This interactive cosmic web simulation procedurally generates a filament-and-node skeleton, then animates thousands of galaxies migrating from a uniform scatter into that skeleton in real time, illustrating how gravity turns a nearly smooth early universe into today's web of filaments, clusters and voids.
The real cosmic web forms because gravitational collapse is anisotropic: overdense regions first flatten into sheets, then narrow further into filaments, then finally collapse fully into cluster nodes at filament intersections. This simulation mimics that end state procedurally — scattering node seeds, threading filaments between nearby seeds, and letting most galaxies drift toward one of the two structures — while a minority remain in sparse, slowly draining voids.
Increase filament clustering to funnel more galaxies onto the thread-like filaments instead of scattering them in the background. Increase void size to reduce the number of node seeds and open up larger empty regions between them. Raise settling speed to watch the migration from a uniform starting scatter into structure happen faster, and press Reseed to regenerate a fresh random skeleton and replay the settling animation.
The cosmic web was first predicted theoretically before being confirmed observationally: the 1986 CfA Redshift Survey revealed that galaxies are arranged in sheets and filaments around vast voids, rather than scattered randomly through space, matching what gravitational-collapse theory had predicted.
This cosmic web simulation procedurally builds a network of node seeds and connecting filaments, then interpolates thousands of particles from a uniform random scatter onto that network over a few seconds, visually replaying — in dramatically compressed form — the billions of years over which gravity turned tiny primordial density fluctuations into today's filaments, clusters and voids.
Node seeds represent future galaxy clusters; the thread connecting the nearest seed pairs represents a filament; most particles are assigned to a node or filament target, while a minority remain scattered in the voids, mirroring the real matter-density contrast between these regions.
Galaxies sets particle count; filament clustering shifts more particles onto filaments versus the diffuse background; void size reduces the number of node seeds so empty regions grow larger; settling speed controls how quickly the migration animation plays out. Reseed regenerates a new random skeleton.
The Sloan Great Wall, a real filamentary structure discovered in 2003, stretches roughly 1.37 billion light-years — one of the largest coherent structures ever identified in the observable universe.
The cosmic web is the large-scale arrangement of matter in the universe: galaxies concentrated along thread-like filaments and dense cluster nodes, surrounded by vast, nearly empty voids, all scaffolded by the gravity of dark matter.
Gravitational collapse from small initial density fluctuations is anisotropic: overdense regions collapse fastest along their shortest axis first, flattening into sheets, then further into filaments, and finally into dense nodes where filaments intersect — producing the web-like pattern rather than a uniform or purely random distribution.
Voids are the vast, roughly spherical regions of the universe with far below average matter density, left behind as gravity drained matter out of them and into the surrounding filaments and walls over cosmic history.
No — this is a procedural, illustrative model that interpolates particles onto a pre-built filament skeleton rather than integrating gravitational forces between every particle pair, which real cosmological N-body codes like the Millennium Simulation do at enormous computational cost.
Large galaxy redshift surveys, starting with the 1986 CfA Redshift Survey and later the Sloan Digital Sky Survey, mapped the actual three-dimensional positions of hundreds of thousands of galaxies and directly revealed the same filament, node and void pattern that gravitational-collapse theory and simulations predict.