Cosmic Web — universe structure-formation simulation

A near-uniform early universe, seeded with tiny density ripples, evolving under gravity into the real large-scale structure of the cosmos: filaments, dense halos/clusters at their intersections, and empty voids between. This is a simulation of gravitational structure formation — not a map of the real sky. ← back to orbital-watch

What's physically real here: a direct-summation N-body simulation starting from Zel'dovich-approximation initial conditions — the same way real cosmological simulations (Millennium, IllustrisTNG) are seeded: particles on a grid are nudged by a smooth random displacement field, then softened Newtonian gravity is integrated with a leapfrog scheme. The cosmic web is emergent — gravity amplifies the tiny initial ripples into filaments and clusters, exactly as it does in the real universe. Points are coloured by peculiar velocity (blue = quiet voids, warm/white = fast-moving gas falling into structure). What's simplified: a couple of thousand particles stand in for ~10¹¹ galaxies, there's no dark-energy expansion term, no gas physics, and gravity is softened at short range. Drag to rotate · scroll to zoom.