But where the heck is the spinor?? Hi lads, I've been reading the other thread "...intrinsic vs orbital angular momentum..." which talks about spinors, r x p, etc, etc. It mentioned ch41 of Misner, Thorne & Wheeler's "Gravitation" book. I've studied all the math there quite thoroughly, no problems with that. But seems like something's missing... In Fig 41.6 on p1149 (the one with two concentric spheres, - the inner sphere connected to the outer by threads, which you're then supposed to twist through 2pi or 4pi, and contort the inner sphere around to show whether you can/can't untwist the threads using only translations of the inner sphere). OK,... yeah, I get it. I've done the related "Dirac belt" thing, and I get that 2pi rotation ain't necessarily the same as 4pi. But where the heck is the actual spinor in MTW's diagram?? Later in the chapter MTW rave on about poles and flags, but isn't that just a combination of a 4-vector and a bivector? Where is the spinor in "flag+pole"??. If I rotate the flag about its axis through 2pi, the flag returns to its original appearance and I don't see anything spinor-like until I start trying to move the pole around (as if the pole was elastic). So I still have no clue where the spinor is in MTW's diagram. Should I be thinking instead of an army of tiny flags all the way along an elastic flagpole? (That way, rotating only one end of the pole through 2pi/4pi leaves obviously different orientations of the flags all the way along the pole, and it's more obvious that all this 2pi-4pi monkey business has something to do with rotation "here" without a matching rotation at "infinity".) LOL, Neuropulp.