Dear Mr. Skilling,
You once ran a piece about the number of daylight hours being the same
everywhere on Earth. Could you please repeat that information?
John Windgrove
Dear John,
The number of daylight hours in a 365-day year is always 4,380 and it
doesn't matter where you might call home. Arctic polar bears experience the
same number of hours of daylight annually as African elephants and Antarctic
penguins. Cloudiness aside, the sun shines for an equal amount of time on
every square inch of the Earth's surface.
The complication is that, because the Earth's axis of rotation is tilted
23.45 degrees from the plane described by its revolution around the sun, the
daily hours of light, planet-wide, are distributed unequally through the
year. At the poles, daylight comes in six-month blocks; at the Equator it is
always within a few minutes of 12 hours a day.
