The magic wavelength of cadmium

Researchers experimentally determined a property of cadmium called the magic wavelength which is considered essential for the development of the most accurate clocks ever envisaged. The researchers hope this may permit simple ...

Team shows atoms can receive common communications signals

Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a new type of sensor that uses atoms to receive commonly used communications signals. This atom-based receiver has the potential to ...

NASA activates Deep Space Atomic Clock

An atomic clock that could pave the way for autonomous deep space travel was successfully activated last week and is ready to begin its year-long tech demo, the mission team confirmed on Friday, Aug. 23, 2019. Launched in ...

Redefining the limits of measurement accuracy

For centuries, humans have been expanding their understanding of the world through more and more precise measurement of light and matter. Today, quantum sensors achieve extremely accurate results. An example of this is the ...

SpaceX launches hefty rocket with 24 satellites, experiments

SpaceX launched its heftiest rocket with 24 research satellites Tuesday, a middle-of-the-night rideshare featuring a deep space atomic clock, solar sail, a clean and green rocket fuel testbed, and even human ashes.

Five things to know about NASA's Deep Space Atomic Clock

NASA is sending a new technology to space on June 22 that will change the way we navigate our spacecraft—even how we send astronauts to Mars and beyond. Built by NASA's Jet Propulsion Laboratory in Pasadena, California, ...

Quantum computing boost from vapour stabilising technique

A technique to stabilise alkali metal vapour density using gold nanoparticles, so electrons can be accessed for applications including quantum computing, atom cooling and precision measurements, has been patented by scientists ...

Adding satnav to turn power grids into smart systems

An ESA-backed project is harnessing satnav to insert an intelligent sense of place and time to power grids, to provide early warning of potentially dangerous electricity network failures.

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Atomic clock

An atomic clock is a type of clock that uses an atomic resonance frequency standard as its timekeeping element. They are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, and to control the frequency of television broadcasts and GPS satellite signals.

Atomic clocks do not use radioactivity, but rather the precise microwave signal that electrons in atoms emit when they change energy levels. Early atomic clocks were masers with attached equipment. Currently the most accurate atomic clocks are based on absorption spectroscopy of cold atoms in atomic fountains such as the NIST-F1.

National standards agencies 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. The clocks maintain 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 synchronized, by using leap seconds, to UT1, which is based on actual rotations of the earth with respect to the mean sun.

This text uses material from Wikipedia, licensed under CC BY-SA