Gravity and The Standard Model
Spin Inversion Symmetry is a very simple conjecture, it says: Every elementary particle in the Standard Model (except 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.
Content written and posted by Ken Abbott email@example.com