A computer cast in brass. Every wheel you see is cut in code — no model files, no textures on a wire. Each tooth engages its neighbour at a ratio chosen two thousand years before the transistor. The machine does not depict the sky. It computes it.
Count the teeth. 47 : 120 carries Mercury's year into Venus's. 8 : 13 finds Earth — the same Fibonacci fraction that traces Venus's pentagram across eight of our years. The error in every stage is under six-tenths of one percent.
Keep pulling back and the gears come apart into the thing they were always computing. The brass was a mnemonic. Every planet on screen is still being driven by the train — the crank in your hand, through eight meshing stages.
The engine winds itself forward to 8 September 2040 — Mercury, Venus, Mars, Jupiter and Saturn gathered inside a ten-degree circle at dusk. Orreries were built for exactly this: to hold a future sky in your palm.
ORBITAL ELEMENTS — NASA JPL, “Keplerian Elements for Approximate Positions of the Major Planets”, J2000 epoch. Gear-train conception after the Antikythera mechanism, c. 150–100 BC. All geometry, texture and sound generated in code.
ORRERY — The Clockwork Cosmos is an astronomical clock come alive. It opens on a brass-and-glass gear mechanism in the Antikythera tradition — every wheel generated in code, no model files — and as you scroll, the camera pulls back and the gears dissolve into the solar system they were always computing. Each planet's motion is literally driven by the visible train: the hand crank is the master wheel, through eight meshing stages.
One crank revolution = 21.99225 days. The crank's 20T pinion turns an 80T wheel — the Mercury shaft, one revolution per 4 crank turns (87.969 d, exact). From there each visible pair carries one planet: 47:120 → Venus (Δ0.018%) · 8:13 → Earth (Δ0.05%, the Fibonacci fraction of Venus's pentagram) · 17:32 → Mars · 5:59 → Jupiter · 8:20 → Saturn · 7:20 → Uranus · 21:41 → Neptune. Every stage is within six-tenths of one percent of the true period — the same trick the Antikythera mechanism pulled two thousand years ago.
SCROLL — ride the four chapters · DRAG THE CRANK (or drag anywhere) — wind time by hand, with detents and inertia · FLOW — autonomous rate, 0.1 day/s to 10 yr/s, HELD at zero · ORRERY/TRUE SCALE — toggle real AU distances · SOUND — procedural WebAudio: tooth ticks, detent clicks, a drone that deepens with distance.
Orbital elements: NASA JPL, “Keplerian Elements for Approximate Positions of the Major Planets”, J2000 epoch; positions integrated by Newton's method from Kepler's equation. Gear-train conception after the Antikythera mechanism, c. 150–100 BC. Chapter IV winds to the real five-planet dusk conjunction of 8 September 2040. All geometry, textures and sound are procedural; three.js r160 via pinned CDN import map; one self-contained HTML file.
Direction & concept — Dima (madeby.dev). Design, engineering & words — Kimi, an AI coding agent by Moonshot AI, working in Kimi Code CLI. One prompt, one self-contained index.html, no build step.