Browse Definitions :
Definition

atomic clock (NIST-F1)

An atomic clock is the most accurate type of timepiece in the world, designed to measure time according to vibrations within atoms. NIST-F1, the United States' standard atomic clock, is said to be so accurate that it would neither gain nor lose a second in over 30 million years. Atomic clocks are used to coordinate systems that require extreme precision, such as Global Positioning System ( GPS ) navigation and the Internet. A group of atomic clocks located in a number of places throughout the world is used in conjunction to establish Coordinated Universal Time ( UTC ).

Like a regular clock, an atomic clock keeps time according to oscillation, which is a periodic variation or movement between two entities or between two states of a single entity, created by changes in energy. In a pendulum-driven clock, for example, the oscillation is the back and forth movement of the pendulum (the oscillator ). Such a clock keeps time according to the frequency of the pendulum's swing, which will be more or less accurate, depending on a number of variables. The precision of an atomic clock, on the other hand, depends upon the fact that an atom, caused to oscillate, will always vibrate at the same frequency.

In 1945, Isidor Rabi, a physics professor at Columbia University, proposed that atomic vibrations could be used to keep time, based on something he'd developed called atomic beam magnetic resonance. Four years later, the National Bureau of Standards (now the National Institute of Standards and Technology ) had developed an atomic clock that used the vibrations of ammonia molecules. NIST-F1, the United States' current standard, uses cesium atoms; it and a similar atomic clock standard in Paris are the most accurate timepieces ever made.

The first commercial cesium-based atomic clocks were manufactured by the National Company, a Massachusetts-based firm; Frequency Electronics, FTS, and Hewlett-Packard ( HP ) are among the companies producing them today. Atomic clocks have never been widely used in consumer products because they are typically large and use too much power. Recently, however, NIST developed an atomic clockwork that overcomes these problems. About the size of a grain of rice and accurate to within one second in 126 years, the new mechanism could soon be manufactured on computer chips and used in consumer market handheld devices, such as radios, GPS systems, and cellular telephones.

This was last updated in March 2011

Continue Reading About atomic clock (NIST-F1)

Join the conversation

2 comments

Send me notifications when other members comment.

Please create a username to comment.

Just reading the English translation of Einstein's article on "On the electrodynamics of moving bodies" and noticed a comment in Section 5 - "7 Not a pendulum-clock, which is physically a system to which the Earth belongs. This
case had to be excluded". My assumption has been that all clocks measure the same equivalent time. Can anyone explain why a pendulum clock is different? Newton actually took account of pendulum clock differences at different latitudes in The Principia.
Cancel
hey,its nice content but little more bit in http://knowledgeistheweapon.blogspot.in/.go and find it
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

SearchCompliance

  • compliance audit

    A compliance audit is a comprehensive review of an organization's adherence to regulatory guidelines.

  • regulatory compliance

    Regulatory compliance is an organization's adherence to laws, regulations, guidelines and specifications relevant to its business...

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

SearchSecurity

  • RSA algorithm (Rivest-Shamir-Adleman)

    The RSA algorithm is the basis of a cryptosystem -- a suite of cryptographic algorithms that are used for specific security ...

  • remote access

    Remote access is the ability to access a computer or a network remotely through a network connection.

  • IP Spoofing

    IP spoofing is the crafting of Internet Protocol (IP) packets with a source IP address that has been modified to impersonate ...

SearchHealthIT

SearchDisasterRecovery

  • network disaster recovery plan

    A network disaster recovery plan is a set of procedures designed to prepare an organization to respond to an interruption of ...

  • virtual disaster recovery

    Virtual disaster recovery is a type of DR that typically involves replication and allows a user to fail over to virtualized ...

  • tabletop exercise (TTX)

    A tabletop exercise (TTX) is a disaster preparedness activity that takes participants through the process of dealing with a ...

SearchStorage

  • enterprise storage

    Enterprise storage is a centralized repository for business information that provides common data management, protection and data...

  • disk array

    A disk array, also called a storage array, is a data storage system used for block-based storage, file-based storage or object ...

  • optical storage

    Optical storage is any storage type in which data is written and read with a laser. Typically, data is written to optical media, ...

Close