Talk:Sothic cycle

Earliest date
An obvious disagreement exists regarding Meyer's earliest date. Grimal gives 4323 BC while Mackey gives 4241 BC. The original year in the article, 4121 BC, was obviously wrong. I find five hits for 4323 BC in a Google search while 4241 BC has 155 hits. Changing time of history indicates that 4323 BC is a modern Sothic date calculation, not that by Meyer himself. The article must make it clear which year was Meyer's and which year is a more modern calculation. Indeed, both years should be mentioned in the article. I have doubts about 4323 BC because there are 1550 years between 4323 and 2773, 90 years more than the traditional Sothic period of 1460 years. If 4323 BC remains in the article, then who calculated it must be cited and how he did so should also be mentioned. — Joe Kress 02:28, 10 November 2006 (UTC)
 * That bothered me too, but all I've got is Grimal, Kitchen, and a smattering of other work which isn't very helpful.Thanatosimii 03:08, 10 November 2006 (UTC)
 * The date on this page also disagrees with the date on:http://en.wikipedia.org/wiki/5th_millennium_BC. Gene Callahan 10:27, August 27, 2007 (UTC)

The date mentioned in Meyer, Aegyptishe Chronology 1904 is July 19, 4241 BCE. This date is based upon a non-adjusted Sothic cycle of 1461 cal yrs and the July 19th date of the Canopic decree and the confluence of the Sothic Rise Festival with 1, Thoth mentioned by Censorinus. This date was incorrectly calculated from July 19 as 138 CE date. This error led Meyer to the quadrennium of 4241 - 4238 BCE. He chose 4241 BCE as the start date of the calendar because it was the earliest. I don't know where 4241 BC came from.

Meyer is credited with the discovery of Sothic dating, but the Sothic cycle was discussed long before and St. Clair, George Creation Records Discovered 1898correctly defines the unaltered Sothic cycle and places Censorinus' date correctly as July 20th 139 CE, coming up with July 20, 4242 BCE as the start of the calendar.

All known dates from Egyptian texts to Ptolemy's Almagest correctly correspond with the system of St Clair, but Meyer got the wrong quadrennium with the error on the date of the Canopic Decree. Meyer did go on to calculate dates internal to the calendar, while St. Clair turned his attention to the astronomy of Egypt. Arguably, St. Clair ties the first dynasty to the start of the calendar while I don't think Meyer does. If St. Clair's system works with the correct quadrennium and was published earlier, why is the discovery attributed to Meyer?

I pose this question in deference to the Berlin school of thought because Meyer's work was more influential. A cynical view would say that St. Clair was overlooked because his work conforms to the ideas of Norman Lockyear and Piazzi Smyth. --JimLowdermilk (talk) 16:20, 31 August 2010 (UTC)


 * The question that should be posed and directly address on the Wikipedia page is "Whose number is 146{0/1}?" Did the Egyptians actually use this figure, or is it a modern creation? That's not been clarified. This article should be cross-checked against the one here https://www.conservapedia.com/Sothic_cycle, which has details not present here. A more important note: the idea, itself (if it is a modern creation) is completely off. The terrestrial year is better approximated as 365 + 1/4 - 1/128 days (which is, at present since around 2000, accurate rounded to the nearest second). The Persian "Solar Hijri" calendar (developed in Persia 1073-1079, instituted in 1079 and modified in 1911) runs close to this estimate (1 second longer on average) for instance, and it was also known in England in the 1000's. The Sothic Cycle based on the 365+1/4-1/128 figure is 46751/31 = 1508 3/31 years, not 1460 or 1461 years. Yes, the figure is *that* sensitive to even the tiniest adjustment in the estimated length of the year! That discrepancy, arising from its extreme sensitivity to year-length estimates, also needs to be noted somewhere. On this basis (and as suggested in the Conservipedia article) the underlying notion is not reliable as a means for dating, and thus, is also not universally accepted in the academia. (Further perspective, both pro and con, can be found under the references cited in the other article.) — Preceding unsigned comment added by 2605:A000:1401:8806:222:69FF:FE4C:408B (talk) 23:30, 17 August 2019 (UTC)

Comment on correlation
The year 140 AD is leap year so if Thoht 1 is July 20 in 139 AD it is July 19 for the next 3 years, all 4 years claimed as the rise of Sothis. The year 2773 BC is likewise a Thoth 1 on July 17 whose previous year is July 18. 4241 BC is a July 19 date for Thoth 1. As for correlation placing Egypt's earliets dates as 2170 BC and 2030 BC and 2001 BC etc; the date for Thoht 1 is Jan 6 in 2001 BC and the winter solstice. The wprt name for new year has been used for sothis but also for solstice and not clear whether winter or summer. Connecting it to Nile flood doesnt help when the myth of Noah's flood is at winter solstice. Further, if Thot is the 7th month then Epagum days begin July 5 in 2001 BC so that the July 10 solstice is Pamenot 1 not 6. Every disagreement in short Genesis has a counterpart application in Egypt. Example, reunification in year 955. If Flood is year 600, and Noah dies in year 350, he dies in the year 350 that the Pharaoh was created. If using a 360-day calendar for those 350 years, then from year 600 it is year 955. Unification of dynasties 1-5 is then the same year and event for dynasties 6-10. The 5th being dead in Genesis in year 340, but in LXX in year 768. The date 1872 BC July 17 is Memphis. But what if its at Fort Quban where sothis rises on July 10 the solstice during the 12th dynasty. That blows those who try to trace July 20 back to a Gregorian solstice in 4242 BC. And at the time of that July 10 date in the year 120 of the 12th dynasty, let's say 1824 BC July 10 as second month Parmuti 16 (versus 8th month 22) we have Paopi 16 on Jan 6, so which is the wprt sopken of in record, winter or summer sothic. —The preceding unsigned comment was added by 69.76.46.169 (talk) 18:08, 3 February 2007 (UTC).

1460 vs 1461

 * The Sothic cycle or Canicular period is a period of 1,461 ancient Egyptian years (of 365 days each) or 1,460 Julian years (averaging 365.25 days each).

it seems like 1461 and 1460 are flipped? or not? im confused. —Preceding unsigned comment added by Sihan (talk • contribs) 12:55, 24 May 2009 (UTC)


 * They're OK. Multiply years and days/year for both and they will be equal. — Joe Kress (talk) 19:13, 24 May 2009 (UTC)

Astral altitude
The majority of the donations to this article ignore the astral altitude of the rising star in relation to altitude of the sun. If the star first appears at -30 min below horizon as light bends, then the sun must be a given distance of altitude below horizon because of its aura of 6 degree civil twilight, 12 degree nautical twilight, and 18 degree astral twilight. This means not only latitude of observation changes it, but so too the precession of the star from earth's axis will change its rising altitude. This is why although the star has been at Julian July 20 at 30 degrees for 2000 years, prior to that it was July 19 in 776 BC and July 18 in 1314 BC and July 17 in 1824 BC. Decades go by and these arrogant haught contributors of knowledge keep ignoring this fact published by Nobel in 1966. —Preceding unsigned comment added by 98.144.120.119 (talk • contribs) 13:35, 29 October 2010

Tacitus
In the Annals of Tacitus he asserts the Egyptians' awareness of a 1461-year cycle, which was said to have recurred in the reigns of Sesostris [Senusret], Amasis [Ahmose] and Ptolemy III. (The context is the mythology surrounding phoenixes.) I don't know if someone with more awareness can edit this or other ancient sources into the article — as it currently stands the page makes it sound like the whole thing is a modern hypothesis or fabrication. —64.17.77.72 (talk) 03:46, 12 September 2015 (UTC)

Diagrams needed
This article would benefit from the addition of imagery in the form of diagrams or charts to illustrate the concept. The idea is new and unfamiliar to me, and I am going to have to make crude drawings in order to fully understand the article. Anyone with graphics ability is welcome to draw some diagrams, upload to Wikimedia, and add them to this article.--Quisqualis (talk) 15:36, 8 February 2017 (UTC)


 * Not entirely sure what kind of diagram you mean. The 365.25 day sidereal year continually moves forward in the 365 day invariable calendar year, until after about roughly 365.25/0.25 years things are back where they started... AnonMoos (talk) 09:21, 11 February 2017 (UTC)

Wrong year numbers?
It seems to me that the year numbers given in the section "Discovery" are wrongly given. Probably this has happened because of a misunderstanding of the "astronomical year numbering". Censorinus' date is generally given as "1 Thoth" at 20 July 139 C.E. (Julian, i.e. JD 1772028), and three Sothic cycles earlier gives us "Meyer's date" at 20 July 4242 B.C.E. (JD 172233), and in the same way we get the alternative date 20 July 2782 B.C.E. (JD 705498) from our calculation of two Sothic cycles before Censorinus' date. Therefore, the years should be "4242 B.C.E." (which is equal to "-4241" in the "astronomical year numbering") and "2782 B.C.E." (equal to "-2781" astronomical), as far as I can understand; but if I am wrong, please correct me. /Erik Ljungstrand (Sweden) — Preceding unsigned comment added by 130.241.158.201 (talk) 11:20, 6 April 2018 (UTC)

Discovery
"This cycle was first noticed by Eduard Meyer in 1904..." This is incorrect. The cycle was well known in antiquity:


 * Censorinus (238, 33) described the cycle as well as its terminus on August 12, AD 139.
 * Syncellus recorded it in detail in the Old Egyptian Chronicle See (Waddell 1964, Manetho, p.227-231)
 * Cullimore (1831b) wrote about it in very great detail, and computed the Sothic Cycle ended in 136 AD.

Therefore to attribute Meyer with the discovery of the Sothic Cycle displays extreme ignorance of the subject.

Sources for the above statements:

Censorinus. 238. William Maude, trans. De Die Natale. New York: The Cambridge Encyclopedia Co. 1900. http://books.google.com/books?id=J7VfAAAAMAAJ.

Cullimore, Isaac. 1833. “On the Hermaic Records.” The Morning Watch, Vol. 6. pp. 389-404. London: J. Nisbet. https://www.google.com/books/edition/The_Morning_Watch/j4U3AAAAMAAJ.

Manetho of Sennebytus. 1964. Manetho. Waddell, W. G., translator. Loeb Classical Library. Cambridge, MA: Harvard University Press.

Cadwallader (talk) 15:11, 12 August 2021 (UTC)

Unsourced addendum to "Precession" section
An apparently sophomoric comment was added to the end of this section which contradicts the information above it. It needs a citation and some harmonization with the rest of the section or it should be deleted. 2001:5A8:4610:2000:DC0F:DEA6:9D06:EA99 (talk) 20:27, 25 November 2023 (UTC)