If an apple was magnified to the size of the Earth, then the atoms in the apple would be approximately the size of the original apple.

I am going to tell you what nature behaves like. If you will simply admit that maybe she does behave like this, you will find her a delightful, entrancing thing. Do not keep saying to yourself, if you can possibly avoid it, 'But how can it be like that?' ...Nobody knows how it can be like that.

The test of all knowledge is experiment. Experiment is the sole judge of scientific truth.

Scientific knowledge is a body of statements of varying degrees of certainty -- some most unsure, some nearly sure, none absolutely certain.

Turbulence is the most important unsolved problem of classical physics.

Don't worry about anything. Go out and have a good time.

To guess what to keep and what to throw away takes considerable skill. Actually it is probably merely a matter of luck, but it looks as if it takes considerable skill.