A pendulum clock is a clock that uses a pendulum, a swinging weight, as its timekeeping element. The advantage of a pendulum for timekeeping is that it is an approximate harmonic oscillator: It swings back and forth in a precise time interval dependent on its length, and resists swinging at other rates. From its invention in 1656 by Christiaan Huygens, inspired by Galileo Galilei, until the 1930s, the pendulum clock was the world's most precise timekeeper, accounting for its widespread use. Throughout the 18th and 19th centuries, pendulum clocks in homes, factories, offices, and railroad stations served as primary time standards for scheduling daily life, work shifts, and public transportation. Their greater accuracy allowed for the faster pace of life which was necessary for the Industrial Revolution. The home pendulum clock was replaced by less-expensive synchronous electric clocks in the 1930s and '40s. Pendulum clocks are now kept mostly for their decorative and antique value.
The second is the unit of time in the International System of Units (SI), historically defined as 1⁄86400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each. "Minute" comes from the Latin pars minuta prima, meaning "first small part", and "second" comes from the pars minuta secunda, "second small part".
A watch is a portable timepiece intended to be carried or worn by a person. It is designed to keep a consistent movement despite the motions caused by the person's activities. A wristwatch is designed to be worn around the wrist, attached by a watch strap or other type of bracelet, including metal bands, leather straps, or any other kind of bracelet. A pocket watch is designed for a person to carry in a pocket, often attached to a chain.
A radio clock or radio-controlled clock (RCC), and often colloquially referred to as an "atomic clock", is a type of quartz clock or watch that is automatically synchronized to a time code transmitted by a radio transmitter connected to a time standard such as an atomic clock. Such a clock may be synchronized to the time sent by a single transmitter, such as many national or regional time transmitters, or may use the multiple transmitters used by satellite navigation systems such as Global Positioning System. Such systems may be used to automatically set clocks or for any purpose where accurate time is needed. Radio clocks may include any feature available for a clock, such as alarm function, display of ambient temperature and humidity, broadcast radio reception, etc.
Seiko Group Corporation, commonly known as Seiko, is a Japanese maker of watches, clocks, electronic devices, semiconductors, jewelry, and optical products. Founded in 1881 by Kintarō Hattori in Tokyo, Seiko introduced the world's first commercial quartz wristwatch in 1969.
A stopwatch is a timepiece designed to measure the amount of time that elapses between its activation and deactivation.
A time clock, sometimes known as a clock card machine or punch clock or time recorder, is a device that records start and end times for hourly employees at a place of business.
A balance wheel, or balance, is the timekeeping device used in mechanical watches and small clocks, analogous to the pendulum in a pendulum clock. It is a weighted wheel that rotates back and forth, being returned toward its center position by a spiral torsion spring, known as the balance spring or hairspring. It is driven by the escapement, which transforms the rotating motion of the watch gear train into impulses delivered to the balance wheel. Each swing of the wheel allows the gear train to advance a set amount, moving the hands forward. The balance wheel and hairspring together form a harmonic oscillator, which due to resonance oscillates preferentially at a certain rate, its resonant frequency or "beat", and resists oscillating at other rates. The combination of the mass of the balance wheel and the elasticity of the spring keep the time between each oscillation or "tick" very constant, accounting for its nearly universal use as the timekeeper in mechanical watches to the present. From its invention in the 14th century until tuning fork and quartz movements became available in the 1960s, virtually every portable timekeeping device used some form of balance wheel.
Citizen Watch Co., Ltd. is an electronics company primarily known for its watches and is the core company of a Japanese global corporate group based in Nishitokyo, Tokyo, Japan. In addition to Citizen brand watches, it is the parent of American watch company Bulova, and is also known for manufacturing small electronic devices such as calculators.
Chronometry or horology is the science of the measurement of time, or timekeeping. Chronometry provides a standard of measurement for time, and therefore serves as a significant reference for many and various fields of science.
A balance spring, or hairspring, is a spring attached to the balance wheel in mechanical timepieces. It causes the balance wheel to oscillate with a resonant frequency when the timepiece is running, which controls the speed at which the wheels of the timepiece turn, thus the rate of movement of the hands. A regulator lever is often fitted, which can be used to alter the free length of the spring and thereby adjust the rate of the timepiece.
A Japanese clock is a mechanical clock that has been made to tell traditional Japanese time, a system in which daytime and nighttime are always divided into six periods whose lengths consequently change with the season. Mechanical clocks were introduced into Japan by Jesuit missionaries or Dutch merchants. These clocks were of the lantern clock design, typically made of brass or iron, and used the relatively primitive verge and foliot escapement. Tokugawa Ieyasu owned a lantern clock of European manufacture.
The Casio F-91W is a digital watch manufactured by Japanese electronics company Casio. Introduced in June 1989 as a successor of the F-87W, it is popular for its low price and long battery life.
Galileo's escapement is a design for a clock escapement, invented around 1637 by Italian scientist Galileo Galilei (1564–1642). Galileo was one of the leading minds of the Scientific Revolution. He was dubbed the founder of theoretical physics. He is also credited with the invention of the celatone and the geometric and military compass. Galileo's escapement was the earliest design of a pendulum clock. Since Galileo was by then blind, he described the device to his son Vincenzio, who drew a sketch of it. The son began construction of a prototype, but both he and Galileo died before it was completed.
The National Watch and Clock Museum (NWCM), located in Columbia, Pennsylvania, is one of a very few museums in the United States dedicated solely to horology, which is the history, science and art of timekeeping and timekeepers.
A chronometer is an extraordinarily accurate mechanical timepiece, with an original focus on the needs of maritime navigation. In Switzerland, timepieces certified by the Contrôle Officiel Suisse des Chronomètres (COSC) may be marked as Certified Chronometer or Officially Certified Chronometer. Outside Switzerland, equivalent bodies, such as the Japan Chronometer Inspection Institute, have in the past certified timepieces to similar standards, although use of the term has not always been strictly controlled.
The history of timekeeping devices dates back to when ancient civilizations first observed astronomical bodies as they moved across the sky. Devices and methods for keeping time have gradually improved through a series of new inventions, starting with measuring time by continuous processes, such as the flow of liquid in water clocks, to mechanical clocks, and eventually repetitive, oscillatory processes, such as the swing of pendulums. Oscillating timekeepers are used in all modern timepieces.
A circadian advantage is an advantage gained when an organism's biological cycles are in tune with its surroundings. It is not a well studied phenomenon, but it is known to occur in certain types of cyanobacteria, whose endogenous cycles, or circadian rhythm, "resonates" or aligns with their environment. It is known to occur in plants also, suggesting that any organism which is able to attune its natural growth cycles with its environment will have a competitive advantage over those that do not. Circadian advantage may also refer to sporting teams gaining an advantage by acclimatizing to the time zone where a match is played.
Gallet (ˈgæl.eɪ) is a historic Swiss manufacturer of high-end timepieces for professional, military, sports, racing, and aviation use. Gallet is the world's oldest clock making house with history dating back to Humbertus Gallet, a clock maker who became a citizen of Geneva in 1466. The Gallet & Cie name was officially registered by Julien Gallet (1806–1849) in 1826, who moved the family business from Geneva to La Chaux-de-Fonds, Switzerland. Prior to this date, operations commenced under the name of each of the Gallet family patriarchs.
Clock is a timekeeping mobile app available since the initial launch of the iPhone and iPhone OS 1 in 2007, with a version later released for iPads with iOS 6, and Macs with the release of macOS Ventura. The app consists of a world clock, alarm, stopwatch, and timer.
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