Meridian of Paris
The meridian of Paris was before the International Meridian Conference used prime meridian . It is located 2 ° 20 ′ 14.025 ″ east of the Greenwich meridian that has been widely used since then . The Paris Meridian runs right through the Paris Observatory .
History of the meridian
The meridian of Paris was determined by a marker on a stone on June 21, 1667, the day of the summer solstice , by Adrien Auzout , Jacques Buot , Bernard Frénicle de Bessy , Jean Picard and Jean Richer , mathematicians and astronomers of the Académie Royale des Sciences , over which the Paris observatory was built. The difference in length to the previously commonly used Ferro-Meridian was usually calculated at 22 ° 30 ′. Until the above-mentioned conference in 1884, it formed an important prime meridian (in addition to the widespread Ferro-Meridian and others) and was also traded at the conference as an alternative to the finally agreed meridian of Greenwich.
Several degree measurements were carried out along the meridian of Paris .
Temps moyen de Paris
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Temps moyen de Paris ( tmP )
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| Zone meridian | 2,337229 ° E
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| Time difference to world time | UTC + 0.155833
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| Applied all year round | ||
| Was valid from - to | March 9, 1911 - August 9, 1978
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| whole French territory | ||
Since March 9, 1911 (Loi du 9 mars 1911), the meridian has also been the standard reference for the Heure légale die Temps moyen de Paris (tmP) , the standard time binding for France. Even after adopting the world time, France remained with the legal reference tmP− 9 ′ 21 ″, not with GMT / UT / UTC itself, whereby the tmP was coordinated with the world time to exactly this difference (common leap seconds ). The value was legally valid until August 9, 1978, only since then has UTC been the standard time of the French Heure légale by decree . France (main country, zone CET / CEST ), for example, had the time tmP + 50 ′ 39 ″, not (after 1968) UTC + 1 - this value only applies after 1978.
Monuments
The meridian is marked by several historical pillars .
Dibbets' artistic homage: Arago medallions
The Dutch conceptual artist Jan Dibbets marked the old prime meridian in 1995 with bronze plaques, the Arago medallions, discreetly embedded in street pavements, sidewalks, courtyards and various buildings, in homage to the physicist and human rights activist François Arago .
Of these originally 135 badges, some have been stolen since the publication of Dan Brown's bestseller The Da Vinci Code. The term " rose line " used in the book for Dibbets' artwork is an invention of Brown. His representation that the meridian crosses the inverted glass pyramid of the Louvre is also wrong. In contrast to what is shown in the film , there is no Arago medallion above the pyramid .
See also
- The Saint-Sulpice noon sign from 1727 is located near the Paris meridian
- Meridian arc
literature
- Kurt Bretterbauer: Meridian of Paris II. In: Stars and Space 2/2008 ( article archive astronomie-heute.de, link to pdf).
- Günther Müller: Meridian of Paris. In: Stars and Space 10/2007, p. 63 ff ( article archive astronomie-heute.de, link to pdf).
- Paul Murdin: Full Meridian of Glory. Perilous Adventures in the Competition to Measure the Earth. 2009, ISBN 978-0-387-75533-5 (English).
- Frédérique Villemur, Paul Facchetti (photo): La Méridienne de Paris, une nouvelle traversée de la capitale. Paris Musées / Actes Sud, Arles 2000, ISBN 2-87900-541-8 (French).
Individual evidence
- ↑ Carte particulière des environs de Paris ... Map of the area around Paris from 1690, with the meridian of Paris at 22 ° 30 'of the Ferro meridian
- ↑ Décret n ° 78-855 du 9 août 1978 (JORF du 19 août 1978) relatif à l'heure légale française , Décret n ° 78-896 du 9 août 1978 fixante à l'heure légale française.
- ↑ L'heure légale française. Institut de mécanique céleste et de calcul des éphémérides , accessed on September 27, 2012 (French, also in English).
Coordinates: 48 ° 50 ′ 11.3 " N , 2 ° 20 ′ 14" E