The concept of time is self-evident. An hour consists of a certain number of minutes, a day of hours and a year of days. But we rarely think about the fundamental nature of time. Time is passing non-stop, and we follow it with clocks and calendars. Yet we cannot study it with a microscope or experiment with it. And it still keeps passing. We just cannot say what exactly happens when time passes. Time is represented through change, such as the circular motion of the moon around the earth. The passing of time is indeed closely connected to the concept...