A poet once said, "The whole universe is in a glass of wine." We will probably never know in what sense he meant that, for poets do not write to be understood... How vivid is the claret, pressing its existence into the consciousness that watches it! If our small minds, for some convenience, divide this glass of wine, this universe, into parts - physics, biology, geology, astronomy, psychology, and so on - remember that nature does not know it! So let us put it all back together, not forgetting ultimately what it is for. Let it give us one more final pleasure: drink it and forget it all!

The present situation in physics is as if we know chess, but we don't know one or two rules.

Only realistic flight schedules should be proposed, schedules that have a reasonable chance of being met. If in this way the government would not support them, then so be it. NASA owes it to the citizens from whom it asks support to be frank, honest, and informative.

Nature does not care what we call it, she just keeps on doing it.

The first principle is that you must not fool yourself and you are the easiest person to fool.

I think it's much more interesting to live not knowing than to have answers which might be wrong.

Victory usually goes to those green enough to underestimate the monumental hurdles they are facing.