you probably wont like this, i certainly don't.
because of the Stern-Gerlach experiment in which a beam of silver atoms was split into two beams by an inhomogeneous magnetic field the quantization of the projecton of angular momentum in the direction of the magnetic field was demonstrated. if the quantum number L=0 the number of beams expected would be one and if L=1 the number of beams expected would be three. but the experiment revealed two beams. the solution was to set the silver atoms orbital angular momentum to zero and say that an electon could have a magnetic moment corresponding to an angular momentum equal to 1/2h where h=plancs constant. this is what is refered to as electron spin even though the notion of an electron as a spinning charged sphere is not totaly realistic.
the possesion of angular momentum is an instrinsic property of electrons like its charge is.
the property of spin in the case of electrons becomes important with respect to the Pauli Exclusion principle. essentialy two electrons that have the same spin may not share the same electron orbital. one needs to be spin up and ther other needs to be spin down.
the whole matter gets more complicated when you get into intrinsic spin....

regards tim

• Photons are easier to understand - yanniru - March 7, 2003 - 06:31 UTC
  • spin axis for photon - sagefr0g - March 8, 2003 - 03:14 UTC