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Cleopatra and the Egyptian Calendar.

 
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Sosigenes
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PostPosted: Fri May 08, 2009 3:14 pm    Post subject: Cleopatra and the Egyptian Calendar. Reply with quote

When Caesar arrived in Egypt, Cleopatra introduced him to her astronomer Sosigenes, who had studied in the great Library of Alexandria.
Caesar was interested in the Egyptian Calendar that the Greeks had been trying to modify, adding leap years to the calendar for some time, but the priests of Thoth was against adding to the 365 day calendar.

At that time the Roman Calendar was completely useless, being about 80 days out of sinc, so Caesar wanted a new calendar for the Roman Empire, he wanted the calendar to start on 1st January, as Roman consuls took office on that date, but where that was in the Roman calendar is anyone's guess, as it was hopeless!

Sosigenes began constructing a new calendar, adding 80 days to the Roman calendar, starting it on 1st January 0045 BC, he made slight mistakes as it was 11 minutes out of being true of a year, but not bad for over 2,000 years ago, before quartz watches, we were lucky to have a watch accurate to 11 minutes in a year!

Cleopatra was very political, very clever as she could speak a number of lanquages, was considered Isis on Earth by her subjects, and knew the Egyptian religion inside out!

But she was also Greek, and the ancient Greeks used sunset as the start of the day, and i can't stop thinking that she had one over on Julius Caesar, by aligning the beloved Isis Star Sirius to the new JULIAN CALENDAR Ha Ha!

Midnight was never used that early, the Greeks and Babylonians used sunset as the start of the day, the Romans and Egyptians used sunrise, as new year in the Egyptian Calendar was when Sirius rose with the Sun.

On 1st Jan. 0045 BC we know without looking that Sirius wouldn't rise with the Sun, however Cleopatra may have mixed her beliefs about Sirius to align Sirius to Sunset......and on this date there is an alignment!

To find Thebes on an astronomy programme, you would have to tap in Luxor, which is 25*N41', 32*E39', add the date of 31 December 0046 BC, and a time of 17:19pm, and hey presto, you will find that the Sun is setting in the West along the Horizon, while Sirius is rising in the East, this is locked and couldn't appear at another location as it uses both horizons!

There are three locations that Sosigenes could of used, Alexandria, Memphis, or the ancient capital, Thebes, near the sacred temples of Karnak and not far from the Valley of the Kings....an ideal spot to start the Julian Calendar, i think you will agree, and fits to Cleopatra being Greek!
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anneke
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PostPosted: Fri May 08, 2009 3:56 pm    Post subject: Reply with quote

Interesting. If we can believe wikipedia, then the story that Sosigenes was consulted came from Pliny the Elder. That dates the story about Sosigenes some 100 years after the events took place.

I'm not questioning the statement. I just find it interesting that the change was associated with scholars from the Library of Alexandria. It makes some sense to me that Julius Caesar would have consulted the best scholars and at that time those would be located in Egypt I think.
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PostPosted: Fri May 08, 2009 5:06 pm    Post subject: Reply with quote

I'm always a little suspicious of using commercial astronomy programs for archaoastronomy. How can I be certain that the date noted as January 1 would have been called January 1 at the time (i.e., is the calendar proleptic or historical? And how can one easily find out?)? And what epoch is the astrronomy program based on? What proper motion does it assign for Sirius? Etc., etc.

I'm not saying these problems are insoluable give the proper equipment, software, and other resources; I'm just saying that I don't trust my copy of "RedShift 5" to provide any definitive proofs for a chronological theory of mine.
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neseret
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PostPosted: Fri May 08, 2009 6:58 pm    Post subject: Reply with quote

Montuhotep88 wrote:
I'm always a little suspicious of using commercial astronomy programs for archaoastronomy. How can I be certain that the date noted as January 1 would have been called January 1 at the time (i.e., is the calendar proleptic or historical? And how can one easily find out?)? And what epoch is the astrronomy program based on? What proper motion does it assign for Sirius? Etc., etc.

I'm not saying these problems are insoluable give the proper equipment, software, and other resources; I'm just saying that I don't trust my copy of "RedShift 5" to provide any definitive proofs for a chronological theory of mine.


FWIW, you might want to take a look at the archaeoastraonomy software at CultureDiff, which was created by the archaeoastronomer Karine Gadre, with specific reference to the ancient Egyptian sky. You can try the software out first for free.

I've worked with Dr. Gadre off and on for some years when I was doing my research on the astronomical implications of the godess Neith and her work is without equal.

HTH.
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Montuhotep88
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PostPosted: Fri May 08, 2009 8:12 pm    Post subject: Reply with quote

Great! I'll check it out. Smile
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Sosigenes
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PostPosted: Sat May 09, 2009 12:37 am    Post subject: Reply with quote

The Alexandrian Calendar had a new year that was Emperor Augustus' birthday, who was no friend of Cleopatra, however this was changed to 1st September in 0462 A.D.

This calendar seems different as it uses both latitude and longitude, probably to cover more of the Byzantine area, as a star rising with the Sun only goes along a straight line of latitude.

Jupiter was a great favourite of the early astronomers as it was thought to bring good fortune.

In Alexandria on 1st September 0462 AD Jupiter and the Sun rose together around 05:36am, now scroll around the astronomy programme to South, and draw a line upwards that will show what stars were culminating, in the middle of the sky, you will find it cuts through the Belt of Orion, a very important area of the sky, being the male influence as it represented Osiris, as Sirius represented Isis!

Stars that culminate were considered very important as the Sun rises!
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PostPosted: Sat May 09, 2009 3:28 am    Post subject: Reply with quote

There are many more problems with the original statement on this thread than so far noted.

First of all:
The typical historian's approach to ancient dates is to use the Julian Calendar for dates prior to 1582 October 15, the date on which Catholic Europe was supposed to switch the the Gregorian Calendar. The date prior to October 15th of that year being October 4th. No change in the sequence of weekdays occurred.

Several issues result. One is that the Protestant countries in Europe did not immediately accede to the new calendar. They came around one by one (and in some cases one part of the country at a time, or by stages, i.e. a day at a time as was done in Sweden) due, most probably to reduce confusion in commerce. England, for example, switched over in 1752. Russia was still using the Julian calendar until early 1918, so that the October Revolution of 1917 took place in November according to the Gregorian Calendar. Greece didn't switch until 1924.

New Year's Day itself presents its own issues. For example, March 25th started the New Year in England until 1752 while in Scotland January 1st was the magic day. So, even after the Acts of Union of 1707 different parts of the United Kingdom practiced New Year's on different days!

Montuhotep is quite right in questioning whether commercial programs correctly handle the non-Gregorian dates prior to 1582. In fact, you can't trust them after that date, as we have just seen. You need to know which calendar was in use where and at what time. The only way you could tell is by looking at the Julian Date which many programs don't display. The Julian Date (JD) (no connection with the Julian Calendar) is a successive day count starting at -4712 Jan 1.5 (Julian Calendar), using so-called Universal Time (roughly = GMT at present). The year -4712 is the equivalent of 4713 BCE. Astronomical observations are reported in Julian Days. As I write, the JD, accurate to four decimals (roughly the nearest minute), is 2454973.5646.

But even if the program gets the JD right, the next issue arises from the its handling of Delta-T, which is controversial. Delta-T is a correction due to variations in the Earth's rotation. It is not exactly predictable. Nor is it easily postdictable due to the imprecision of temporal and geographical information coming from the ancient world. An excellent discussion of this issue can be found at http://eclipse.gsfc.nasa.gov/SEhelp/deltaT.html
Fred Espenak, the author, is a highly regarded expert in the field. At the time in question, about the year -44, the value of Delta-T is about 11000 seconds. There are several different published algorithms which can be used to calculate (a better phraseology would be "guess at" or perhaps "approximate") Delta-T. They give suprisingly disparate results, ranging all over the map. The further back into antiquity you go, the larger the variation becomes. Which algorithm any particular program uses is up to the authors and is not usually published, not because they're ashamed of it, it's just that the average user doesn't know about this stuff and so doesn't care. With variations on the order of hundreds and even thousands of seconds, it's extremely difficult to place ancient astronomical events with great precision. It only takes the Sun a couple of minutes to set (watch it sometime, you'll be amazed at how rapidly it goes down). The error in Delta-T is much greater than that. So you cannot say precisely when sunset occurred on any particular day, assuming, as we've seen above, you know when that day is.

Next there is the problem of refraction. The atmosphere refracts (bends) rays of light, the more air, the more bending. When you look at astronomical bodies near the horizon you are looking through about three times as much atmosphere as you are when you look straight up. Refraction can cause several minutes of difference between an object's true conjunction with the horizon and its apparent conjunction. Furthermore, while it's fairly easy to see the Sun on the horizon it's damned difficult to see a star there, even a bright one, with unaided vision. Even telescopically. Only extenuating circumstances will get me to observe any object closer than fifteen degrees to the ground. Sometimes it can't be helped, but then uncertainty in even the finest measurements ensues.

But there's more. It is extremely unlikely that Kleopatra had anything at all to say about the Roman Calendar. While it is true that the calendar of the Roman Republic was out of step, it is also true that they knew about what it should be, so they lined up the reformed calendar of Caesar with their traditional date of the vernal equinox. Sirius doesn't seem to have entered into their calculations at all.

Anneke is quite correct in stating that Plinius Maior was the first authority we have who named Sosigenes as the author of the Julian calendar. This particular Plinius died while investigating the famous eruption of Vesuvius in +79, more than a hundred years after Caesar's death. But there's little reason to doubt the story. Anneke correctly, I think, feels that Caesar would have consulted an Alexandrian authority. I am unaware of any source saying that Kleopatra introduced Caesar to Sosigenes

(
Sosigenes wrote:
Caesar was interested in the Egyptian Calendar that the Greeks had been trying to modify, adding leap years to the calendar for some time, but the priests of Thoth was against adding to the 365 day calendar.

For internal reasons, very probably a mixture of religious, political, and traditional issues. Not only that, being able to depend on a 365 day calendar makes it very easy to use in accounting practices. It also provides a solid basis for computing astronomical events over millenia to naked eye precision, which is why Copernicus used it in his famous book as late as the 16th century in our era.

A calendar need not accurately count years. The Jewish and Muslim calendars are prime examples of this. The Gregorian Calendar is used world-wide for ease of commercial transactions, but it, also, is not actually based on the length of the year. It's purpose is to calculate Easter according to a rather complex, and quite arbitrary, algorithm.

Sosigenes wrote:
At that time the Roman Calendar was completely useless


On the contrary, it was very useful. The length of the year could be, and was, manipulated for political reasons, for example, to cut a consul's year in office short or to get a particular officer installed earlier rather than later, or later rather than earlier. It could be very difficult to live with (see one of Cicero's letters to Atticus), but very useful at times.

)

So assuming for sake of argument that it was Sosigenes, he didn't make a mistake. He was in error. Two different things. He was using the best information available to him. The ancient world knew about the extra quarter of a day in a year, but that's about the extent of their knowledge. Moreover, it was easy to figure into a calendrical scheme: add one extra day every four years. Except that that's not what happened. The Romans counted inclusively. For example, they figured that year 5 was four years prior to year 8. Count 'em - 5, 6, 7, 8 - four of 'em, you see. So after the adoption of the Julian calendar they sometimes had a leap year every three years, by our reckoning. It wasn't until fairly late in Augustus' reign that they corrected the error. The exact sequence of leap years during that perod is also somewhat in doubt and, therefore, so is a particular date.

So there are lots of places where errors can creep in. Montuhotep is right. Use extreme caution and research the issues. Most of all, DO NOT DEPEND on planetarium programs to produce events accurate to particular instances of time. The authors may make claims of great precision in order to sell copies, but the software is only useful for getting a general picture of the sky. A case in point is Occult (nothing to do with astrology - we're into science, not fraud) which is used by the International Occultation Timing Association (IOTA) to predict asteroid occultations of stars and lunar grazes. Expeditions are mounted based upon its results. Yet it is continually updated and is not useful for any but a few years around its latest date of publication.
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Sosigenes
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PostPosted: Sat May 09, 2009 3:13 pm    Post subject: Reply with quote

Hi BobManske,

Nice to talk to you, i left things simple to see what reactions i had.

Yes i'm fully aware that the Romans got in a muddle, and at one stage were adding a leap year every three years, probable as Caesar died soon after, and the new calendar wasn't fully understood, although the Romans made records, we don't have records to today to tell us how they coped with it, but after realising that they got things wrong they attempted to put this right, if they did this accurately or not, we don't know, but it was in their best interests that they did.

The Empire was fed by farmers, if you don't eat then you don't have an Empire, and no one wanted to return to a time in the Roman Calendar, when the Seasons were out of sinc.

When understanding that they had been adding too many leap days, it would be fairly easy to put things right, and thus return the Calendar to starting on 1st Jan. 0045 B.C.

If you don't like Thebes on 0045 B.C. move it back to Aswan, where Sirius is slightly higher, as the Sun sets, its still in Egypt.

The Alignment that i'm talking about, cannot move to far as it is fixed by both horizons, unlike Sirius rising with the Sun, that shows up at other locations along a straight line of of Latitude.

New York is 40*N42'15", so on 2 Aug 2009 Sirius will rise with the Sun, within 1 minute 38 secs, at approx 05:58am, However Madrid is 40*N24' so the same will happen there at 07:17:55am being in a different time zone.

However i'm with you in thinking that the Romans got in a muddle, but you have no evidence that they didn't get adjusted properly, after realising the mistake.

I can't say that they did adjust properly also, so readers may think we are non the wiser......but is there any other accumulative evidence, yes there is!

You are right the Council of Nicea, being Iznik in modern Turkey is very important that happened in 325 AD, this was about calcalating Easter, with the ecclesiastic full moon as this isn't a fixed date, and 21st March was chosen as a yard stick to calcalate this!

There was soon problems, as the Julian Calendar was adding a day every 128 years, it was only a slight problem, being that 3 leap days had to be taken out every 400 years.

The Greeks and Egyptians had done all the hard work, this wasn't rocket science, and many knew that the calendar was wrong, the Venerable Bede was lobbying for adjustments around 731 AD, so were many others.

Obviously the calendar getting out of sinc, would trouble priests that wanted to calcalate Easter and had difficulty, so as it was so important why was it over 700 years later that we got calendar reform?

The first clue is looking at 4th October 1582, at 23:59pm in Rome on your astronomy programme, being the last minute of the Julian Calendar.

All of you will see what i see, Sirius rising at that location.

Most of my astronomy programmes only show the calendar reform in 1582 when ten days were taken out of the Calendar, therefore going forward from this date, when other countries were still using the Julian Calendar, i have to make adjustments, however this doesn't apply to 1582.

Our perceptions in 1582 were influenced by the emergence of the clock, early in the 14th century large clock towers were put up in Italian cities, another advance was the invention of the spring powered clocks between 1500 and 1510, by Peter Henlein of Nuremburg, which made clocks more portable! The minute hand to clocks was invented by Jost Burgi in 1577, five years before calendar reform, Burgi's invention was part of a clock made for Tache Brahe, so although cutting edge technology the clock was available in 1582.

Anyhow these people wasn't stupid, there were other ways to calcalate midnight, the Gregorian Calendar that we follow today is accurate within seconds and won't need any leap day adjustments for over 3,000 years, it would be silly to think that they couldn't calcalate midnight in 1582!

Use your astronomy programme set it to the Prime Meridian, being Greenwich, UK, 1st January 2008 at midnight, when both hands of the clock point upwards in a straight line, now scroll around your astronomy programme to find South, and draw a straight line upwards......what star is culminating in the centre of the sky? Interesting isn't it?

I will talk about time zones and how this was calcalated, later if i get the chance....accumulative evidence does matter. Beliefs of this sort were calcalated using 1* Degree orb, which is four minutes of time.

Calendars are like cars they get modified!
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PostPosted: Sun May 10, 2009 6:10 am    Post subject: Reply with quote

We get people like this coming through here about every two months or so. So here I go, once again (sigh), saying there are plenty of forums where people eat this kind of stuff up. This ain't one of 'em. There are some very serious, very well educated, very knowledgeable people on this forum, and we don't have to put up with us.

So, here goes:

Sosigenes wrote:
The Empire was fed by farmers, if you don't eat then you don't have an Empire, and no one wanted to return to a time in the Roman Calendar, when the Seasons were out of sinc.


It's spelled "synch" by the way. The farmers had absolutely nothing to do with the Roman calendar. Zero. The Roman Republican calendar was basically a lunar calendar. If you plant or reap crops by such a calendar you can easily go wrong at times by close to a month. Instead, they planted by the seasons, weather, and possibly moonlight for night work. The Roman calendar in the years before -45 were indeed out of synch with the solar year. If Roman farmers had planted according to that calendar, empire wide disaster would have occurred. They didn't and it didn't. The crops were planted and came in on time. If there were any shortages it wasn't because they were looking at the calendar. Roman farmers were never consulted or considered in the formulation of the calendar. What they cared about was the nunidinae, the market day, which continued, like the weekday (presumably), through all the changes. (Incidentally, nunidinae is derived from "ninth day", another example of Roman inclusive counting, since market days occurred every eighth day).

Sosigenes wrote:


If you don't like Thebes on 0045 B.C. move it back to Aswan, where Sirius is slightly higher, as the Sun sets, its still in Egypt.

The Alignment that i'm talking about, cannot move to far as it is fixed by both horizons, unlike Sirius rising with the Sun, that shows up at other locations along a straight line of of Latitude.



As has already been pointed out, the alignments you are talking about with your planetarium program are invalid. You do not know which days you're talking about nor do you have any clue as to the correct value of delta_t during that period, so any use of such a program to locate events to the indicated precision is illegitimate.

The program is worthless for that purpose.

You CAN use such a program to get a general picture of the sky on some indicated date in antiquity whose actual identity you usually have no way of ascertaining. You can get that general picture providing you know what you're doing with the program and you have not shown any evidence of that.


Sosigenes wrote:

New York is 40*N42'15", so on 2 Aug 2009 Sirius will rise with the Sun, within 1 minute 38 secs, at approx 05:58am, However Madrid is 40*N24' so the same will happen there at 07:17:55am being in a different time zone.


That is a completely irrelevant statement. It adds nothing to the discussion, and quite frankly, appears to function as nothing but a smokescreen, an attempt to divert attention. Ain't gonna work.

Sosigenes wrote:

You are right the Council of Nicea, being Iznik in modern Turkey is very important that happened in 325 AD, this was about calcalating Easter, with the ecclesiastic full moon as this isn't a fixed date, and 21st March was chosen as a yard stick to calcalate this!


You have no idea how gratifying it is to hear you say that I was right about the Council of Nicea (Nicaea/Nikaia, really), particularly since I never mentioned it or any of its decisions. To be right about things I never even talked about is indeed wonderful. I shall treasure this moment always.

Sosigenes wrote:

Obviously the calendar getting out of sinc, would trouble priests that wanted to calcalate Easter and had difficulty, so as it was so important why was it over 700 years later that we got calendar reform?

This sentence is almost incomprehensible. Please read your stuff before you post it - an occasional mistake is fine, but this badly needs editing. Nevertheless I think I get the drift. And this quoted statement, too, is irrelevant to the subject. The background issue in the case of this particular point is that there was a reform, not when. The question really is: does a particular planetarium program (e.g. the one you're using) handle the reform correctly going back in time prior to the Gregorian reform? It probably does, but have you ascertained that? And how?

Sosigenes wrote:

The first clue is looking at 4th October 1582, at 23:59pm in Rome on your astronomy programme, being the last minute of the Julian Calendar.

All of you will see what i see, Sirius rising at that location.


Couldn't care less. We have already established that Sirius had nothing at all to do with either the Roman or Julian calendars or the Gregorian calendar so this point is also irrelevant, even if it is true and, since it is irrelevant, I'm not going to bother to find out.

Sosigenes wrote:

Most of my astronomy programmes only show the calendar reform in 1582 when ten days were taken out of the Calendar, therefore going forward from this date, when other countries were still using the Julian Calendar, i have to make adjustments, however this doesn't apply to 1582.

It sure does apply. If you dial up an English date for anytime after that in 1582, you'll get it wrong by your statement.

Sosigenes wrote:

Our perceptions in 1582 were influenced by the emergence of the clock, early in the 14th century large clock towers were put up in Italian cities, another advance was the invention of the spring powered clocks between 1500 and 1510, by Peter Henlein of Nuremburg, which made clocks more portable! The minute hand to clocks was invented by Jost Burgi in 1577, five years before calendar reform, Burgi's invention was part of a clock made for Tache Brahe, so although cutting edge technology the clock was available in 1582.


No. The issue which generated the Gregorian reform in 1582 had absolutely nothing to do with portability of clocks or minute hands or the rising or setting of Sirius or whatever. It had everything to do with calculating the date of Easter. We have already established that.

Sosigenes wrote:

Anyhow these people wasn't stupid, there were other ways to calcalate midnight, the Gregorian Calendar that we follow today is accurate within seconds and won't need any leap day adjustments for over 3,000 years, it would be silly to think that they couldn't calcalate midnight in 1582!


Again, this statement has absolutely nothing to do with the discussion. But it is funny because it's even irrelevant within itself! It is internally irrelevant. I love it.

Sosigenes wrote:

Use your astronomy programme set it to the Prime Meridian, being Greenwich, UK, 1st January 2008 at midnight, when both hands of the clock point upwards in a straight line, now scroll around your astronomy programme to find South, and draw a straight line upwards......what star is culminating in the centre of the sky? Interesting isn't it?

No, it isn't. Not interesting at all and, here's that word again: irrelevant to the subject at hand.

Sosigenes wrote:

I will talk about time zones and how this was calcalated, later if i get the chance

I really hope you don't get the chance.


You have advanced two main theses:
1) That you can dependably use a planetarium program to produce the sky, with the accuracy you describe, at the dates in antiquity that you are interested in, and
2) That Sirius, rising, setting, whatever was involved in the Julian and Gregorian calendar reforms.

Both of these theses have been shown to be wrong. End of story. Now, go ahead and make your response which I won't bother to read and then, with any luck at all, the thread will die its well-deserved death.
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