N-body Galaxy — live gravity simulation

Every star here pulls on every other star through Newton's law of gravity, re-integrated each frame. The spiral structure, the central bar, and the orbits all emerge from that — nothing is scripted. This is a simulation of gravitational dynamics, not the real Milky Way's measured positions. ← back to orbital-watch

What's physically real here: this is a direct-summation N-body simulation — the same method used in computational astrophysics — using softened Newtonian gravity and a leapfrog integrator, so momentum and orbital dynamics behave correctly. Spiral density waves and the central bar are emergent, not drawn in. What's simplified: a few hundred–thousand "stars" stand in for billions, gravity is softened at short range to keep it stable, and there's no gas, dark-matter halo, or relativity. Drag to rotate the view · scroll to zoom.