system
Given the following post, respond as if you're commenting on Reddit:
human
I've read mention in particle physics that the spin of elementary particles is more abstract than actual "spin." Can someone explain this to me?
gpt
The "spin" of a big, classical object like the earth is the angular momentum from its *rotation*, as opposed to its *revolving* around the sun (i.e. the orbital angular momentum). The total angular momentum of any classical body is the sum of its spin and its orbital angular momentum.

Point particles act like they can have spin angular momentum, even though they are to be regarded as points with no size. If particles have no size, then *what* exactly is rotating or spinning?

The better way to think about this, therefore, is that the spin angular momentum of a particle is not to be interpreted as *something* spinning, but rather an intrinsic property of the particle, similar to its mass or charge.