Know your place in the world and evaluate yourself fairly, not in terms of the naïve ideals of your own youth, nor in terms of what you erroneously imagine your teacher's ideals are.

There’s so much distance between the fundamental rules and the final phenomenon, that it’s almost unbelievable that the final variety of phenomenon can come from such a steady operation of such simple rules.

There are 10^11 stars in the galaxy. That used to be a huge number. But it's only a hundred billion. It's less than the national deficit! We used to call them astronomical numbers. Now we should call them economical numbers.

Science is uncertain.

To develop working ideas efficiently, I try to fail as fast as I can.

So this piece of dirt waits four and a half billion years and evolves and changes, and now a strange creature stands here with instruments and talks to the strange creatures in the audience. What a wonderful world!

There is enough energy in a single cubic meter of space to boil all the oceans in the world.