Googling around, I see people saying that water takes the steepest path downhill. Of course, this is just an approximation. Things like inertia, friction, etc. will cause deviations. I’m curious about why this is a good approximation to begin with. Are there a collection of hypotheses we can make...

I have a question concerning exactly how we get to the following two conclusions in quantum mechanics (which are both experimentally obtained as I understand it): Identical particles are indistinduishable All wave functions of identical particles are either symmetric or antisymmetric I believe ...