Time is something that we are all familiar with, it governs our lives even more so than money and we are constantly ‘at war’ with time as we battle to conduct our daily tasks before it runs out.
Yet when we start to examine time we discover that the concept of time we begin to realise that a non-ending linear distance between different events that we call time is purely a human invention.
Of course time exists but it certainly doesn’t follow the rules that the human concept of time does. It is not never ending or constant and changes and warps depending on speed of observers and the pull of gravity. In fact it was Einstein’s theories on relativity that gave human kind its first glimpse as to what time really is and how it affects our daily lives.
Einstein described a four-dimensional space-time, where time and space are inextricably woven together. This space-time gets warped and bent by gravity slowing time (or our perception of it). Einstein also, he suggested that the speed of light was the only constant in the universe and time altered depending on the relative speed to it.
When it comes to keeping track of time, Einstein’s theories can hamper any attempts at chronology. If both gravity and relative speed can affect time then it becomes difficult to measure time accurately.
We long ago abandoned the idea of using the celestial bodies and Earth’s rotation as a reference for our timekeeping as it was recognised in the early twentieth century that Earth’s rotation wasn’t at all accurate or reliable. Instead, we have depended n the oscillations of atoms to keep track of time. Atomic clocks measure atomic ticks of particular atoms and our concept of time is based on these ticks with every second being equal to over 9 billion oscillation of the caesium atom.
Even though we now base time on atomic oscillations, technologies such as GPS satellites (Global Positioning System) still have to counter the effects of lower gravity. In fact the effects of time can be monitored so accurately thanks to atomic clocks that those at different altitudes above sea level run at slightly differing speeds which has to be compensated for.
Atomic clocks can also be used to synchronise a computer network ensuring that they are running as accurately as possible. Most NTP time servers operate by utilising and distributing the time signal broadcast by an atomic clock (either through GPS or long wave) using the protocol NTP (Network Time Protocol).