Skyscript Astrology Forum

Graham Fox wrote:I know there's no hard evidence that 1/365.24th of a year (or the true daily equivalent ) was used until later, but does Ptolemy specify elsewhere that he really means 1/360th of the earth's daily rotation = 1 solar year? Or did someone else specify it before Prolemy?

Frankly, I can't say for sure whether Ptolemy does define this, and if so, where; and I haven't the time to do the detective work at present. But as far as I know (and I am open to correction from those who know this material better -- Chris Brennan?), Hellenistic authors always used the 1? = 1 year formula. We don't always bother to define concepts which we know to be understood and agreed upon by our readers.

If not, how does Robbins know Ptolemy's thinking of the "ideal" figure of 360? This in effect means we're saying that the full circle = 360 years. Why 360?

Well, why 12 signs? Astrology has always been prone to this 'idealizing' tendency, perhaps because it is rooted in a view of the world where the Ideal is also the Real. (Although I feel I should add that I do not believe we are justified in attempting to extract a full-blown metaphysical system from the early astrological texts.)

Martin
Thanks for clarification. As you say, why twelve? It seems to boil down to whether we're more persuaded by the elegance and and order of the more "ideal" and traditional whole number approach (1?=1yr), or the "natural analogy" of one day (or distance sun appears to move in a day) of Naibod and variants.
If the former, and the number 360 is the key, maybe it would be worth investigating a key of 1? of sidereal rotation = 360 sidereal days - an "ideal" year, as is sometimes used for Hindu dasha, and some think was also sometimes used in Hellenistic astrology. I started doing this about a year ago for a few charts - the relevant key is 1?=0.983 years (or 1 yr = 1.017?), if I'm not mistaken. Lost interest at the time, as Naibod or Kepler/Brahe seemed to give better results. But the powers of self-suggestion are great.
Anyway, for we mathematically and astronomically challenged, Rumen Kolev neatly clarifies the other (Naibod) principle :

In one tropical year ( the time it takes for the Sun to return to the same point on the ecliptic ) there are 365.242191 days. This is the quantity of days " present ", so to speak, in one full circle of 360 degrees If we divide the circle into 365.242191 parts, one part will turn out to be 59 minutes 8.33 seconds. This is figuratively speaking, how many degrees (minutes and seconds of arc) there are in one day. But since one day symbolizes one year, then 59 minutes 8.33 seconds should stand as the key for one year.

Thanks for help
Graham

...why 12 signs?

This is derived from the twelve lunar months. Kepler on this:

4-2 [In ancient times] the farmers had to seek their calendar in the sky... When the Moon was full, they could easily see, for example, that the first full moon appeared in the Ram's horns, the second near the Pleiades, the third near the Twins, etc. and finally that the thirteenth again appeared in the first constellation, the Ram's horns. Thus the full moons divided the whole circle into 12 parts.
The full moons, however, do not make exactly 12 pieces, but rather 37 pieces in 3 years; thus each year there is a different starting point. Nonetheless, the exact division of 12 remained, along with the same starting point.

It appears that this ancient division of the zodiac into twelve equal parts rests mainly on human arbitrariness, and that the signs in reality or naturally are not so precisely separate from each other, or that their characteristics, as defined by these limits, overlap... As far as the cardinal point and the first point of Aries is concerned, that is indeed something natural.

source:
Kenneth G. Negus: Kepler's Astrology
http://cura.free.fr/docum/15kep-en.html ?4-2

I agree with Kepler and I look almost only at the aspects between planets and with angles. He also viewed the twelve houses this way. Quite an unorthodox view but I kind of like it.

But the powers of self-suggestion are great.

This is one of my greatest troubles with directions and progressions in general. I wonder how others deal with this problem.

Eddy wrote:

It appears that this ancient division of the zodiac into twelve equal parts rests mainly on human arbitrariness, and that the signs in reality or naturally are not so precisely separate from each other, or that their characteristics, as defined by these limits, overlap...

Yes, this nicely illustrates the difference between the ancient/medieval mindset and the 'modern' (17th century) one.

Eddy wrote: source:
Kenneth G. Negus: Kepler's Astrology
http://cura.free.fr/docum/15kep-en.html ?4-2

I agree with Kepler and I look almost only at the aspects between planets and with angles. He also viewed the twelve houses this way. Quite an unorthodox view but I kind of like it.

Hi Eddy,

in the beginning or better: before the translation of this Kepler-text are some lines of its original in German. Can you or anyone else post the link to Kepler's original ? That would be very fine. Thank you!

Johannes

Hi, Johannes

you can find ist

http://cura.free.fr/DIAL.html
get the PDF
Astronomi Opera Omnia vol I

on page 543
Tertius Interveniens


Wolfgang

Hello All,

I have been away from the thread longer than I intended.

Rene:
Fantastic visuals. The saying 'a picture is worth a thousand words' was never more true.

Deb
I am planning a detailed reply to you when time allows. In short I accept my summary of Anonymous of 379 was criminally simplistic. I did know about his use of ecliptical projection but got rather caught up in a polemical flourish......

You have misunderstood what I was saying about Hephaistio and declination. Its really a suggestion from Joseph Crane not myself. Moreover, I did go to the trouble of quoting Hephaistio's use of zodical projection of stars way back in the earlier part of this thread
(before it was renamed). I refer you back there. I think you must have just been gazing at my condensed comments on this new titled thread.

You have made an extremely important point about the use of extra-zodiacal stars projected on to the ecliptic by Anonymous of 379. Although expressed in a low key way this totally contradicts what Robert Hand, Bernadette Brady and Joseph Crane have been saying. Very interesting. What you are stating does seem correct. I will come back on that and several other things you have raised. The issue seems to hinge on how we interpret the term 'co-arising'.

More generally, I was fully aware that the bulk of the tradition supported zodiacal projection for extra-zodiacal stars. Although, I certainly didn't appreciate just how much until relatively recently. This is one area where I do not find the approach of traditional astrology (at least stemming from the Greeks) very convincing. I guess I must be a Babylonian at heart on this issue.....

Mark

HI WOLFGANG,

THANK YOU SO VERY MUCH ! WHAT A LINK !!!

Johannes

Thanks Wolfgang, I almost had forgotten that CURA had added historical material on their website.

I can find no German version of Astronomi Opera Omnia, vol. 1 Unfortunately I don't read Latin.

(continued in new thread - "Primaries -keys")