ABSTRACT

Along the evolution path of human species, the sense of time originated from the heavenly rhythm of solar bodies. Our sense of flow of time revolves around the sun: a day is defined by the cycle of sunrise and sunset, a month by the cycle of the moon, and a year by the predictable rhythm of the seasons. During a long period, slowly, we built tools to trace the flow of time more predictably: the sundial was used to track the passage of a day, and celestial observation was used to track seasonal milestones, such as the solstice. Gradually, we developed means to measure the flow of time more accurately: dividing time into shorter units of hour, minute, and second. As our tools of 122measuring time progressively increased in precision, however, some flaws in the celestial metronome began to be noticed: the clockwork of the heavens turned out to be more or less wobbly. Therefore, in 1967, the measurement of time was traded, going from the largest entity in the solar system to one of the smallest in the universe: “the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium-133 atom” (Merriam-Webster). This is the current definition of second, and it is the most stable one so far. A “second” is in the structural foundation of the electronic system: flow of time is built from it. It is one of the cornerstones, if not the most important one, of our modern electronic-centric life.