Posted by Richard N Williams on September 2nd, 2011
Researchers have discovered that the British atomic clock controlled by the UK’s National Physical Laboratory (NPL) is the most accurate in the world.
NPL’s CsF2 caesium fountain atomic clock is so accurate that it wouldn’t drift by a second in 138 million years, nearly twice as accurate as first thought.
Researchers have now discovered the clock is accurate to one part in 4,300,000,000,000,000 making it the most accurate atomic clock in the world.
The CsF2 clock uses the energy state of caesium atoms to keep time. With a frequency of 9,192,631,770 peaks and troughs every second, this resonance now governs the international standard for an official second.
The international standard of time—UTC—is governed by six atomic clocks, including the CsF2, two clocks in France, one in Germany and one in the USA, so this unexpected increase in accuracy means the global timescale is even more reliable than first thought.
UTC is essential for modern technologies, especially with so much global communication and trade being conducted across the internet, across borders, and across timezones.
UTC enables separate computer networks in different parts of the world to keep exactly the same time, and because of its importance accuracy and precision is essential, especially when you consider the types of transactions now conducted online, such as the buying of stocks and shares and global banking.
Receiving UTC requires the use of a time server and the protocol NTP (Network Time Protocol). Time servers receive a source of UTC direct from atomic clocks sources such as NPL, who broadcast a time signal over long wave radio, and the GPS network (GPS satellites all transmit atomic clock time signals, which is how satellite navigation systems calculate position by working out the difference in time between multiple GPS signals.)
NTP keeps all computers accurate to UTC by continuously checking each system clock and adjusting for any drift compared to the UTC time signal. By using an NTP time server, a network of computers is able to remain within a few milliseconds of UTC preventing any errors, ensuring security and providing an attestable source of accurate time.