The length of a day and the temp, depend on its latitude and also on how old the earth is. A polar day is 6 equatorial months. The Earth is spinning slower and slower and there are fewer days per year than there used to be. Please read on.
“The Spherical Shape of the Earth
Because the Earth is a sphere, the surface gets much more intense sunlight, hence heat, at the equator than at the poles. On the equinox, the Sun passes directly overhead at noon on the equator and a square centimeter of ground receives about 1 calorie of heat energy (see solar constant). On the same day, at 60°N, the latitude of Anchorage, Alaska, or Oslo, Norway, or St. Petersburg, Russia, the Sun rises no higher than 30° above the horizon at noon and heats a given parcel of ground with only a half the intensity as at the equator. At the poles, the Sun appears to sit on the horizon for periods upwards of 24 hours, and its rays skim horizontally over the surface.”
“Earth rotates on its axis; this causes us to experience day and night. But Earth’s axis is tilted 23.5 degrees (the angle is measured between Earth’s equatorial plane and the plane in which it orbits our Sun). As Earth orbits our Sun, the axis points toward the same location in space — almost directly toward Polaris, the North Star. This means that during Earth’s movement around our Sun each year, our polar regions spend loooooooong periods pointed toward our Sun in the summer (for example, July in the northern hemisphere, or December in the southern hemisphere) and long periods pointed away from our Sun during the winter. At latitudes greater than 66.5 degrees (90 degrees minus 23.5 degrees, the tilt of the axis), the regions above the Arctic and Antarctic circles on our globe, days of constant darkness or light occur.”
“Because of this tilt and Earth’s movement around our Sun, there is a time when Earth’s north pole is tilting 23.5 degrees toward our Sun. This is the summer solstice, the first day of the northern hemisphere summer and the longest day of the year in the northern hemisphere. On December 21 or 22, Earth’s north pole is tilting 23.5 degrees away from our Sun and the south pole is tilted toward our Sun. This is the winter solstice, the shortest day of the year in the northern hemisphere. Twice each year — during the equinoxes (“equal nights”) — Earth’s axis is not pointed toward our Sun. The spring equinox in March marks the beginning of the transition from 24 hours of darkness to 24 hours of daylight at the north pole. The fall equinox in September marks the shift into 24 hours of darkness at the north pole. During the equinoxes every location on Earth (excluding the extreme poles) experiences a 12-hour day length.”
“Good news for overachievers: Earth’s days are getting longer!
Researchers examining ancient corals noted that annual growth patterns suggested there were more days in a year in Earth’s distant past. Fossil corals, 380 million years old, from the Devonian Period recorded 400 daily cycles. About 290 million years ago in the Pennsylvanian Period, there appear to have been 390 daily cycles each year. Assuming that Earth’s revolution around our Sun has not changed dramatically, this means that the number of hours per day has been increasing and that Earth’s rotation has been slowing. Today’s day length is 24 hours. During the Pennsylvanian Period a day was ~22.4 hours long. In the Devonian Period, a day was ~21.8 hours long. Earth’s rotation appears to be slowing approximately 2 seconds every 100,000 years. Why are Earth’s days getting longer? Some scientists suggest that tidal cycles create a “drag” on Earth, causing it to slow down.”
Quoted from : http://www.moonsighting.com/6monthdays.html
|Where on earth the night or day is 6 months long?
Actually, except for poles, no where is the 6 months long day and6 months long night. Look in the table, that even at 70 miles away
from the pole, there are 10 days when sun rises and sets.
Also note that up to 65 degrees latitude the sun rises and sets daily.
|Latitude||Approximate Location||Miles from North Pole||Sun Remains below horizon||Sun Remains above horizon||Sun Rises and Sets||Fasting Time for Muslims|
|40:00N||Philadelphia, Pennsylvania||3500 mi||—–||—–||365 days||11-16 hrs|
|65:00N||Fairbanks, Alaska||1750 mi||—–||—–||365 days||17-23 hrs|
|66:30N||Arctic Circle||1575 mi||Dec17-Dec 26 (10 days)||May 29-Jul 13 (47 days)||308 days||Special Case|
|70:00N||Dead Horse, Alaska||1400 mi||Nov 25-Jan 16 (53 days)||May 17-Jul 27 (72 days)||240 days||Special Case|
|80:00N||Franz Josef Land, North Russia||700 mi||Oct 21-Feb 19 (122 days)||Apr 14-Aug 19 (128 days)||115 days||Special Case|
|84:00N||North-most, Greenland||420 mi||Oct 10-Mar 2 (144 days)||Apr 2-Sep 9 (161 days)||60 days||Special Case|
|89:00N||0:0 Longitude, No land mass||70 mi||Sep 27-Mar 15 (170 days)||Mar 20-Sep 21 (185 days)||10 days||Special Case|
|89:45N||0:0 Longitude, N. Pole, No land||20 mi||Sep 26-Mar 17 (173 days)||Mar 18-Sep 23 (190 days)||2 days||Special Case|