Lecture 10: Telling Time
What time is it? This lecture is the first part of a two-part\nexploration of the astronomical origins of our time-keeping and calendar\nconventions. Today we will discuss the division of the year into\nseasons by the motions of the Sun, and the oft-forgotten origins of our\nholidays in in the solar Quarter and Cross-Quarter days, the division of\nthe year into 12 months based approximately on the cycle of lunar\nphases, the traditional division of the month into weeks reflecting the\nseven moving celestial bodies, and the division of the day into hours,\nminutes, and seconds. We will also discuss the difference between the\nSolar and Sidereal days, and the introduction of timezones used in modern\ncivil timekeeping. Recorded 2006 Oct 3 in 100 Stillman Hall on the\nColumbus campus of The Ohio State University.