But I don't understand what they mean by spin, momentum, axis, etc. That is, how do you measure for such? What do these qualities "look like" in an experiment?
What do quarks look like? What does a charm quark look like as opposed to other quarks? What does a muon or boson or whatnot look like? How do you tell them apart?
I've not yet found a sufficiently dummied down book to take me by the nose and explain it step-by-step.
I read Alice in Quantumland, and it wasn't an easy read.
It gets even better. Quantification requires observation. Observation changes results. What you see is not what you get.
“How do you tell them apart?”
You already answered that...Mass, charge, momentum, spin, color, and whatever else I can’t remember because it’s too late.