Recording the Passed:
Throughout history we see a symbiotic relationship between time keeping and scientific advancement. Scientific advancement allows for more precise measurement of the passage of time which in turn allows for more precise scientific measurement. As ime keeping became more accurate so did human need for it to be so. Contemporary society is dependent on precise time. All modern technologies such as transportation, communication, financial transactions, manufacturing, electric power, to name a few, rely on precision time keeping and timing. Modern science and technology continue to drive innovation in time keeping which in turn will drive advances in science and technology and the cycle will continue on. More than a half billion watches are sold worldwide. The measurement of the passage of time not only allows us to look back clearly but forward as well.

1500bc
Egyptians create “Shadow Clock” also known as a sun dial. The dial was divided into ten parts with two twilight hours indicated. It required a 180 degree rotation at noon to measure the afternoon hours. The most accurate time measurement device to date, but limited to daytime measurement only do to its reliance on the sun.


325bc
Greeks begin using Clepsydras (Greek for water thieves). Clepsrydras are among the first devices not to be reliant on the movement of celestial bodies to calculate the passage of time. The earliest version of an alarm clock is found in a Greek Clepsydras. Greeks and Romans continue to refine/advance the device between 100 BC and 500 AD. Eventually the inability to accurately calculate/control the flow of water led to other approaches, yet water clocks were still in use in regions of Africa through the early 20th century.


1761
John Harrison, carpenter and self-taught clock maker, wins prize offered by by british government in 1914 to create a time keeping device accurate enough for ship navigation. Harrison’s pocket watch looses only five seconds on a voyage between England and Jamaica.


1949
The Nation Institute of Technology and Standards (NIST) creates the first atomic clock using Amonia. This is soon replaced by the more accurate Cesium atomic clock. In 1967 the Cesium atom’s frequency is internationally recognized as the new unit for time measurement. For the first time the second is not measured by the earth’s motions in space.


1975
Sinclaire releases “The Black Watch”, one of the first production digital watches. Using quartz crystal technology which became the dominant time keeping technology in 1927 due to its accuracy and cost. It remains the predominant mechanism used today. Though the “Black Watch” turned out to be a “lemon” it was a sign of things to come.