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- Callippic_cycle abstract "For astronomy and calendar studies, the Callippic cycle (or Calippic) is a particular approximate common multiple of the year (specifically the tropical year) and the synodic month, that was proposed by Callippus during 330 BC. It is a period of 76 years, as an improvement of the 19-year Metonic cycle.A century before Callippus, Meton discovered the cycle of 19 years that counted 6,940 days, which exceeds 235 lunations by almost a third of a day, and 19 tropical years by four tenths of a day. It implicitly gave the solar year a duration of 6940⁄19 = 365 + 1⁄4 + 1⁄76 days = 365 d 6 h 18 min 56 s. But Callippus knew that the duration of the year was more closely 365 1⁄4 days (= 365 d 6 h), so he multiplied the 19-year cycle by 4 to obtain an integer number of days, and then omitted 1 day from the last 19-year cycle. Thus he computed a cycle of 76 years that consists of 940 lunations and 27,759 days, and has been named the Callippic cycle for him.Although the cycle's error has been computed as one full day in 553 years, or 4.95 parts per million., in actuality 27,759 days in 76 years has a mean year of exactly 365 1⁄4 days, which relative to the mean northward equinoctial year is about 11 minutes too long per year, in other words the cycle drifts another day late per 130 10⁄11 years, which is considerably worse than the drift of the unrounded Metonic cycle. If the Callippic cycle is considered as closer to its unrounded length of 27,758 3⁄4 days (based on 940 lunations) then its accuracy is essentially the same as the unrounded Metonic cycle (within a few seconds per year). If it is considered as 940 lunations less one day then the Callippic mean year will be shortened by 1⁄76 of a day (18 minutes 57 seconds), making it grossly too short, and it will also grossly drift ahead with respect to the mean lunar cycle at the rate of 1⁄940 of a day (1 minute 31 seconds) per lunar month. If the cycle length is truncated to 27,758 days then the mean year is 365 days 5 hours 41 minutes 3 seconds, or almost 8 minutes too brief per year, and it will drift ahead of the mean lunar cycle by about (3⁄4)⁄940 day (1 minute 9 seconds) per lunar month. Altogether, the purported accuracy of this cycle is not impressive, but it is of historical interest.The first year of the first Callippic cycle began at the summer solstice of 330 BC (28 June in the proleptic Julian calendar), and was subsequently used by later astronomers. In Ptolemy's Almagest, for example, he cites (Almagest VII 3, H25) observations by Timocharis during the 47th year of the first Callippic cycle (283 BC), when on the eighth of Anthesterion, the Pleiades star cluster was occulted by the Moon.The Callippic calendar originally used the names of months from the Attic calendar, although later astronomers, such as Hipparchus, preferred other calendars, including the Egyptian calendar. Also Hipparchus invented his own Hipparchic calendar cycle as an improvement upon the Callippic cycle. Ptolemy's Almagest provided some conversions between the Callippic and Egyptian calendars, such as that Anthesterion 8, 47th year of the first Callippic period was equivalent to day 29 of the month of Athyr, during year 465 of Nabonassar. However, the original, complete form of the Callippic calendar is no longer known.".
- Callippic_cycle wikiPageExternalLink almagestephemeris.htm.
- Callippic_cycle wikiPageID "1827917".
- Callippic_cycle wikiPageLength "4433".
- Callippic_cycle wikiPageOutDegree "30".
- Callippic_cycle wikiPageRevisionID "683165819".
- Callippic_cycle wikiPageWikiLink Almagest.
- Callippic_cycle wikiPageWikiLink Anthesterion.
- Callippic_cycle wikiPageWikiLink Astronomy.
- Callippic_cycle wikiPageWikiLink Attic_calendar.
- Callippic_cycle wikiPageWikiLink Calendar.
- Callippic_cycle wikiPageWikiLink Callippus.
- Callippic_cycle wikiPageWikiLink Category:Ancient_Greek_astronomy.
- Callippic_cycle wikiPageWikiLink Category:Calendars.
- Callippic_cycle wikiPageWikiLink Category:History_of_astronomy.
- Callippic_cycle wikiPageWikiLink Egyptian_calendar.
- Callippic_cycle wikiPageWikiLink Hathor_(month).
- Callippic_cycle wikiPageWikiLink Hipparchic_cycle.
- Callippic_cycle wikiPageWikiLink Hipparchus.
- Callippic_cycle wikiPageWikiLink Least_common_multiple.
- Callippic_cycle wikiPageWikiLink Meton.
- Callippic_cycle wikiPageWikiLink Meton_of_Athens.
- Callippic_cycle wikiPageWikiLink Metonic_cycle.
- Callippic_cycle wikiPageWikiLink Month.
- Callippic_cycle wikiPageWikiLink Month_of_Hathor.
- Callippic_cycle wikiPageWikiLink Moon.
- Callippic_cycle wikiPageWikiLink Nabonassar.
- Callippic_cycle wikiPageWikiLink Occultation.
- Callippic_cycle wikiPageWikiLink Parts-per_notation.
- Callippic_cycle wikiPageWikiLink Parts_per_notation.
- Callippic_cycle wikiPageWikiLink Pleiades.
- Callippic_cycle wikiPageWikiLink Proleptic_Julian_calendar.
- Callippic_cycle wikiPageWikiLink Ptolemy.
- Callippic_cycle wikiPageWikiLink Solstice.
- Callippic_cycle wikiPageWikiLink Timocharis.
- Callippic_cycle wikiPageWikiLink Tropical_year.
- Callippic_cycle wikiPageWikiLink Year.
- Callippic_cycle wikiPageWikiLinkText "76-year cycle".
- Callippic_cycle wikiPageWikiLinkText "Callippic cycle".
- Callippic_cycle wikiPageWikiLinkText "Callippic".
- Callippic_cycle hasPhotoCollection Callippic_cycle.
- Callippic_cycle wikiPageUsesTemplate Template:Frac.
- Callippic_cycle wikiPageUsesTemplate Template:Greek_astronomy.
- Callippic_cycle wikiPageUsesTemplate Template:Reflist.
- Callippic_cycle subject Category:Ancient_Greek_astronomy.
- Callippic_cycle subject Category:Calendars.
- Callippic_cycle subject Category:History_of_astronomy.
- Callippic_cycle hypernym Multiple.
- Callippic_cycle type Convention.
- Callippic_cycle type Disease.
- Callippic_cycle type Work.
- Callippic_cycle type Calendar.
- Callippic_cycle type Convention.
- Callippic_cycle type Source.
- Callippic_cycle type Work.
- Callippic_cycle comment "For astronomy and calendar studies, the Callippic cycle (or Calippic) is a particular approximate common multiple of the year (specifically the tropical year) and the synodic month, that was proposed by Callippus during 330 BC. It is a period of 76 years, as an improvement of the 19-year Metonic cycle.A century before Callippus, Meton discovered the cycle of 19 years that counted 6,940 days, which exceeds 235 lunations by almost a third of a day, and 19 tropical years by four tenths of a day.".
- Callippic_cycle label "Callippic cycle".
- Callippic_cycle sameAs Kallippischer_Zyklus.
- Callippic_cycle sameAs Ciclo_callippico.
- Callippic_cycle sameAs Ciclo_calíptico.
- Callippic_cycle sameAs m.05_4zt.
- Callippic_cycle sameAs Kalipov_ciklus.
- Callippic_cycle sameAs Каліппів_цикл.
- Callippic_cycle sameAs Q1508108.
- Callippic_cycle sameAs Q1508108.
- Callippic_cycle sameAs 蔀.
- Callippic_cycle wasDerivedFrom Callippic_cycle?oldid=683165819.
- Callippic_cycle isPrimaryTopicOf Callippic_cycle.