Precision is becoming increasingly important in modern technologies and none more so than accuracy in time keeping. From the internet to satellite navigation, precise and accurate synchronicity is vital in the modern age.
In fact many of the technologies that we take for granted in today’s world, would not be possible if it wasn’t for the most accurate machines invented – the atomic clock.
Atomic clocks are just timekeeping devices like other clocks or watches. But what stands them apart is the accuracy they can achieve. As a crude example your standard mechanical clock, such as a town centre clock tower, will drift by as much as a second a day. Electronic clocks such as digital watches or clock radios are more accurate. These types of clock drift a second in about a week.
However, when you compare the precision of an atomic clock in which a second will not be lost or gained in 100,000 years or more the accuracy of these devices is incomparable.
Atomic clocks can achieve this accuracy by the oscillators they use. Nearly all types of clock have an oscillator. In general, an oscillator is just a circuit that regularly ticks.
Mechanical clocks use pendulums and springs to provide a regular oscillation while electronic clocks have a crystal (usually quartz) that when an electric current is run through, provides an accurate rhythm.
Atomic clocks use the oscillation of atoms during different energy states. Often caesium 133 (and sometimes rubidium) is used as its hyperfine transitional oscillation is over 9 billion times a second (9,192,631,770) and this never changes. In fact, the International System of Units (SI) now officially regards a second in time as 9,192,631,770 cycles of radiation from the caesium atom.
Atomic clocks provide the basis for the world’s global timescale – UTC (Coordinated Universal Time). And computer networks all over the world stay in sync by using time signals broadcast by atomic clocks and picked up on NTP time servers (Network Time Server).