| Most people have vaguely heard of the atomic | | | | server that receives the time from an atomic |
| clock and presume they know what one is but | | | | clock. |
| very few people know just how important atomic | | | | Devices like the NTP time server often receive |
| clocks are for the running of our day to day lives | | | | atomic clock signals form places such as NIST or |
| in the twenty first century. | | | | NPL via long wave radio. Another method for |
| There are so many technologies that are reliant | | | | receiving time from atomic clocks is using the |
| on atomic clocks and without many of the tasks | | | | GPS network (Global Positioning System). |
| we take for granted would be impossible. Air | | | | The GPS network and satellite navigation are in |
| traffic control, satellite navigation and internet | | | | fact a good example of why atomic clocks are |
| trading are just a few of the applications that are | | | | needed with such high accuracy. Modern atomic |
| reliant on the ultra precise chronometry of an | | | | clocks such as those found at NIST, NPL and |
| atomic clock. | | | | inside orbiting GPS satellites are accurate to within |
| Exactly what an atomic clock is, is often | | | | a second every 100 million years or so. This |
| misunderstood. In simple terms an atomic clock is | | | | accuracy is crucial when you examine how |
| a device that uses the oscillations of atoms at | | | | something like a cars GPS satellite navigation |
| different energy states to count ticks between | | | | system works. |
| seconds. Currently caesium is the preferred atom | | | | A GPS system works by triangulating the time |
| because it has over 9 billion ticks every second | | | | signals sent from three or more separate GPS |
| and because these oscillations never change it | | | | satellites and their onboard atomic clocks. Because |
| makes them a highly accurate method of keeping | | | | these signals travel at the speed of light (nearly |
| time. | | | | 100,000km a second) an inaccuracy of even one |
| Atomic clocks despite what many people claim | | | | whole millisecond could put the navigational |
| are only ever found in large scale physics | | | | information out by 100 kilometres. |
| laboratories such as NPL (UK National Physical | | | | This high level of accuracy is also required for |
| Laboratory) and NIST (US National Institute of | | | | technologies such as air traffic control ensuring |
| Standards and Time). Often people suggest they | | | | our crowded skies remain safe and is even critical |
| have an atomic clock that controls their computer | | | | for many Internet transactions such as trading in |
| network or that they have an atomic clock on | | | | derivatives where the value can rise and fall |
| their wall. This is not true and what people are | | | | every second. |
| referring to is that they have a clock or time | | | | |