Indexing the archive…
Your Universe of Digital Possibilities
A black hole bends nothing you can see — it bends the paths light takes. This instrument integrates the real photon geodesics of the Schwarzschild metric, one per pixel, so the accretion disk behind the hole arcs up and over the shadow, and a thin photon ring marks where light orbited before escaping. Drag to fly around it; switch the curvature off to see the same scene in flat space, and watch every distortion disappear at once.
Clocks deeper in the well tick slower (the −(1−rs/r) term). The event horizon is at rs = 2GM/c², where the escape speed reaches light.
A photon travels perfectly straight; spacetime is curved, so its path curves with it. This is the exact orbit equation the instrument integrates per ray — not a thin-lens shortcut like The Well. The extra u² term is general relativity; drop it and you get Newton’s half-strength, straight-ish light.
At exactly this radius gravity bends light into a circle. Rays that graze it wind around the hole many times before escaping, stacking into the thin bright photon ring at the rim of the shadow.
The dark disc is bigger than the horizon itself: any ray aimed inside the critical impact parameter bcrit is swallowed. Lensing magnifies the rs horizon into a √27 ≈ 5.2 rs silhouette — the ring the Event Horizon Telescope photographed in 2019.
Clocks tick slower deeper in the well; light climbing out loses energy and reddens, diverging as r → rs. Together with the disk’s orbital Doppler shift it makes the approaching side blaze blue-white and the receding side fall dim and red.
Where The Well bends a flat sky with the weak-field thin-lens formula, this integrates the strong-field geodesics themselves — so light wraps the hole and the disk lenses over its own shadow. The shadow you see is bigger than the horizon, the photon ring is light that orbited before escaping, and the clock on the disk runs slow enough to redden its own glow. It is the sharpest face the rack gives the Time question: at the horizon, an infalling clock — seen from outside — simply stops. Penrose proved this is no fluke of a tidy solution; collapse to a horizon is what gravity does.