I am firmly convinced that quantum mechanics is directly related to electromagnetism. Also I am reading Luis de la Peña and Ana María Cetto ‘s 2015 book The Emerging Quantum. With regards to Stochastic Electrodynamics (SED) I guess you could put me one more step into the mix – as I think that electrodynamics arises from pure geometry. From that point SED generates quantum mechanics.
In this two page paper, I look at how the relationship between the dimensions of a Kerr singularity and the strength of the electric Coulomb effect compare. The size (or rather ratio) of the Kerr ring singularity is exactly equal to the ratio of the electric to gravitational force between two electrons! Thus a number which is thought to be of electromagnetic origin can be determined by general relativity only.
Its a PDF: (also posted at ResearchGate)
Andersen, T. C. on ORCID
General Relativity 