History of timekeeping devices

History of timekeeping devices

The current sexagesimal system of time measurement dates to approximately 2000BC from the Sumerians. Many ancient civilizations observed astronomical bodies, often the Sun and Moon, to determine times, dates, and seasons. The oldest known sundial is from Egypt; it dates back to around 1500 BC, and was discovered in the Valley of the Kings in 2013.

About History of timekeeping devices in brief

Summary History of timekeeping devicesThe current sexagesimal system of time measurement dates to approximately 2000 BC from the Sumerians. The Egyptians divided the day into two 12-hour periods, and used large obelisks to track the movement of the sun. They also developed water clocks, which were probably first used in the Precinct of Amun-Re, and later outside Egypt as well. The sundial, another early clock, relies on shadows to provide a good estimate of the hour on a sunny day. The first mechanical clocks, employing the verge escapement mechanism with a foliot or balance wheel timekeeper, were invented in Europe at around the start of the 14th century. The pendulum clock remained the most accurate timekeeper until the 1930s, when quartz oscillators were invented. Atomic clocks are far more accurate than any previous timekeeping device, and are used to calibrate other clocks and to calculate the International Atomic Time. A standardized civil system, Coordinated Universal Time, is based on atomic time. Many ancient civilizations observed astronomical bodies, often the Sun and Moon, to determine times, dates, and seasons. The oldest known sundial is from Egypt; it dates back to around 1500 BC, and was discovered in the Valley of the Kings in 2013. Stone circles, such as England’s Stonehenge, were built in various parts of the world, especially in Prehistoric Europe. They are thought to have been used to time and predict seasonal and annual events such as equinoxes or solstices. As those megalithic civilizations left no recorded history, little is known of their calendars or timekeeping methods.

Mesoamericans similarly modified their usual vigesimal counting system when dealing with calendars to produce a 360-day year. The first calendars may have been created during the last glacial period, by hunter-gatherers who employed tools such as sticks and bones to track phases of the moon or the seasons. A third clock, developed in 1500 BC, measured the passage of time by its non-linear T-square shape by casting a shadow on a non-square crossbar. It was positioned over the eastward in morning so that the rising sun cast a shadow over the marks, turned west at noon and was similar in shape to a c-square clock, measured in the same manner: the obelisk also indicated whether it was morning or afternoon, as well as summer and winter. The invention of the mainspring in the early 15th century allowed portable clocks to be built, evolving into the first pocketwatches by the 17th century, but these were not very accurate until the balance spring was added to the balance wheel in the mid 17th Century. By the 1980s, quartz clocks became the world’s dominant timekeeping technology in both clocks and wristwatches, and by the 1990s they were used in watches and clocks. The earliest known clock with a water-powered escapements mechanism, which transferred rotational energy into intermittent motions, was invented in the 3rd century BC in ancient Greece.