NEW: THE THREE-BODY PROBLEM Two orbiting bodies follow neat, predictable paths. Add a third and almost anything can happen. This update adds a full Three-Body mode, so you can explore one of the most famous unsolved puzzles in physics. Switch between 2-Body and 3-Body mode at any time and pick a classic setup: • Figure-8: three equal stars chase each other along a single figure-eight path, one of the most beautiful orbits ever discovered. • Lagrange Triangle: three bodies rotate as a perfect equilateral triangle. See how long the balance lasts. • Sun, Planet & Moon: a stable system where a moon loops around its planet while both circle the star. • Pythagorean: three stars start completely still. Gravity pulls them into close encounters until one is thrown out into deep space. • Custom: set all three masses, the spacing and the starting speed yourself. Small changes can lead to very different outcomes. EINSTEIN’S GRAVITY ON EVERY PAIR The general relativity correction now applies between every pair of bodies. Even the most perfect orbits slowly drift and break apart, so you can watch relativity change the classic solutions in real time. COLLISIONS AND EJECTIONS Bodies that get too close merge into one, with momentum conserved. If a body reaches escape velocity, the app detects it and tells you which one was ejected. NEW METRICS Three-Body mode shows elapsed time, energy drift, closest approach, peak speed as a fraction of light speed, and whether the system is still bound. IMPROVEMENTS • A centre-of-mass marker shows the point the whole system orbits around. • The spacetime grid now bends around every body, not just the central star. • Trails and force lines are drawn for each body in its own colour. • Bodies are drawn in the correct front-to-back order as you rotate the camera. • Your favourite two-body scenes, including black hole mode, work exactly as before. Rotate the camera, record a video, and share your favourite moments of chaos!

Version 2026.2 — Orbital Chaos Update Screen Recording Record your orbital simulations while they're running and share the clip directly from the app. Tap the record button during a simulation, tap it again to stop, and the iOS share sheet lets you save to Photos, send via Messages, AirDrop, or any other app. Tidal Disruption When a planet ventures too close to a massive star or black hole, tidal forces overcome its self-gravity. Inside the Roche limit, material is stripped from the planet and streams toward the central body in a glowing arc — cyan as it leaves the planet, deepening through orange to red as it falls inward and heats up. The planet's mass decreases in real time as material is lost. Push it close enough and the planet will be entirely consumed. Real Collisions Previously, every orbit was stable. That was wrong. The physics engine now correctly handles unstable orbits: place a planet too close to a star and it will spiral inward and collide. In black hole mode, crossing the ISCO puts the planet on a plunging trajectory toward the event horizon. No more immortal orbits. Zoom Stability The dynamic zoom now tracks the centre of mass of the two-body system rather than a fixed origin point. This prevents the view from slowly zooming out over many orbits when the planet is large relative to the star — a side effect of tiny momentum drift in the relativistic integrator accumulating over time.

Orbits can be saved and shared with your friends