Till a few years back.clocks which used digital technology were the ones which were the most accurate.They were reputed to function within one thousandth of the set time,however,the time being set had to entered manually;this was the biggest drawback of such clocks.Considering as if this accuracy was not enough,the scientists went ahead and discovered a technology where the time to be entered could be controlled automatically,and thus giving the atomic clocks were born.Yes,you are reading it correctly,Atomic clocks.These clocks use radioactive properties for calculating time accuartely.Well,the answer to how these atomic clocks functions is as following.



The applications of atomic clocks are more farfetched than you can possibly imagine. Without these clocks, GPS is not possible, internet connections between far apart regions are nearly impossible, just to mention a few. So actually what is there in these wonderful clocks that make them so precise? Are they radioactive?There are a few basic things that you need to know first, the time in the US is maintained by a clock called the "US naval observatory’s master clock".

These clocks can perform maintaining a precision of 10-9 seconds per day, making almost accurate time calculations, and they are not radioactive to a level that would cause concern, they are perfectly safe for public use. These clocks rely on microwave signals which are emitted from atoms when they change energy levels. Technically speaking, one second is defined as 9,192,631,770 cycles of radiation corresponding to the transition between two energy levels of the ground state of the caesium-133 atom. Too technical for a common man to understand, it means that within a second a caesium atom will make that many numbers of transitions from ground state. If a definite means of measuring that many numbers of transitions is found, then it will be the most precise clock ever made. This is the working logic behind atomic clocks. These clocks just make use of caesium as oscillating mass and a spring to measure time precisely. The frequency with which this clock’s nucleus oscillates is used as the basic measure to calculate time.

There is no need to set the time of this clock manually. These clocks receive signals from the master clocks located far away. The master clocks transmit the accurate time also calculating the time lag between time taken to travel along air, so when the beam of signal reaches the watch, time is adjusted automatically by in built software to display the most accurate time possible, these are atomic wrist watches.There are three types of atomic clocks; they are caesium clocks, hydrogen clocks and rubidium clocks, amongst these the rubidium clocks are the most compact. But for practical public use, it is nearly impossible to carry these radioactive clocks which are big and bulky. So watch companies made use of a simple transmitter receiver pairing to eliminate this problem. A master clock is set up in certain places using the principle described earlier and wrist watches are fixed with a low power receiver. Whenever a user buys such a clock, his clock runs normally as other clocks but there is a small twist in the functioning mechanism.

Thus these creations stand testament to human ingenuity and creativity and push us a little bit closer towards mastering the time domain.