All the evidence, experimental and even a little theoretical, seems to indicate that it is the energy content which is involved in gravitation, and therefore, since matter and antimatter both represent positive energies, gravitation makes no distinction.

— Richard P. Feynman

Einstein's gravitational theory, which is said to be the greatest single achievement of theoretical physics, resulted in beautiful relations connecting gravitational phenomena with the geometry of space; this was an exciting idea.

— Richard P. Feynman

For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.

— Richard P. Feynman

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 P. Feynman

If you realize all the time what's kind of wonderful - that is, if we expand our experience into wilder and wilder regions of experience - every once in a while, we have these integrations when everything's pulled together into a unification, in which it turns out to be simpler than it looked before.

— Richard P. Feynman

I practiced drawing all the time and became very interested in it. If I was at a meeting that wasn't getting anywhere - like the one where Carl Rogers came to Caltech to discuss with us whether Caltech should develop a psychology department - I would draw the other people.

— Richard P. Feynman

I think that when we know that we actually do live in uncertainty, then we ought to admit it; it is of great value to realize that we do not know the answers to different questions. This attitude of mind - this attitude of uncertainty - is vital to the scientist, and it is this attitude of mind which the student must first acquire.

— Richard P. Feynman

I thought one should have the attitude of 'What do you care what other people think!'

— Richard P. Feynman

It is in the admission of ignorance and the admission of uncertainty that there is a hope for the continuous motion of human beings in some direction that doesn't get confined, permanently blocked, as it has so many times before in various periods in the history of man.

— Richard P. Feynman

I was born not knowing and have had only a little time to change that here and there.

— Richard P. Feynman