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.

I thought one should have the attitude of 'What do you care what other people think!'

Things on a very small scale behave like nothing that you have any direct experience about. They do not behave like waves, they do not behave like particles, they do not behave like clouds, or billiard balls, or weights on springs, or like anything that you have ever seen.

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.

For far more marvelous is the truth than any artists of the past imagined it. Why do the poets of the present not speak of it? What men are poets who can speak of Jupiter if he were a man, but if he is an immense spinning sphere of methane and ammonia must be silent?

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

The uncertainty principle protects quantum mechanics. Heisenberg recognized that if it were possible to measure the momentum and the position simultaneously with a greater accuracy, the quantum mechanics would collapse. So he proposed that it must be impossible.

The probability of an event is always represented by a single final arrow-no matter how many arrows were drawn, multiplied, and added to achieve it.

In the Raphael Room, the secret turned out to be that only some of the paintings were made by the great master; the rest were made by students. I had liked the ones by Raphael. This was a big jab for my self-confidence in my ability to appreciate art.

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.

It is a part of the adventure of science to try to find a limitation in all directions and to stretch the human imagination as far as possible everywhere. Although at every stage it has looked as if such an activity was absurd and useless, it often turns out at least not to be useless.

He detested hierarchy and enjoyed the friendship of people in all walks of life. He was, like Shakespeare, an actor with a talent for comedy.

In talking about the impact of ideas in one field on ideas in another field, one is always apt to make a fool of oneself.

The students had, for example, a special ceremony in which they granted each Nobel-Prize-winner the special Order of the Frog. When you get this little frog, you have to make a frog noise.

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

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.

With the exception of gravitation and radioactivity, all of the phenomena known to physicists and chemists in 1911 have their ultimate explanation in the laws of quantum electrodynamics.

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.

I did that once when I was a student at MIT. I got sick and tired of having to decide what kind of dessert I was going to have at the restaurant, so I decided it would always be chocolate ice cream, and never worried about it again—I had the solution to that problem.

There are other conservation laws. They are not as interesting as those I have described, and do not deal exactly with the conservation of numbers. Suppose.

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

To every man is given the key to Heaven. The same key opens the gates of Hell.

You just have to know what the right laws are under the right circumstances, and design the device with the correct laws. You cannot expect old designs to work in new circumstances. But new designs can work in new circumstances...

You might say that the only reason for the anti-neutrino is to make the conservation of energy right. But it makes a lot of other things right, like the conservation of momentum and other conservation laws, and very recently it has been directly demonstrated that such neutrinos do indeed exist.

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 nineteenth century will be judged as Maxwell's discovery of the laws of electro dynamics.

When I would hear the rabbi tell about some miracle such as a bush whose leaves were shaking but there wasn't any wind, I would try to fit the miracle into the real world and explain it in terms of natural phenomena.

Thus 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 size.

Professor Feynman? Hey! Why are you bothering me at this time in the morning? I thought you'd like to know that you've won the Nobel Prize. Yeah, but I'm sleeping! It would have been better if you had called me in the morning.—and I hung up. My wife said, Who was that? They told me I won the Nobel Prize.

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?

I think it's much more interesting to live not knowing than to have answers which might be wrong. [...] I don't have to know an answer. I don't feel frightened not knowing things, by being lost in a mysterious universe without any purpose, which is the way it really is, as far as I can tell.

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.

The female mind is capable of understanding analytic geometry... 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.

Physics is to mathematics like sex is to masturbation.

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.

Nobody ever figures out what life is all about, and it doesn't matter. Explore the world. Nearly everything is really interesting if you go into it deeply enough.

The worthwhile problems are the ones you can really solve or help solve, the ones you can really contribute something to.... No problem is too small or too trivial if we can really do something about it.

How you get to know is what I want to know.

That's the trouble with not being in your own field: You don't take it seriously.

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

I was terrible in English. I couldn't stand the subject. It seemed to me ridiculous to worry about whether you spelled something wrong or not, because English spelling is just a human convention--it has nothing to do with anything real, anything from nature. Any word can be spelled just as well a different way.

At first it appears as if the law of conservation is false, but energy has the tendency to hide from us and we need thermometers and other instruments to make sure that it is still there.

Finally, I said that I couldn't see how anyone could be educated by this self-propagating system in which people pass exams, and teach others to pass exams, but nobody knows anything.

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.

My rule is, when you are unhappy, think about it. But when you're unhappy, don't. Why spoil it? You're probably happy for some ridiculous reason and you'd just spoil it to know it.

Today we say that the law of relativity is supposed to be true at all energies, but someday somebody may come along and say how stupid we were.

This is water vapor, which is always found above liquid water. (There is an equilibrium between the steam vapor and the water which will be described later.) In.

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.

In any decision for action, when you have to make up your mind what to do, there is always a 'should' involved, and this cannot be worked out from, 'If I do this, what will happen?' alone.

What Do You Care What Other People Think?