Our universe was born with the Big Bang and with it time was also born. No one can explain exactly what it is. Albert Einstein, the famous physicist, tried it once and said that time is a ‘measure to arrange things one after the other’. We have defined equal sections from the second to the year to understand when an event occurred in the past. For 5000 years, people have been trying to invent all possible instruments for measuring time such as sundials, water clocks, and pendulum clocks. Since 1949 we have the precise atomic clock, which becomes slow by one second in 30 billion years.
