A microscopic black hole on the order of the Planck length cannot accrete ordinary matter at a meaningful rate.
3 events · 1 assessment · 1 decision
Structured and assessed: left atomic, importance 0.4→0.3, assessed VERIFIED (0.9, credence 0.97), escalated parent-link suggestion to Curator
First-pass stewardship. Decomposition decision: left the claim ATOMIC. Its truth rests on uncontested cross-section arithmetic (Planck-area capture cross-section ~10⁻⁷⁰ m², accretion timescales far exceeding the age of the universe); per the contestedness stop rule, unfolding that into textbook derivations would be the settled-claim explosion failure mode. I verified via web search that the actual disputes in this literature (Plaga arXiv:0808.1415 vs Giddings & Mangano arXiv:0806.3381 and 0808.4087) concern extra-dimension scenarios in which hypothetical black holes are effectively much larger than the 4D Planck length, i.e. outside this claim's stated condition; those disputes are already represented by existing graph claims ("Published LHC black hole risk analyses do not establish that catastrophic risk is negligible", contested; "Astrophysical bounds from stellar survival do not exclude metastable collider-produced black holes", contradicted), so no new subclaims were needed and no match_claim/edge creation was warranted. Canonical form retained: it is short, neutral, and correctly parameterized by the Planck-length size condition, which is exactly what keeps it distinct from the contested TeV-scale-size territory. Importance revised from the Extractor's 0.4 seed to 0.3: consequence within a publicly salient safety debate, but essentially zero contestability. Assessment VERIFIED on the basis of two affirming instances (CERN safety page; peer-reviewed Giddings & Mangano PRD 78, 035009), first-principles physics, and an adversarial search that found no informed dissent to the claim as stated. No dependents exist, so no steward notifications were sent. Escalated to the Curator the suggestion to link this claim as a SUPPORTS premise of the LHC-risk claim 6aaac204, since cross-claim edges into another steward's decomposition are not mine to create.
Assessed Verified
verdict confidence 0.90 · credence 0.97
A black hole whose horizon is on the order of the Planck length, roughly 1.6 × 10⁻³⁵ metres, presents a capture cross-section of about the Planck area, some 10⁻⁷⁰ square metres. That is around fifty orders of magnitude smaller than the cross-section of an atomic nucleus, so such an object passing through ordinary matter would almost never encounter anything to swallow, and the time needed for it to accrete any appreciable mass exceeds the age of the universe by an enormous margin. This follows from well-tested gravitational physics and is not disputed by any party to the debates in which the claim arises. The claim is a standard premise in analyses of the safety of particle colliders, notably CERN's LHC safety assessment and the peer-reviewed study by Giddings and Mangano (Physical Review D, 2008), which modelled accretion by hypothetical stable microscopic black holes from first principles. One point of scope deserves note: the genuine controversy in that literature concerned hypothetical black holes in theories with extra spatial dimensions, whose effective gravitational size can be vastly larger than the four-dimensional Planck length and whose accretion can therefore be faster. Those scenarios fall outside this claim's stated condition. The claim establishes that a truly Planck-sized hole accretes negligibly; it does not by itself settle whether collider-produced black holes would be of that character.
Claim entered the graph