In my earlier response to PsykoKidd's question: >To paraphrase: The question was, "Over the span of a year do all >places on earth recieve on average exactly 12 hours of daylight >and 12 hours of night."
I erred in my example. It should have read: Example: At a point on the equator where a new year began exactly at sunrise, it will again be sunrise about* 365.25 days later. Therefore, a non-leap, 365 day calendar year will end about 6hrs before sunrise. Since days are divided equally into 12 daylight hrs and 12 night hrs at the equator, the location will have had 12 * 365 - 6 = 4374 total hrs of darkness, but will have had 12 * 365 = 4380 total hrs of light for the calendar year. A place 180° away in longitude, but also on the equator, will have had 4380 hrs of darkness, but only 4374 hrs of light for that same year. (*The decimal .25 day is a rounded value, used to avoid a clutter of additional digits to the right of the decimal point, which while more exact, would be no bettter for illustrating the principle.) Apologetically, Blushing Bill
