Black hole electrons are supposed to match all the observable of quantum-electrodynamics (QED) electrons completely; if they don't, then you have something othe

Black hole electrons are supposed to match all the observable of quantum-electrodynamics (QED) electrons completely; if they don't, then you have something other than a "black hole electron". Moreover, the idea is not to substitute some QED electrons with black hole electrons, but that all electrons are charged spinning black holes. If that breaks chemistry, it also breaks the idea of black hole electrons. The original (1938) idea behind black hole electrons was mainly to simply some of the calculations of charges moving in curved spacetime (computers not being available yet), before the development of quantum electrodynamics (1965 Nobel prize in physics), and before the development of an exact analytical solution to the Einstein Field Equations (of General Relativity) for spinning black holes (1963, and 1965 for spinning with electric charge). In particular, they wanted to understand how electromagnetic interactions could change the trajectories of charged particles in both an electromagnetic and gravitational field (and conversely, how the mass of an electron affects the development of an uncharged cloud of gas around it). Einstein and his 1938 coauthors certainly knew some things about electrons, and in particular that they have intrinsic angular momentum (Stern-Gerlach experiment in 1921). Knowing how many details had to be minimized or even ignored in their ease-of-calculation approach, they were surprised it worked as well as it seemed to. "Ease" here is compared to what they thought they would have to work with. Here's their very-much-not-easy paper: <https://sci-hub.se/https://www.jstor.org/stable/1968714?origin=crossref https://sci-hub.se/https://www.jstor.org/stable/1968714?orig...>. That surprising "why does this work at all?" (it doesn't work especially well) is sometimes thought-provoking, but attempts to formalize the idea that fundamental particles are geometrical (black holes are a feature of spacetime geometry, so a black hole electron must be mostly geometrical) rather than excitations in quantum fields have rarely made progress. In general, the attempts that have come closest to reproducing successes of quantum field theory have had the most difficult to calculate equations.