"Space is like a jungle—sometimes you get what you want, and sometimes you get eaten."

"Crash programs fail because they are based on the theory that, with nine women pregnant, you can get a baby a month."

"We will reach for the stars, and we will find them."

"Not joining [the Nazi Party] would have meant that I would have had to abandon the work of my life."

"Science does not have a moral dimension. It is like a knife. If you give it to a surgeon or a murderer, each will use it differently."