Atomic clocks: History and Development

Atomic clocks have been with us for over fifty years and most people have heard of them and I know you are very accurate, but how accurate are they and why do we need accurate clock?

Atomic clocks are used by many of us, although we are not aware of. Moment to say is broadcast around the world and collected some time using the NTP server to synchronize the network, are of vital importance for many technologies such as global satellite navigation and the 'schedule of TV signal.

Before the development of more accurate atomic clock timing devices were electronic watches that losing a second or two every week. These have largely replaced mechanical clocks that are less accurate still.

Humanity has always had a fascination for keeping track of time, but knowing the exact time has never been more important. A second or even a difference of minutes will not affect our daily lives.

However, as technology advanced the need for more precise timing is increased. The satellites are expected to navigate and communicate with Earth for hundreds, thousands, even millions of miles away requires an accurate synchronization. The light and radio waves can then travel 300.000 kilometers per second for slight inaccuracies in time can be huge differences.

The first accurate atomic clock was built in Great Britain's National Physical Laboratory in 1955 by Dr Louis Essen, who founded the clock on the oscillation of cesium -133. The idea was actually first conceived in 1879, when Lord Kelvin proposed that the time-keeping based on how they behaved the atoms would be a better way to count time intervals than anything else.

The first generation of atomic clocks (also known as cesium oscillators) used the frequency of an atom oscillates 9,192,631,770 times per second. Model of Essen was the precision of a second every 300 years, but the evolution of cesium oscillator means that it can now achieve a precision of one second every 80 million years.

Yet, as ever more sophisticated technologies, scientists are looking for a better and more accurate clocks. Rubidium clocks do not provide better accuracy than the standard models of cesium, but they are smaller and less expensive (cesium oscillators are usually only in the physics laboratory scale).

Clocks using only a single atom have been developed that provide more accuracy. A clock based on a single atom of mercury has reached an accuracy of one second in 400 million years and is expected to clock a new type of strontium, which uses light will be even better.

The future of atomic clocks is steadily increasing, with a degree of precision, reducing the size and cost of them. The American National Institute of Standards and Technology (NIST) presented a chip the size of atomic clocks, which guarantees a millisecond precision.

Atomic clocks are now part of our life without the time of the signals that transmit to the world that are supported by modern communication and NTP server shopping on the Internet and GPS technology, such as satellite navigation becomes impossible.