Re: could not electron spin cause magnitism

Yes, electron spins definitely do cause magnetic fields.  In fact this is
what happens in an ordinary magnet.  If you have ever held two magnets
together (in the right orientation) you will have noticed that they do
attract and that bigger magnets do indeed attract more strongly than
smaller ones.  Why doesn't everything attract that way?  There are two
reasons.  First in many materials, half the electrons point up and half
point down, so the spin forces cancel each other out.  Second even when 
the electrons don't cancel each other out in each atom, their directions
are randomized by thermal motion, and the net force tends to zero.  It is
only in special materials where there are additional chemical forces which
tend to align nearby electrons in the same directions, that the force
of magnetism can avoid being randomized by thermal forces, and you
see macroscopic effects.