Clock Wikipedia. A clock is an instrument to measure, keep, and indicate time. The word clock is derived via Dutch, Northern French, and Medieval Latin from the Celtic words clagan and clocca meaning bell. A silent instrument missing such a striking mechanism has traditionally been known as a timepiece. 1 In general usage today, a clock refers to any device for measuring and displaying the time. Watches and other timepieces that can be carried on ones person are often distinguished from clocks. 2The clock is one of the oldest human inventions, meeting the need to measure intervals of time shorter than the natural units the day, the lunar month, and the year. Devices operating on several physical processes have been used over the millennia. Whole Class Clock The Whole Class Clock allows teachers to set any time and transfer between analogue and digital displays. A sundial shows the time by displaying the position of a shadow on a flat surface. There is a range of duration timers, a well known example being the hourglass. Water clocks, along with the sundials, are possibly the oldest time measuring instruments. A major advance occurred with the invention of the verge escapement, which made possible the first mechanical clocks around 1. Europe, which kept time with oscillating timekeepers like balance wheels. 3456 Spring driven clocks appeared during the 1. During the 1. 5th and 1. The next development in accuracy occurred after 1. A major stimulus to improving the accuracy and reliability of clocks was the importance of precise time keeping for navigation. The electric clock was patented in 1. The development of electronics in the 2. The timekeeping element in every modern clock is a harmonic oscillator, a physical object resonator that vibrates or oscillates at a particular frequency. 4 This object can be a pendulum, a tuning fork, a quartz crystal, or the vibration of electrons in atoms as they emit microwaves. Analog clocks usually indicate time using angles. Digital clocks display a numeric representation of time. Two numeric display formats are commonly used on digital clocks 2. Most digital clocks use electronic mechanisms and LCD, LED, or VFD displays. For convenience, distance, telephony or blindness, auditory clocks present the time as sounds. There are also clocks for the blind that have displays that can be read by using the sense of touch. Some of these are similar to normal analog displays, but are constructed so the hands can be felt without damaging them.
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