The game I play is a very interesting one. It's imagination in a straightjacket, which is this: that it has to agree with the known laws of physics. ... It requires imagination to think of what's possible, and then it requires an analysis back, checking to see whether it fits, whether its allowed, according to what's known, okay?
Richard P. FeynmanThe present situation in physics is as if we know chess, but we don't know one or two rules.
Richard P. FeynmanThe electron is a theory. But the theory is so good we can almost consider them real.
Richard P. Feynman