This simulation visualizes how mass-energy ($T_{\mu\nu}$) curves spacetime according to Einstein's Field Equations. You can control the mass of the central object and observe its effects on the surrounding fabric of spacetime, particles, and light rays.
The grid represents the fabric of spacetime, which is distorted by the mass of the central object. The flowing particles represent matter following "geodesics"—the straightest possible paths through this curved space.
The "Entropy View" visualizes the idea that a black hole's entropy—a measure of its internal information or "states"—is proportional to its surface area. The shimmering particles on the event horizon represent this encoded information. These states interact with each other, creating a dynamic "boiling" surface bound by the black hole's gravity.