Richard P. Feynman

Quotes

1. 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.

   p. 14

2. 

   Nature's imagination far surpasses our own.

   p. 162

3. 

   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.

   p. 58

4. 

   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.

   p. 15

5. 

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

   p. 34

6. 

   So we have these wide principles which sweep across all the different laws, and if one takes too seriously its derivations, and feels that this is only valid because this [assumed more fundamental principle] is valid, you cannot understand the interconnections of the different branches of physics. Some day, when physics is complete, then maybe with this kind of argument we'll know all the laws, then we can start with some axioms (and no doubt somebody will figure out a particular way of doing it) and then all the deductions will be made. But while we don't know all the laws, we can use some to make guesses at theorems which extend beyond the proof.

7. 

   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.)

   p. 129

8. 

   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.

   p. 127

9. 

   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!

10. 

    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.

    p. 15

11. 

    One of the most important things in this 'guess — compute consequences — compare with experiment' business is to know when you are right. It is possible to know when you are right way ahead of checking all the consequences. You can recognize truth by its beauty and simplicity. It is always easy when you have made a guess, and done two or three little calculations to make sure that it is not obviously wrong, to know that it is right. When you get it right, it is obvious that it is right — at least if you have any experience — because usually what happens is that more comes out than goes in. Your guess is, in fact, that something is very simple. If you cannot see immediately that it is wrong, and it is simpler than it was before, then it is right. The inexperienced, the crackpots, and people like that, make guesses that are simple, but you can immediately see that they are wrong, so that does not count. Others, the inexperienced students, make guesses that are very complicated, and it sort of looks as if it is all right, but I know it is not true because the truth always turns out to be simpler than you thought.

    p. 171

12. 

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

    p. 129