THE SHAPE OF LIGHT
One black hole. A sky seen twice.Move around it. Follow a ray.
Click the sky to inspect a ray. The diagram traces it backward from your camera.
Horizon Photon sphere Light path
Diagram retains the GR reference; the sky currently shows straight light in flat space.
Loading the validated light paths and star field…
THE SCIENCE / V0
Light follows null geodesics in the Schwarzschild geometry, the exact vacuum solution for an isolated, nonrotating, uncharged black hole. The renderer samples precomputed numerical paths for a static observer at five distances.
The event horizon is at 1 rₛ, and the photon sphere at 1.5 rₛ. The dark shadow is an apparent capture region on the sky, not a picture of the horizon’s surface. There is no glowing material in this version: bright arcs are distorted images of the background.
The synthetic star field is illustrative and lies at infinity. The model omits black-hole spin, accretion gas, observer motion, spectral shifts, and evolving spacetime. Changing distance chooses a new stationary observer; it does not simulate falling.
Turn lensing off to see straight light in flat space, without capture. The optional celestial grid belongs to the distant sky, not to a physical sheet around the black hole.
At the exact shadow boundary a ray can orbit indefinitely. A very narrow unresolved band just outside it is rendered black; higher-order subpixel structure is not resolved. The ray diagram uses Schwarzschild radial coordinates in a plane and is not a local ruler or an embedding of space.
Validated against independent integration, the weak-field deflection limit, and the analytic capture threshold. Numerical report ↗ · Equations and sources ↗