Just last week (12 March 2021) a team of scholars that included a mathematician, a physicist, and a clockmaker (among others) unveiled an answer to one of the greatest puzzles in history — how the famed “Antikythera Mechanism” worked.
Since 1901, when a diver off the coast of Greece (Antikythera, to be exact) found an unusual lump amidst the wreckage of a ship from the ancient world (70-60CE), experts have tried to figure out what the mess of corroded ironwork was. Just cleaning and detangling it took decades, but finally 82 pieces were uncovered to reveal a devise of astonishing complexity — a wholely unique item of ancient technology.
The thing was both a calendar and a computer — with (probably) 37 different gears, it could calculate the synodic cycles of the five planets known at the time. Considering that the synodic period of, say, Venus is 462 years (because that is how long it takes for Venus to repeat the same path in the sky across the stars as we see it) — these calculations are crazy challenging.
Ultimately, the device could display the calendar date, path and phase of the moon, and the placement of the planets, even predicting eclipses. Those who built the Antikythera Mechanism had access to Babalyonian astronomy, mathematics from Plato’s academy, and understanding of fine metallurgy — nothing like it appeared for over 1,000 years.
The new discovery made use of a three-dimensional type of x-ray called Computed Tomography (able to see discrete planes within an object) that revealed extra Greek texts which describe how to use the device. This ultimately allowed scholars to figure out how gears likely intersected that could model the “epicycles” needed to make sense the motion of the planets from the Greeks’ geocentric point of view (as though the earth were the center of the universe).
This image reconstructs the Antikythera Mechanism in light of the new findings — you can see it was a box with descriptions on the covers with a front plate for display and the intricate gears nestled inside.
The number of people alive in that century who could understand the device must have been very, very small.
The video explaining the Antikythera Mechanism is fantastic, and you can find a link to it with this URL: vimeo.com/518734183
Source(s): “A model of the cosmos in the Ancient Greek Antikythera Mechanism,” Tony Freeth et al., _Scientific Reports,” 11, Article number 5821 (2021), publishes 12 March 2021.
