Skyscript Astrology Forum

I have just posted this short article on the subject: https://vicdicara.wordpress.com/2017/08 ... al-zodiac/

I look forward to your comments.

I especially expect to hear how Martin will contend my representations of Pa?casiddh?ntika and B?hatsa?hita.

Hi Vic

I'm a tropical astrologer with limited understanding of the relevant Indian texts, but I wanted to comment because I didn't quite follow all your logic.

Some propose that the zodiac we use today... evolved from these primordial sidereal systems

Can you expand on which academics propose otherwise?

Instead, I believe that the 12-fold Zodiac co-existed with the multifold sidereal divisions since ?the beginning,? or close to it.

But wait, I'm not following this. You mention an 'evolution' based on lunar motivations and not from sidereal ones, then you say you don't agree with this and instead say that the 12 fold zodiac existed with the sidereal divisions since the beginning - but you haven't said which sidereal divisions, nor why you imagine that lunar motivations would mutually exclude a sidereal (or indeed any) frame of measurement?

S?rya Siddh?nta also explicitly defines a tropical zodiac

Can you define what you mean by a tropical zodiac, especially the zodiac part and what you imply these texts were not just defining but their motivation or use of that definition? It's interesting you say "a" tropical zodiac and not "the" tropical zodiac, so I'm interested in what you see as the distinction between what is defined in these texts and the tropical zodiac as we know it today.

Prior to him, the oldest extant record of an at least oblique reference to the tropical zodiac is in ?g Veda (1.164.11 & 48), which even modern scholars date as an ancient text.

Do you see this reference as one to the tropical zodiac? Can you explain why?

There is no reason to insist that the more abstract 12-fold tropical system must have escaped the science of the ancients, for it is not at all difficult to notice that the Moon essentially has 12 cycles in the course of a year, and this fact is the fundamental basis of the 12-fold system.

I must not be following some implicit logic here but what has the cycle of the Moon got to do with a necessity for measurement in tropical and not, say, sidereal or something else? After all Rocheberg's work shows that the Babylonians conceptualised the ecliptic both as the path of the moon as well as measured that path sidereally.

India essentially dropped their already somewhat non-conformist 28th asterism, Abhijit, and abstracted their asterisms into 27 equal-sized portions, fitting them very neatly into the 12-fold zodiac.

Can you expand on this? I've heard this theory in a few different ways. One theory is that there are both 27 and 28 nakshatras in antiquity, suggesting instead a competing astronomical/astrological tradition from the 27 nakshatra system eventually won out. I remember also reading a post by Varuna here who once suggested that the drop from 28 to 27 had less to do with the tropical zodiac and more to do with mathematically defining them as 13 or so degrees of the ecliptic to better fit the arc the moon travels in a day (I may be misremembering this). In other words, why draw the conclusion that this had anything to do with the tropical zodiac?



I'll return to some of the other points a bit later.

Hi Vic,

Like Paul I have no real knowledge of the Indian texts since I study Hellenistic astrology. There was one point that stuck out to me. In your conclusion, you write:

Sidereal divisions were more prominent in earlier times, when immediate observational interpretation was the only viable option. Tropical divisions then gained preeminence as improved calculations enabled astrology to expand through computational interpretation.

Apart from there really being no evidence for this implication (that only a lack of computational ability stopped the ancients from using the tropical measurement), the inverse is actually borne out historically. If I can direct you to Alexander Jones' work Astronomical Papyri from Oxyrhynchus (https://books.google.co.uk/books/about/ ... okzymQ43IC), you will see that in the 4th century AD Theon of Alexandria actually uses Ptolemy's tables and then recalculates the planetary longitudes into a sidereal reference (which is actually pretty close to the Raman ayanamsa).

In your section 'Transitions to the Tropical', you make a few demonstrably false claims, one being that the tropical divisions only were named 'Cancer, Leo and Virgo'. Demonstrable in that Theon used a sidereal, 12 division measurement as late as the 4th century, and also by a brief survey of the Jones book I cited which contains fragments of horoscopes from the centuries before Theon which also divide the circle into 12 and give these divisions the names of the constellations they overlap.

You end with:

[after Hipparchus] the tropical zodiac became clearly established and accepted almost everywhere in the world.

This simply is not the case. From the earliest records we have up until the late Arab period there is ample evidence of a sidereal frame of reference used, though after the 4th century, certainly not exclusively. There is some dispute as to what exactly Vettius Valens in the 2nd century AD was using (my own view is that he is using a sidereal measurement), but regardless, he states that the equinox is in the 8th degree of Aries (1.2). If the twelve-fold division was purely tropical as you say, then what exactly is the equinox placed in in the measurement Valens is using? Even if the measurement he used was notionally tropical (as Jones asserts in the article I have cited below), it disproves your claim that there was a uniform and wholesale adoption of Ptolemy's version of the tropical zodiac i.e. the first degree of Aries is measured from the vernal equinox. I would also add, and this is perhaps more pertinent to your Indian sources, that a huge facet of astrological history that neither of us has mentioned thus far is the influence of the Sassanians both in the transmission of older doctrines and the invention of new ones. Pingree asserts that they drew exclusively on the Greeks and the Indians, and they used a sidereal measurement.

If you are interested in reading analysis of actual horoscopes from our earliest records, along with the Jones book I cited above, might I recommend:

Nick Kollerstrom (2001) 'On the Measurement of Celestial Longitude in Antiquity' in Proceedings of the XXth International Congress of History of Science (Li?ge, 20?26 July 1997). Volume XII. Optics and Astronomy, ed. G?rard Simon and Suzanne D?barbat. De Diversis Artibus 55. Turnhout: Brepols, 145?159.

Alexander Jones (2010) 'Ancient Rejection and Adoption of Ptolemy's Frame of Reference for Longitudes' in Ptolemy in Perspective: Use and Criticism of his Work from Antiquity to the Nineteenth Century, ed. Alexander Jones.

hi vic,

thanks for sharing.. it is an interesting simplified story that you weave. some of the conclusions you make seem speculative at best and possibly flat out wrong at worst! it was an interesting overview non the less!

Vic, a few quotes from your article and my responses:

"I do not believe in this evolutionary theory..."

"I believe that the 12-fold Zodiac co-existed..."

The problem is if we're trying to demonstrate the truth of a principle, belief as such doesn't enter the picture. We all need to cite the relevant text references, and the facts-to-date unearthed by scholars.

"Ptolemy, however, does not present himself as the inventor of this system, but suggests that he is representing older, Babylonian knowledge..."

You haven't backed up this statement by verifiable quotes from Ptolemy that we as readers can check.

"It seems undeniable that the very ancient cultures used the sidereal divisions more than the topical divisions."

To be accurate, 'Seems' in this particular statement should be replaced by IS undeniable. There is no debate that 'ancient cultures' (which you haven't defined) used sidereal rather than tropical measurements for the twelve 30 degree signs of the zodiac.

"However, when [Francesca Rochberg] compares the planetary positions given in the records with the planetary positions arrived at by modern calculation, the average deviation between the two is near or above 4?."

Here again you haven't given a reference for your statement. But we do have records of planetary longitudes in Babylonian horoscopes from Rochberg, and they are very much in line with the Fagan-Bradley and Lahiri sidereal zodiacs. The degree comparisons between Babylonian and tropical longitudes are several degrees larger as shown in the tables in this link:

http://users.snowcrest.net/sunrise/arochberg.htm
"Planetary Longitudes In Babylonian Horoscopes"

"Thus, evidence is not conclusive that the Babylonians indeed used a sidereal 12-fold zodiac, even for a short time."

Based on all current scholarship, this statement is patently false as the initial longitudes of zodiac signs were marked by specific stars with no mention of equinoctial and solstice points. Vic, you have apparently not completed your homework on this topic?

"So, even if early people initially applied the 12-fold uniform zodiac in a sidereal context, it is sure and certain that they all switched to tropical quite soon thereafter."

You are rather vague here regarding dates. Alexander Jones has given the precise historical picture of dates on when the sidereal to tropical conversion occurred in the fourth century:

http://skyscript.co.uk/forums/viewtopic.php?t=7423

Also, please see the original article by Jones which Konrad cited above, as the link here on Skyscript is a summary only.

Paul wrote:

Some propose that the zodiac we use today... evolved from these primordial sidereal systems

Can you expand on which academics propose otherwise?

No. Academics is not my field.

Paul wrote:

Instead, I believe that the 12-fold Zodiac co-existed with the multifold sidereal divisions since ?the beginning,? or close to it.

But wait, I'm not following this. You mention an 'evolution' based on lunar motivations and not from sidereal ones, then you say you don't agree with this and instead say that the 12 fold zodiac existed with the sidereal divisions since the beginning - but you haven't said which sidereal divisions, nor why you imagine that lunar motivations would mutually exclude a sidereal (or indeed any) frame of measurement?

IF there was an evolution from sidereal to tropical it would be based on non-stellar things.

I don't think there was such an evolution, I think that stellar and non-stellar frameworks existed from the beginning. Different cultures had different sidereal divisions. All had 12 solar divisions. In all cases they coexisted.

Paul wrote:

S?rya Siddh?nta also explicitly defines a tropical zodiac

Can you define what you mean by a tropical zodiac, especially the zodiac part

A 12-fold division with symbols such as ram, bull, etc. which is anchored to the solstices and equinoxes, measured by the increase and decrease of light and shadow.

I should have used "the" instead of "a."

Paul wrote:

Prior to him, the oldest extant record of an at least oblique reference to the tropical zodiac is in ?g Veda (1.164.11 & 48), which even modern scholars date as an ancient text.

Do you see this reference as one to the tropical zodiac? Can you explain why?

Because it ties 12 divisions to days and nights and solar movements which cause seasons. As I said, however, it is oblique.

Paul wrote:

There is no reason to insist that the more abstract 12-fold tropical system must have escaped the science of the ancients, for it is not at all difficult to notice that the Moon essentially has 12 cycles in the course of a year, and this fact is the fundamental basis of the 12-fold system.

I must not be following some implicit logic here but what has the cycle of the Moon got to do with a necessity for measurement in tropical and not, say, sidereal or something else? After all Rocheberg's work shows that the Babylonians conceptualised the ecliptic both as the path of the moon as well as measured that path sidereally.

12 moons are the basis for measuring a year, which is the basis of a tropical system with 12 equal divisions. That's my logic

Paul wrote:

India essentially dropped their already somewhat non-conformist 28th asterism, Abhijit, and abstracted their asterisms into 27 equal-sized portions, fitting them very neatly into the 12-fold zodiac.

Can you expand on this? I've heard this theory in a few different ways. One theory is that there are both 27 and 28 nakshatras in antiquity, suggesting instead a competing astronomical/astrological tradition from the 27 nakshatra system eventually won out. I remember also reading a post by Varuna here who once suggested that the drop from 28 to 27 had less to do with the tropical zodiac and more to do with mathematically defining them as 13 or so degrees of the ecliptic to better fit the arc the moon travels in a day (I may be misremembering this). In other words, why draw the conclusion that this had anything to do with the tropical zodiac?

As I said, Abhijit was already non-conformist and unusual.
The 13.3 degree necessity was inspired by the desire to make them match perfectly with the rashi and navamsha, imo.

Konrad,

Thank you. Interesting information. I see it in two ways: (1) confusion about which system to stick with took about 400 years to die out. (2) to express "ayanamsa" (as we would say in Vedic astrology) almost requires us to have a sidereal version of the 12-fold zodiac. So we would say, "The equinotical point is now at 8? of Sidereal Aries" or better yet, "8? of the 1st sidereal division"

Vic

Vic DiCara wrote:Konrad,

Thank you. Interesting information. I see it in two ways: (1) confusion about which system to stick with took about 400 years to die out. (2) to express "ayanamsa" (as we would say in Vedic astrology) almost requires us to have a sidereal version of the 12-fold zodiac. So we would say, "The equinotical point is now at 8? of Sidereal Aries" or better yet, "8? of the 1st sidereal division"

Vic

Vic,

As long as you qualify that this is just your belief and that it really has no textual evidence to support it, and in fact, that the textual evidence contradicts it, then I can't really argue with what you are putting forward.

Vic DiCara wrote: No. Academics is not my field.

Okay I guess. It strikes me as odd to bother to write on the history of the sidereal zodiac though if you're not too interested or bothered in scholars and researchers in the subject have to say on the matter too. Maybe I'm just projecting too much of myself here, but I would have expected that if an issue is interesting enough to go to the bother of writing about and collecting some feedback on, it would be no less interesting to read about, especially as others may have something to contribute that expands your own thinking or makes something else click that you wouldn't have put together before.

I don't think academics has to be anyone's "thing" necessarily but it's still nice to know what the consenus is so we know where we fit into things that way.

When you say:

For if the modern zodiac did indeed evolve from more ancient systems, the evolution was driven by non-stellar / non-sidereal facts, primarily the presence of 12 lunar cycles within one solar cycle

It's hard to know what to do with this because you don't actually provide any rationale for why it cannot evolve from stellar things to begin with, and there's nowhere left to go to research or expand on this. We're just left with a statement/conclusion with no rationale to go with it. As an audience, that is somewhat not satisfying to my curiosity, especially as the history as I understand it is that the tropical almost certainly did derive from sidereal issues/reasons. It's sort of like you want to have your cake and eat it too here - you want to move on to talking about why it's not an evolution, but you also want to prevent anyone from taking up the mantle of it being an evolution to support the sidereal system in some way, so through out a little statement that even though it's not an evolution, if it was, it wouldn't support sidereal or be related to sidereal in any way. But nothing to back this up with and nowhere to go to try to expand on it. If you weren't here to address it (and you may choose not to) then we'd really have nothing to go on but to shrug.

Instead, as I see it, the tropical zodiac emerged precisely out of a need to measure astronomical realities which are not stellar, but also to position or locate or lock down an apparent sidereal movement of the equal zodiac. It's also undeniably the case, as I see it, that the zodiac originally emerged from a standpoint of measurement of the year and the division of the moon's cycle through the year, as you say, but I cannot see how we would not equally acknowledge the sidereal roots which continued to drive another form of measurement - even if all the sidereal impetus was solely to provide a fiducial point relative to the earth, this is still driven by a sidereal impetus because it's this sidereal disparity which caused the use of the vernal point to begin with.

If you're a sidereal astrologer today, you're holding true to the stellar patterns and framework that can be understood from the map of the sky, and if you aren't, it's because you fundamentally see the zodiac as not being in or from the sky alone, but rather the relationship the ecliptic has to the earth. But I personally cannot see why we wouldn't recognise the sidereal fingerprints all over the ancient evolution of tropical.

Different cultures had different sidereal divisions. All had 12 solar divisions. In all cases they coexisted.

Right, but this doesn't tell us how the tropical zodiac might be associated with it. Your argument, as I understand it, is to reject the evolutionary hypothesis in favour of the idea that the tropical and sidereal zodiacs existed side by side.

But this certainly isn't evidence of a zodiac. This is evidence of recognition of the synodic periods of the Moon through the year - well, okay, but does anyone ever dispute that? I was confused where you going and what you were trying to say so I explicitly asked you to define the tropical zodiac and you did so:

A 12-fold division with symbols such as ram, bull, etc. which is anchored to the solstices and equinoxes, measured by the increase and decrease of light and shadow.

But as we can see, there's nothing tropical about the fact that there are 12 moons in a year even by your own definition of the tropical zodiac. Now if we imagined a world where the new moon always started on the vernal equinox and exactly 12 synodic months later started again at that point then you may at least have some point. But that's not the case. So there's nothing explicitly tropical about recognising 12 months - if there was some quality about the first moon having symbols of the ram etc. you may again be on to something. But there's no evidence of anything of the sort, and in the Babylonian period in which this was devised, we didn't have a ram here anyway, it was the hired man.

Because it ties 12 divisions to days and nights and solar movements which cause seasons. As I said, however, it is oblique.

Does it though? I can see the Rig Veda recognises the year and recognises dividing it up into four quarters - we can guess that these four quarters are the seasons. But is that it? Is the fact that a culture recognises seasons enough to say "they're using the tropical zodiac" - even obliquely? Consider your own definition of the tropical zodiac when you think that through.

I'm all for promoting the tropical zodiac or even for someone to show how one might use the two zodiacs side by side - I struggle to see how you can do it without abstracting meaning from one to another, or else, as you do, use a tropical zodiac and other sidereal considerations, but I think it's a much bigger thing to imagine that this was always the way it was done, or even that it was the way that it was envisioned to be done. You may be right, I don't know, but I do think that's where studying what has been said by others who have studied it think may be illuminating.

Konrad wrote:

Vic DiCara wrote:Konrad,

Thank you. Interesting information. I see it in two ways: (1) confusion about which system to stick with took about 400 years to die out. (2) to express "ayanamsa" (as we would say in Vedic astrology) almost requires us to have a sidereal version of the 12-fold zodiac. So we would say, "The equinotical point is now at 8? of Sidereal Aries" or better yet, "8? of the 1st sidereal division"

Vic

Vic,

As long as you qualify that this is just your belief and that it really has no textual evidence to support it, and in fact, that the textual evidence contradicts it, then I can't really argue with what you are putting forward.

You know there is textual evidence and historical evidence as well. But yes, it is my interpretation of the textual and historical evidence, which surely differs from yours and from what you feel is standard and correct.

Paul wrote:I don't think academics has to be anyone's "thing" necessarily but it's still nice to know what the consenus is so we know where we fit into things that way.

That I can't tell you which academics believe this or that doesn't mean I have not done research.

Paul wrote:As I see it, the tropical zodiac emerged precisely out of a need to measure astronomical realities which are not stellar, but also to position or locate or lock down an apparent sidereal movement of the equal zodiac.

I agree. But what I find is definition of tropical measurements in ancient texts, alongside definitions of sidereal measurements. For example, in the pur??as or siddh?ntas they are side-by-side. In MulApin, I believe (have not studied it, but am told by a person who has) that the 12 solar months with the equinox in the middle of the first, along with 18 asterisms through which the moon passes. So both systems are there.

I believe that the evolution was in practice not in theory. The emphasis shifts from the use of observational and sidereal things, to things that are more difficult to observe and require more calculation (like the 12fold equal system).

Rochbergs work I cited, she seems to feel the same way.

Paul wrote:It's this sidereal disparity which caused the use of the vernal point to begin with.

There I disagree.

Paul wrote:I personally cannot see why we wouldn't recognise the sidereal fingerprints all over the ancient evolution of tropical.

I don't see those fingerprints, what are they?

What I see are rulerships, elements, modes and even the sizes and number of the divisions having nothing to do with stars and everything to do with the sun's relation to the equator (sometimes also the Moon's relation to the sun, in the case of the number and size).

Paul wrote:But as we can see, there's nothing tropical about the fact that there are 12 moons in a year

It has nothing to do with stars, and the year is best measured by the length of shadow (tropical).

Paul wrote:I can see the Rig Veda recognises the year and recognises dividing it up into four quarters - we can guess that these four quarters are the seasons.

Veda's treat the year as having six seasons, not four.

The fact that it is 12-fold (not 18, 28 or 36) is what betrays it as luni-solar and not stellar.

Paul wrote:I'm all for promoting the tropical zodiac or even for someone to show how one might use the two zodiacs side by side

My suggestion and practice is to use the tropical 12-fold, and the sidereal 27-fold.

I've edited the article a bit, taking feedback into account: vicdicara.wordpress.com/2017/08/02/the-historical-argument-for-a-sidereal-zodiac/