Variable Daylight Loss
Name: Brian F.
As winter approaches, why is the amount of daylight lost
each day not the same?
Think of the line that the Sun takes as a sine-wave, so the daily difference
near the solstices (when the Sun is on a tropic) is nearly negligible, but at
the equinoxes (when the Sun is at the equator) there is a very big daily
difference. To complicate matters, the line isn't a perfect sine-wave, but is
distorted due to the orbital motion of the Earth. This means that the
earliest sunrise does not occur on the same day as the latest sunset. The
differences are about two weeks for the northern summer solstices (June) and
a three-weeks for the northern winter solstices (December). The greater
difference in December is caused by the Earth's faster orbital motion at that
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Update: June 2012