When the nano second counts
From ancient stone structures to modern watches and smartphones. Time measurement has always been one of the primal things for humanity.
We need clocks for basic things like cooking and appointments. But when it comes to more difficult things, time measurement must be a perfect as possible. Especially in the fields of science.
Scientist from the old days used their mechanical instruments. In today's world the mechanical devices have been replaced by electronic, digital devices.
Some of our day-to-day technologies are actually sensitive to extremely small changes in time measurements. GPS technology, for instance, is sensitive to the changes in time predicted by Einstein's theory of general relativity. That is, even the infinitesimally small changes in time wrought by orbiting the Earth can make a difference in a GPS system determining your location. If these systems had even more precise measurements of time, they could judge your location more accurately.