The origin of spin is some what a puzzle to me, everything spin from galaxies to planets to weather to electrons.
Where has all the angular momentum come from? Why is it so natural?
I was also thinking do photons spin? we always think of the wave as a standard 2d sin wave but could this rotate in 3d? What implications would this have?
And what about spacetime how does all the spinning effect?
This has always been avoided in all lectures and classes I ever went to.