Apparatus
Sources
Detection quotes verified results. Modeled, inferred and observed are kept distinct.
Registers
- Hard
Astronomy and physics, with observed / measured / calculated / modeled / inferred / simulated / open labeled.
- Lived
Exact human chronology and the minimum artifact that establishes it.
- Open
Questions that appear when Hard and Lived are set beside one another. Not mechanism.
Neighbors
- Horizon
Philosophical treatment.
- THE 42 INDEX · GW231029
Compact provenance object.
- The Book of 42
The letters.
GW231029
GW231029_111508, GWTC-4.0. Primary catalog: GWOSC event page. Compact numerical provenance lives at THE 42 INDEX. Component masses are source-frame, 90% credible intervals, waveform-model dependent.
Kerr thin-disk efficiency
Novikov–Thorne thin, Keplerian, radiatively efficient disk. Efficiency η is the binding energy at the ISCO: the share of rest-mass energy that can reach infinity as radiation before matter plunges. Extreme limit 1 − 1/√3 ≈ 42.3%. Thorne, Astrophysical Journal 191, 507 (1974).
Plates
- M87* shadow. Event Horizon Telescope Collaboration / ESO eso1907a. Interferometric reconstruction.
- Sagittarius A*. Event Horizon Telescope Collaboration / ESO eso2208. Interferometric reconstruction.
- M87 optical jet. NASA / ESA / Hubble heic2411b. NASA, ESA, A. Lessing, E. Baltz, M. Shara, J. DePasquale (STScI). Documentary image of the jet, not of the horizon.
- M87 jet, multi-wavelength. Chandra / Hubble / Webb / VLA, 2026. NASA/CXC/Univ. Laval/C. Poitras et al.; processing NASA/CXC/SAO/L. Frattare.
- Cygnus X-1. Illustration: NASA / CXC / M. Weiss. Stellar-mass black hole with an X-ray companion; dynamics plus accretion, not a photograph of the horizon.
- Gravitational lens / Einstein ring LRG 3-757. ESA / Hubble / NASA potw1145a. Telescope photograph of a lensed background galaxy, not a black-hole horizon.
- LIGO Hanford Observatory, aerial. NOIRLab / LIGO / NSF / AURA / T. Matsopoulos.
- Living field on the cover, in Spin, and in Information: a computed lensing shader. Model, not observation.