Mystery of Ancient Calculator Finally Cracked

jcaruso writes, "It's been more than 100 years since the discovery of the 2,000-year-old Antikythera Mechanism, but researchers are only now figuring out how it works." From the article: "Since its discovery in 1902, the Antikythera Mechanism — with its intricate and baffling system of about 30 geared wheels — has been an enigma... During the last 50 years, researchers have identified various astronomical and calendar functions, including gears that mimic the movement of the sun and moon. But it has taken some of the most advanced technology of the 21st century to decipher during the past year the most advanced technology of the 1st century B.C."

Comments

Re:Physical Perl

[Thornae]

Remember folks, always document your calculators

They did.
From the article:
'... X-rays exposed writing on surfaces mashed together in the Mechanism, and never before seen... He declines to be specific about what the writing says. "But it was basically an instruction manual on using the mechanism, and what its purpose was," he says.'

And the clock stopped...

[Nefarious Wheel]

...thus, by tracking back to which epicycles were extant in the cosmos at that time, we were able to pinpoint the moment of the crime (a piracy, perhaps?).

Actually this story is a little old, people have had the Antikythera device scoped out for a couple of years now. It's a sort of geared astrolabe using an epicyclic model (an astronomical paradigm adopted in Ptolomy's ptime) and the parts inside the corroded find were derived by some good ol'fashioned NMI scanning.

An astrolabe is basically a clock -- an analogue computer that correlates time, star position and latitude. Look 'em up -- they're beautiful instruments and very logically constructed. Each point indicates a star, the off-centre circles (al'mucanthers) are the projections of the celestial latitudes from the polar axis (think of a bunch of hoops on one spindle of a Tower of Hanoi model, then crank the spindle off the perpendicular by a few degrees, to give you an idea of the projection. Light source on top, your shadow rings are the al'mucanthers). Move the star pointer to one of those circles, then read the index off the rim of the device (the Mater). Because of their simplicity and elegance (the mathematical model, not the construction!) they were used up until Columbus' time. If the Antikythera device had been a better predictor, we might well have seen more of them. And a lot more gears. The only thing we still use from the development of the astrolabe today is the flat head screw, seen on one model in 1565.

wikipedia

[laggist]

heh.. lots of nice pics and write-up here