31
Mark wrote:Hello Juan,...
This substantially concurs with what I have been suggesting here. I knew this had to be the case as I had read so many Islamic online sources(citing the Hadith) which were emphatic that Hijrah began in the month of Safar. Although I am still not exactly clear what chart you are proposing for Islam from the link on the Hijrah.
Although there is some uncertainty in the exact dates when translated to the Julian calendar, there seems to be (inferred from my readings at the time I wrote the article) universal historical agreement that the Hijra took place around September or at least early Fall of A.D. 622, and some historical sources I mentioned give very specific dates. My impression is that it is probably possible to assertain the exact dates for astrological study, as you are trying to do here.

But I don't feel this is necessary because we already have a very accurate reference point for the beginning of Islam in the July 16 A.D. 622 chart. This chart is sometimes called --unfortunately, confusingly, and wrongly-- "the Hijra chart", a mistake reproduced (and given authority to) by Campion and other writers. This is the chart of the zero point of the "Era of Islam", and personally, I feel it is a better reference astrological point or radix than the chart of any historical event related to the Hijra that happened that year.

Why do I feel that? First, because I have worked with it extensively (in the past, I must say) and have obtained what to me are very significant, accurate results, mainly by the study of sidereal transits and synastries. I must note however, that a lot (not all) of this research involved the centaurs and will therefore be dismissed by many astrologers. And second, because in its function as a calendar it is a standard, universally accepted reference point that has structured human experience over many centuries and which was established with great care with regards to historical events (for the people involved) when it was inaugurated, and therefore carries more weight (to me) than any other alternative.

I know this way of thinking is not accepted at face value by many astrologers, but it conforms to my view about how astrological reference points or "radixes" are established. Of this I would like to quote what I wrote at the end of my article on the Horoscope of Muhammed (the link is in my previous post):

Astrologers tend to think that traditional dates --dates based on legend or myth, without "true" historical foundation-- are worthless. I think this is a mistake. It is the "epiphanical" and imaginative meaning we give to a date what matters, not if the date refers to a "real" physical event. There is (often) nothing physical about the time we choose to do a horary chart, for example, or about many inceptional event charts. "Events" are often purely subjective or fictional, and are non-events for other people.

We have for example the date "December 25, 1 B.C. at midnight in Bethlehem", a date celebrated by all Christendom for 2 millenia, and nobody seems to think that the date is astrologically significant! I confess I have never done any serious work with this chart, probably afraid of being considered an ignorant fool by the whole astrological establishment. This unfortunately is not considered serious work.

On the other hand, besides of course the "chart of Islam" made for 16 July 622 at sunset, which I think is very powerful, we have the date of Muhammed's death (8 June 632), which apparently is indisputable historically speaking. There is no need to speculate on the true date of birth for astrological purposes when we have the true date of death. Unless we are rotten materialists who think Astrology deals only with the physical or the biological, the horoscope of death often offers a better perspective of an individual?s spiritual constitution, especially, as in this case, when the real (and in this case monumental) spiritual legacy they left to the whole of mankind became effective after (or because) they died.
Juan

32
But I don't feel this is necessary because we already have a very accurate reference point for the beginning of Islam in the July 16 A.D. 622 chart. This chart is sometimes called --unfortunately, confusingly, and wrongly-- "the Hijra chart", a mistake reproduced (and given authority to) by Campion and other writers. This is the chart of the zero point of the "Era of Islam", and personally, I feel it is a better reference astrological point or radix than the chart of any historical event related to the Hijra that happened that year.
Hi Juan,

My perspective is that mundane astrology is derived from two basic sources. Firstly, timed or electional events. Secondly, prior ingress, conjunction and lunation charts that precede major events. The latter are not just second best alternatives but rather chronometers that establish the basis for later event charts. I therefore dont propose the charts I have offered as in any way definitive. We dont have information for Muhammed's birth, his first revelation of the Koran, his first preaching etc. I will have a look at your work on his time of death. However, hoping one timed event chart will totally some up something like a world religion is unlikely in my view. Instead medieval astrologers looked at the chart for the Jupiter-Saturn conjunction preceding the birth of Muhammed.

However your choice of what I call 'The Islamic Calendar chart' doesn't strictly meet either criteria. Instead it was a date chosen in time retrospectively by Muhammed's successsor for largely practical reasons. No significant event or planetary configuration etc is tied to this chart. I suppose one can argue, as this date was later chosen as the start of Islamic history, it has a symbolic significance. Hence it could be compared to the role of the 4th of July in American consciousness even though the modern United States of America doesn't date from then. However, there is no actual incident here such as the Declaration of Independence to really base this on. I therefore remain sceptical about this kind of approach.

If I was going to work with that kind of purely symbolic chart I think 37 Cenned has made a convincing case for timing the chart from when the crescent Moon became visible. In that respect s/he has improved on the work of Mark Lerner , Michael O'Reilly and Nicholas Campion although perhaps not in the way originally intended.

Mark
As thou conversest with the heavens, so instruct and inform thy minde according to the image of Divinity William Lilly

33
Mark wrote:Your choice of chart doesn't strictly meet either criteria. Instead it was a date chosen retrospectively by Muhammed's successsor. No significant event or planetary configuration etc is tied to this chart.
This is not correct. It is tied to a culturally very significant astronomical point of the lunisolar cycle (lunar visibility). This is a real astronomical event or configuration which in turn is tied to a very significant historical event (the Hegira).
I suppose one might argue as this date was later chosen as the start of Islamic history it has a symbolic significance. Hence it could be compared to the role of the 4th of July in American consciousness even though the modern United States of America doesn't date from then.
And "symbolical significance" makes it less astrological or traditional? Does the moment of birth of a human being have anything more than symbolical significance? As a rule --I think-- any specific moment of time that we decide to call "the birth of a nation" cannot be anything but symbolical and arbitrary. Why do we decide that the arrival of Mohammed to Medina, rather than the first visibility of the Moon just prior to it that marked the zero point of their time-reckoning, should be picked as the astrological zero point of Islam?

Whatever the answer or reasoning is (as long as it is not "tradition") allows us to figure out and explore deeper the underlying assumptions we astrologers work with.
If I was going to work with that kind of symbolic chart I think 37 Cenned has made a convincing case for timing the chart from when the crescent Moon became visible. In that respect s/he has improved on Campion's proposed chart although perhaps not in the way intended. - Mark
As I understand, there has always been controversy among chronologists between the 15th and 16th of July, since both seem to be possible zero points when converting between Islamic and Julian dates. I provided a quote in the little appendix I wrote that explains this uncertainty and why it cannot be solved in a definitive way; I also used the method of control suggested by the author (the day of the week) to support my choice of the 16th. I think providing the quote here will be useful:
The Islamic Lunar Calendar is based on the schematic rules applied in historiography (e.g. Encyclopaedia of Islam, Wuestenfeld tables etc.) with two options on the output side : Era beginning 16 July 622 (most accepted date) or 15 July 622. The difference is NOT consistently one day only (there would not have been any need for two options then) as according to the sources consulted the exact sequence of intercalary Islamic years depends on the choice of the era (first day). Anyhow, everybody aware a bit of the problems of the Islamic Lunar calendar knows that a conversion based on arithmetic or even on astronomic data has a margin of error of one day (possibly even more). (Reasons: Actual sighting of the moon in different regions by different people; overlapping of days due to the beginning of the new Islamic day at sunset vs. midnight in modern chronology). Therefore, the day of the week is always given as a convenient method of control. - Gerhard Behrens in the documentation of his software "Computus":
Juan

34
Mark wrote:
Your choice of chart doesn't strictly meet either criteria. Instead it was a date chosen retrospectively by Muhammed's successsor. No significant event or planetary configuration etc is tied to this chart.
Juan wrote:
This is not correct.
Well within the terms I defined in my post above it is correct! I refer you to my previous post.
It is tied to a culturally very significant astronomical point of the lunisolar cycle (lunar visibility). This is a real astronomical event or configuration which in turn is tied to a very significant historical event (the Hegira).
Of course its a real astronomical event. My point is that there is no historical event linked to the chart. In regards the astronomy naturally any chart we select will have an astronomical basis! Equally, I was also referring to 'base charts' from which significant events can be seen to develop such as conjunctions, lunations, ingresses etc. Here things are rather back to front aren't they? We have a lunation but nothing significant happens immediately after it. Instead this particular month is selected because it was the first month in the ancient Arabic Lunar calendar. If you feel the approach is valid by all means run with it. I just remain personally unconvinced. But then a lot of modern mundane astrology leaves me unimpressed. Thats probably why we see this issue so differently.
And "symbolical significance" makes it less astrological or traditional?
Well I dont want to be cornered into implying there is something wrong with pure symbolism! I have read Geoffrey Cornelius and his argument on the 'astrological moment'. All I was stating was that this date was selected years later. In that sense its not a timed chart or a prior configuration that could be seen to create a significant event. Its therefore not a chart in the usual way we work. Whether it is still significant or not is up to each astrologer to decide. If I recall Cornelius works with a chart displayed by the sceptics in an article against astrology and argues this can be valid. So if this chart speaks to you its your call.
Why do we decide that the arrival of Mohammed to Medina, rather than the first visibility of the Moon just prior to it that marked the zero point of their time-reckoning, should be picked as the astrological zero point of Islam?
I was simply exploring if a timed chart could be obtained for this. I dont hold to the view that religions, nations etc necessarily have one birth moment or chart. So there is no one astrological 'zero point' in mundane astrology as I see it. Rather multiple indicators we need to work with. I am currently looking at lunation and ingress charts for early Islam too.
Whatever the answer or reasoning is (as long as it is not "tradition") allows us to figure out and explore deeper the underlying assumptions we astrologers work with.
Not sure what you are trying to say here. Could you elaborate please?

Mark
As thou conversest with the heavens, so instruct and inform thy minde according to the image of Divinity William Lilly

35
Mark wrote:Well within the terms I defined in my post above it is correct! I refer you to my previous post.
You mentioned two types of events to be used as astrological radix: the timed or elective historical events and the astronomical "beginnings" such as a cardinal ingress, lunation, conjunction, etc. I'm saying this date is both: it is an elected moment decided upon carefully because of its cultural, historical, and astronomical significance.

True, nothing happened at that precise moment or day, but nothing happens either at the moment of a conjunction or an ingress, and in the case of the July 16 (or 15) chart, we have something peculiar that separates it from the way we use conjunctions and ingresses that to me is the key to its significance: that once this date was established as zero point, everything, absolutely everything from then on, is tied to it.

In other words, to me, it doesn't matter that the date was established 16 years later in A.D. 638 out of convenience, what matters is that it became a universal, mathematical (chronological in this case) reference frame.

Two things I see are implicit in our differing views: from a general perspective the concept --or rather our underlying assumptions-- of what constitutes a valid traditional, canonical, conventional, astrological zero point or "radix", and from a more particular perspective whether an after-the-fact calendrical event has or should be given enough astrological significance or weight to be used as "radix".

This was discussed (from another angle) recently by Ed Falis in the "Primary Directions" thread, and I am only stretching the concept a little bit: essentially, the zero point of a calendar is a mere arbitrary convention, but so is any other zero point used in Astrology, such as the zero point of the zodiac, or a cardinal ingress, or the use of the instant of birth of a person or of anything else as the reference point for the whole of a life --which is an extreme example of arbitrariness that lies at the very heart of Astrology.

Astronomical events or fiducials used as zero points contain a kind of necessity in astrological terms: Astrology is supposed to be about astronomical events, but these astronomical events or fiducials must always be ASSIGNED to events in our lives by means of a mental process that has nothing to do with Astronomy and is all about metaphors and symbolization. The choice of the moment of birth as the reference point from which to examine the rest of the newborn's life is an example of this symbolization. Why do we choose the beginning instead of the middle or the end as points of reference? the answer is: underlying mental and cultural assumptions.

These arbitrary "zero points" are always justified in one way or another, but once established, this justification or reasons behind them are secondary, what matters astrologically is that they (can or can't) become the basis of our analytical reference frames.

Of course its a real astronomical event. My point is that there is no historical event linked to the chart.
You can say the same of every chart of an astronomical event, such as ingresses and lunations
In regards the astronomy naturally any chart we select will have an astronomical basis! Equally, I was also referring to 'base charts' from which significant events can be seen to develop such as conjunctions, lunations, ingresses etc. Here things are rather back to front aren't they? We have a lunation but nothing significant happens immediately after it. Instead this particular month is selected because it was the first month in the ancient Arabic Lunar calendar.
Lunations or ingresses, if we are to follow traditional astrological usage, refer only to events until the next lunation or equivalent ingress, and are of limited scope in time. This is not what the "chart of Islam" is about. We are talking of the chart of an event (cultural, historical, and astronomical, incarnated in the Islamic calendar) that happened only once and became the historical reference point or frame from which all Muslims look at the world.

Like you, I don't believe that nations have only one absolute "birth moment", and one wonders why such an ancient chart from A.D. 622 could illuminate events happening throughout the many and varied Islamic countries today. Is this chart still valid today? Is it useful? Ten years ago, when I studied it extensively, I concluded that it is very valid and powerful even today. I have not dealt with it for a number of years now.
All I was stating was that this date was selected years later. In that sense its not a timed chart or a prior configuration that could be seen to create a significant event. Its therefore not a chart in the usual way we work.
I don't think the notion you describe here is "the usual way we [all] work". Charts do not create significant events, they just screen them, we use them as analytical tools or reference frames. I think this is how we all work, regardless of the theoretoical assumptions we may have or don't have. As I see it the Chart of Islam (or of any nation for that matter) is not the chart of the Hegira or of specific events that happened around the time the chart was made. This is why it is not necessary or even desirable that it be the chart of one of those specific events. It is something more universal and transcendental, it extends very far beyond the events of the time.

How much does a national chart extend in time? I think this is something we have to explore empirically in each case. Can a chart of A.D. 622 be "alive" and shed light on events of today?
I was simply exploring if a timed chart could be obtained for this. I dont hold to the view that religions, nations etc necessarily have one birth moment or chart. So there is no one astrological 'zero point' in mundane astrology as I see it. Rather multiple indicators we need to work with.
Yes. I agree. But here we are seeing a "zero point" that is of a different nature: it is not the result of a personal interpretation or way of seeing things, it is not a subjective matter or decision, but an absolute, unrepeatable, universally accepted and universally used unique zero point. This, I think, is its special value.
Whatever the answer or reasoning is (as long as it is not "tradition") allows us to figure out and explore deeper the underlying assumptions we astrologers work with.
Not sure what you are trying to say here. Could you elaborate please?
Mark
I elaborated this point a little in previous paragraphs (I hope).

Juan

36
Mark:

In your Feb 13 note to Juan, after dismissing the validity of the initial sighting of the new lunar crescent?methodology that both he and I use?as a significant moment for the start of a new month or year, you say that you are ?currently looking at lunation and ingress charts for early Islam too.?

If so you should be aware that Rumen Kolev in his Babylonian Astrology & Astronomy (2000) writes ?In Tetrabiblos book 1, chapter 8, Ptolemy describes the temperament and influences of the Moon in her different phases. Unfortunately the word ??????? meaning ?rise? or ?appearance? is translated as New Moon in many translations (e.g. Robbins, page 45). It should be New Crescent. Cardan in his commentary to Tetrabiblos translates it correctly as ?oriens? (rise).?

As a result of this common mistranslation astrologers have over the centuries erroneously believed lunation charts should be calculated for the moment of the conjunction of the luminaries. Except at the solar eclipse, the Moon is invisible at the moment of the conjunction.

Which lunation charts do you intend looking at, Mark?

As confirmation of Kolev, please note that:

David Brown in his Mesopotamian Planetary Astronomy-Astrology (2000) tells us that the earliest identified astrological text at the time (not to be superseded for another 50 years) ?was published by the Russian assyriologist Woldemar Shilejko in 1927 (in the Russian journal Doklady Akademi Nauk, SSSR). The text contains predictions based on the state of the sky on the day when the crescent moon just becomes visible, at the beginning of the New Year.?

The ?1927? Dr Brown quotes may be a typo as I believe the initial issue of Doklady Akademi Nauk did not appear until 1933. That does not however nullify his description of the content of the early text.

Cheers

'first light' crescent moons

37
Interesting reading Mark?s thread here with the interchange of thoughts from 37CENNED, Juan, and Mark. I think all of you are raising interesting points about this possible horoscope. For many years I have recognized the ancients deemed the ?first light? of anything from the heavens as an important astrological/astronomical moment. Yet I see very little work being applied to these ?first light? moments by today?s astrologers, probably because of the complications of calculating these moments; whereas, the ancient astrologers/astronomers were observing these moments of timed ?first lights.? Also, these ?first light? moments were definitely implemented into the ancients calendars. The ancient Egyptians? began their calendar year with the heliacal rising of Sirius as well as beginning their months with the ?first light? of the crescent moon. It has been documented by other writers the origins of these ?first lights? moons comes from ancient Egypt and this tradition was still in use in 622 AD. Could we astrologers today be missing something important, mundanely, by not striking charts for these ?first light? moments? As Juan pointed out, the horoscope(s) discussed here seems to be some type of an ?elected? scope for an entire religion. This makes me think these ?first light? crescent scopes could hold a key for individual elections scopes. Have modern/past astronomers made a mistake in reckoning the true ?New Moon? which has led astrologers astray for striking ?New Moon? charts? I have not done a-lot work with the conventional ?New Moon? charts with mundane astrology but have always felt they were somewhat un-reliable. I know the ancients looked upon the dark Moon (?New Moon?) as an evil omen to begin anything. Juan, you are an excellent astronomer?can the ?first light? crescent moons be easily calculated and computerized? 37CENNED?I know you are doing work with these ?first light? crescent moons. Will you post or drop me a PM if you develop or see where a reliable list for our calendar year for these ?first light? moons are ever published/online?I would appreciate.

Regards, Steve
With all our modern knowledge and scientific equipment, and with the the great strides made in mathematics, we astrologers have done nothing to even remotely compare with the achievements of the astrologers of antiquity. Cyril Fagan

38
Juan wrote:
You mentioned two types of events to be used as astrological radix: the timed or elective historical events and the astronomical "beginnings" such as a cardinal ingress, lunation, conjunction, etc. I'm saying this date is both: it is an elected moment decided upon carefully because of its cultural, historical, and astronomical significance.

True, nothing happened at that precise moment or day, but nothing happens either at the moment of a conjunction or an ingress, and in the case of the July 16 (or 15) chart, we have something peculiar that separates it from the way we use conjunctions and ingresses that to me is the key to its significance: that once this date was established as zero point, everything, absolutely everything from then on, is tied to it.
Sorry I think you are comparing apples and pears here. Lets look at say a Jupiter-Saturn conjunction. That is a indicator of trends for a 20 year period. An Aries ingress chart is usually relevant to a quarter and the overall year too. The length in effect of solar and lunar eclipses is debated with some suggesting months and others years. Generally, the effect of a solar eclipse is seen as lasting longer. Then we have lunation charts. We tend to use them until the next lunation occurs.

However, its not quite that simple. For example in the absence of an elected chart for the founding of a dynasty medieval astrologer such as Abu?Mashar suggested using an ingress chart for the entire dynasty. In particular the Aries ingress which preceding the founding of the dynasty. Equally, medieval astrologers used a chart for the Jupiter-Saturn conjunction prior to the birth of Muhammed as an indicator of the new faith.

However, all these charts fall within the timed orbit of the ?base? chart whether it was the birth of Muhammed or the founding of a dynasty. The Islamic Calendar chart isn?t like that. The faith wasn?t formed within the span of that lunation was it? Actually, one might seriously question why we are obsessing on the Hijra itself at all. Why was this selected and not the say the date of Muhammed?s birth, his first revelation of the Koran or his first preaching of the faith? Surely, they were more pivotal dates in the birth of the faith?

The medieval writer Al Biruni in his ?The Chronology of Ancient Nations? explains how this was debated by the early Muslims. The Hijra was not selected because it was seen as the most important date in Islamic history. It was simply selected because of ambiguity regarding other key events in the life of Muhammed. He points out the Muslims also considered adopting other calendars such as that of the Greeks and Persians. The calendar was adopted to assist the smooth running of Islamic Arabia as there had developed confusion of trade and commercial transactions. The motivation to create the calendar was therefore not primarily religious but rather pragmatic. I accept there was a cultural distinctiveness in adopting the traditional Arabic New Year. However, the selection of the new year before the year of the hijrah was in many respects a fairly arbitrary decision. It wasn?t carefully elected by astrologers as you suggest. If it had been why do none of the Islamic astrologers refer to this as significant?

Its undeniable this date has retrospectively assumed a significance for Muslims. However, in my view that doesn't make a sound astrological case for adopting this chart.

Juan wrote:
In other words, to me, it doesn't matter that the date was established 16 years later in A.D. 638 out of convenience, what matters is that it became a universal, mathematical (chronological in this case) reference frame.
I guess that is the nub of our disagreement. I think this distinction matters a great deal.

Juan wrote:
Two things I see are implicit in our differing views: from a general perspective the concept --or rather our underlying assumptions-- of what constitutes a valid traditional, canonical, conventional, astrological zero point or "radix", and from a more particular perspective whether an after-the-fact calendrical event has or should be given enough astrological significance or weight to be used as "radix".
Agreed.

Juan wrote:
This was discussed (from another angle) recently by Ed Falis in the "Primary Directions" thread, and I am only stretching the concept a little bit: essentially, the zero point of a calendar is a mere arbitrary convention, but so is any other zero point used in Astrology, such as the zero point of the zodiac, or a cardinal ingress, or the use of the instant of birth of a person or of anything else as the reference point for the whole of a life --which is an extreme example of arbitrariness that lies at the very heart of Astrology.
Timing astrology to events, or previous astrological configurations is not arbitrary in my view. However, if you support Geoffrey Cornelius and his perspective I can see that there is case can be made for this approach.

Juan wrote:
Astronomical events or fiducials used as zero points contain a kind of necessity in astrological terms: Astrology is supposed to be about astronomical events, but these astronomical events or fiducials must always be ASSIGNED to events in our lives by means of a mental process that has nothing to do with Astronomy and is all about metaphors and symbolization. The choice of the moment of birth as the reference point from which to examine the rest of the newborn's life is an example of this symbolization. Why do we choose the beginning instead of the middle or the end as points of reference? the answer is: underlying mental and cultural assumptions.
I think we are both at risk of repeating ourselves here. However, just to recap timing a chart from a historical event or a previous configuration is not about the subjectivity of the astrologer. These are agreed conventions that all astrologers use. You are arguing the chart you have advocated is meaningful because you choose to give it meaning. I think you are on much more subjective ground than using the moment of birth or a timed event as a basis for a chart. As for your issue on past/future and relativity it seems we are into the realm of the philosophy forum.

Most mundane, natal and electional astrology works from the notion of ?seed? moments or generators. Horary is a bit different since there the seed is the question itself. However, Cornelius argues the astrologer?s consciousness shapes meaning and significance from a chart. Still, the astrologer doesn?t select any time for a horary question he likes. S/He usually have to work with the time they receive a question. Nevertheless, if you want to use the ?divinatory astrology? argument to your chart you are at liberty to do so. If you adopt that view you can argue any chart the astrologer thinks is significant can be adopted and does not need any ?seed? moments to refer to.

Juan wrote:
Lunations or ingresses, if we are to follow traditional astrological usage, refer only to events until the next lunation or equivalent ingress, and are of limited scope in time. This is not what the "chart of Islam" is about. We are talking of the chart of an event (cultural, historical, and astronomical, incarnated in the Islamic calendar) that happened only once and became the historical reference point or frame from which all Muslims look at the world.
I have covered this above but I just wanted to say you are incorrect in assuming ingress charts are always limited in scope. Medieval astrology often proposes ?foundational ingress charts? for dynasties and kingdoms. These can still be used today. In a sense your argument is rather similar. The problem is that the lunation you have selected didn?t coincide with the birth of Islam. Anyway, we could probably debate this until the cows come home. :D In essence I remain unconvinced and sceptical about your chart and nothing you have said has so far has he convinced me otherwise. I think we are going to have to agree to disagree on this.

Whatever chart we choose to work on we need to test it with historical events in Islamic history. Perhaps a more productive way forward might be to agree on some key dates to test our charts against? I think you said you had tested out your favoured chart in this way. What events did you use?

regards

Mark
As thou conversest with the heavens, so instruct and inform thy minde according to the image of Divinity William Lilly

39
37 Cenned wrote:
In your Feb 13 note to Juan, after dismissing the validity of the initial sighting of the new lunar crescent?methodology that both he and I use?as a significant moment for the start of a new month or year, you say that you are ?currently looking at lunation and ingress charts for early Islam too.?
I didn't dismiss your methodology as such. What I challenged was the selection of this particular new Moon to sum up the Islamic faith. As I have already discussed with Juan there are no specific historical events tied to this chart ( ie a lunation period). You were previously strongly arguing here that this was the lunation chart preceding the event of the Hijrah. Now that that position is no longer credible I wonder whether you still have faith in this chart?

37 Cenned wrote:
As a result of this common mistranslation astrologers have over the centuries erroneously believed lunation charts should be calculated for the moment of the conjunction of the luminaries. Except at the solar eclipse, the Moon is invisible at the moment of the conjunction.
I think you are making a very interesting and thought provoking point here. I was aware the Babylonians timed the New Moon based on the appearance of the crescent. Maybe you could consider opening a specific thread on this issue? It clearly has a significance that extends well beyond the remit of this topic. I suggest the traditional forum would be a suitable place.

Mark
Last edited by Mark on Mon Feb 14, 2011 4:13 pm, edited 1 time in total.
As thou conversest with the heavens, so instruct and inform thy minde according to the image of Divinity William Lilly

Re: 'first light' crescent moons

40
Steve wrote:Juan... can the ?first light? crescent moons be easily calculated and computerized?
I had just finished re-calculating 37CENNED data when I read this (see below). His explanation has helped me see with more clarity and detail the astronomical issues involved in the concept of "first visibility of the lunar crescent".

As you can see from "CNN" 's explanation, the calculation is based on observational parameters --which in the real world can vary from one location to another. The actual "limit of visibility" can only be approximated mathematically, one has to be there "in situ" to confirm if the lunar rim was visible or not, and maybe this is one (or the) reason why in conventional astrological terms (i.e., horoscopics) this is not used, and instead we use a purely abstract, arbitrary, non-observational mathematical reference point (a geocentric sun/moon longitudinal conjunction).

If we were to calculate the time of the New Moon from a "real" observational standpoint, then it would happen that (because of lunar parallax) the exact time of the conjunction would be different depending on where you are. From the purely geocentric, abstract, and commonly agreed astrological conventional standpoint, this variance would not exist and the time will be the same for everybody. (Personally, btw, I --like most astrologers-- favour working with conventions rather than "real world" data).
37CENNED wrote:The prior Moon-Sun conjunction occurred at 23:05 Cancer on 14th July, 622 at 8:04:26 AM local time, when 27:58 Leo was rising at Mecca and the luminaries were in the 11th house.
Please correct me if I am wrong, but these are geocentric calculations. I re-calculated using topocentric (parallax) coordinates, and found that in the real world, the New Moon occurred at 6h21m local time (6h18m apparent time), in 23,02 Cancer in the 12th house, when the Asc. at Mecca was 4,50 Leo. This changes your results a little bit, but not significantly (it doesn't change your final conclusion):

you get: the Moon was visible in the sky for 21.2 minutes after sunset but the crescent was so thin, just 0.28%, that it was virtually invisible. I get: the Moon was visible for 15m after sunset, and the disk was 0.2%

you get: the following evening, 15th July, the Moon was visible in the evening sky following sunset for over an hour, 73.5 minutes according to modern calculations, and 2.86% of its hemisphere was illuminated at this time. I get: the Moon was visible (theoretically) for 68.1 minutes, 2.6% of its rim was illuminated

you get: at moonset on 15th July the azimuth difference between the Sun and Moon was 12 degrees 7 minutes, and according to Carl Schocht the crescent will be visible if the altitude difference (the arcus visionis) between the two lights is 8.8 degrees or more. Here it is almost double that, 15 degrees 10 minutes. I get: acimut difference at moonset is 11,49' and altitude difference 14,15'.

for the 15th July sunset chart you give 6:52:40 PM LT - 16:13:24 UT. I get 6:38:40 PM LT (6:35:30 apparent time) - 15:59:28 UT. (NOTE: the exact UT equivalents are tricky because they are dependent on the algorithm for delta-t that your software is using)

Juan

41
It is fully eleven years since I calculated the time of sighting of the first lunar crescent (NOT sunset!) at Mecca on 15th July 622. Since then I have changed my computer from PC to Apple together with most of the associated software. I therefore now have difficulty replicating the original values I quoted. Instead I will briefly describe something of the process I followed and its history.

Based on observational data, and apparently widely used for centuries, the following two-part rule of thumb was initially used by Babylonian astrologers to find the lunar crescent?s first visibility:

1. At local sunset, the Moon?s age must be more than 24 hours?that is, from the time of the conjunction to the time of sunset on the evening of observation a full period of 24 hours should have elapsed.

2. The arc of separation (the equatorial difference in right ascension) between the Moon and the Sun must be greater than 12 degrees?that is, the Moon should set at least 48 minutes after sunset. This criteria subsequently became known as ?the lag?.

In the Indian Surya-Siddharta written circa 500 AD the 48-minutes time lag continued to be used and there was also a discussion of how to predict the tilting of the Moon?s horns. In the Pancha Siddhantika of Varaha Mihira both the longitude and declination distances between the Sun and Moon were used to identify when the new crescent would appear in the sky.

In the 8th century AD, Ya?quib ibn Tarig proposed using a time lag of 40 minutes and an arc of light (the angle between the centers of the Sun and Moon) of 15 degrees.

In the 9th century, in his Handbook of Astronomy, Muhammed ibn al-Battani gave detailed instructions for computing the Moon?s azimuth when it would be first seen, together with the inclination of the Moon?s horns with respect to the ecliptic.

Muhammed ibn al-Biruni in his Chronology of Ancient Kingdoms recommended al-Battani?s method. Even so, al-Biruni himself derived a simpler method that relates the difference between the azimuths of the Sun and Moon to the Arcus Visionis, the Sun?s altitude when the Moon is exactly on the horizon.

Both al-Battani?s complete but complex solution and al-Biruni?s simplified version then appear to have been forgotten. Compilers of Muslim calendars, the months of which commence on the day the new lunar crescent is first sighted, reverted to the ancient Babylonian two-part rule of thumb listed above.

It was only as recently as 1910 that al-Biruni?s approach was independently rediscovered by the British astronomer J. K. Fotheringham. It was then improved by Karl Schoch.

Table 1:
AD - AV
0 - 10.7
1 - 10.7
2 - 10.6
3 - 10.5
4 - 10.4
5 - 10.3
6 - 10.1
7 - 10.0
8 - 9.8
9 - 9.6
10 - 9.4
11 - 9.1
12 - 8.8
13 - 8.4
14 - 8.0
15 - 7.6
16 - 7.3
17 - 7.0
18 - 6.7
19 - 6.3

The above table lists the minimum AV (Arcus Visionis) for the Moon to become visible for different ADs (Azimuth differences) between the Sun & Moon at moonset, according to Schoch. All values are in degrees.

The Azimuth Difference is the difference between the azimuths of the Sun and Moon at the time of moonset at the particular location.

As earlier stated, the arcus visionis is the altitude of the Sun (in absolute values) when the Moon is exactly on the horizon at moonset. As the Sun must be below the horizon for the new crescent to be seen, all of these AV values are obviously negatives.

This means that if the two luminaries share the same azimuth at moonset, the Sun must have an altitude of 10.7 degrees in absolute values for the crescent to be seen that evening. If the AV is 9.8 degrees the AZ Diff needs to be 8 degrees or more.

In 1979 an official report by the Royal Greenwich Observatory stated ?it is unlikely that the new crescent will be visible unless the elongation exceeds 10 degrees and the altitude of the Moon exceeds 5 degrees when the depression of the Sun is 3 degrees.?

In 1994 Muhammed Ilyas, the current acknowledged authority on lunar visibility, wrote: ?the Moon must have an altitude of at least +6 degrees at the time of sunset.?

However, none of these authorities seem to have concerned themselves with attempting to predict the time when the new crescent is visible at a particular location. They have confined themselves only to whether or not it will be visible on a particular evening. In ancient Babylon and in present-day Muslim communities the intent was to know the evening when the new crescent would become visible and then go out and see it. That may be very well for future observations but it doesn?t help the astrological researcher who is attempting to learn how varying planetary positions in past new crescent charts can be associated with subsequent happenings at that location. We need to have an idea of the rising degree at the time the new crescent would, should or most likely was sighted.

The only recent criterion I know of comes from astronomer Bernard Yallop, who says that the time of best visibility of the new lunar crescent is given by the following simple empirical relations:

Time (Moon best visible) = A + 4/9 of (B ? A)

where A = time of sunset, B = time of moonset

Unfortunately, at the time Dr. Yallop suggests the Moon has invariably been visible for some time in the evening sky. It may be the best time to go look for it, but it is not usually when the new crescent could have first been seen.

My own research, carried out in the late 1990s, aimed at identifying the rising degree at the time the new crescent may actually become visible, uses the Schoch values given in Table 1 to identify the day and then the difference in altitude at both sunset and moonset to identify the Sun?s altitude at the time of the likely initial sighting. The equation I derived is as follows:

Sun altitude when Crescent first visible = 0.2381 X ? 0.5256 Y ? 0.2435

where X = altitude difference of Sun and Moon at moonset
and Y = altitude difference of Sun and Moon at visible sunset

For both altitude differences X & Y and for the time of moonset, the Moon is taken with parallax.

Having obtained the solar altitude, the SolarFire rectification module within the Horary mode is used to identify the moment when the Sun has this altitude.

Cheers
Last edited by 37CENNED on Mon Feb 14, 2011 6:26 pm, edited 1 time in total.

42
Hello 37 Cenned,

I really do hope you follow up my suggestion of opening up your own thread on the subject of the first lunar crescent. Either on the mundane or traditional forum. The traditional forum especially has a very erudite readership so I think you might find some of the responses there very well informed and useful. Your ideas in this area deserve a wider readership.

regards

Mark
As thou conversest with the heavens, so instruct and inform thy minde according to the image of Divinity William Lilly