**Spin Inversion Symmetry (SIS)**

SIS is a conjecture I made about elementary particle physics. It says every elementary particle in the Standard Model (except for the Higgs) of spin s has a partner of spin 1/s.

So the bosons (spin 1) in the Standard Model are their own partner, but the fermions (spin 1/2) in the Standard Model have spin 2 partners.

Of course, for this to work we need at least one spin 2 particle. Maybe more. So gravity appears automatically.

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 gravity (a Boson spin 2 structure) "condensing" into spin 1/2 Fermions.

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 abbottsystems@gmail.com