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Jan 1, 1000
Sundial Used in Egypt - 1500 B.C.
Ancient Egyptians used sticks and poles to shadow the sun and find the time. This was a advancement in place of telling the time by looking at the seasons and at day and night. It is a circle with marking to symbol the time of day.
http://www.time-for-time.com/history.htm -
Jan 1, 1000
Greeks Use Water Clock - 400 B.C.
The Water Clocks were measured by how long it took water to flow from a vessel. These clocks were calibrated with the sundials which were the more popular clocks of the time period.
http://www.time-for-time.com/clocks.htm -
Jan 1, 1000
Saxons Use Candles as Clocks - 980 A.D.
These clocks measured how large a candle was after burning for a period of time, this was calibrated with the sundials and water clocks, then this length was marked and thats how these candles told time. They use the length that the candle had left to mark the time of day it was.
http://ezinearticles.com/?Candle-Clocks---History-and-Purpose&id=2132920 -
Period: Jan 1, 1000 to
Timeline of the Clock
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Jan 1, 1400
First Mehanical Clocks are Built in Europe
The first mechanized clocks were built in Renaissance Europe by using sets of weights and springs to keep the clock ticking. The first mechanized clocks in Europe used a mainspring and a balance wheel.
http://www.time-for-time.com/timeline.htm -
Galileo and Pendulums
Galileo used math to calculate that the length of the pendulum determines the frequency, or magnitude. This is the basis for the pendulum clocks that will be built in the future.
http://www.time-for-time.com/timeline.htm -
Huygens and Harrison
Huygens made the worlds first pendulum clock that was more accurate and precise on time and lost less time then any clocks before it, but there was one downfall it can't go on waters. Harrison makes a pendulum clock that can go on sea and land, and also only loses 5 seconds from a trip from England to Jamaica.
http://www.time-for-time.com/timeline.htm -
Professor Rabi Suggests Time Based on Atoms
Rabi suggests that we based time not solely on celestial objects but we engineer and make clocks that are calibrated by atomic elements. Leads way to the definition of a second being defined as a number of times a elctron rotates around a Cesium atom.
http://www.time-for-time.com/timeline.htm -
First Atomic Clock Built
The first atomic clock is built that is more accurate then any clock and is measured by using a chemical called ammonia. Proves Rabi's research to be true about atomic clocks being more capable then other clocks.
http://www.time-for-time.com/timeline.htm -
Second is Formally Defined
The second is formally defined as the number of times it takes a electron of a Cesium atom to rotate around, which is 9,192,631,770. Revolutionizes clocks, loses less than 1/16 of a second per year.