Winter solstice

This article is about the astronomical phenomenon. For other uses, see Winter solstice (disambiguation).
"Midwinter" redirects here. For other uses, see Midwinter (disambiguation).
Winter solstice

Lawrence Hall of Science visitors observe sunset on the day of the winter solstice using the Sunstones II.
Also called Midwinter, Yule, the Longest Night, Jól
Observed by Various cultures
Type Cultural, astronomical
Significance Astronomically marks the beginning of shortening nights and lengthening days
Celebrations Festivals, spending time with loved ones, feasting, singing, dancing, fires
Date Between December 21 and December 23 (NH)
Between June 20 and June 21 (SH)
Frequency Twice a year (once in the northern hemisphere, once in the southern hemisphere, six months apart)
Related to Winter festivals and the solstice
Winter solstice in Northern Hemisphere over Asia

Winter solstice (or hibernal solstice) is an astronomical phenomenon marking the shortest day and the longest night of the year. In the Northern Hemisphere this is the December solstice and in the Southern Hemisphere this is the June solstice.

The axial tilt of Earth and gyroscopic effects of its daily rotation mean that the two opposite points in the sky to which the Earth's axis of rotation points (axial precession) change very slowly (making a complete circle approximately every 26,000 years). As the Earth follows its orbit around the Sun, the polar hemisphere that faced away from the Sun, experiencing winter, will, in half a year, face towards the Sun and experience summer. This is because the two hemispheres face opposite directions along Earth's axis, and so as one polar hemisphere experiences winter, the other experiences summer. The winter solstice is considered by some to mark the end of autumn and the start of winter.[1]

More evident from high latitudes, a hemisphere's winter solstice occurs on the shortest day and longest night of the year, when the sun's daily maximum elevation in the sky is at its lowest.[2] The winter solstice itself lasts only a moment in time, so other terms are used for the day on which it occurs, such as "midwinter", or the "shortest day". It is often considered the "extreme of winter" (Dongzhi in the Chinese calendar). In meteorology, winter in the Northern Hemisphere spans the entire period of December through February. The seasonal significance of the winter solstice is in the reversal of the gradual lengthening of nights and shortening of days. The earliest sunset and latest sunrise dates differ from winter solstice, however, and these depend on latitude, due to the variation in the solar day throughout the year caused by the Earth's elliptical orbit (see earliest and latest sunrise and sunset).

Worldwide, interpretation of the event has varied across cultures, but many have held a recognition of rebirth, involving holidays, festivals, gatherings, rituals or other celebrations around that time.[3]

History and cultural significance

Japanese Sun goddess Amaterasu emerging from a cave

The solstice may have been a special moment of the annual cycle for some cultures even during neolithic times. Astronomical events were often used to guide activities such as the mating of animals, the sowing of crops and the monitoring of winter reserves of food. Many cultural mythologies and traditions are derived from this. This is attested by physical remains in the layouts of late Neolithic and Bronze Age archaeological sites, such as Stonehenge in England and Newgrange in Ireland. The primary axes of both of these monuments seem to have been carefully aligned on a sight-line pointing to the winter solstice sunrise (Newgrange) and the winter solstice sunset (Stonehenge). It is significant that at Stonehenge the Great Trilithon was erected outwards from the middle of the monument, i.e. its smooth flat face was turned towards the midwinter Sun.[4] The winter solstice was immensely important because the people were economically dependent on monitoring the progress of the seasons. Starvation was common during the first months of the winter, January to April (northern hemisphere) or July to October (southern hemisphere), also known as "the famine months". In temperate climates, the midwinter festival was the last feast celebration, before deep winter began. Most cattle were slaughtered so they would not have to be fed during the winter, so it was almost the only time of year when a plentiful supply of fresh meat was available. The majority of wine and beer made during the year was finally fermented and ready for drinking at this time. The concentration of the observances were not always on the day commencing at midnight or at dawn, but at the beginning of the pagan day, which in many cultures fell on the previous eve.[5] Because the event was seen as the reversal of the Sun's ebbing presence in the sky, concepts of the birth or rebirth of sun gods have been common and, in cultures which used cyclic calendars based on the winter solstice, the "year as reborn" was celebrated with reference to life-death-rebirth deities or "new beginnings" such as Hogmanay's redding, a New Year cleaning tradition. Also "reversal" is yet another frequent theme, as in Saturnalia's slave and master reversals.

Iranian people celebrate the night of the Northern Hemisphere's winter solstice as, "Yalda night", which known to be the "longest and darkest night of the year". In this night all the family gather together, usually at the house of the oldest, and celebrate it by eating, drinking and reading poems (esp. Hafez). Nuts, pomegranates and watermelons are particularly served during this festival.

The pagan Scandinavian and Germanic people of northern Europe celebrated a twelve-day "midwinter" (winter solstice) holiday called Yule (also called Jul, Julblot, jólablót, midvinterblot, julofferfest). Many modern Christmas traditions, such as the Christmas tree, the Christmas wreath, the Yule log, and others, are direct descendents of Yule customs. Scandinavians still call Yule "Jul". In English, the word "Yule" is often used in combination with the season "yuletide" [6] a usage first recorded in 900. It is believed that the celebration of this day was a worship of these peculiar days, interpreted as the reawakening of nature. The Yule (Jul) particular god was Jólner, which is one of Odin's many names. The concept of Yule occurs in a tribute poem to Harold Hårfager from about AD 900, where someone said "drinking Jul". Julblot is the most solemn sacrifice feast. At the "julblotet", sacrifices were given to the gods to earn blessing on the forthcoming germinating crops. Julblotet was eventually integrated into the Christian Christmas. As a remainder from this Viking era, the Midsummer is still important in Scandinavia, and hence vividly celebrated.

Sol Invictus ("The Unconquered Sun") was originally a Syrian god who was later adopted as the chief god of the Roman Empire under Emperor Aurelian. His holiday is traditionally celebrated on December 25, as are several gods associated with the winter solstice in many pagan traditions.[7]

The Christmas carol In The Bleak Midwinter refers to the Winter solstice in its title.

Observances

Although the instant of the solstice can be calculated,[8] direct observation of the solstice by amateurs is impossible because the sun moves too slowly or appears to stand still (the meaning of "solstice"). However, by use of astronomical data tracking, the precise timing of its occurrence is now public knowledge. One cannot directly detect the precise instant of the solstice (by definition, one cannot observe that an object has stopped moving until one later observes that it has not moved further from the preceding spot, or that it has moved in the opposite direction). Further, to be precise to a single day, one must be able to observe a change in azimuth or elevation less than or equal to about 1/60 of the angular diameter of the sun. Observing that it occurred within a two-day period is easier, requiring an observation precision of only about 1/16 of the angular diameter of the sun. Thus, many observations are of the day of the solstice rather than the instant. This is often done by observing the sunrise and sunset or using an astronomically aligned instrument that allows a ray of light to be cast on a certain point around that time. Before the scientific revolution, many forms of observances, astronomical, symbolic

Holidays celebrated on the winter solstice

Length of the day on the winter solstice of the Northern Hemisphere

The following tables contain information on the length of the day on the Winter solstice of the Northern Hemisphere. The data was collected from the website of the Finnish Meteorological Institute on 22 December 2015.[9] The data is arranged geographically and within the tables from the shortest day to the longest one.

Scandinavia and the Baltic states
City Sunrise
22 Dec 2015		 Sunset
22 Dec 2015		 Length of the day
Rovaniemi 11:08 13:24 2 h 16 min
Reykjavik 11:22 15:30 4 h 08 min
Trondheim 10:02 14:33 4 h 31 min
Tórshavn 9:51 15:00 5 h 09 min
Helsinki 9:25 15:14 5 h 49 min
Oslo 9:19 15:13 5 h 54 min
Tallinn 9:18 15:21 6 h 03 min
Stockholm 8:44 14:49 6 h 05 min
Riga 9:01 15:44 6 h 43 min
Copenhagen 8:38 15:39 7 h 01 min
Vilnius 8:41 15:55 7 h 14 min
Europe
City Sunrise
22 Dec 2015		 Sunset
22 Dec 2015		 Length of the day
Edinburgh 8:42 15:40 6 h 58 min
Moscow 8:58 15:59 7 h 01 min
Berlin 8:15 15:54 7 h 39 min
London 8:04 15:54 7 h 50 min
Kiev 7:56 15:56 8 h 00 min
Paris 8:42 16:56 8 h 14 min
Rome 7:35 16:42 9 h 07 min
Madrid 8:35 17:52 9 h 17 min
Lisbon 7:51 17:19 9 h 28 min
Athens 7:38 17:09 9 h 31 min
Africa
City Sunrise
22 Dec 2015		 Sunset
22 Dec 2015		 Length of the day
Cairo 6:47 17:00 10 h 13 min
Dakar 7:30 18:46 11 h 16 min
Addis Abeba 6:36 18:12 11 h 36 min
Americas
City Sunrise
22 Dec 2015		 Sunset
22 Dec 2015		 Length of the day
Anchorage 10:15 15:42 5 h 27 min
Vancouver 8:05 16:17 8 h 12 min
Seattle 7:55 16:21 8 h 26 min
Ottawa 7:40 16:23 8 h 43 min
New York City 7:17 16:32 9 h 15 min
Washington, D.C. 7:23 16:50 9 h 27 min
Los Angeles 6:55 16:48 9 h 53 min
Miami 7:03 17:35 10 h 32 min
Honolulu 7:05 17:55 10 h 50 min
México City 7:06 18:04 10 h 58 min
Managua 6:01 17:26 11 h 25 min
Bogotá 5:59 17:51 11 h 52 min
Asia and Oceania
City Sunrise
22 Dec 2015		 Sunset
22 Dec 2015		 Length of the day
Magadan 8:55 14:55 6 h 00 min
Petropavlovsk 9:37 17:10 7 h 33 min
Khabarovsk 8:49 17:07 8 h 18 min
Ulan Bator 8:40 17:03 8 h 23 min
Vladivostok 8:41 17:40 8 h 59 min
Beijing 7:33 16:53 9 h 20 min
Tokyo 6:48 16:32 9 h 44 min
Shanghai 6:49 16:57 10 h 08 min
Lhasa 8:47 19:02 10 h 15 min
Delhi 7:10 17:29 10 h 19 min
Hong Kong 6:59 17:45 10 h 46 min
Manila 6:17 17:33 11 h 16 min
Bangkok 6:37 17:56 11 h 19 min
Singapore 7:02 19:05 12 h 03 min

See also

References

  1. ↑ http://www.metoffice.gov.uk/learning/learn-about-the-weather/how-weather-works/when-does-spring-start
  2. ↑ An Introduction to Physical Science, 12th Ed., James Ship-man, Jerry D. Wilson, Aaron Todd, Section 15.5, p 423, ISBN 978-0-618-92696-1, 2007.
  3. ↑ "Winter Solstice celebrations: a.k.a. Christmas, Saturnalia, Yule, the Long Night, start of Winter, etc.". Religious Tolerance.org. December 3, 1999. Retrieved December 22, 2011.
  4. ↑ Johnson, Anthony, Solving Stonehenge: The New Key to an Ancient Enigma. (Thames & Hudson, 2008) pp. 252–253
  5. ↑ "Christmas: An Ancient Holiday". History.com. Retrieved December 22, 2011.
  6. ↑ Yule. The American Heritage Dictionary of the English Language, Fourth Edition. Retrieved December 3, 2006.
  7. ↑ Capoccia, Kathryn (2002). "Christmas Traditions". Retrieved 2008-12-27.
  8. ↑ Meeus, Jean (2009). Astronomical Algorithms (2nd English Edition with corrections as of August 10, 2009 ed.). Richmond, Virginia: Willmann-Bell, Inc. ISBN 0-943396-61-1.
  9. ↑ "Paikallissää Helsinki" [‘Local weather in Helsinki’] (in Finnish). Finnish Meteorological Institute. 2015-12-22. Unknown parameter |access date= ignored (|access-date= suggested) (help)

Further reading

External links

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