The Great Singularity Circle Jerk

Strip the empirical claim to what has actually been measured, and the inventory is short. Stars orbit something dark and very massive at the center of our galaxy; we have tracked S2's twenty-year ellipse around Sagittarius A* and can fit its motion to general relativity, within a few percentage points. X-ray binaries throughout the disk emit spectra consistent with accretion onto compact, gravitationally deep objects whose mass functions exceed any neutron-star upper limit. Gravitational-wave detectors record the chirps of two such compact objects spiraling together, and the resulting waveforms agree with numerical-relativity templates built from a vacuum solution of Einstein's equations called the Kerr metric. The Event Horizon Telescope, a planet-scale interferometer operating at 230 gigahertz, has imaged the immediate vicinity of M87* and Sagittarius A* and produced rings of emission whose diameters are consistent with what the Kerr exterior predicts. That is the entire empirical content. Compact dark masses with near-Kerr exterior geometry, observed across four independent channels, in approximate agreement with the same family of solutions. Everything else, every claim about event horizons as one-way membranes you can cross but never return from, every assertion about singularities of infinite density at the center, every paragraph in every popular science book about Hawking radiation and the information paradox, every theoretical edifice of complementarity and firewalls and ER=EPR and replica wormholes and the Page curve, sits past the empirical anchor. None of it has astrophysical observational contact. None of it is implied by what we have measured. All of it depends on extrapolating the same vacuum solution into regimes where the equations themselves break down and then treating the breakdown as the content of the breakdown rather than as the signal of the model's reach being exceeded.