Gargantua: Black Hole Sim

Collide galaxies, watch supermassive black holes spiral together and merge, and fly around a lensed black hole — all in real time, all from real physics.

Gargantua is a real-time galaxy-collision and supermassive-black-hole simulator that runs entirely on your device's GPU — and every pixel is driven by actual physics, not a pre-rendered animation.

Spin up a spiral galaxy, smash two galaxies together and watch tidal tails and bridges form, or follow a pair of supermassive black holes as they spiral in, chirp, and merge into a spinning Kerr remnant. Then fly around a black hole and see its accretion disk wrap over the shadow in the gravitationally-lensed "Interstellar" view.

REAL PHYSICS, LIVE • Newtonian N-body gravity with a Barnes-Hut octree, on Metal GPU compute • Exponential-disk galaxies with a true Freeman rotation curve and a persistent spiral density wave • Dark-matter halos, dynamical friction, SPH gas, radiative cooling, and star formation • Black-hole binary inspiral handoff to the analytic Peters chirp + Kerr remnant • Backward-ray-traced gravitational lensing (Schwarzschild to Kerr spin) with a Doppler-beamed disk

MODES • Single spiral galaxy • Two-galaxy collision (stars, or full physics with gas + dark matter + black holes) • Supermassive black-hole merger finale, with a gravitational-wave ripple • Gravitational lensing — the black-hole shot

TOUCH CONTROLS • Drag to orbit, pinch to zoom, two-finger pan • Live speed, pause, quality, and black-hole spin / accretion-disk controls • Tap Share to save or send a high-resolution image of your view

Universal — looks gorgeous on iPhone and iPad.