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Richard Feynman

230 quotes

“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“If we have confidence in a law, then if something appears to be wrong it can suggest to us another phenomenon.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“It is impossible, by the way, when picking one example of anything, to avoid picking one which is atypical in some sense.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“[T]he total amount that a physicist knows is very little. He has only to remember the rules to get him from one place to another...”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“chapter 2, “The Relation of Mathematics to Physics,” p. 58; video”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“I think I can safely say that nobody understands quantum mechanics.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“Nature's imagination far surpasses our own.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“That was the beginning and the idea seemed so obvious to me that I fell deeply in love with it. And, like falling in love with a woman, it is only possible if you don't know too much about her, so you cannot see her faults. The faults will become apparent later, but after the love is strong enough to hold you to her. So, I was held to this theory, in spite of all the difficulties, by my youthful enthusiasm.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“I don't know about philosophy of Mayans. We have very little information due to the efficiency of the Spanish es and... mostly their priests, who burned all the books... hundreds of thousands of books, and there's three left... [O]ne of them has this Venus calculation... Just imagine our civilization reduced to three books... left by accident.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“That's called monochromatic light, light of one color. ...I'm going to discuss all my phenomena for a while with light of one color, because it's simpler”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“If we make an instrument that can detect light, that's as sensitive as it can possibly be made. ...This ...is called a photomultiplier.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“The probability of an event is always... the square of an amplitude... the size [area] of a circle corresponding to an arrow. An arrow is called an amplitude. For every event you calculate an amplitude (which is an arrow on a plane). The probability is the area corresponding to that arrow.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“[T]his rule explains several of the ordinary phenomena... such as angle of incidence equals angle of reflection, and , that light bends... from air to water, and travels in straight lines... It's all hidden in that one rule.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“The idea of quantum mechanics that I want to describe now is a positive thing. It's a way that we actually use to make calculations and understand nature. Excuse me, to make calculations! We really don't understand it very well... Understanding real nature, we are unable to do.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“What I would like to do now... is to... try to tell you what actually what physicists do when they make calculations, so they can predict... correctly the probabilities of events for all the experiments, at least in a certain range where they know some things about electrons and photons... and light and matter and chemistry and ordinary phenomena not involving gravitation in detail or nuclear phenomena in d... Well, actually today... nuclear phenomena are now probably under control too.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“The different colored light... correspond to particles of different energy, that is energy comes in lumps and these lumps have different sizes for the different colored light. [I]t was hard... virtually impossible to understand... that the reflection of light... from layers of different thicknesses varies by using particles... [T]hat makes a problem which I want to describe...”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“[T]o make it easy... we'll suppose that all the light... is exactly one color... At night... they have these yellow street lights... that's a sodium light... and that emits light all of one color... Then take the soap bubble and blow it at night.. and then you'll see the bands... [You] can take... very thin glass... you can see very thin bands, even in a reasonable size thickness... [S]uppose then that we do have light like from sodium-vapor so that all the light... is always photons of exactly the same energy. We call it monochromatic, one color light.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“There has never been a satisfactory model of the very simple process of reflection of light from thin surfaces or... for any other phenomenon. Satisfactory in the old fashioned classical view. A logical hocus-pocus has to be done quantum mechanically in order in order to describe these things... This is another example of the type of difficulty when you try to reason in a straight forward... in a classical way about a simple phenomenon.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“So there are two aspects of an amplitude. An amplitude is a sort of two dimensional thing and therefor you can represent it... on a plane as an arrow. So an amplitude is a physical thing, which also is identical, we... make it very equal by using three lines [ ≡ ] instead of two [ = ], the same as these arrows that I've been talking about on a plane, and that's, by the way, for those that know mathematics, that can be equivalent to representing everything by s. You can do it algebraically, in other words, not just by drawing the arrows.AMPLITUDE ≡ ARROW ( ≡ COMPLEX NUMBERS)”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“It is to be emphasized that no matter how many [Probability 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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“[O]ne additional problem.., which took twenty years to overcome.., has to do with ideal electrons and photons and the numbers n and j. If electrons were ideal and went... only by... direct path..: n would... be the [electron] mass.., and j its "charge" (the amplitude for the electron to couple with the photon). But no... ideal electrons exist.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“[T]he experimentally measured m, and... charge, e, of the electron are different from the numbers in our calculations, n and j.”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“When calculating terms with couplings, we must consider... all possible points... down to... two couplings... with zero distance between... [W]hen we try to calculate... down to zero distance, the equation blows up... and give meaningless answers... like infinity... [W]hen [QED]... first came out... [p]eople were getting infinity for every problem... [T]hat's where there is no n or j that makes sense...”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“[I]nstead of including all... coupling points to... distance... zero, if one stops the calculation when the distance is very small... billions of times smaller than anything observable... (presently 10-16 centimeters)... there are definite values... n and j... so the calculated mass... match the m observed... and the calculated charge matches the observed... e. ...[T]he catch: if somebody... stops the calculation at a different distance... their... n and j come out different!”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“There is a... profound.., beautiful question associated with the observed coupling constant e... the amplitude for the real electron to emit or absorb a real photon.., [and] experimentally determined... close to 0.08542455. (My physicist friends... remember it as the inverse of its square: about 137.03597... It has been a mystery... since discovered more that fifty years ago, and all good physicists... worry about it.)”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“Immediately you would like to know where this number for a coupling comes from: is it related to pi, or perhaps to the base of natural logarithms? Nobody knows. It's one of the greatest damn mysteries of physics: a magic number that comes to us with no understanding by man. You might say the "hand of God" wrote that number, and "we don't know how He pushed His pencil." We know what kind of a dance to do experimentally to measure this number very accurately, but we don't know what kind of dance to do on the computer to make this number come out — without putting it in secretly!”
Richard Feynman (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source
“[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 (1918–1988) said by 1988 at the latest wikiquote, CC BY-SA 4.0 source