Black Hole Accretion Disk

About this page

This is a real-time GPU visualization of a black hole, complete with an accretion disk, photon ring, and faint background starfield. The central event horizon remains perfectly dark, while light from the hot plasma disk and lensed starfield creates the familiar silhouette seen in images such as those from the Event Horizon Telescope.

What you’re seeing

The photon ring arises from light bending multiple times around the black hole before reaching the observer. The accretion disk is hotter near its inner edge: the approaching side is Doppler-boosted into bluish-white tones, while the receding side is redshifted. A background starfield is lensed and distorted, reinforcing the sense of extreme curvature of spacetime.

While this is a stylized approximation rather than a full general-relativistic ray-tracing, the essential effects are captured: gravitational redshift, relativistic beaming, and the iconic dark silhouette of the event horizon.

Observing black holes

Black holes cannot be observed directly. Instead, astronomers detect them through their influence on surrounding matter. Accretion disks emit intense X-rays as gas spirals inward, heating to millions of degrees. On cosmic scales, supermassive black holes can power quasars—some of the brightest and most energetic objects in the universe.

Tech notes

This simulation runs entirely in WebGL2 with custom GLSL shaders. The disk shader approximates relativistic effects using Doppler boosting (D³) and gravitational redshift (√(1 - rₛ/r)). A bloom pass enhances the photon ring’s glow, while stars are drawn as GPU-instanced particles for performance. The result is an accessible yet visually striking model of black hole physics running in the browser.