Heliacal Appearances (Phaseis):Greece/Babylon

[Victor Reijs]

Hello all of you,

The atmospheric extinction is by my observations stable around a spot with radius of around 500 and even 1000 miles- especially if these region is in the same climatic area.
From Istanbul through Bulgaria and to Austria the atmospheric extinction is virtually the same.
From Istanbul further south though it is getting different at much higher rate.

Looking at the visibility over the day and days, it looks that your place, Varna, indeed has a quite stable visibility (http://www.iol.ie/~geniet/eng/extinction.htm#changeable). As the visibility is determined by the extinction coefficient (http://www.iol.ie/~geniet/eng/atmoastroextinction.htm ), you can say that the ext. coefficient is also very stable in your region.

But for instance in Ireland the visibility can change dramatically over the days(http://www.iol.ie/~geniet/eng/extinction.htm#changeable and http://www.wunderground.com/global/Region/EU/Visibility.html). Also in present day Babylon the extinc. coeff. is not really that stable over the day or days (http://www.iol.ie/~geniet/eng/extinction.htm#changeable and http://www.wunderground.com/global/Region/A2/Visibility.html).
So one really has to measure the extinc. coeff. (as you propose to determining the extinc. coefficient by using the stars).

Unluckily for (pre-)historic event or predictions this is not possible. And assuming a stable extinc. coeff. is not always really possible, so one need to work with a range of extinc. coeff. I normally use the range of 0.15 to 0.4 [-] for realistic range of astronomical extinction coefficients.

All the best,

Victor

[Rumen_Kolev]

Looking at the visibility over the day and days, it looks that your place, Varna, indeed has a quite stable visibility

But for instance in Ireland the visibility can change dramatically over the days

Victor

Victor, this is a good place to continue our discussion.
FIRST, I would like to ask you : How do you exactly 'look at the visibility...in Varna....' ???
Are you in the space-shuttle and watch from there the quantity of aerosols in the atmosphere with special googles ???

[this is not only a joke! there is someone on the internet who obviously is so absolutely challenged that he really does this- measuring the extinction with space-data for the aerosols above a given place on Earth !!!!!!!!!! ]

But now I can put here a question :
WHY do you think we CANNOT measure the extinction at a given place on Earth with the space-data for the aerosols above that given place ???
Or do you think we CAN ???

RK

[Victor Reijs]

FIRST, I would like to ask you : How do you exactly 'look at the visibility...in Varna....' ???

See the link I gave of http://www.wunderground.com . All weather stations do visibility measurements regulary every day. No need for satellites;-)

All the best,


Victor

[Rumen_Kolev]

You think that the extinction is determined by the visibility.
Things are not that simple.
There must be a correlation between visibility and extinction, but the visibility is only one of the variables.
All these 'empty talk' I do here, would be superfluous if only I talked with people who had few practical observations.

The extinction at a certain spot , from 0 to 10 degrees above the horizon, is different from that at the same altitude but 60 degrees or more away in azimuth.

This has to do with the trajectory of the light from a star on the horizon (or less than 10 degrees above) skewed trough the horizontal levels of the atmosphere, I suppose.

Again, in the end, you know what is the Best: Go out there and measure it with the altitude of the night-rise of the stars...

[Victor Reijs]

The extinction at a certain spot , from 0 to 10 degrees above the horizon, is different from that at the same altitude but 60 degrees or more away in azimuth.
This has to do with the trajectory of the light from a star on the horizon (or less than 10 degrees above) skewed trough the horizontal levels of the atmosphere, I suppose.

Indeed. What you describe here is the combination of the Airmass due to the altitude of the object and the astronomical ext. coefficient.
There is a strong correlation between visibility range (related atmospheric absorption/scattering coefficient [per km]) and astronomical extinction coefficient [dimensionless] (http://www.iol.ie/~geniet/eng/atmoastroextinction.htm), even without including the Airmass. By the way; the astr. extinction coefficient has additional aspects involved (like Ozone) than the atmospheric abs/scat coefficient.
These practical things (as visibility range) are there not for nothing, they are based on real day to day observations. Indeed get out there and see the visibility range (like every meteorologist does).

Again, in the end, you know what is the Best: Go out there and measure it with the altitude of the night-rise of the stars...

As stated in my earlier reaction; I fully agree for certain circumstances. But what if I need to evaluate something in the future or in the past (happens most of the lot of time in my area: archaeoastronomy)? Doing real observations just does not work in that situation (no time machine here;-).
Nothing is stable in this world and certainly not the astr. ext. coefficient in certain regions. I can speak from experience here in Ireland; observing the whole sky when doing daily rise/set observations of the Moon for a few months in a row (although in many cases clouds obstructed the view;-).

All the best,


Victor

[Roy_Kirkland]

What I heard by chance once was that in India no-one marries when Venus is invisible ! (do not know details and quotes tough)

Hi Rumen -

Most of the writing on the subject is in the Surya Siddhanta, which is basically a mytho-astronomical textbook and the main text for computing charts and calendars. I do not remember any reference to it in Kalaprakasika, an important textbook on electional astrology. There may be some mention of Heliacal Phenomena scattered about in the books on Natal Astrology but if you are going to look for the lore, you need to study the subject as combustion.

Most of the use of invisibility is found in electional astrology, but the common texts on the subject only deal with the big 5 positional/relational phenomena (Sign, Nakshatra, Yoga, Tithi, Karana) that are the standard factors for building electional charts. I have seen almanacs (panchangam) in the past that account for "invisibility". When they do, they give the dates by strictly following the orbs set forth in the SS above - they are larger than either Ptolemy or Schoch. The information in that book seems to be taken from Ptolemy, but uses larger orbs. Interesting though: their electional methods are more calendric, which means that visible and environmental considerations (length of day, which has to do with solar declination etc.) are more important in that branch of Indian astrology, and also that they are building their considerations around what the client wants to know - "when should I do X, Y or Z" - Again, the majority of the work is about performing religious duties, or warding off the bad luck that comes from inappropriately timed haircuts or ear piercing.

As far as their interpretation is concerned, the majority has to do with the religious folklore upon which their tradition is built, i.e. people who have Venus invisible should chant Mritunjaya Mantra for penance, protection and good marriage. Sometimes these phenomena are listed in connection with the annual chart for the New Moon in Pisces (Sidereal - this is the core of their Mundane technique) to foresee dangers to crops, from weather and so forth. Even in these sources there is just the barest mention - the sign/house/planet/nakshatra considerations take up most of the subject matter (after the religious portion is removed)

[Rumen_Kolev]

Hey Victor,

You ask what to do in order to assess the extinction in Ireland thousands of years ago.
You should check the historic-meteo-atmospheric-climatic data and guess it.
However,
WHY do you need the ext. to do archaeoastronomy there ???
Do you think there are some stone allignments to the h. rise of stars in Ireland ???

Anyway, have you ever measured the ext. in Ireland now ? With the night rise of the stars???
Do you have data ?

What happened with your 'researching-wondering' over the AR-CS (acro-nychal, cosmic-set) paradigma ?
Do you think my definitions of these are OK ?

[Rumen_Kolev]

Hi everyone interested in Hellenistic Astrology,

In a Greek horoscope from the year +81 from Alexandria,
I believe I found something quite interesting!

A proof that the ancient Hellines in Alexandria, or at least some of them, from around the time of JESUS used the Real Heliacal Phases of the planets
and NOT the gross approximations like 'the 15-degree-ecliptical-distance rule' that was described by some Greek-writing authors and that is now used by Schmidt Robert . [While I respect Schmidt's work and idealistic devotion, I probably do not share his opinion on all topics...]

On pages 21-28 in 'GREEK HOROSCOPES' by O. NEUGEBAUER, 1987,
there is a horoscope for Alexandria, +81 year, March 31, around 21h time [time zone 2 hours east] (on page 27)

On page 22, section VII, rows 157-164, the Greek text says:
'stilbwn ... pro epta fasin pepoihmenos: dio oikodespothsei to diathema...'

Mercury ... before seven [days were passed] has been making a phase: because of this it rules (oikodespothsei ) the chart...

[translation of Neugebauer O. on page 24 Col VII]

In the text Mercury is in 10 degrees Aries and the Sun is in 14 degrees Aries.

There is no way that Mercury could stand at 15 degrees distance from the Sun +-7 days from the birth.
Mercury moves max with 2 degrees pro day.

If we go 7 days before birth
then Mercury will be 14 degrees back in the ecliptic ( 7 days x 2deg. = 14 deg.):
that is Mercury in 26 deg. of Pisces and the Sun would be then in 7 deg. of Aries (Sun 7 deg. back in the ecliptic for 7 days).
Distance Mercury-Sun = 11 degrees

If we go 7 days after birth
then Mercury will be 14 degrees forward in the ecliptic ( 7 days x 2deg. = 14 deg.):
that is Mercury in 24 deg. of Aries and the Sun would be then in 21 deg. of Aries.
Distance Mercury-Sun = 3 degrees

========================================

Then WHY the text says that Mercury is making a phase before seven (days are elapsed) ?!
Very simple.
Because Mercury really is making his First Evening Appearance 6 days after the birth, on April 06, in the year +81 in Alexandria.
[with Sun at 5 degrees below horizon, Mercury is 3.6 degrees above horizon and with magnitude of -2.4 is becoming visible as an Evening Star for the First time after superior conjunction: I have observed personally similar appearances of Mercury when close to his perigee. This is shown by the program PLACIDUS 6.0 the module Porphyrius Magus]

Alexandria, +81 year, March 31, around 21h time; GREEK HOROSCOPES by O. Neugebauer, pages 21-28
The 'ef6' in red above MERCURY shows that 6 days after birth Mercury makes his EVENING FIRST phase (appearance as evening star).

Greek-Horoscopes_p23_Neugebauer.gif (147.61 KiB) Viewed 1210 times

Alexandria, +81 year, April 06,
Day of First Evening Appearance of Mercury.
Target data is what must be satisfied in order for Mercury to be visible.
Real data is what is the real data in fact. dAz is distance in azimuth between Sun and Mercury.
Alt Star is the altitude of Mercury. Alt Sun is the altitude of the Sun (below horizon).
SO, Mercury must be higher than the target of 3.3 degrees in order to be seen.
Mercury is, at 3.6 degrees, in fact higher than the target of 3.3 and so Mercury is visible!
GREEK HOROSCOPES by O. Neugebauer, pages 21-28

Greek-Horoscopes_p23_Neugebauer_h_phase.gif (59.01 KiB) Viewed 1204 times

Now everything is clear.
It is clear that at that time the Hellines still knew how to compute the Real Heliacal Phases of the planets.
And it is clear that they computed and used them in the way the Babylonians computed and used them.


*******************NOTE on NEUGEBAUER OTTO**********************************
If someone still has illusions about the level of understanding of Ancient Astrology from the side of the 'expert' Otto NEUGEBAUER,
let him look at the comments by Neugebauer exactly on this place of the text on page 26 Col. VII and page 28 Col. VII.
Neugebauer takes the superior conjunction to be the 'phase' that the text is talking about !

( All Greek authors talk ONLY about First and Last appearances and the Stations as the phases to be considered )
[maybe some took acronychal rise and cosmic set too]
(NO-one took conjunction as a phase to be considered for a planet when evaluating who is to be Kurios or Oikodespotes)
In fact, the word PHASE has taken meaning in modern languages as a synonym for STAGE.
In GREEK, though, 'PHASIS' meant APPEARANCE and was used for VISIBLE phenomena of the stars and the planets in their heliacal (synodic) cycle.
I cannot recall Greek authors to have used the word 'fasis' (phasis) for conjunction with the Sun. Instead the word 'SYNODIKOS' was used.
[If someone has proof on using 'fasis' for conjunction with the Sun (by Greek authors)- may he/she show me the author and place.]

More than that!
This 'super-expert' [actually super-ignorant] also thinks that 'before 7' means before the 7th of the month (Egyptian) !!!
[the birth has occurred on the 6th of the Egyptian month]

With this Neugebauer shows that he does not know anything about the "heliacal phase +-7 days from birth" principle in Hellenistic Astrology that is attested and described by numerous authors including Porphyry !!!
So much on the competence of Otto Neugebauer !
***************************************************************************************

[Abd-Allah Meyers]

Greetings,

Yet another thread to reappear from under the beams?

Concerning the corporeal observable values and the approximated values might we have, at least in part, a case of "accidental" versus "essential"? Many astrologers have not lived and do not live in places where astronomical observations are regularly possible due to weather, climate, topography, etc. Let us for example assume a severe sandstorm in Iraq, not only completely obscuring the dawn and dusk skies but making human presence at outdoors observatories impossible. Should we therefore astrologically assume that a calculated heliacal rising or setting did not occur because of the sandstorm?

Astrologically we know comparable questions, e. g. 'true' lunar nodes and Black Moon versus 'mean' or, in case of the Black Moon various combinations, 360 day or 365.24xxxxxxx day years, synodic lunar months versus 1/12 of solar year, etc.

In our passion for apparent accuracy have we perhaps forgotten that our corporeal world of generation and corruption by its very definition never perfectly renders the underlying ideas?

Best regards,

Abd-Allah Meyers

[Rumen_Kolev]

Yes AbdUllah,

The Mesopotamians actually made distinction between 'computed' (ideal) and actual heliacal phase.
They noted both in most of their diaries.

The computed (ideal) phase, though, was not computed with the simple +-15-degrees-from-the-Sun rule that we see in many Hellines.
It was computed with the period of the given phase and planet and on the basis of past observations.
The Hellines forgot the periods.
This simple 15-degrees rule is an over simplification and approximation and is not attested by the Mesopotamians.

As such its efficiency as a metaphysical Pointer must be limited (but probably not non-existant).