EpiStack

A-30 - Even hypothetically stable neutral black holes would have destroyed observed white dwarfs and neutron stars - their survival closes the last case

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Properties8
type
argument
id
A-30
statement
Granting stable, neutral, accreting micro black holes for the sake of argument, the Giddings-Mangano analysis bounds their growth with conservative macroscopic-physics accretion scenarios: with seven or more spacetime dimensions at the LHC scale, accretion in Earth is so slow that harm would take billions of years; with five or six dimensions, accretion is fast — but then cosmic-ray-produced holes, stopped even when neutral inside dense white dwarfs and neutron stars, would have destroyed those stars in highly visible events on timescales far shorter than their observed lifetimes; the observed persistence of white dwarfs and neutron stars therefore shows such holes are not produced, at the LHC or anywhere.
source
S-1 - LSAG report- Review of the Safety of LHC Collisions
locator
§4, final ¶¶ (ref [2], Giddings-Mangano)
affects_observations
status
approved
reason_if_not_false
checked

Reasoning:

  1. Accretion rate for a stopped hole is model-dependent, so Giddings-Mangano set worst-case bounds from well-founded macroscopic physics across the extra-dimensional scenarios that motivate production (which motivate production, not stability).
  2. Dichotomy over dimensionality: for D ≥ 7 the extra dimensions are so small that the strong-gravity growth phase ends while the hole is still microscopic — Earth accretion times exceed billions of years, longer than the solar system’s natural lifetime, so even in the worst case the LHC poses no Earth-scale risk. For D = 5, 6 gravitational interactions are strong enough that accretion would be astrophysically visible.
  3. In the visible regime, ultra-high-energy cosmic rays striking white dwarfs and neutron stars would have produced such holes copiously; the density of these stars stops even neutral holes (no charge needed — this is what closes the last loophole of the charge-stopping argument). Rapid accretion would then destroy the star, with an explosive, highly visible endpoint, on timescales much shorter than observed white-dwarf/neutron-star lifetimes.
  4. Observed old white dwarfs and neutron stars exist in abundance; therefore cosmic rays do not produce stable neutral accreting holes, and neither will the LHC. Combined with the D ≥ 7 slow-accretion branch, every dimensionality is covered: danger is excluded either by accretion being negligibly slow or by astrophysical observation.

Validity verdict (step 6)

Reconstruction: a case analysis over dimensionality, traced for exhaustiveness: D >= 7 - accretion slower than solar-system lifetimes, harmless even granting stability; D = 5,6 - accretion fast, but then WD/NS (which stop even neutral holes - the premise that closes the last loophole) would have been visibly destroyed by cosmic-ray-produced holes on timescales far shorter than their observed ages. Observed old WDs/NSs then exclude the dangerous branch. Valid conditional on its premises (neutral stopping in dense stars, copious production on them, the GM accretion-rate bounds) - each of which is a separate node priced in steps 7-8. Undercutting probe: a scenario evading both branches would need accretion fast in Earth but slow/invisible in WDs - excluded by the same GM analysis’s density scaling.

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