About 80 B.C. off the small Greek island of Antikythera, a shipsank in rough seas. It carried a remarkable device called the Antikythera Mechanism, the most complex mechanical device from antiquity.

The front dial tracked the motions of the moon and sun along the months and zodiac. The inner dial (months) was moveable. It is thought that the inside part of the dial was painted with the constellations.

The rear dials are slightly trickier, since hardly anything of them survived. Their purpose had to be deduced by counting gear teeth and calculating their ratios. The upper rear dial calculated the synodic month (a period of 27.5 days, calculated by subtracting the sun's motion from the moon's), while the lower rear dial probably showed
lunar eclipses over four year cycles. Both rear dials had smaller subdials which probably showed some yearly cycle but their exact purpose will probably never be known.

A clever planar differential calculated the synodic month.


CONTROLS

Use the mouse to move the camera around the device.
Press the left mouse button and move the mouse up and down to zoom
in and out.

1 Toggle side panels
2 Toggle front/rear panels
3 Toggle base plate
4 Toggle gears and pointers
5 Toggle axles
6 Toggle tooth counts and dial labels

RIGHT Turn crank clockwise
LEFT Turn crank counterclockwise

T Toggle crank speed (slow-medium-fast)
B Toggle gear textures, from bronze to polka dot
(Polka dot textures clearly show you the relationships
between the gears. Connected gears and their axles are
colored the same)
G Toggle camera target gear, or gear at which the camera is pointed

ESC Quit

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