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!

chapter 2, “The Relation of Mathematics to Physics” referring to the law of conservation of angular momentum, 1965

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

chapter 1, “The Law of Gravitation,” p. 27: video, 1965

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.

chapter 2, “The Relation of Mathematics to Physics”, 1965

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.

chapter 2, “The Relation of Mathematics to Physics,” p. 58, 1965

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.

statement after an introduction mentioning that he played bongo drums; Messenger Lectures at Cornell University, p. 13, 1965

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.

chapter 1, “The Law of Gravitation,” p. 13: video, 1965

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.

chapter 1, “The Law of Gravitation,” p. 15: video, 1965

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

statement (c. 1965), quoted in "An irreverent best-seller by Nobel laureate Richard Feynman gives nerds a good name", People Magazine (22 July 1985), 1965

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.

chapter 3, “The Great Conservation Principles,” p. 75, 1965

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.

volume I; lecture 1, "Atoms in Motion"; section 1-2, "Matter is made of atoms"; p. 1-3, 1964

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

volume I; lecture 46, "Ratchet and Pawl"; section 46-5, "Order and entropy"; p. 46-8, 1964

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.

volume II; lecture 26, "Lorentz Transformations of the Fields"; section 26-1, "The four-potential of a moving charge"; p. 26-2, 1964

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.

volume I; lecture 4, "Conservation of Energy"; section 4-1, "What is energy?"; p. 4-2, 1964

It requires a much higher degree of imagination to understand the electromagnetic field than to understand invisible angels. ... I speak of the E and B 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.

volume II; lecture 20, "Solution of Maxwell's Equations in Free Space"; section 20-3, "Scientific imagination"; p. 20-9 to 20-10, 1964

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

Reflecting on the failure of his presentation at the "Pocono Conference" of 30 March - 1 April 1948., 1948