- ammonia clock
- nounan atomic clock based on vibrational frequency of the nitrogen atom in the ammonia molecule• Hypernyms: ↑atomic clock
Useful english dictionary. 2012.
Useful english dictionary. 2012.
atomic clock — noun a timepiece that derives its time scale from the vibration of atoms or molecules • Hypernyms: ↑timepiece, ↑timekeeper, ↑horologe • Hyponyms: ↑ammonia clock, ↑caesium clock * * * noun, pl ⋯ clocks [count] : a special kind of clock … Useful english dictionary
Atomic clock — Nuclear clock redirects here. For the clock as a measure for risk of catastrophic destruction, see Doomsday Clock. For a clock updated by radio signals (commonly but inaccurately called an atomic clock ), see Radio clock. For the album by Zion I … Wikipedia
Atmos clock — Atmos is the brand name of a mechanical clock manufactured by Jaeger LeCoultre in Switzerland which doesn t need to be wound. It gets the energy it needs to run from small temperature changes in the environment, and can run for years without… … Wikipedia
atomic clock — n. an extremely accurate clock whose precision depends upon the very constant frequency at which atoms (or molecules) of certain substances, as of cesium, rubidium, or ammonia, absorb or emit electromagnetic radiation … English World dictionary
atomic clock — noun an extremely accurate type of clock which is regulated by the vibrations of an atomic or molecular system such as caesium or ammonia … English new terms dictionary
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maser — /may zeuhr/, n. a device for amplifying electromagnetic waves by stimulated emission of radiation. Cf. laser. [1950 55; m(icrowave) a(mplification by) s(timulated) e(mission of) r(adiation)] * * * Device that produces and amplifies… … Universalium
Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… … Universalium
Uranus — This article is about the planet. For other uses, see Uranus (disambiguation). Uranus … Wikipedia
History of timekeeping devices — For thousands of years, devices have been used to measure and keep track of time. The current sexagesimal system of time measurement dates to approximately 2000 BC, in Sumer. The Ancient Egyptians divided the day into two 12 hour periods, and… … Wikipedia