why is december 21 the shortest day of the year??

Question

for homework,my teacher told me to tell him y december 21 is the shortest day of the year. he said it has somethin to do with the sun bc its dark on that day too. does anyone no???

try to include details please.

try to use a short answer and its not really homework. its just a question that no1 knew the answer to so he said to find it out on the internet. is yahoo answers part of the internet? yes

Answer 1

Because you live in the Northern Hemisphere, and the tilt of the Earth with respect to the sun makes the days shorter or longer depending on where it is in its orbit.

Answer 2

A solstice is either of the two events of the year when the sun is at its greatest distance from the equator plane. The name is derived from Latin sol (sun) and sistere (stand still), because at the solstice, the Sun stands still in declination, that is, it reaches a maximum or a minimum. The term solstice can also be used in a narrower sense of being the instance in time that such a passage happens. The solstices then, together with the equinoxes, are related to the seasons. In some languages they are considered to start or separate the seasons; in others they are considered to be center points (in English, for example, the period around the June solstice is known as midsummer, and Midsummer's Day is the 24 June — now two or three days after the solstice).

The two solstices can be distinguished by different pairs of names, depending on which feature one wants to stress.

Summer solstice and winter solstice. These names can be used when one wants to relate the solstices to the seasons. The seasons of the northern hemisphere and southern hemisphere are opposites (the summer solstice of one hemisphere is the winter solstice of the other) so these names can be ambiguous.
June solstice and December solstice. An alternative to the previous set, but without the ambiguity for which hemisphere they are intended. Still not universal, however, as not all people on Earth use a solar based calendar where the solstices occur every year in the same month (as they do not in the Jewish calendar, for example), and the names are also not useful for other planets (Mars, for example), even though they do have seasons.
First point of Cancer and first point of Capricorn. Alternative names for the previous set. One disadvantage is that due to the precession of the equinoxes these astrological signs where these solstices are located, do not correspond any longer with the actual constellations.
Taurus solstice and Sagittarius solstice. Names that indicate in which constellations the two equinoxes are currently located. These terms are not widely used, the more so because until December 1989 the first solstice was in Gemini according to official IAU boundaries.
Northern solstice and southern solstice, indicationg the direction of the sun's movement. These names are neutral and unambiguous.

Answer 3

The calendar and the Earth's motion around the Sun are not precisely synchronised, because the rotation of the Earth around it's axis is not very cooperative, and does not divide neatly into the period of the year. That's why we have leap-years, which is a workable, but rather crude method of keeping the calendar more or less in rhythm with the astronomical year. So there is a slight jump every four years in the actual calendar day when certain points in the orbit are reached, and then they begin to drift again. Again, there is not an exact correlation between longest day and shortest day and the calendar because these astronomical bodies have a mind of their own, and don't seem to care what inconvenience they cause to humans on the third planet !

Answer 4

A solstice is either of the two events of the year when the sun is at its greatest distance from the equator plane.

More Information on solstice:

In the northern hemisphere, the Winter solstice is day of the year (near December 22) when the Sun is farthest south. However, in the southern hemisphere, winter and summer solstices are exchanged so that the winter solstice is the day on which the Sun is farthest north. The winter solstice marks the first day of the season of winter. The declination of the Sun on the (northern) winter solstice is known as the tropic of capricorn (-23° 27').
http://scienceworld.wolfram.com/astronomy/WinterSolstice.html


A solstice is either of the two events of the year when the sun is at its greatest distance from the equator plane. The name is derived from Latin sol (sun) and sistere (stand still), because at the solstice, the Sun stands still in declination, that is, it reaches a maximum or a minimum. The term solstice can also be used in a narrower sense of being the instance in time that such a passage happens. The solstices then, together with the equinoxes, are related to the seasons.

The two solstices can be distinguished by different pairs of names, depending on which feature one wants to stress.

Summer solstice and winter solstice. These names can be used when one wants to relate the solstices to the seasons. The seasons of the northern hemisphere and southern hemisphere are opposites (the summer solstice of one hemisphere is the winter solstice of the other) so these names can be ambiguous.
http://en.wikipedia.org/wiki/December_solstice

Read more here

Answer 5

Shortest = having the least amount of daylight. And that is only true in the Northern Hemisphere. For the Southern Hemisphere, it is the longest (ie: most daylight) day of the year.

Think about the tilt of the earth and you'll have your answer, but I'm not going to do your homework for you. :-)

Answer 6

It's not the shortest day -- it has the same number of hours in it (24) as any other day!

It's the day with the least amount of sunlight -- the amount of time from sunrise to sunset is the shortest (in the northern hemisphere) of any other day in the year. It has to do with the earth's axis and tilt and position relative to the sun.

Answer 7

I have no idea, sorry, wish I could help ya answer it.
Try using the Google search engine and type in "why is december 21st the shortest day of the year?" something like that.

good luck!

Answer 8

Did you know that due to daylight savings time it isn't the longest night anymore?

Use this to baffle your teacher.