Sidney Coleman

"Not only God knows, I know, and by the end of the semester, you will know."

"People get a lot of confusion, because they keep trying to think of quantum mechanics as classical mechanics"

"Every successful physical theory swallows its predecessor alive. But it does so by interpreting the concepts of the old theory in terms of the new, not the other way around. Thus our aim is not "the interpretation of quantum mechanics." It is the interpretation of classical mechanics."

"The career of a young theoretical physicist consists of treating the harmonic oscillator in ever-increasing levels of abstraction."

"Sidney Coleman was not only a leader in theoretical particle physics, but also a hugely gifted and dedicated teacher. In his courses he found just the right balance between rigor and intuition, enlivened by wit, humor and a deep store of anecdotes about the history of physics. Very often these were first-hand accounts; if he wasn't a participant, he was an eyewitness."

"If you haven't read his Erice Lectures, you don't know the heights that scientific writing can attain."

"Steve Weinberg was giving the gauge seminar one Wednesday and was, as I recall nearly finished or just finishing his talk. Sidney had not arrived. So-Young Pi asked Steve a question and Steve replied (as I recall) “That’s a good question. I don’t know the answer; I haven’t thought about it.” At that exact instant Sidney enters the room, hears Steve’s reply, heads for the coffee pot, and says “I know the answer; what’s the question?” He was told the question, and he answered it. (Correctly, of course.)"