"You see, wire telegraph is a kind of a very, very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Do you understand this? And radio operates exactly the same way: you send signals here, they receive them there. The only difference is that there is no cat."
"Two things are infinite: the universe and human stupidity; and I'm not sure about the universe."
"Any fool can know. The point is to understand."
"One thing I have learned in a long life: that all our science, measured against reality, is primitive and childlike -- and yet it is the most precious thing we have."
"A question that sometimes drives me hazy: am I or are the others crazy?"
"I never made one of my discoveries through the process of rational thinking"