From d687bfe50da070f1cc47a05657419ed7d9c2954d Mon Sep 17 00:00:00 2001 From: ytliu0 Date: Sat, 11 May 2024 11:04:53 -0500 Subject: [PATCH] corrected a typo --- computation.html | 2 +- src/computation.html | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/computation.html b/computation.html index 39330f2..7f842a2 100755 --- a/computation.html +++ b/computation.html @@ -1 +1 @@ -Calendar Calculation \ No newline at end of file +Calendar Calculation \ No newline at end of file diff --git a/src/computation.html b/src/computation.html index d5c6b61..434857f 100755 --- a/src/computation.html +++ b/src/computation.html @@ -252,7 +252,7 @@

Footnotes and References

  • [Vondrák] J. Vondrák, N. Capitaine, P. Wallace, "New precession expressions, valid for long time intervals", Astron. Astrophys., 534, A22 (2011).

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  • [Xiaoan] Many scholars at that time objected using dingqi for calendar calculation and intercalation. Two of the famous scholars were Wáng Xīchǎn (王錫闡) and Méi Wéndǐng (梅文鼎). Wáng not only criticized using dingqi for intercalation, but only pointed out a sneaky thing the Imperial Astronomical Bureau did in order to avoid being ridiculed. He pointed out that there was a leap month after month 7 in N1661, but then two major solar terms Z11 (Winter Solstice) and Z12 (Great Cold) appeared in month 11. The subsequent major solar term Z1 (Rain Water) was originally placed on the last day of month 12, but then the first month of N1662 would not contain any major solar term. The Astronomical Bureau decided to move the New Year Day a day ealier so that it would contain Z1, thus moving the month without major solar term to the last month of N1661. Looking at the imperial planetary almanac for N1662 on the Digital Library of Qing Archives managed by the National Palace Museum in Taiwan, I see that the month 1 conjunction was listed on a yǐ hài day (18 February, 1662). However, from the positions of the Sun and Moon given by the almanac, it's clear that the conjunction should have been on the following day (19 February). This cofirms Wáng's claim. Such a sneaky operation was only done once. There were seven more cases in the Qing calendars where two months without a major solar term appearing within several months. One such case occurred in the first month of N1833. The situation was exactly the same as that of N1662 originally planned: the major solar term Z1 appeared on the last day of month 12 in N1832 and there was no major solar term in the first month of N1833. The conjunction date was not altered in this case. After the fall of the Qing dynasty, the first month of N1985 also did not contain a major solar term. The first month of N2034 won't contain a major solar term either.

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  • [Xiaoan] Many scholars at that time objected using dingqi for calendar calculation and intercalation. Two of the famous scholars were Wáng Xīchǎn (王錫闡) and Méi Wéndǐng (梅文鼎). Wáng not only criticized using dingqi for intercalation, but only pointed out a sneaky thing the Imperial Astronomical Bureau did in order to avoid being ridiculed. He pointed out that there was a leap month after month 7 in N1661, but then two major solar terms Z11 (Winter Solstice) and Z12 (Great Cold) appeared in month 11. The subsequent major solar term Z1 (Rain Water) was originally placed on the last day of month 12, but then the first month of N1662 would not contain any major solar term. The Astronomical Bureau decided to move the New Year Day a day earlier so that it would contain Z1, thus moving the month without major solar term to the last month of N1661. Looking at the imperial planetary almanac for N1662 on the Digital Library of Qing Archives managed by the National Palace Museum in Taiwan, I see that the month 1 conjunction was listed on a yǐ hài day (18 February, 1662). However, from the positions of the Sun and Moon given by the almanac, it's clear that the conjunction should have been on the following day (19 February). This cofirms Wáng's claim. Such a sneaky operation was only done once. There were seven more cases in the Qing calendars where two months without a major solar term appearing within several months. One such case occurred in the first month of N1833. The situation was exactly the same as that of N1662 originally planned: the major solar term Z1 appeared on the last day of month 12 in N1832 and there was no major solar term in the first month of N1833. The conjunction date was not altered in this case. After the fall of the Qing dynasty, the first month of N1985 also did not contain a major solar term. The first month of N2034 won't contain a major solar term either.

    The history of the controversies on using dingqi in calendar calculation was similar to the situation of using dingshuo (true lunar conjunction) in calendar calculation. Before the 7th century, lunar conjunctions in a calendar were calculated based on Moon's mean motion, which were called the pingshuo (mean conjunctions). In the fifth century, astronomer Hé Chéngtiān (何承天) advocated using dingshuo in calendar calculation. However, the frequent appearances of three consecutive long months and two consecutive short months were strongly opposed by other people and dingshuo was not implemented. In 619, the Wuyinyuan astronomical canon (戊寅元曆) broke the tradition and used dingshuo in calendar calculation, but dingshuo was abandoned after the appearance of four consecutive long months in 645. About 20 years later, the Linde astronomical canon (麟德曆) reintroduced dingshuo, but a new jinshuo rule (進朔法) was introduced to reduce the frequency of several consecutive long and short months. This rule was also adopted by the subsequent astronomical canons until 1281 when the Shòushí canon (授時曆) abolished the rule. At that time, no one cared about four consecutive long months or three consecutive short months. Today, some people don't even know that sometimes four consecutive long months appear in the Chinese calendar. Even though dingqi has been used in calendar calculation for almost 400 years, some people still criticize it to this day and advocate the restoration of pingqi. However, these people don't advocate the restoration of pingshuo.