Mathematics is distinguished from the sciences by the freedom it enjoys in choosing basic assumptions from which consequences can be deduced by applying the laws of logic. We call the basic ...

Measurement postulate is crucial to quantum mechanics. If we measure a quantum system, we can only get one of the eigenvalues of the measured observable, such as position, energy and so on, with a ...

I have very fond memories of high school geometry. Memorizing theorems wasn't too hard, and solving proofs was like solving the logic puzzles that I did for fun anyway. But the theorems were scattered ...