News tagged with atomic clocks
Precision time: A matter of atoms, clocks, and statistics
Time is of the essence, especially in communications, navigation, and electric power distribution, which all demand nanosecond precision or better. Keeping these beating hearts of technology in near-perfect global synchronization ...
Feb 01, 2012 |
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Physicists create first 'frequency comb' to probe ultraviolet wavelengths
Physicists at JILA have created the first "frequency comb" in the extreme ultraviolet band of the spectrum, high-energy light less than 100 nanometers (nm) in wavelength. Laser-generated frequency combs are the most accurate ...
Feb 01, 2012 |
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World timekeepers split on scrapping leap second
Timekeepers meeting in Geneva failed to agree Thursday on a proposal to abolish a 40-year-old practice of adding the occasional second to world time.
Jan 19, 2012 |
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'Leap second' under the gun at Geneva time talks
Timekeepers gathered in Geneva on Thursday to thrash out a contested proposal to abolish a 40-year-old practice of adding the occasional second to world time.
Space & Earth / Space Exploration
Jan 19, 2012 |
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Countries consider time out on the 'leap second'
It's high noon for the humble leap second. After ten years of talks, governments are headed for a showdown vote this week on an issue that pits technological precision against nature's whims.
Space & Earth / Earth Sciences
Jan 17, 2012 |
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The nuclear, biological and climate threat - 2011 reviewed
In this special issue of the Bulletin of the Atomic Scientists, published by SAGE, experts reflect on 2011 and highlight what to look out for in 2012 in the areas of nuclear energy, nuclear weapons, biosecurity, and climat ...
Technology / Energy & Green Tech
Jan 06, 2012 |
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More accurate than Santa Claus: First Galileo satellite orbit determination with high precision
Every year for Christmas, the North American Air Defence Command NORAD posts an animation on their website, in which the exact flight path of Santa Claus' sled led by reindeer Rudolf is precisely located (http://www.noradsanta.org/en/). The path of navigation satellites, however, ...
Space & Earth / Space Exploration
Dec 23, 2011 |
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New generation GPS satellite starts tests in Colo.
A $5.5 billion upgrade to the Global Positioning System moved a step closer to launch this week when a prototype arrived at a Lockheed Martin complex in Colorado to begin months of tests.
Dec 13, 2011 |
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Research team shows nuclear clock could be 60 times more accurate than atomic clock
(PhysOrg.com) -- For almost sixty years, the world has considered the atomic clock the gold standard for keeping time. Its accuracy is such that it drifts by only about four seconds over a period of about ...
Nov 09, 2011 |
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Nobel Prize-winning physicist Norman Ramsey dies
(AP) -- Norman Ramsey, who shared the 1989 Nobel Prize in physics for his research into molecules and atoms that led to the creation of the atomic clock, has died in Massachusetts. He was 96.
Nov 07, 2011 |
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Putting artificial atoms on the clock
Around the turn of the century, scientists began to understand that atoms have discrete energy levels. Within the field of quantum physics, this sparked the development of quantum optics in which light is ...
Nov 07, 2011 |
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Scientists meet to discuss usefulness of GMT
Leading scientists from around the world are meeting in Britain from Thursday to consider a proposal that could eventually see Greenwich Mean Time relegated to a footnote in history.
Nov 03, 2011 |
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NASA to test new atomic clock
When people think of space technologies, many think of solar panels, propulsion systems and guidance systems. One important piece of technology in spaceflight is an accurate timing device.
Space & Earth / Space Exploration
Oct 17, 2011 |
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Factfile on Galileo, Europe's rival to GPS
Following is a snapshot of Europe's Galileo space-based navigation system, the first satellites of which are scheduled to be launched on Thursday from Kourou, French Guiana.
Space & Earth / Space Exploration
Oct 16, 2011 |
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New record for measurement of atomic lifetime
Researchers at the Niels Bohr Institute have measured the lifetime of an extremely stable energy level of magnesium atoms with great precision. Magnesium atoms are used in research with ultra-precise atomic ...
Sep 07, 2011 |
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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.
For more information about Atomic clock, read the full article at
Wikipedia.
This text uses material from Wikipedia and is available under the GNU Free Documentation License.
