Richard Feynman

I... a universe of atoms, an atom in the universe.

The scientist has a lot of experience with ignorance and doubt and uncertainty, and this experience is of very great importance, I think. When a scientist doesn__ know the answer to a problem, he is ignorant. When he has a hunch as to what the result is, he is uncertain. And when he is pretty damn sure of what the result is going to be, he is still in some doubt. We have found it of paramount importance that in order to progress, we must recognize our ignorance and leave room for doubt. Scientific knowledge is a body of statements of varying degrees of certainty _ some most unsure, some nearly sure, but none absolutely certain. Now, we scientists are used to this, and we take it for granted that it is perfectly consistent to be unsure, that it is possible to live and not know. But I don__ know whether everyone realizes this is true. Our freedom to doubt was born out of a struggle against authority in the early days of science. It was a very deep and strong struggle: permit us to question _ to doubt _ to not be sure. I think that it is important that we do not forget this struggle and thus perhaps lose what we have gained.

But there is nothing in biology yet found that indicates the inevitability of death.

I noticed that the [drawing] teacher didn't tell people much... Instead, he tried to inspire us to experiment with new approaches. I thought of how we teach physics: We have so many techniques - so many mathematical methods - that we never stop telling the students how to do things. On the other hand, the drawing teacher is afraid to tell you anything. If your lines are very heavy, the teacher can't say, "Your lines are too heavy." because *some* artist has figured out a way of making great pictures using heavy lines. The teacher doesn't want to push you in some particular direction. So the drawing teacher has this problem of communicating how to draw by osmosis and not by instruction, while the physics teacher has the problem of always teaching techniques, rather than the spirit, of how to go about solving physical problems.

This is not a new idea; this is the idea of the age of reason. This is the philosophy that guided the men that made the democracy that we live under. The idea that no one really knew how to run a government led to the idea that we should arrange a system by which new ideas could be developed, tried out, and tossed out if necessary, with more new ideas brought in__ trial and error system.

I took a little walk outside for a while. I was surprised that I wasn't feeling what I thought people were supposed to feel under the circumstances. May be I was fooling myself. I wasn't delighted, but I didn't feel terribly upset, perhaps because we had known for a long time that it was going to happen.It's hard to explain. If a Martian(who, we'll imagine never dies except by accident) came to Earth and saw this peculiar race of creatures-these humans who live about seventy or eighty years, knowing that death is going to come--it would look to hi like a terrible problem of psychology to live under those circumstances, knowing that life is only temporary Well, we humans somehow figure out how to live despite this problem: we laugh, we joke, we live.The only difference for me and Arlene was, instead of fifty years, it was five years. It was only a quantitative difference--the psychological problem was just the same. The only way it would have become any different is if we had said to ourselves, "But those other people have it better, because they might live fifty years." But that's crazy. Why make yourself miserable saying things like, "Why do we have such bad luck? What has God done to us? What have we done to deserve this?"--all of which, if you understand reality and take it completely into your heart, are irrelevant and unsolvable. They are just things that nobody can know. Your situation is just an accident of life..We had a hell of good time together...

You can__ say A is made of B or vice versa. All mass is interaction.

I believe, therefore, that although it is not the case today, that there may some day come a time, I should hope, when it will fully appreciated that the power of governments should be limited; that governments ought not to be empowered to decide the validity of scientific theories, that this is a ridiculous thing for them to try to do; that they are not to decide the description of history or of economic theory or of philosophy.

A few years after I gave some lectures for the freshmen at Caltech (which were published as the Feynman Lectures on Physics), I received a long letter from a feminist group. I was accused of being anti-women because of two stories: the first was a discussion of the subtleties of velocity, and involved a woman driver being stopped by a cop. There's a discussion about how fast she was going, and I had her raise valid objections to the cop's definitions of velocity. The letter said I was making the women look stupid. The other story they objected to was told by the great astronomer Arthur Eddington, who had just figured out that the stars get their power from burning hydrogen in a nuclear reaction producing helium. He recounted how, on the night after his discovery, he was sitting on a bench with his girlfriend. She said, "Look how pretty the stars shine!" To which he replied, "Yes, and right now, I'm the only man in the world who knows how they shine." He was describing a kind of wonderful loneliness you have when you make a discovery. The letter claimed that I was saying a women is incapable of understanding nuclear reactions. I figured there was no point in trying to answer their accusations in detail, so I wrote a short letter back to them: "Don't bug me, Man!

I learned from her that every woman is worriedabout her looks, no matter how beautiful she is.