How Does Earth Move Through Space?
For millennia people have used these celestial movements as a way of measuring time.
However the creation of a rock solid and convenient way to measure time has not been a simple goal to reach.
For instance, do you know why we have leap seconds, leap days and leap years?
Or what the difference is between the Julian calendar and the Gregorian calendar and why we changed from one to the other?
The answer to these questions and a whole lot more can be found in this very interesting video by Vsauce.