My experience has been in a short 77 years that in the end when you fight for a desperate cause and have good reasons to fight, you usually win.

Really exotic methods of propulsion . . . will have to be devised to get there. How it will be done, I do not know. Whether it will be done, I am not quite certain. But I would bet it can be done.

When Columbus took off, the purpose was to improve trade relations with China. That problem has not been solved to this very day, but just look at the by-products.

It is often claimed that knowledge multiplies so rapidly that nobody can follow it. I believe this is incorrect. At least in science it is not true. The main purpose of science is simplicity and as we understand more things, everything is becoming simpler. This, of course, goes contrary to what everyone accepts.

Physics without mathematics is meaningless.

A fact is a simple statement that everyone believes. It is innocent, unless found guilty. A hypothesis is a novel suggestion that no one wants to believe. It is guilty, until found effective.

The best weapon of a dictatorship is secrecy; the best weapon of a democracy is openness.