The world awaits the big eclipse that will darken skies on August 21, 2017 and super-computers and mega-telescopes— the most complicated systems known to humankind— are all monitoring the details.
It’s remarkable to think that the Ancient Greeks had this technology to predict eclipses over 2,000 years ago.
The ancient device, discovered by sponge divers in 1900 and named the Antikythera mechanism, was used to identify astronomical events happening in the Mediterranean sky.
When archeologists first examined the wreckage, they found a shoe-box-size contraption covered with dials and filled with about 30 gears made of bronze.
The mysterious device had broken up into dozens of pieces, but archaeologists painstakingly deciphered its secrets.
The hand-cranked gearbox would have allowed ancient Greek astronomers to figure out the position of the sun, moon and stars at any given time in the future.
Scientists have used 3D imaging to reveal some of the text on the box, which provides instructions on how to use it.
“Before, we could make out isolated words, but there was a lot of noise — letters that were being misread or gaps in the text,” Alexander Jones, a professor of the history of science at New York University, said in an interview with LiveScience.
“Now, we have something that you can actually read as ancient Greek. We can tell what these texts were saying to an ancient observer.”
For instance, the new information reveals that there was a zodiac chart on the front of the gearbox showing the planets moving through the different constellations, the study found.
In 2014, examining scientists had another eureka moment when they deciphered the dial and algorithm used to predict eclipses.
A four-turn spiral on the corroded machine revealed eclipses using specific glyphs to denote the exact time and type of eclipse. Lunar eclipses, for instance, were denoted by the glyph for Σ, which was short for the moon goddess ΣΕΛΗΝΗ (Selene), and solar eclipses were denoted by H, which is short for the sun god ΗΛΙΟΣ (Helios).
The Antikythera mechanism could not only predict the timing of eclipses but also reveal specific characteristics of those eclipses and exact details, including the amount of obscuration, the angular diameter of the moon (which is the angle covered by the diameter of the full moon) and the position of the moon at the time of the eclipse.
Though the full meaning of eclipse events in Greek culture isn’t entirely clear, it’s evident that the eclipses were seen as important omens.
The ancient historian Herodotus claimed that the eclipse of Thales (c. 585 B.C.) literally stopped a war between Median king Cyaxares and Lydian king Alyattes, who saw the darkness as a sign to stop fighting.
Watch the 20-minute video prepared by the Greek Ministry of Culture that accompanies the mechanism in various exhibitions and museums.