Week (wk)
The week, symbolized by wk, is 7 days long. Its history is rooted in ancient traditions, including Babylonian, Jewish, and Roman customs. The seven-day week originated because of religion and culture, and later became established through Christianity and Islam. Although the week is not based on astronomy, it is now widely used in calendars and daily life. Its long use shows how strong traditions are in setting time.
Second (s)
The second is the fundamental SI unit used to measure time. At first, it was defined as 1/86,400 of the average length of a solar day. However, because the Earth’s rotation is not perfectly consistent, this method was imprecise. In 1967, scientists redefined the second based on atomic properties: one second equals the duration of 9,192,631,770 cycles of radiation from a cesium-133 atom. This atomic standard ensures remarkable accuracy in timekeeping, which is essential for technologies like GPS, communications, and scientific experiments. The second remains a cornerstone for tracking and organizing time in today’s world.