The Date of Alexander's Birth

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Paralus
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Re: The Date of Alexander's Birth

Post by Paralus »

Taphoi wrote: Thu Oct 17, 2019 6:17 pm I can do no more that suggest that you and any other Pothosian who is interested in the matter should google "Eudoxus zodiac".
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Andrew
Your authority is Google? Perhaps a rephrasing of the question. What is the ancient evidence for Eudoxus adopting the constellations of the zodiac from Babylon and subsequently intoducing these same constellations to the Greeks along with the concept of the line the sun traces through same?
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Re: The Date of Alexander's Birth

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Paralus wrote: Thu Oct 17, 2019 9:14 pm Your authority is Google? Perhaps a rephrasing of the question. What is the ancient evidence for Eudoxus adopting the constellations of the zodiac from Babylon and subsequently intoducing these same constellations to the Greeks along with the concept of the line the sun traces through same?
Beautifully legalistic rephrasing - same answer. Anyone who has googled "Eudoxus zodiac" will know by now that it is generally accepted that Eudoxus introduced the zodiac to Greece.

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Re: The Date of Alexander's Birth

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Taphoi wrote: Fri Oct 18, 2019 12:25 pm
Paralus wrote: Thu Oct 17, 2019 9:14 pm Your authority is Google? Perhaps a rephrasing of the question. What is the ancient evidence for Eudoxus adopting the constellations of the zodiac from Babylon and subsequently intoducing these same constellations to the Greeks along with the concept of the line the sun traces through same?
Beautifully legalistic rephrasing - same answer.
No answer then. Expected little else.
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Wicked men, you sin against your fathers, who conquered the whole world under Philip and Alexander.

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Re: The Date of Alexander's Birth

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Taphoi wrote: Thu Oct 17, 2019 6:12 pm You are missing my point: my evidence from actual analysis of actual dates (above) is that Timaeus calculated the New Moon whereas the Babylonians at the same date relied totally on actual observations.
Crikey Andrew! The logic, if that is the word, of that argument has more leaps than Track and Field day at the Olympics.

We are still waiting for you to provide a spot of evidence that any Greek calendar before 300 relied on calculating the start of the month or had a way to compensate for the king or archon adding and subtracting months or days to taste. (One date in one [s]historian[/s] biographer and moral philosopher synchronizing with an eclipse is not evidence, because a stopped clock is right twice a day).
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Re: The Date of Alexander's Birth

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Taphoi wrote: Fri Oct 18, 2019 12:25 pm Beautifully legalistic rephrasing...
I'd suggest the retaining of independent counsel but, like Rudi Giuliani each time he speaks, you're doing quite fine on your own recognisance.
Taphoi wrote: Fri Oct 18, 2019 12:25 pm ...it is generally accepted that Eudoxus introduced the zodiac to Greece.
Your contention, then, is that the Greeks knew nothing of of Sagittarius, Scorpio, Gemini or the other nine constellations along the ecliptic until Eudoxus, using information he learned from Babylonia, introduced same to them? Nor that the Greeks knew of this ecliptic and the relationship of the sun to same until Eudoxus gave them the benefit of his Babylonian knowledge? What source evidence have you for that contention? And, no, the final question was not rhetorical.
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Wicked men, you sin against your fathers, who conquered the whole world under Philip and Alexander.

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Re: The Date of Alexander's Birth

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sean_m wrote: Fri Oct 18, 2019 9:53 pm We are still waiting for you to provide a spot of evidence that any Greek calendar before 300 relied on calculating the start of the month or had a way to compensate for the king or archon adding and subtracting months or days to taste. (One date in one [s]historian[/s] biographer and moral philosopher synchronizing with an eclipse is not evidence, because a stopped clock is right twice a day).
If you would like to begin to understand the matter of Greek calculations of Lunar phases and other celestial motions, I refer you to relevant sections of Greek & Roman Chronology by Alan Samuel. Samuel has a section on Eudoxus and cites various Greek sources, notably Aristotle, to show that Eudoxus promulgated a basic spheres-type theory of the Moon and other celestial bodies, which in later elaborations led to the Almagest of Claudius Ptolemy and the amazing celestial modelling work of Hellenistic astronomers such as Hippocrates. Obviously, the point of such models was to calculate and predict the motions of the Moon and other bodies for calendrical purposes and the model of Eudoxus would certainly have sufficed to predict the day of New Moon with very good accuracy, subject to occasional observational tweaks, which need not have been made at the actual time of New Moon (in total contrast to the cloudy Babylonian religiosity in their literal observations of first crescent or last crescent etc). It is completely uncontroversial that the more sophisticated Greeks of Alexander’s time were therefore calculating and predicting long in advance New Moon, Full Moon and other phases. The supposition that Greek calendars after the middle of the 4th century BC relied upon crescent observations is therefore an ignorant mistake. The agreement of Timaeus’s date for Gaugamela/Arbela with the concept that he was using a calculated date for the New Moon is merely an additional confirmation of the fact of which we are already aware, because we have sufficient references to Eudoxus’s Lunar motion modelling work: that the Greek astronomers of Alexander’s time were calculating and predicting New Moons.
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Re: The Date of Alexander's Birth

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Taphoi wrote: Sat Oct 19, 2019 10:10 am
sean_m wrote: Fri Oct 18, 2019 9:53 pm We are still waiting for you to provide a spot of evidence that any Greek calendar before 300 relied on calculating the start of the month or had a way to compensate for the king or archon adding and subtracting months or days to taste. (One date in one [s]historian[/s] biographer and moral philosopher synchronizing with an eclipse is not evidence, because a stopped clock is right twice a day).
If you would like to begin to understand the matter of Greek calculations of Lunar phases and other celestial motions, I refer you to relevant sections of Greek & Roman Chronology by Alan Samuel.
I read Samuel a few days ago. He says flat out: no date in any Greek calendar before 300 can be converted into a Julian day except by cross-reference with an eclipse, because we don't have records of all the arbitrary changes introduced by the king or archon. In many cities we don't even know the names and orders of all the months!

The question was not "could some Greek astronomers predict the start of the lunar month?" The question, which you still have not answered, is what evidence you have that any Greek calendar before 300 relied on calculating the start of the lunar month, or had ways of compensating for the king or archon adding or subtracting days and months to taste.
Taphoi wrote: Sat Oct 19, 2019 10:10 amThe supposition that Greek calendars after the middle of the 4th century BC relied upon crescent observations is therefore an ignorant mistake.
I am sure that Samuel, or his ghost, is devastated to hear that.
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Re: The Date of Alexander's Birth

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sean_m wrote: Sat Oct 19, 2019 12:30 pm The question was not "could some Greek astronomers predict the start of the lunar month?" The question, which you still have not answered, is what evidence you have that any Greek calendar before 300 relied on calculating the start of the lunar month, or had ways of compensating for the king or archon adding or subtracting days and months to taste.
Taphoi wrote: Sat Oct 19, 2019 10:10 amThe supposition that Greek calendars after the middle of the 4th century BC relied upon crescent observations is therefore an ignorant mistake.
I am sure that Samuel, or his ghost, is devastated to hear that.
Just to be clear what we agree about: some Greek calendars, notably the Athenian Archon Calendar, were subject to arbitrary tweaks. And yes we don't always know when tweaks were applied and when not. Just as we don't know how many days after the New Moon the Babylonian lunar month kicked off.

What I am saying is that Plutarch appears to have got his Alexander dates from Timaeus. Timaeus evidently got the date of Gaugamela/Arbela exactly right, therefore it is likely that he got the date of Alexander's birth exactly right. I am adding that by the middle of the 4th century BC there is copious evidence that the Greeks had decent models of lunar and solar and planetary motion. Therefore they could calculate New Moons. Therefore they did. Therefore there is no reason to think that Timaeus, as somebody who understood the importance of Lunar accuracy, did not have the means to obtain an accurate date for Alexander's birth.

Do you not accept that if the Greeks had models of Lunar motion, they would have used them to calculate and predict exact New Moon dates? It is a totally different point that some Greek calendars were sometimes messed up by political tweaks and nobody least of all me is disputing that (I have written about Arrian's horribly messed up dating of Gaugamela to Pyanapsion according to the Archon calendar).

Best wishes,

Andrew
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Re: The Date of Alexander's Birth

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Taphoi wrote: Sun Oct 13, 2019 3:12 pm I did a couple of quick calculations and realised that the correction to the calculations of New Moons from NASA’s Lunar eclipses due to the eccentricity of the Lunar orbit (which I mentioned above) could in extreme circumstances be as much as a day (although it would only normally be hours.)
However, I found a site online that gives accurate modern computations of the Julian dates and times of all Lunar phases including New Moon here:
http://www.astropixels.com/ephemeris/ph ... -0399.html
So I can now tell you to within minutes when Hekatombaion started in July 356BC (wait for it….)
June 15th (Julian) at 08:42 Universal Time, which was about 10:15am local time in Macedonia.
Okay. I misread the new online chart of ancient Lunar Phases. I accidentally read the June line instead of the July line. So the New Moon was July 14th 17:18 UT or about 19:00 local time in Greece. The Lunar orbit's major axis must have been aligned to maximise the error on my previous calculation from NASA's eclipses. So Alexander was indeed born on 19th July Julian in 356BCE (unless the Macedonians or Timaeus counted the previous evening as part of the next day, in which case it is still 20th July). Apologies to Jeanne :oops:
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Re: The Date of Alexander's Birth

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Actually the list of New Moons at http://www.astropixels.com/ephemeris/ph ... -0399.html also gives a New Moon at 21:04UT, Jun 10th 323BC. That would mean that June 10th was 30th Daisios and June 9th was 28th Daisios. That overthrows the accepted dates for Alexander's death as well as my date for Alexander's birth. Checking the NASA Lunar Eclipses against the Full Moons in this list, NASA typically gives a time that is ~5hours later. That correction would move the New Moon to just after Midnight 15th July 356BC local time in Greece. So the whole issue seems to be on a knife edge. Still looks like our dates for Alexander's death might be wrong though, depending on exactly how the dates were calculated and whether the previous evening was counted with the next day or the evening went with the preceding day (but there is some evidence that Timaeus used midnight).
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Re: The Date of Alexander's Birth

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The mist is beginning to clear. I downloaded my old list of Lunar Eclipses around a decade or so ago. The NASA database is still online here: http://xjubier.free.fr/en/site_pages/lu ... Canon.html
But they have moved their Lunar eclipse times back about 5 hours in time. NASA now gives 18:24 UT for the Gaugamela/Arbela eclipse, whereas the new online database of Lunar Phases gives 18:14, so there is now only a 10 minute discrepancy and it also appears that Fred Espenak of NASA is responsible for both lists anyway.
There seems to have been a tweak to the Lunar models in the last decade that has moved all the timings back by nearly a quarter of a day and that is shifting some of the Alexander dates back a day.
But has the model stopped moving now?
It should also be remembered that if any massive bodies (e.g. comets) that we don't know about have passed very close to the Earth-Moon system at any date in the interim, all these calculations will be invalid anyway :roll:
Best wishes,
Andrew
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