Do protons and muons and neutrons or other particles have spin? Why or why not?
Every elementary particle has a characteristic spin property, and composite particles have total spins which are the sum of their constituent spins (where the sum is done in the weird quantum mechanical way we discussed today). You can consider these spin values to be experimentally measured properties. Protons and neutrons have spin 1/2, which comes from the sum of constituent spins. Muons, which are in almost every way like electrons except for mass, also have spin 1/2.
