Spin Inversion Symmetry (SIS)
SIS says every elementary particle in the Standard Model (except for the Higgs) of spin s has a partner of spin 1/s. It also applies to the hypothetical Graviton.
I have no theoretical justification for SIS, but I do have a rather amusing story of how I came up with it.
I was imagining how you might model a spin 1/2 elementary particle with an everyday object. After a bit of thought I decided on a Mobius strip (strip of paper joined after applying 1 half turn). I figured 1 half turn = spin 1/2.
Then I made a strip with 4 half turns and discovered something rather elegant.. it will naturally "flip" into a double thickness Mobius strip.
In other words a strip with 4 half turns (spin 2) naturally flips into a strip with 1 half turn (spin 1/2).
That's a Boson to Fermion transition. Think of space time (a Boson spin 2 structure) "condensing" into spin 1/2 Fermions.
It explains why every elementary matter particle has spin 1/2. They have no choice!
So there you have it - a desktop version of SIS. All you need is paper, scissors, a touch of glue, and a vivid imagination!
Content written and posted by Ken Abbott firstname.lastname@example.org