Hi, a fairly quick question. I'm reading Bruce Schumm's book "Deep Down Things" and he says that in SU(2) you have to rotate by 720 degrees to return to your starting point. This is clearly the same definition as a spinor. My question is, then, does rotation in SU(2) automatically imply the rotation of a spinor? Or is a spinor a special case of a rotation in SU(2)? Any help much appreciated.