Is a mobius strip spin 1/2 object?

[Sammywu]

Remember Phiysicist always say electron has a spin of 1/2; I can't remember how it was derived?

But I noticed a mobius strip exihibit interesting attribute. Can we consider a mobius strip a spin 1/2 object?

 

[mathman]

Electron spin 1/2 is an intrinsic quantum theory property. A mobius strip is a twisted piece of paper - it has nothing to do with quantum teory.

 

[GRQC]

Originally posted by mathman
Electron spin 1/2 is an intrinsic quantum theory property. A mobius strip is a twisted piece of paper - it has nothing to do with quantum teory.

Well, a mobius strip is a non-orientable manifold, not a "twisted piece of paper". The obvious "connection" between the orientation of a unit normal vector on a mobius strip and 2-spinors (the representations of angular momentum states) is that they both require rotations of 4\pi to regain their original orientation.

So, mobius strip normal orientation and spinor rotations aren't that different.

Shouldn't this discussion be in the Quantum Physics subforum?

 

[Mike H]

As has been mentioned by many people before us, the entire spin-1/2 business falls out of relativistic Q.M.

The Mobius strip property is an analogy that is used in discussions of spin, at least pedagogically - I remember it being mentioned in undergraduate Q.M., as well as in the ever so delightful Principles of Magnetic Resonance by C.P. Slichter. It's intended to serve as a useful first step to understanding rotations.

 

[Sammywu]

I thought my high school Physics teacher already showed us the spin 1/2 of electrons by examining its angular momentum against its light absortion spectrum.

That's why I thought this could be put in here as all it involves is rotation and angular momentum.

What you told me now is that the electrons' spins are more likely a QM quantity not related to a classical anugular rotation. I am not familiar with the modern QM at all. But didn't this spin 1/2 come originally from applying classical theory to the spectrum?