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3500 BCE
Sun Watch
The Egyptians made the first sundial, in which the shadow formed by the staff indicates the hours throughout the day -
725 BCE
water clock
in China a mechanical clock was developed that had a complex gear system and 60 buckets of water corresponding to 60 seconds -
600 BCE
clepsidras and hourglasses
Water and sand clocks were developed in Babylon, Egypt and Judea. -
Period: 200 BCE to 101 BCE
time count
division of the day in 24 hours based on the equinoxes and segmentation in 60 minutes, each with 60 seconds with the studies of the Greek astronomer Eratosthenes. -
1000
first mechanical clock
about 1200 in northern europe, but there are records in asia too -
1335
Public clock
in Milan, the first public clock that marked the hours was erected -
1500
pocket clock
first pocket clocks unveiled, precursors of: spiral spring -
1580
pendulum clock
from the studies of Galileo the pendulum clock was created -
Wristwatch
possibly created by santos dumont becoming popular at the end of the second world war -
Period: to
quartz clock
diffusion of quartz watches where mechanical vibrations of this mineral are used -
atomic clock
the second was redefined as the duration of 9,192,631,770 periods of radiation resulting from the energy transitions of the cesium atom -
digital clock
first commercially launched using piezoelectric crystal, capable of generating electrical pulses at a constant frequency (usually 50 or 60 Hz -
digital technology
Advances in digital technology have evolved clocks
