clocks = for measuring time
historically, clocks and time descriptions seem to have existed as long as we have archeological evidence about mankind
so it relates directly to the position of the earth around the sun
what interests us is what devices have been used to calculate time
there seem to be similarities in the systems:
1. they define a standard
2. they deal with constant phases
3. they have a starting point
actually when you look at time, the concept is a very uncertain one, due to stars/sun/moon/water on earth, etc..
which produces inaccuracies and uncertainty, and so we arrive at the non-linear nature of time
the measurement of time is of course a cultural feature
using: sun (egyptians, greek, indians, chinese, arabs, romans, english invented even a portable sundial)
water clocks (egypt, china, …) and sand clocks
galileo was using heartbeat in his experiments to measure time
at night stars were used and nocturnals were made
also combinations to correct, for instance the octogonal tower of the winds on acropolis athens
and the famous su song construction 1090 AD who made mechanical clocks with a water wheel
most of the mechanical devices have to deal with
- power source
- a regulator to beat out ticks
- the escapement mechanism to release energy
an interesting change was the application of the pendulum from the 16th century on (galileo, marsenne, huygens)
still there was an accuracy problem of approx. 15 mins per day
from mid 18th century the first cuckoo clocks appeared in bavaria, the origin is uncertain but the combination with the mechanical bird is strange, no?
in the 18th century too the first more exact marine chronometers appear
in the 20 century we see the invention of
- electric clocks
- quartz chrystal
- atomic clock
the history of complex astronomical clocks goes back to greek antiquity (archimedes, but also in persia, and china)
interesting ideas:
- time zones (greenwich)
- daylight savings (benjamin franklin first introduced it in 1784 in us, and in europe it was implemented during WW1 by the germans)
- worldwide standards, atomic time since 1972 (UT1 + UT2 = UTC, starting at midnight)
- networks and internet, greenwich mean time (GMT)
nicearticle by Mike Chirico about time, clocks and … Linux