"The problem of making a nuclear reactor is not a problem of physics, but a problem of engineering."

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

"The greatest tragedy of science is the slaying of a beautiful hypothesis by an ugly fact."

"Ignorance is never better than knowledge."

"It is not possible that such a small difference in the atomic weights of hydrogen and helium could have such tremendous consequences."