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New Research Shows the Antikythera Mechanism Tracked the Sun

Olden Lore

The 2,000-year old “computer” has a newly discovered function: tracking the sun using geometry and an intricate system of gears. What makes this such an amazing discovery is that it accounts for — and corrects — the fact that the Earth’s orbit around the Sun (as well as the Moon’s orbit around Earth) is an ellipse. Despite not being able to depend on a perfect circle and also the fact that this device was made 2,000 years ago, the developers figured out a way to accurately measure the position of celestial bodies.
According to Wired:

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In 2006, Tony Freeth of Cardiff University and colleagues showed that a clever configuration of two overlapping gears, with the top gear laid off-center from the bottom gear, could give the moon’s marker its irregular speed. Because of the Earth’s elliptical orbit around the sun, the sun makes a similarly variable trip across the sky, speeding up and slowing down over the course of the year. But the effect is much more subtle than for the moon.

This means that there had to have been extremely intricate gears to accurately track this subtle change, but no such parts were found in the shipwreck when the device was found in 1901. However, there was a workaround: The Antikythera mechanism’s face features all 12 signs of the zodiac. In order to properly track the sun, the distance between some of the signs had to be stretched:

If the spaces on the front wheel of the mechanism were of different widths … then the hand representing the sun would take longer to travel through the part of the year lumped under the zodiac sign of Taurus than through Libra. The delay would make the sun look like it was moving slower at some times of year and faster at others, even though the gears turning the hand moved at a constant speed.

This was just a theory produced by the research team, but then they viewed x-rays of the device and found that “the two circles representing the zodiac and the Egyptian calendar were divided differently, and in just the right way to account for the sun’s irregular speed.” So, even 2,000 years ago, the developers of the Antikythera mechanism were way ahead of everyone.

Some familiar with the Antikythera mechanism don’t agree with the “zodiac-stretching” theory, however science historian James Evans of the University of Puget Sound says the idea is so accurate that you could bet your retirement on it (or “5%” of it). He does admit that the device is more suited as a thing of “wonder” and not precise timekeeping.

But seriously, when you consider that a portion of our countrymen living today think the Earth is flat, ancient science is all the more impressive.

(Wired via Gizmodo)

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