In a proposed 2021 reconstruction, a surviving 63-tooth bronze gear is the key to how the ancient Antikythera mechanism may have modeled Venus's 462-year cycle.
ILLUSTRATION · AIIn a proposed 2021 reconstruction, a surviving 63-tooth gear from Fragment D forms part of a Venus mechanism built around the 462-year period relation inscribed on the device.
The Antikythera mechanism has challenged researchers since its discovery in 1901. It survives in fragments, only a third of the original, and its front gearing has long been the hardest part to explain.
In 2021, a team at University College London led by Tony Freeth published a new model of the front 'Cosmos' display in Scientific Reports, designed to conform to the surviving physical evidence and the inscriptions.
The gear in Fragment D
Fragment D contains a small bronze gear. Its original tooth count can be reliably determined as 63, the paper says, because all but three of the teeth survive.
An inscription on the device records numbers for Venus that translate into the period relation (289, 462). The team reconstructs the Fragment D components as the epicyclic gears of a Venus mechanism, with the 63-tooth gear in the gear train that models that relation.
A proposal, not a proof
The model is a reconstruction. It shows one way the ancient designers could have built the planetary display with the gears that survive, and it remains a proposal to be tested against further evidence.
More facts
The Golden Gate Bridge's two main cables hold 80,000 miles of steel wire. Each cable is made of 27,572 separate wires bundled together.
The Hoover Dam complex, the dam, powerplant and related works, holds 4.36 million cubic yards of concrete: enough to pave a 16-foot-wide highway from San Francisco to New York.
