were honesty, independence, willingness to admit ignorance.

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

This is not very important what I’m doing. I’m just proving something.

Agnostic for me would be trying to weasel out and sound a little nicer than I am about this.

It’s all generated, maybe, by the fact that the attitude of the populace is to try to find the answer instead of trying to find a man who has a way of getting at the answer.

If you can find any other view of the world which agrees over the entire range where things have already been observed, but disagrees somewhere else, you have made a great discovery.

All we know so far is what doesn’t work.

You have to have absolute confidence. Keep right on going, and nothing will happen.

I have to keep going to find out ultimately what is the matter with it in the end.

I learned from my father to translate: everything I read I try to figure out what it really means, what it’s really saying.

When you get as old as I am, you start to realize that you’ve told most of the good stuff you know to other people anyway.

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.

It is our responsibility to leave the people of the future a free hand.

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.

We are never right, we can only be sure we are wrong.

I don’t think that the laws can be considered to be like God because they have been figured out.

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

The problem of creating something new, but which is consistent with everything which has been seen before, is one of extreme difficulty.

Maybe that is why young people make success. They don’t know enough.

A great deal more is known than has been proved.

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

I’m not responsible for what other people think I am able to do; I don’t have to be good because they think I’m going to be good.

As usual, nature’s imagination far surpasses our own, as we have seen from the other theories which are subtle and deep.

There is no harm in doubt and skepticism, for it is through these that new discoveries are made.

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

Words can be meaningless. If they are used in such a way that no sharp conclusions can be drawn.

Another thing I must point out is that you cannot prove a vague theory wrong.

I find that teaching and the students keep life going, and I would never accept any position in which somebody has invented a happy situation for me where I don’t have to teach. Never.

If you know that you are not sure, you have a chance to improve the situation. I want to demand this freedom for future generations.

As revealed by physics, the truth is so remarkable, so amazing!

We are lucky to live in an age in which we are still making discoveries.

This is not yet a scientific age.

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.

An ordinary fool isn’t a faker; an honest fool is all right. But a dishonest fool is terrible!

I have a limited intelligence and I’ve used it in a particular direction.

Science is of value because it can produce something.

One does not, by knowing all the physical laws as we know them today, immediately obtain an understanding of anything much. I love only nature, and I hate mathematicians.

Few people realize the number of things that are possible.

I’m trying to find out NOT how Nature could be, but how Nature IS.

It is probably better to realize that the probability concept is in a sense subjective, that it is always based on uncertain knowledge, and that its quantitative evaluation is subject to change as we obtain more information.

Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question – to doubt – to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained.

In a way, the Nobel Prize has been something of a pain in the neck, though there was at least one time that I got some fun out of it, Shortly after I won the Prize, Gweneth and I received an invitation from the Brazilian government to be the guests of honor at the Carnaval celebrations in Rio.

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.

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.

I think a power to do something is of value. Whether the power is a good thing or a bad thing depends on how it is used, but the power is a value.

Strange! I don’t understand how it is that we can write mathematical expressions and calculate what the thing is going to do without being able to picture it.

The idea is to try to give all the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another.

I believe that a scientist looking at nonscientific problems is just as dumb as the next guy.

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

I learned from her that every woman is worried about her looks, no matter how beautiful she is.

From a long view of the history of mankind the most significant event of the nineteenth century will be judged as Maxwell’s discovery of the laws of electrodynamics.

You see, one thing is, I can live with doubt and uncertainty and not knowing. I think it’s much more interesting to live not knowing than to have answers which might be wrong.

We have this terrible struggle to try to explain things to people who have no reason to want to know.

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

The other great heritage is Christian ethics – the basis of action on love, the brotherhood of all men, the value of the individual, the humility of the spirit. These two heritages are logically, thoroughly consistent.

I have to disregard everybody else, and then I can do my own work.

I don’t have to be good because they think I’m going to be good.

All the time you’re saying to yourself, ‘I could do that, but I won’t,’ – which is just another way of saying that you can’t.

When I found out that Santa Claus wasn’t real, I wasn’t upset; rather, I was relieved that there was a much simpler phenomenon to explain how so many children all over the world got presents on the same night! The story had been getting pretty complicated – it was getting out of hand.

If there is something very slightly wrong in our definition of the theories, then the full mathematical rigor may convert these errors into ridiculous conclusions.

But there is nothing in biology yet found that indicates the inevitability of death.

There in wine is found the great generalization: all life is fermentation.

To test whether you have learned an idea or a definition, rephrase what you just learned without using the new word.

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

There is no authority who decides what is a good idea.

We’ve learned from experience that the truth will come out.

I don’t believe I can really do without teaching. The reason is, I have to have something so that when I don’t have any ideas and I’m not getting anywhere, I can say to myself, “At least I’m living; at least I’m doing something. I’m making some contribution.” It’s just psychological.

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

There is a computer disease that anybody who works with computers knows about. It’s a very serious disease and it interferes completely with the work. The trouble with computers is that you ‘play’ with them!

You can’t say A is made of B or vice versa. All mass is interaction.

Scientific knowledge is an enabling power to do either good or bad – but it does not carry instructions on how to use it.

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.

The truth always turns out to be simpler than you thought.

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.

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. That is all there is to it.

Science is a way of trying not to fool yourself.

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

Nature’s imagination far surpasses our own.

The present situation in physics is as if we know chess, but we don’t know one or two rules.

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

I always do that, get into something and see how far I can go.

If we want to solve a problem that we have never solved before, we must leave the door to the unknown ajar.

No problem is too small or too trivial if we can really do something about it.

I am not interested in what today’s mathematicians find interesting.

Scientific knowledge is a body of statements of varying degrees of certainty – some most unsure, some nearly sure, none absolutely certain.

What we need is imagination, but imagination in a terrible strait-jacket.

If you don’t like it, go somewhere else, to another universe where the rules are simpler.

If I could explain it to the average person, I wouldn’t have been worth the Nobel Prize.

A poet once said, “The whole universe is in a glass of wine.” We will probably never know in what sense he meant that, for poets do not write to be understood. But it is true that if we look at a glass of wine closely enough we see the entire universe.

Nature does not care what we call it, she just keeps on doing it.

If a guy tells me the probability of failure is 1 in 100,000, I know he’s full of crap.

What did you ASK at school today?

Poets say science takes away from the beauty of the stars – mere globs of gas atoms. I, too, can see the stars on a desert night, and feel them. But do I see less or more?

It is simple, therefore it is beautiful.

Observation, reason, and experiment make up what we call the scientific method.

Learn what the rest of the world is like. The variety is worthwhile.

The same equations have the same solutions.

Mathematics is not just a language. Mathematics is a language plus reasoning.

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.

People often think I’m a faker, but I’m usually honest, in a certain way – in such a way that often nobody believes me!

Our responsibility is to do what we can, learn what we can, improve the solutions, and pass them on.

I’m going to play with physics, whenever I want to, without worrying about any importance whatsoever.

Work hard to find something that fascinates you.

Listen, I mean that from my knowledge of the world that I see around me, I think that it is much more likely that the reports of flying saucers are the results of the known irrational characteristics of terrestrial intelligence than of the unknown rational efforts of extra-terrestrial intelligence.

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.

What is not surrounded by uncertainty cannot be the truth.

If an apple was magnified to the size of the Earth, then the atoms in the apple would be approximately the size of the original apple.

Science is uncertain.

Don’t pay attention to “authorities,” think for yourself.

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

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

The thing that doesn’t fit is the thing that is most interesting.

If you have any talent, or any occupation that delights you, do it, and do it to the hilt. Don’t ask why, or what difficulties you may get into.

If it disagrees with experiment, it’s wrong.

The test of all knowledge is experiment. Experiment is the sole judge of scientific truth.

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.

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

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

If you keep proving stuff that others have done, getting confidence, increasing the complexities of your solutions – for the fun of it – then one day you’ll turn around and discover that nobody actually did that one! And that’s the way to become a computer scientist.

Everything is made of atoms.

Don’t think about what you want to be, but what you want to do. Keep up some kind of a minimum with other things so that society doesn’t stop you from doing anything at all.

Winning a Nobel Prize is no big deal, but winning it with an IQ of 124 is really something.

It appears that there are enormous differences of opinion as to the probability of a failure with loss of vehicle and of human life. The estimates range from roughly 1 in 100 to 1 in 100,000. The higher figures come from the working engineers, and the very low figures from management.

People may come along and argue philosophically that they like one better than another; but we have learned from much experience that all philosophical intuitions about what nature is going to do fail.

To develop working ideas efficiently, I try to fail as fast as I can.

Progress in science comes when experiments contradict theory.

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

Science is the belief in the ignorance of experts.

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?’

If you can’t explain something to a first year student, then you haven’t really understood

Work as hard and as much as you want to on the things you like to do the best.

The inside of a computer is as dumb as hell but it goes like mad!

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

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

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.

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!

What would happen if we could arrange the atoms one by one the way we want them?

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.

Some people think Wheeler’s gotten crazy in his later years, but he’s always been crazy.

I couldn’t claim that I was smarter than sixty-five other guys – but the average of sixty-five other guys, certainly!

You do not know anything until you have practiced.

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!

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.

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.

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

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.

I love to think. I once considered taking drugs as an attempt to better understand an altered state of mind; however, I decided not to. I didn’t want to chance ruining the machine.

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

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.

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.

No man is rich who is unsatisfied, but who wants nothing possess his heart’s desire.

The electron is a theory. But the theory is so good we can almost consider them real.

All mass is interaction.

It turns out that all life is interconnected with all other life.

I have the advantage of having found out how hard it is to get to really know something. How careful you have to be about checking your experiments. How easy it is to make mistakes and fool yourself. I know what it means to know something.

There is nothing in biology yet found that indicates the inevitability of death. This suggests to me that it is not at all inevitable and that it is only a matter of time before biologists discover what it is that is causing us the trouble.

You see, I get so much fun out of thinking that I don’t want to destroy this pleasant machine that makes life such a big kick.

Victory usually goes to those green enough to underestimate the monumental hurdles they are facing.

Today’s brains are yesterday’s mashed potatoes.

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.

We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt.

Know your place in the world and evaluate yourself fairly, not in terms of the naive ideals of your own youth, nor in terms of what you erroneously imagine your teacher’s ideals are.

Precise language is not the problem. Clear language is the problem.

I think nature’s imagination Is so much greater than man’s, she’s never going to let us relax.

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

The easiest person to fool is yourself.

All theoretical chemistry is really physics; and all theoretical chemists know it.

But logic is not all, one needs one’s heart to follow an idea.

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.

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.

Turbulence is the most important unsolved problem of classical physics.