Solstice

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The length of the day on June 21 at different latitudes
At the solstices, the ecliptic, as the apparent path of the sun on the celestial sphere, has the greatest angular distance from the celestial equator ; it cuts it in the vernal equinox .

A solstice or equinox , also solstice ( Latin for "sun standstill") called, takes place twice a year run. This date is in latitudes outside between the tropics lying tropics , the highest or the lowest midday sun reached:

  • At the winter solstice , the sun is at its lowest midday height above the horizon - in the northern hemisphere on December 21st or 22nd ; In 2019, the winter point was passed on December 22nd at 05:19 am CET , in 2020 on December 21st at 11:02 am CET and in 2021 on December 21st at 4:59 pm CET.

In the southern hemisphere the situation is reversed: During the northern winter, summer prevails in the southern hemisphere and vice versa . Over locations on the equator, the apparent path of the sun to the equinoxes and equinoxes runs precisely through the zenith ; but during the northern summer it runs a little more northerly, during the southern summer it runs a little more south, in both cases therefore not quite as high as the zenith.

Twice in the course of a tropical year , the sun, while apparently moving along the ecliptic north or south of the celestial equator, takes positions with the greatest angular distance. The two turning points are also called solstices and, depending on the hemisphere, referred to as summer or winter solstice . After passing these points of extreme declination - in the summer point or in the winter point - their position approaches the celestial equator again, which is reached in the spring point and autumn point . Together with these two equinoxes ( equinoxes ), the two solstices terminate the astronomical seasons .

Astronomical basics

definition

The exact definition is: The solstices are the times when the apparent geocentric ecliptical longitude of the sun is 90 ° or 270 °.

  • Apparently means: taking into account aberration and nutation .
  • Geocentric means: seen from a fictitious observer in the center of the earth. The definition is therefore independent of the location of a real observer; the solstices therefore occur at the same time worldwide (which however corresponds to different times depending on the local time zone ).

A simple planetary geometric definition reads: Solstice: The angle of the center of the sun, the center of the earth and the earth's pole is extreme. Two cases: extreme angle minimal -> summer solstice; Extreme angle maximum -> winter solstice; the two earth hemispheres thus have both cases at the same time, alternately. (Equinox: The angle of the center of the sun, the center of the earth and the pole of the earth is right)

The two points in time coincide within a few minutes (see equation of time ) with those points in time at which the sun reaches its greatest northern or southern declination - about 23 ° 26 ′ 20 ″ - and thus its northernmost or southernmost position on the celestial sphere . The small time difference results from the fact that it is actually the barycentre of the earth / moon system that moves evenly in the earth's orbital plane ( ecliptic ) around the sun, while the earth itself orbits this common center of gravity and is usually slightly above it or below this level. Seen from the geocenter, the sun is therefore not exactly on the ecliptic (it has an ecliptical latitude not equal to zero). On the one hand, it does not pass exactly the northernmost or southernmost point of the ecliptic; on the other hand, its variable ecliptical latitude means that the maximum declination is usually not assumed exactly at the solstice points.

Inferences

Annual course of the earth around the sun. Far left: Summer in the northern hemisphere. Far right: Winter in the northern hemisphere.
The twilight at midnight in Europe on June 21st

The solstices mark the beginning of the astronomical summer and the astronomical winter . When the sun reaches its greatest north or south declination of 23.4 °, it is perpendicular to the so-called tropics of the earth (namely the parallels at 23.4 ° north or south latitude). So she stands

  • on June 21 or 20 over the tropic of the tropics (summer solstice in the northern hemisphere, winter solstice in the southern hemisphere),
  • on December 21 or 22 over the tropic of the tropics (winter solstice in the northern hemisphere, summer solstice in the southern hemisphere).

The following applies to both hemispheres: At the winter solstice, the sun reaches its lowest point in relation to the passage of the meridian during the course of the year . At this point in time, the shortest day and the longest night prevail because the greater part of the daily solar path lies below the horizon. Conversely, the sun reaches its highest level at the summer solstice. At this point in time there is the longest day and the shortest night because the greater part of the daily solar path lies above the horizon.

Near the polar circles there is a day without sunrise at the winter solstice and a day without sunset at the summer solstice ( midnight sun , " white nights "). Next poleward prevails then weeks or months of the polar day or the other pole, the polar night . During these periods without twilight , the daily path of the sun lies completely above or below the horizon.

Between the solstices, the sun crosses the celestial equator and then stands vertically above the earth's equator. These times are the equinoxes or equinoxes. Equinoxes and solstices mark the beginning of the respective astronomical seasons .

Although the day of the winter solstice is the shortest day, on the winter solstice in the northern hemisphere the earliest sunset occurs about ten days earlier and the latest sunrise occurs about ten days later. The reason for this is the equation of time . At the summer solstice in the northern hemisphere, this effect makes about four days.

date

Because the solar year is almost six hours longer than the calendar common year with exactly 365 days, the time of the solstices shifts each year by almost six hours to a later time. Since a leap day is inserted in February in leap years such as 2016, 2020 and 2024 (highlighted in bold in the table) , the calendar date is usually one day before that of the previous year.

Without the Gregorian calendar reform , their date would shift seven to eight days per millennium . This was prevented by the fact that - contrary to the switching rule of the Julian calendar - the secular years (these are years whose number is divisible by 100) no longer receive a leap day, unless the year is divisible by 400. But even this switching rule (a year therefore has 365.2425 days.) Can only approximate the actual length of the year (365.2422 days) (a period of 400 years actually consists of 146,096.88 days - in terms of the calendar, however, 146,097 days - in 3200 Years one day too many!).

In the Central European Time Zone , the summer solstice of this century will fall on June 20 or 21 from the 2020 leap year. In the 20th century, it could also enter on June 22nd. This is the effect of the leap day in 2000.


year Summer solstice Winter solstice
2015 June 21st 6:38 p.m. CEST December 22 05:48 CET
2016 June 21st 12:34 a.m. CEST 21st December 11:44 am CET
2017 June 21st 6:24 a.m. CEST 21st December 17:28 CET
2018 June 21st 12:07 p.m. CEST 21st December 23:23 CET
2019 June 21st 5:54 p.m. CEST December 22 05:19 CET
2020 20th June 11:44 p.m. CEST 21st December 11:02 am CET
2021 June 21st 05:32 a.m. CEST 21st December 16:59 CET
2022 June 21st 11:14 a.m. CEST 21st December 10:48 p.m. CET
2023 June 21st 4:58 p.m. CEST December 22 04:27 CET
2024 20th June 10:51 p.m. CEST 21st December 10:20 am CET
2025 June 21st 04:42 a.m. CEST 21st December 16:03 CET
2026 June 21st 10:24 a.m. CEST 21st December 21:50 CET
2027 June 21st 4:11 p.m. CEST December 22 03:42 CET

For more details, see the Season article .

Winter point and summer point

At the moment of the winter solstice, the sun is in the so-called winter point compared to the background stars - one of the two points of the ecliptic that are exactly 90 ° from the spring point ( right ascension = 18h). He is currently in the constellation Sagittarius (Latin: sagittarius); the galactic center is roughly in this direction .

Similarly, at the moment of the summer solstice, the sun is at the so-called summer point (right ascension = 6h) in the constellation Taurus .

Due to the precession of the earth's axis, the winter point and the summer point move once through the entire zodiac over the course of 25,780 years ( cycle of precession ) . In antiquity , the winter point was still in the constellation Capricorn (hence also the " Tropic of Capricorn ") and will shift to the constellation Serpent Bearer in about 300 years .

In early antiquity, the summer point was in the constellation Cancer (hence the " Tropic of Cancer "), its migration is shown in the following table over a whole cycle of precession. If you take the modern boundaries of the constellations as a basis, then it is in the following constellations:

Constellation sector Transit time entry center exit
shooter 33.3 ° 2380 years 13030 BC Chr. 11840 BC Chr. 10650 BC Chr.
Snake bearer 18.6 ° 1340 years 10650 BC Chr. 9980 BC Chr. 9310 BC Chr.
Scorpio 6.7 ° 480 years 9310 BC Chr. 9070 BC Chr. 8830 BC Chr.
scale 23.0 ° 1650 years 8830 BC Chr. 8005 BC Chr. 7180 BC Chr.
Virgo 44.1 ° 3160 years 7180 BC Chr. 5600 BC Chr. 4020 BC Chr.
Lion 35.7 ° 2570 years 4020 BC Chr. 2735 BC Chr. 1450 BC Chr.
cancer 20.1 ° 1440 years 1450 BC Chr. 740 BC Chr. 10 v. Chr.
Twins 27.9 ° 2000 years 10 v. Chr. 990 AD AD 1989
(Oct 20, 1989)
bull 36.7 ° 2620 years 1990 AD
(near Orion)
3300 AD 4610 AD
Aries 24.7 ° 1770 years 4610 AD 5495 AD 6380 AD
fishes 37.2 ° 2670 years 6380 AD 7715 AD 9050 ad
Aquarius 24.0 ° 1710 years 9050 ad 9905 AD 10760 c.
Capricorn 28.0 ° 2010 years 10760 c. 11765 A.D. A.D. 12770
shooter 33.3 ° 2380 years A.D. 12770 13960 c. 15150 A.D.

The point of spring ( right ascension = 0h) and autumn point (right ascension = 12h), in which the sun is at the equinox , lie at an angle of 90 ° to the summer point and winter point .

Solstice line

The earth's orbit with equinox (green) and solstitial line (red), as well as the main axis of the
ellipse (turquoise) with aphelion and perihelion .

The line connecting the positions of the earth at the time of the summer solstice and the winter solstice is called the solstice line. This line goes through the middle of the sun, its extension outside the earth's orbit through the summer point and the winter point. It is perpendicular to the equinox line.

History and culture

The worship of the sun and the returning light goes back to traditions in prehistoric times . The sun is essential for earthly survival. The summer solstice had an aspect of death and impermanence in it. This contrasted with the lengthening days after the winter solstice, which embodied life and resurrection. These turning points were reflected accordingly in rite and mythology . It is noteworthy that the sun is always assigned to the male principle in western cultures, but there is an exception in the Germanic language area, which sees the mother in the sun.

The greater the difference between the harsh winter and the warm summer, the more intensely this day has always been celebrated. In northern Europe, where the nights no longer get dark in the summer season (one also speaks of the white nights ), solstice celebrations - known as the midsummer festival - are more important than, for example, in southern Europe.

Summer solstice

Golowan Festival - Solstice celebration on June 20, 2008 in Cornwall
“Saint Jean” - Midsummer's Day on June 26, 1993 in Brittany

The summer solstice is seen as the beginning of the summer season in many countries, such as Central Europe and the USA . In Ireland, however, the period from May 1st (see also Beltane ) to July 31st is considered summer; the summer solstice is roughly in the middle of the season. In many countries where the calendar summer on 20./21. June begins, the day of the summer solstice is still referred to as midsummer, which may be traced back to an ancient common Stone Age calendar. In the Belchen system , for example, the sun rises at the summer solstice from Alsace Belchen over the north-east of the Kleiner Belchen , which enables the time of the summer solstice to be determined independently of anthropogenic objects.

The tower of Jericho from the 9th millennium BC. Chr. Indicates the knowledge of the summer solstice, and later Stone Age places of worship such as Stonehenge recorded this point in time by means of the relatively easily ascertainable points of the sun rising and setting , which at the beginning of winter lie approximately in the south-east and south-west. The Nebra Sky Disc, an important Bronze Age find, also documents the solstice.

Some people have always regarded the day of the summer solstice as a mystical day; some celebrate it with secular or religious celebrations. Solstice festivals had a firm place , especially in the Germanic, Nordic, Baltic , Slavic and Celtic religions . The largest unorganized summer solstice celebration in Europe takes place in Stonehenge, the largest in Germany on the Externsteinen . The southernmost summer solstice celebration has been held in the Spanish region of Alicante since 1929 . The Golowan Festival takes place in Cornwall and was first described by William Borlase in 1754 . Since the Christianization of Europe, these celebrations have often been associated with the saint of June 24th, John the Baptist , who was considered a particularly powerful saint ( St. John's Day ). Some of the solstice customs that have survived to this day, such as the St. John's bonfires , are named after him. In Brittany, for example, St. John's Day is sometimes not celebrated until the following weekend. Again, the date is shortly after the actual summer solstice.

The typical June-summer weather and the spring-like mood of growth in nature in the middle latitudes of the northern hemisphere is ideal for open-air events of all kinds. The solstice is a welcome occasion (and for some a conscious reason) for parties or celebrations around this day. Midsummer celebrations are of different religious and philosophical communities such as free religious and freethinkers organized, associations, political parties, volunteer fire departments, municipalities and tourism associations. Pagan or neo-pagan religious communities usually celebrate the solstice with a fire on the 21st. This festival is sometimes referred to as Litha .

For Ásatrú , the so-called Midsummer Festival, after the Yule Festival, is the second most important festival of the year. The summer solstice fire festivals in the Pyrenees are recognized as an intangible world cultural heritage .

Winter solstice

The winter solstice was an important festival in many ancient and early medieval cultures , often celebrated a few days before or after the actual solstice date. At the time of the Julian calendar , the solstices were on December 25th and June 24th.

It is disputed whether and in what form the Teutons and other peoples in Northern Europe celebrated the Yule Festival around the winter solstice . It would then have been practiced with fire and light symbolism at the winter solstice. Historically verifiable written evidence is available in the form of calendar sticks with rune symbols . It is undisputed that the word Yule Festival was in use before Christianization. The church had tried in vain to replace the word with other terms ( Norrøn : "Dróttins burðar tíð", Old Swedish: "gudz födzlo hötidh"). The Old English, Nordic and Gothic documents all come from Christian times. It is therefore difficult to get a picture of the various festivals from the scarce sources of Norse literature . This applies to the aforementioned “alfablót” of the Scandinavians and the “night of the mothers” among the Anglo-Saxons.

The Christian Christmas , which celebrates the birth of Jesus , takes place after the actual winter solstice. When Christmas was introduced in the 4th century, it was placed on the traditional winter solstice calendar day, December 25th, which was the actual winter solstice day at the time the Julian calendar was introduced. In the 4th century, the winter solstice was in fact already on December 21st, but in some calendars it was still on December 25th for a long time. on which the feast of the Roman sun god Sol Invictus was celebrated. In the course of time, the winter solstice moved further and further forward in the calendar until it returned to December 21st with the Gregorian calendar reform, which restored the conditions of the 4th century. came to rest. This roughly coincides with St. Thomas' Day on the calendar of saints on December 21st. Depending on the faith, there are different focal points and number of festivals in Christianity. Sometimes a six-day post-celebration begins on Boxing Day, and some rituals do not take place until January.

Zoroastrians and Muslim peoples of the Iranian culture and Central Asia celebrate Yalda night at the winter solstice . In India and Nepal, Makar Sankranti takes place at the end of December / beginning of January . In Satanism, too, the solstices have the character of a holiday.

Political occupation

At the time of National Socialism , the supposedly old Germanic solstice celebrations were "revived" and integrated into the symbolism of "people, blood and soil " as official holidays , especially by the SS .

In the GDR , the socialist youth association Free German Youth organized midsummer celebrations.

The Externsteine are an important place for solstice celebrations . Followers of neo-pagan and esoteric groups take part in this; however, the solstice celebration also attracts neo-Nazis.

Midsummer celebrations by right-wing extremist groups in particular cause a stir . At the Pretzien solstice celebrations organized by a local association in 2006 , a US flag and a copy of Anne Frank's diary were burned without the rest of the audience intervening. Since these events, right-wing extremist solstice celebrations in Germany have been increasingly broken up by the police. Midsummer celebrations by politically right-wing and right-wing extremist groups are mainly reported in the press.

Film, theater, opera

William Shakespeare's comedy A Midsummer Night's Dream (dt. " A Midsummer Night's Dream ") is during a summer solstice in the classical unities of time, place and action of the closed drama . In addition to the other two, Richard Wagner takes "the beautiful festival, St. John's Day" (bass aria) as the classic unit of time in his cheerful opera Die Meistersinger von Nürnberg . Ingmar Bergman also adheres to the three classic units in his 1955 film "The Smile of a Summer Night" ( Sommarnattens leende ).

Determination of the circumference of the earth

Eratosthenes determined about 200 BC. At a summer solstice (highest point of the sun) the circumference of the earth .

literature

Web links

Commons : Solstice  album with pictures, videos and audio files
Wiktionary: Solstice  - explanations of meanings, word origins, synonyms, translations

References and footnotes

  1. Kosmos Verlag: Kosmos Himmelsjahr 2020 Sun, moon and stars in the course of the year . Ed .: Hans-Ulrich Keller. 1st edition. Kosmos, Stuttgart, ISBN 978-3-440-16280-4 , pp. 7; 130; 134 .
  2. ^ A b Edgar Charles Polomé : Germanism and religious ideas . In: Heinrich Beck (ed.): Germanic problems from today's perspective . Real Lexicon of Germanic Antiquity, Supplementary Volumes, Volume 1, de Gruyter, Berlin, New York 1999, ISBN 3-11-016439-6 , p. 278.
  3. a b c Werner Weissmann: Sun, Grail, Demons . Significant occidental symbols in myth, religion and art. WUV Universitätsverlag, Vienna 2003, ISBN 3-85114-778-2 , p. 267 f . ( online at books.google.de ).
  4. ^ William Borlase: Antiquities of Cornwall , 1754
  5. The crux with the rituals. From secular alternatives to church offers. In: NZZ online , December 4, 2009, accessed on June 23, 2010.
  6. Summer solstice: The summer solstice in the Wachau and in the Nibelungengau. ( Memento from March 17, 2010 in the Internet Archive ) In: sonnenwende.at
  7. a b Playing with fire. In: The star. June 21, 2010.
  8. Information on Litha. In: wicca.com (English)
  9. Fritz Steinbock: The Holy Festival. Rituals of traditional Germanic paganism in modern times. Daniel Junker Verlag, 2004, p. 125.
  10. Hans Förster: The celebration of the birth of Christ in the old church. Contributions to research into the beginnings of the Epiphany and Christmas festivities . Mohr Siebeck, Tübingen 2000, ISBN 3-16-147291-8 , p. 116 ( online - see footnote no. 13: The pagan Germanic tribes also celebrated a great joyous festival at the time of the winter solstice, the so-called Yule Festival).
  11. ^ Andreas Nordberg: Jul, disting och förkyrklig tideräkning. ( Memento of December 24, 2013 in the Internet Archive ) (PDF; 2.1 MB) Kalendrar och kalendarisk riter i det förkristna Norden . Uppsala 2006, p. 65.
  12. Anders Hultgård : Jul. In: Heinrich Beck (Hrsg.): Reallexikon der Germanischen Altertumskunde. Volume 16, de Gruyter, Berlin 2000, page 101.
  13. Konrad Onasch : Christmas in the Orthodox church year. Evangelische Verlags-Anstalt, Berlin 1958.
  14. Solemnity - Circumcision of the Lord. (No longer available online.) Russian Memorial Church, archived from the original on March 30, 2013 ; Retrieved December 25, 2010 .
  15. ^ In: Anton Szandor LaVey : Die Satanische Bibel , Index Verlag, Zeltingen-Rachtig 2007 (1969), ISBN 978-3-936878-05-9 , p. 114.
  16. Dresden. Midsummer celebration of the FDJ on the banks of the river Elbe with a view of the old town, June 1960. In: deutschefotothek.de
  17. No solstice celebration for the right-wing scene. ( Memento from June 26, 2010 in the Internet Archive ) In: Frankfurter Rundschau. June 21, 2009. Retrieved June 21, 2010
  18. Saxony-Anhalt. Police put an end to right-wing extremists' solstice celebrations. In: Spiegel-online , June 22, 2008, accessed June 23, 2010.
  19. Escheder Hof becomes a meeting place for the neo-Nazi scene. In: Welt-online , June 16, 2009, accessed June 23, 2010

Remarks

  1. (...) So let us hold on to the ancient sacred practice of the solstice celebration. The solstice fire, however, is to us the glow of the loder, to which we transfer all non-German beings so that they can consume them. (...) From: Aurelius PolzerSolstice. In:  Marburger Zeitung , No. 69/1900 (XXXIX. Volume), June 21, 1900, p. 3 f. (Online at ANNO ). Template: ANNO / Maintenance / mbz. - Aurelius Polzer (1848–1924) was one of the intellectual pioneers of National Socialism . From: K (arl) -H (eing) BurmeisterPolzer Aurelius. In: Austrian Biographical Lexicon 1815–1950 (ÖBL). Volume 8, Verlag der Österreichischen Akademie der Wissenschaften, Vienna 1983, ISBN 3-7001-0187-2 , p. 189.