This work shows how the best atomic clocks might be synchronized across remote sites on Earth and, as time signals are transferred over longer distances, even between spacecraft. NIST researchers previously described in detail how they transferred time signals over the air link between two of the clocks, the NIST ytterbium and JILA strontium clocks, and found the process worked as well as the fiber-based method and 1,000 times more precisely than conventional wireless transfer schemes. The team’s measurements were so accurate that uncertainties were only 6 to 8 parts in 1018-that is, errors never exceeded 0.000000000000000008-for both fiber and wireless links. The study compared the aluminum-ion clock and ytterbium lattice clock, located in different laboratories at NIST Boulder, with the strontium lattice clock located 1.5 kilometers away at JILA, a joint institute of NIST and the University of Colorado Boulder. The new measurements were challenging because the three types of atoms involved “tick” at vastly different frequencies, because all the many network components had to operate with extreme accuracy, and because the wireless link required cutting-edge laser technology and design. “These comparisons are really defining the state of the art for both fiber-based and free-space measurements-they are all close to 10 times more accurate than any clock comparisons using different atoms performed so far,” NIST physicist David Hume said. These atomic clock comparisons place the scientific community one step closer to meeting the guidelines for redefinition of the second. Even the atomic clock time has a deviation but is 99.999999999999 (much more 9's behind the decimal point)% accurate.In a significant advance toward the future redefinition of the international unit of time, the second, a research team led by the National Institute of Standards and Technology (NIST) has compared three of the world’s leading atomic clocks with record accuracy over both air and optical fiber links.ĭescribed in the March 25 issue of Nature, the NIST-led work is the first to compare three clocks, based on different atoms, and the first to link the most advanced atomic clocks in different locations over the air. Measured over billions of years there will always be a small deviation. Almost, because it is impossible to display 100% correct time. With a watch controlled by an atomic clock, you (almost) always have the correct time at hand. For example, Citizen indicates that the latest radio-controlled Citizen Promasters have a deviation of no more than 1 second per 1 million years!Īlso read: '5 cool men's watches without battery!' These radio controlled watches have only a minimal deviation. The main advantage of a watch with atomic clock time is that it is very accurate and very precise. How accurate is a watch with an atomic clock? So our Citizen radio-controlled watches are actually atomic clock watches. That makes these types of timepieces very accurate. So watches with atomic clock time receive a signal and use that signal to set the time correctly. We even have them in our shop, you can find them here. There are many such watches on the market and Citizen, among others, has a collection of radio-controlled Promasters that receive the signal from an atomic clock. But controlling a watch with the signal from an atomic clock is possible. Okay, an atomic clock in a watch is not possible. We'll explain how that works.Ĭitizen AT9030-55L Atomic clock time watch But a watch can be controlled by an atomic clock. An atomic clock is not going to fit in the average wristwatch because it is a complex, expensive and large installation. Consider, for example, GPS satellites, but much closer to home we also find applications that are synchronized by an atomic clock: alarm clocks, station clocks, traffic lights, switches. In fact, we all use technology that is controlled by an atomic clock. Tip: Citizen Eco Drive watches with solar cell > The atomic clock is therefore incredibly accurate with a deviation of no more than 1 second every 5 billion years. They vibrate so constantly that you can set a clock to them. Those atoms vibrate very constantly and with a very high frequency.

An atomic clock is the most accurate in timekeeping, but what about watches? Are there watches with an atomic clock or are there movements as accurate as an atomic clock?Īn atomic clock is a clock that is controlled by the vibrations of atoms. You would almost forget that a good timepiece should really excel in one thing: accurately displaying the time. Altimeters, depth gauges, chronographs, you name it and you will find a watch equipped with these tools. Nowadays you can buy watches with all kinds of extensive and useful functions.

Atomic clocks with accuracy