🌌 3D Spacetime Curvature Simulator: Gravity Well, Orbits, Light Lensing, Multiple Masses and Time Dilation Lab

A 3D spacetime sheet that deforms around a star, black hole, binary or galactic centre: orbits follow the curvature, a light ray bends by the real 4GM/(c^2 b) angle, you can launch extra masses, and clocks run slower in deeper wells. Includes a cross-section, top view, potential funnel, time-dilation table and eight in-page numerical checks.