Why Quantum Mechanics Is Weird and Why That’s OK

This is an honors course for non-physics majors and majors alike. It will require knowledge of mathematics at the level of solving linear algebraic equations in two variables and a lack of fear when being told that that corresponds to doing “linear operations” and can be written in terms of “matrices”. Those concepts will be explained in the class. The class will also explain the basic ideas of probability theory, which are at the heart of quantum mechanics. Indeed, all of the
“weirdness” of quantum mechanics consists of the fact that the “intuitively obvious” statement that “the probability of going from A to B in time t is equal to the sum of the probabilities of going from A to B in time t through all possible paths that could have taken you from A to B in time t” is WRONG. We’ll explain why it’s wrong in a completely consistent mathematical definition of “quantum probability” and then why it’s true to an incredibly good approximation for anything made of a lot of atoms in a typical state. That’s the reason it seems intuitively obvious to us. We’ll then outline how quantum ideas underly our understanding of atoms, molecules, atomic nuclei, the elementary constituents of atomic nuclei and so on. On the way, we’ll debunk certain silly ideas about QM that have been popularized by philosophers and novelists (see the current Apple+ series Dark Matter for example).