New maps of the chaotic space-time inside black holes

Nature and Status of Singularities

• Several commenters object to the article’s “point of infinite density” phrasing as misleading.
• Distinction is drawn between:
  • Mathematical singularities in general relativity (where equations break down / go to infinity).
  • Physical reality, where quantum effects are expected to remove true infinities, though no complete theory exists.
• Claims that singularities are “disproven” are criticized as overstatements:
  • A recent Kerr paper is said to invalidate an earlier proof of a specific singularity, not singularities in general.
  • Both video explainers and papers are interpreted as “the classical proof is wrong,” not “singularities don’t exist.”
• Clarifications:
  • Event horizon ≠ singularity; the former is not a physical singularity and is regular in better coordinates.
  • Singularity in GR doesn’t talk about baryons/fermions; that’s quantum language.
  • From an infalling observer’s perspective, reaching the singularity takes finite proper time, even if external observers never see it happen.

What We Actually Have Evidence For

• Strong thread arguing: we only have empirical evidence for ultra-compact massive objects whose behavior matches GR black holes.
• Disagreement over whether we have direct evidence of event horizons:
  • Images (EHT) and tidal disruption events are consistent with horizons but are theory-dependent.
  • Some insist this doesn’t prove all GR features (horizons, singularities, information loss).
• Hawking radiation is discussed:
  • Standard view: emission is generated just outside the horizon; no ordinary matter or detailed information escapes.
  • Others loosely talk as if matter “passes back out,” which is challenged on information-theoretic grounds.
• A highly speculative idea of an inner “second horizon” and crystalline core is proposed and largely rejected as unevidenced.

Inside Black Holes and Coordinate Intuitions

• Lay confusion about “space and time swapping” inside a black hole is addressed:
  • This is a statement about a particular coordinate choice (Schwarzschild coordinates), not a literal physical swap.
  • Physically meaningful questions must be coordinate-invariant (geodesics, causal structure).
• Cosmologist-style explanation: locally, crossing a large black hole’s horizon feels ordinary; inside, all future-directed paths inevitably lead inward.

GR, Quantum Gravity, and Measurement

• Several comments note: singularities and horizons are classical GR predictions; quantum gravity is expected to modify them, but details are unknown.
• Side discussion on:
  • Gravity’s nonlinearity (e.g., Mercury’s perihelion).
  • Competing views on the measurement problem (Copenhagen vs many-worlds vs gravity-induced collapse).

Meta: Tone and Disagreement

• Small subthread debates snark vs name-calling and how using “you” personalizes conflict.
• Emphasis on replying to arguments rather than attacking individuals, while still allowing firm correction of factual errors.