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- Atomic_clock abstract "An atomic clock is a clock device that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element. Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.The principle of operation of an atomic clock is not based on nuclear physics, but rather on atomic physics and using the microwave signal that electrons in atoms emit when they change energy levels. Early atomic clocks were based on masers at room temperature. Currently, the most accurate atomic clocks first cool the atoms to near absolute zero temperature by slowing them with lasers and probing them in atomic fountains in a microwave-filled cavity. An example of this is the NIST-F1 atomic clock, one of the U.S.'s national primary time and frequency standards.The accuracy of an atomic clock depends on two factors. The first factor is temperature of the sample atoms—colder atoms move much more slowly, allowing longer probe times. The second factor is the frequency and intrinsic width of the electronic transition. Higher frequencies and narrow lines increase the precision.National standards agencies in most industrialised and semi-industrialised countries maintain an accuracy of 10−9 seconds per day (approximately 1 part in 1014), and a precision set by the radio transmitter pumping the maser. These clocks collectively define a continuous and stable time scale, International Atomic Time (TAI). For civil time, another time scale is disseminated, Coordinated Universal Time (UTC). UTC is derived from TAI, but approximately synchronised, by using leap seconds, to UT1, which is based on actual rotations of the Earth with respect to the solar time.".
- Atomic_clock thumbnail FOCS-1.jpg?width=300.
- Atomic_clock wikiPageExternalLink Q10.
- Atomic_clock wikiPageExternalLink femtosecond.
- Atomic_clock wikiPageExternalLink optical.
- Atomic_clock wikiPageExternalLink 104302.
- Atomic_clock wikiPageExternalLink 4023777.stm.
- Atomic_clock wikiPageExternalLink nist.time.gov.
- Atomic_clock wikiPageExternalLink a112z506.pdf.
- Atomic_clock wikiPageExternalLink tycho.usno.navy.mil.
- Atomic_clock wikiPageExternalLink its.htm.
- Atomic_clock wikiPageExternalLink miniclock.htm.
- Atomic_clock wikiPageExternalLink server.php?show=ConWebDoc.971.
- Atomic_clock wikiPageExternalLink time.
- Atomic_clock wikiPageExternalLink www.ptb.de.
- Atomic_clock wikiPageExternalLink atomic_clocks.aspx?keywords=atomic.
- Atomic_clock wikiPageID "25453985".
- Atomic_clock wikiPageRevisionID "606737926".
- Atomic_clock application Global_Positioning_System.
- Atomic_clock caption "FOCS 1, a continuous cold caesium fountain atomic clock in Switzerland, started operating in 2004 at an uncertainty of one second in 30 million years.".
- Atomic_clock classification Clock.
- Atomic_clock fuelSource Electricity.
- Atomic_clock hasPhotoCollection Atomic_clock.
- Atomic_clock industry Science.
- Atomic_clock industry Telecommunication.
- Atomic_clock invented "1949".
- Atomic_clock inventor "US National Bureau of Standards".
- Atomic_clock name "Atomic clock".
- Atomic_clock powered "Yes".
- Atomic_clock subject Category:Atomic_clocks.
- Atomic_clock subject Category:Clocks.
- Atomic_clock subject Category:Electronic_test_equipment.
- Atomic_clock subject Category:Horology.
- Atomic_clock comment "An atomic clock is a clock device that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element.".
- Atomic_clock label "Atomic clock".
- Atomic_clock label "Atomuhr".
- Atomic_clock label "Atoomklok".
- Atomic_clock label "Horloge atomique".
- Atomic_clock label "Orologio atomico".
- Atomic_clock label "Reloj atómico".
- Atomic_clock label "Relógio atômico".
- Atomic_clock label "Zegar atomowy".
- Atomic_clock label "Атомные часы".
- Atomic_clock label "ساعة ذرية".
- Atomic_clock label "原子時計".
- Atomic_clock label "原子鐘".
- Atomic_clock sameAs Atomové_hodiny.
- Atomic_clock sameAs Atomuhr.
- Atomic_clock sameAs Ατομικό_ρολόι.
- Atomic_clock sameAs Reloj_atómico.
- Atomic_clock sameAs Horloge_atomique.
- Atomic_clock sameAs Jam_atom.
- Atomic_clock sameAs Orologio_atomico.
- Atomic_clock sameAs 原子時計.
- Atomic_clock sameAs 원자_시계.
- Atomic_clock sameAs Atoomklok.
- Atomic_clock sameAs Zegar_atomowy.
- Atomic_clock sameAs Relógio_atômico.
- Atomic_clock sameAs m.0x_2.
- Atomic_clock sameAs Q227467.
- Atomic_clock sameAs Q227467.
- Atomic_clock wasDerivedFrom Atomic_clock?oldid=606737926.
- Atomic_clock depiction FOCS-1.jpg.
- Atomic_clock isPrimaryTopicOf Atomic_clock.
