Richard Feynman Quotes

Experiment is the sole judge of scientific “truth.” But what is the source of knowledge? Where do the laws that are to be tested come from? Experiment, itself, helps to produce these laws, in the sense that it gives us hints. But also needed is imagination to create from these hints the great generalizations — to guess at the wonderful, simple, but very strange patterns beneath them all, and then to experiment to check again whether we have made the right guess. This imagining process is so difficult that there is a division of labor in physics: 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.

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.

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.

We could, of course, use any notation we want; do not laugh at notations; invent them, they are powerful. In fact,mathematics is, to a large extent, invention of better notations.

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

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.

ONE DAY at Princeton I was sitting in the lounge and overheard some mathematicians talking about the series for ex, which is 1 + x + x2/2! + x3/3!

The questions of the students are often the source of new research. They often ask profound questions that I’ve thought about at times and then given up on, so to speak, for a while. It wouldn’t do me any harm to think about them again and see if I can go any further now. The students may not be able to see the thing I want to answer, or the subtleties I want to think about, but they remind me of a problem by asking questions in the neighborhood of that problem. It’s not so easy to remind yourself of these things.

I said, “There’s a long tradition behind life in India that comes from a religion and philosophy that is thousands of years old. And although these people are not in India, they still pass on those traditions about what’s important in life — trying to build for the future and supporting their children in the effort — which have come down to them for centuries.

Western civilization, it seems to me, stands by two great heritages. One is the scientific spirit of adventure — the adventure into the unknown, an unknown that must be recognized as unknown in order to be explored, the demand that the unanswerable mysteries of the universe remain unanswered, the attitude that all is uncertain. To summarize it: humility of the intellect.

That night, Brazilian TV audiences saw the director of the Center for Physical Research welcome the Visiting Professor from the United States, but little did they know that the subject of their conversation was finding a girl to spend the night with!

Perhaps you will not only have some appreciation of this culture; it is even possible that you may want to join in the greatest adventure that the human mind has ever begun.

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.

So our problem is to explain where symmetry comes from. Why is nature so nearly symmetrical? No one has any idea why. The only thing we might suggest is something like this: There is a gate in
Japan, a gate in Neiko, which is sometimes called by the Japanese
the most beautiful gate in all Japan; it was built in a time when
there was great influence from Chinese art. This gate is very elaborate,
with lots of gables and beautiful carving and lots of columns
and dragon heads and princes carved into the pillars, and so on.
But when one looks closely he sees that in the elaborate and complex
design along one of the pillars, one of the small design elements
is carved upside down; otherwise the thing is completely
symmetrical. If one asks why this is, the story is that it was carved
upside down so that the gods will not be jealous of the perfection
of man. So they purposely put an error in there, so that the gods
would not be jealous and get angry with human beings.
We might like to turn the idea around and think that the true
explanation of the near symmetry of nature is this: that God made
the laws only nearly symmetrical so that we should not be jealous
of His perfection!

"How can we tell whether the rules which we "guess" at are really right if we cannot analyze the game very well? There are, roughly speaking, three ways.

First, there may be situations where nature has arranged, or we arrange nature, to be simple and to have so few parts that we can predict exactly what will happen, and thus we can check how our rules work. (In one corner of the board there may be only a few chess pieces at work, and that we can figure out exactly.)

A second good way to check rules is in terms of less specific rules derived from them. For example, the rule on the move of a bishop on a chessboard is that it moves only on the diagonal. One can deduce, no matter how many moves may be made, that a certain bishop will always be on a red square. So, without being able to follow the details, we can always check our idea about the bishop's motion by finding out whether it is always on a red square. Of course it will be, for a long time, until all of a sudden we find that it is on a black square (what happened of course, is that in the meantime it was captured, another pawn crossed for queening, and it turned into a bishop on a black square). That is the way it is in physics. For a long time we will have a rule that works excellently in an over-all way, even when we cannot follow the details, and then some time we may discover a new rule. From the point of view of basic physics, the most interesting phenomena are of course in the new places, the places where the rules do not work — not the places where they do work! That is the way in which we discover new rules.

The third way to tell whether our ideas are right is relatively crude but prob-ably the most powerful of them all. That is, by rough approximation. While we may not be able to tell why Alekhine moves this particular piece, perhaps we can roughly understand that he is gathering his pieces around the king to protect it, more or less, since that is the sensible thing to do in the circumstances. In t