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ผู้เขียน หัวข้อ: History of the clock  (อ่าน 8 ครั้ง)

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History of the clock
« เมื่อ: 12 ตุลาคม 2017, 06:30:35 PM »
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History of the clock

The need to measure time arose with the development of agriculture. Farmers used timing to determine the best sowing times and early lunar calendars.

The Egyptians were the first people who developed widely a means of counting time with calendars and clocks. About 2800 v. They had founded a calendar of 365 days based on their observations of the rise and establishment of bright stars like Sirius and the periodic floods of the Nile on which their agriculture depended. About 2100 v. The Egyptians had found a way to divide the day in 24 hours. At about the same time they made the first sundials or shadow clocks to measure the time during the day. A sundial shows the day in the place of the shadow of an object on which fall the rays of the sun.

Around 1500 BC, when Egypt had invented another more accurate way of telling the time, the water clock or a clepsydra, which used the constant drainage of the water of a ship, to drive a mechanical device that indicated the hour.
The enemies of the Babylonian astronomers voted for the Clepsydra, taking into account the balance caused by the change in the distance between the Earth and the Sun as it moves in an elliptical orbit. By this effect noon could be half an hour before or after the time when the sun is highest in the sky.

Around 270% The Alexandrian engineer Ctesibio designed water clocks, ringing bells, drawing dolls and singing mechanical birds. The water clock remained in use until the development of mechanical watches almost 3000 years later.

However, measuring the short time intervals was possible with the hourglass. The search for exact clocks began with the growing late medieval trade and the first fruits of the scientific revolution. This necessity leads to mechanical clocks that have measured time with simple weighted pendulums. But these were not portable.

The first watches

he invention of the springs and mechanism of inhibition led to the era of portable watches. Inhibition is a mechanism that controls and limits the unwinding of the clock, which otherwise converts a simple unwinding into a controlled and periodic energy release. Inhibition does so by interconnecting with a transmission in a simple manner that switches between a "driven" state and a "free" state, with an abrupt lock at each end of the cycle. Inhibition also for the same reason produces the characteristic noise of mechanical clocks.

 
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