Although time and its measurement is a fundamental component of human life, a special type of clock which takes matters to the next level is the so-called astronomical clock and whose purpose is not to measure time per se but to convey astronomical information and, in particular, the relative position of the Sun and Moon as well as the zodiacal constellations and, in some cases, the position of the planets all as a function of time.

The oldest such effort to effectively emulate the overhead celestial sphere (ie a mini-planetarium) is the Antikythera Mechanism which was discovered in 1901 totally by accident by sponge divers off the coast of the Greek island of Antikythera. It has been dated to approximately 80 BC and it is believed to be the work of Poseidonius of Rhodes. The Antikythera Mechanism is currently on display at the National Archaeological Museum in Athens, Greece.

Note: The city of Vicenza in northern Italy with a population of approximately 110,000 inhabitants is best-known for its stunning architecture designed by the architect Andrea Palladio during the 16th-century and which includes the Basilica Palladiana (a UNESCO monument). Forming part of the basilica is the 82-meter tall tower to the north and which boasts the colourful and simplistic astronomical clock seen below. Built in 1174 AD, the tower would reach its present height following an extension in the fifteenth century.

A cursory look at the clock will immediately reveal that it differs from more orthodox clocks constructed during the Renaissance with the time of day based on a 12-hr dial using the roman numerals I through XII as opposed to the 24-hr dial (I through XXIV) virtually everywhere else in Italy and throughout Europe. Hash marks between the hourly intervals, representing mid-hr (ie 30 minutes), are also present on the outermost ring so as to coincide with the bell sounds made every 30 and 60 minutes. A smaller ring follows with hash marks indicating 15-minute intervals. The central portion of the clock is painted in a cobalt blue colour, thus representing the night sky, and includes a sphere depicting the Moon and its phases. Finally, the presence of two dials allow for the precise indication of time with the shorter dial representing the hour of day whereas the longer dial represents minutes within the hour. Following the bombing of the tower by Allied forces during WWII, the clock mechanism was replaced using a radio-controlled atomic clock interface for ultimate precision.

Note: For a view of the astronomical clock using greater focal length, please click here and here.

Note: For additional results involving astronomical clocks from around the world, please click here.