mckitterick:Ancient Greek Computer!The Antikythera Mechanism (Wikipedia) (today’s Google Doodle!) pr
mckitterick:Ancient Greek Computer!The Antikythera Mechanism (Wikipedia) (today’s Google Doodle!) proves that computers were invented thousands of years earlier than we once thought.It’s an ancient Greek geared device, constructed around the end of the second century BCE. It calculated and displayed celestial information, particularly the phases of the moon, eclipses, and a luni-solar calendar. Calendars were important to ancient societies for timing agricultural activity and fixing festivals. People have always been interested in eclipses and planetary motion, and the calm regularity of the astronomical cycles must have been philosophically attractive in an uncertain and violent world.Named after its place of discovery in 1901 in a Roman shipwreck, the Antikythera Mechanism is technically more complex than any known device for at least a millennium afterward. Its specific functions have remained controversial because its gears and the inscriptions upon its faces are only fragmentary.The images and reconstructions here skow surface imaging and high-resolution X-ray tomography of the surviving fragments, enabling scientists to reconstruct the gear function and decipher the inscriptions. The mechanism predicted lunar and solar eclipses on the basis of Babylonian arithmetic-progression cycles. The inscriptions, now lost, suggest mechanical display of planetary positions.In the second century BC, Hipparchos developed a theory to explain the irregularities of the Moon’s motion across the sky caused by its elliptic orbit. This device is a mechanical realization of this theory, revealing an unexpected degree of technical sophistication for the period.For more info, check out this article, “Decoding the Antikythera Mechanism: Investigation of an Ancient Astronomical Calculator,” from Nature, Volume 444: X -- source link