# Antikythera — A Cosmos in Bronze

> An interactive, research-informed reconstruction of the ancient Greek Antikythera mechanism. A single HTML file contains the numerical engine, native WebGL renderer, 2D dial readers, calibration tools, model-event finder, theory and verification records.

The source language is English. Google Website Translator provides optional online translation of interface text and the manual. The mechanical model works offline. Google Analytics uses measurement ID G-PM09XGNS48. Neither Google service is required for the calculations.

## Application and documentation

- [Open the mechanism](Antikythera.html): Rotate, zoom, pinch, inspect the front and rear, expose gearwork, or separate the layers.
- [Operating instructions](Antikythera.html#quick): Hand drive, time controls, playback, keyboard and touch operation, calibration and exports.
- [Evidence and scope](Antikythera.html#evidence): Distinguishes attested features, reconstructed mechanisms and explicit assumptions.
- [Mechanical mathematics](Antikythera.html#math): Gear-ratio arithmetic and common annual drive.
- [Lunar variability](Antikythera.html#moonTheory): Eccentric pin-and-slot geometry and phase display.
- [Calendar dials](Antikythera.html#rearTheory): Metonic, Saros, Exeligmos, games and hypothetical Callippic indications.
- [Eclipse register](Antikythera.html#eclipseTheory): The selected Freeth 2014 Eclipse Year Model and supplied-hour correction.
- [Planetary restoration](Antikythera.html#planetTheory): Circular epicyclic models using the stated synodic period relations.
- [Calibration and dates](Antikythera.html#calTheory): Epochs, offsets, explicit Gregorian/Julian conversion and astronomical year numbering.
- [Model events](Antikythera.html#events): Lunar phases, planetary conjunctions, oppositions, stations and inner-planet elongations.
- [Precision and limitations](Antikythera.html#limits): Mathematical accuracy, mechanical fidelity and historical uncertainty.
- [Primary research bibliography](Antikythera.html#sources): Original research papers and institutional sources.
- [Languages and browser operation](Antikythera.html#webFeatures): Translation, online dependencies, mobile layout, rendering and offline fallback.
- [Verification](Antikythera.html#checks): Rerunnable numerical checks and the dated core audit.

## Model facts

The default mechanism year is 365.25 days. The mean lunar ratio is 254/19 turns per year, yielding 235 synodic months in 19 years. The Metonic dial traverses five turns in 235 months; the Saros dial traverses four turns in 223 months. The Exeligmos spans 669 months and selects approximate hour corrections of 0, 8 or 16. The games cycle spans four years. A 76-year subsidiary and the node indication are explicitly conjectural.

The lunar differential uses the mean Sun. The interface separately reports the reconstructed true-Sun phase and distinguishes phase-scaled lunar age from elapsed time since a solved model new Moon. The event finder measures the same mechanical equations; its dates are not modern observational ephemerides.

## Interpretation boundaries

This is an idealized kinematic reconstruction, not a uniquely established original machine or manufacturing-certified CAD model. The internal spatial arrangement is interpretive. Gear contact forces, backlash, collisions and manufacturing tolerances are not simulated. Planetary circular models omit real eccentricities, inclinations and perturbations. Missing inscriptions, eclipse hours, festival schedules and the complete parapegma are not fabricated. The civil Metonic table is a disclosed regularized completion rather than a complete recovered transcription.

The embedded v1.1 audit is dated 3 October 2026. Web revision 1.2 adds the translation interface, Analytics integration, semantic manual markup and loading/layout improvements on 22 October 2026. Its added online services mean the earlier audit's no-network observation applies to the earlier offline core, not to the hosted web revision.

## Primary research

- [Freeth et al., 2006](https://doi.org/10.1038/nature05357): Lunar and calendrical core, tomography and gearing.
- [Freeth et al., 2008](https://doi.org/10.1038/nature07130): Rear calendars, games and eclipse indications.
- [Freeth, 2014](https://doi.org/10.1371/journal.pone.0103275): Eclipse Year Model used by this application.
- [Freeth et al., 2021](https://doi.org/10.1038/s41598-021-84310-w): Conjectural planetary architecture and period relations.

## Deployment

This file uses relative links and should be served beside Antikythera.html. If the application's public filename or location changes, update these links. Serve robots.txt at the host root; combine its rules with any existing site-wide policy. This document supplies context and navigation, not crawler access control or a guarantee of search rankings.