For the physicist or engineer, two systems that obey the same equations have a kind of identity-or at least an analogy. And that, after all, is all our word analog means. A digital watch is nothing like the sun; an analog watch is the memory of a shadow’s circuit around a dial.

— Jimmy Soni and Rob Goodman, A Mind at Play

In 1965 in a paper beautifully titled “Path, Trees and Flowers,” Edmonds developed a bit more complicated method for finding the augmenting paths in general friendship diagrams. … Edmonds goes into a long digression on the nature of an efficient algorithm. While he realizes that no formal definition can completely capture the intuitive idea of efficiency, he suggests a notion of efficiency by having a procedure that uses computation time that is “algebraic” in the size of the problem, for example, 100^4 or 100^2 or 100^12. Later this class of problems would become known as P (for “polynomial,” which replaced Edmond’s “algebraic”) and come to represent problems we can solve efficiently. That’s the P side of the P versus NP question.

— Lance Fortnow, The Golden Ticket

There’s two kinds of people in the world, those that do work and those who take credit. Keep in the first group—there’s much less competition there.

— Gerald Weinberg, Donald C. Gause and Sally Cox, Are You Lights On?

I don’t know what’s the matter with people: they don’t learn by understanding; they learn by some other way—by rote, or something. Their knowledge is so fragile!

— Richard P.Feyman, Ralph Leighton, Edward Hutchings and Albert R. Hibbs, “Surely You’re Joking, Mr. Feyman!”

Taking the time to evaluate which problem to solve is one of the best predictors I’ve found of a team’s long-term performance.

— Will Larson, An Elegant Puzzle