# Spin 1/2 particles

1. Jun 17, 2004

### Alkatran

Well, I just read about particles which you have to spin around twice to get back to their original form (If you spin it 360 degrees it won't be the same...)

Now, this is sortof counter-intuitive so I need a bit of clarification. The closest I could get to explaining this in my mind was a mobeus strip (a ring with one half-twist it, making the inside the outside...) since, if you spin it once, technicly you are now looking at the other side of it. Is this the right path to be thinking down?

2. Jun 17, 2004

### geistkiesel

Spin 1/2 means simply the aprticle entering an inhomogeneous magnetic field along the y-axis will be observed to move up or down along the z-axis.This is the proverbial "coin flip". Spin is something of a misnomer and a carry over from classical considerations that spinning electric charges, or orbiting electric charges were the "spin" that induces the magnetic monopoles that give rise to the induced motion in the z axis. The induced motion, the quantum motion if you will is purely a magnetic effec. The reason it is +1/2 and -1/2 is that the difference in spin is 1, which has implications regarding spin angular momentum. Spin 1 particle have three possible state, +1, +- (0) and -1, where again the difference in 'spin' between states is 1.
To answer yopu question regarding 'spin' particles, is NO.

3. Jun 17, 2004

### Antonio Lao

A half-twist or 180 degrees twist of a Moebius strip formed a one-sided surface. If you cut thru the middle of the strip you get a narrower ring but longer circumference. I think, the larger ring might still be one-sided. But a 360 degrees twist formed back a two-sided surface with a complete cycle. If cut thru the middle, two rings is formed that are linked together. This is the topology that I am using in my research of describing the local structure of spacetime.

4. Jun 17, 2004

### Alkatran

I knew what the strip was, that's why i was trying to use it as an explanation.

5. Jun 17, 2004

### Antonio Lao

Maybe you can help me understand more about what other topologies there are in multiple twists of Moebius strip?

If I assumed two topologies for the fully twisted strip, I can used one topology to represent 1/2 integer spin particles (fermions) and the other topology for integral spin particles (bosons). I could even come up with a method of calculating the mass ratio among the particles. Furthermore, by the use of matrices, the calculation for charge and mass is very much simplified. I don't have to solve any equation like Schroedinger's or of Dirac's or any other.