zoidsoft wrote:... but it hasn't mentioned directing planets to planets.

Now you start with Alchabitius, I assume that you will use an equation formula? Last night I was thinking about planet to planet in Alchabitius. If for example planet A on cusp II is to be directed to planet B on cusp XII then the problem is that with one known position (the coordinates of the zodiacal position of planet A) the two new positions of MC and Asc are required to find cusp XII. With these two unknowns I would calculate the MC for planet A minus 60? and the accompanying Ascendant. Then look at the cusp XII of these and its rectascensional distance to the MC and use this distance again in the first calculation, repeating this procedure till it's precise enough to the arc minute.

It's interesting to see that planet to planet calculations for relatively easy to calculate house cusps like those of Alchabitius take a longer procedure than planet to planet calculations for house systems which cusps have to be calculated with repeating equation formulae to approximate the cusp, Placidus for example. For the latter the procedure is reversed, Placidus planet to planet are quickly done. Or I must be mistaken and there's a short cut for planet to planet in Alchabitius.

zoidsoft wrote:I see. I suppose it is impossible to have one without the other. A direction that is in the primary motion where a significator near the asc meets a promissor in the 11th house that mathematically speaking there is no difference in measurement whether one conceptializes it as before birth or after because the arc is the same.

I think there's a difference in measurement though. For example (I'm using Placidus semi arcs here) if there's Venus on cusp XII and Jupiter on cusp XI and if you want to calculate the time when there's a square in direction then either Jupiter is directed to cusp IX or Venus to cusp VIII (ignoring the possibility of a very high age of the person for this technical example). Doing a direction for before birth Venus would be directed backwards to cusp II and Jupiter backwards to cusp III. Going backwards and through the nocturnal arc below the horizon the speed of the planets would be different from the forwards results where the planets are in their diurnal arcs. So, unless I'm totally wrong in my mathematical reasoning, there is a mathematical difference between before birth and the (traditional) converse concept.

just bumped into the other parts of Mankasey's
http://www.dearbrutus.com/buyprimarydirections.html

If the arc of direction is the same in both directions, then how is the measurement going to be different? I'm defining here that point A arcs to point B, to measure from B to A should be the same. If latitude changes, then the points change.

Eddy wrote:Now you start with Alchabitius, I assume that you will use an equation formula?

A friend of mine who took Zoller's course showed me how to do the Alchabitius semi arc method, so I've got notes. I hope it is the same as the one derived from Alchabitius house system. I would assume so but in astrology the way much of the field eludes standardization, it is a dangerous assumption.

zoidsoft wrote:A friend of mine who took Zoller's course showed me how to do the Alchabitius semi arc method, so I've got notes. I hope it is the same as the one derived from Alchabitius house system. I would assume so but in astrology the way much of the field eludes standardization, it is a dangerous assumption.

Very dangerous indeed! If you have my book, please see pp. 56-57. If not, here is the gist: there is no necessary correlation between house division and method of direction. The so-called Placidus method of direction is exactly the same (or rather, gives exactly the same result) as the so-called Alcabitius method. Makransky invented a directional method based on the Alcabitius house system, but that was entirely untraditional. (Plantiko, for those who read German, did the same.)

steven wrote:A converse direction is not something occuring before birth. It is the significator carried to the promissor instead of the promissor carried to the significator - but in both cases both are carried by primary motion.

Absolutely right, and very concisely put.

Martin Gansten wrote:

steven wrote:A converse direction is not something occuring before birth. It is the significator carried to the promissor instead of the promissor carried to the significator - but in both cases both are carried by primary motion.

Absolutely right, and very concisely put.

OK. Thanks for settling this.

Martin Gansten wrote:Very dangerous indeed! If you have my book, please see pp. 56-57. If not, here is the gist: there is no necessary correlation between house division and method of direction. The so-called Placidus method of direction is exactly the same (or rather, gives exactly the same result) as the so-called Alcabitius method. Makransky invented a directional method based on the Alcabitius house system, but that was entirely untraditional. (Plantiko, for those who read German, did the same.)

OK. I have just skimmed the latter part of Makransky's text, but I had the impression that he was equating a primary direction method with a house system.

I started programming the primary directions with Dorotheus directing the ascendant thorough the bounds by oblique ascensions back in 2005 and that was finished several years ago. It inappropriately uses oblique ascensions for the planets, etc, but Valens does this too using very rough math. I came across Ptolemy's objection of using ascensions for planets not on the ascendant due to astronomically incorrect movement...

I read your book back in summer 2009 then got derailed by a number of issues not the least of which was the design of the Terran Atlas, but I'm back on it. Your page 56 looks like an explanation of Regiomontanus PD's.

What I want to do here is cover each method as it developed in history and I believe that the method that came after Dorotheus was Ptolemy/Alchabitius used up until Bonatti. Correct me if I'm wrong. It would be helpful to have a list and while I seem to remember that your text went in chronological order, I'm not sure that some methods that I have come across are not the same by a different name, so what I'm trying to do is get an authentically correct representation of PD's as they were used depending upon the era of practice and school of thought, then group these settings as themes so that the user who is not acquainted with the technicalities does not make a mistake setting up significators with latitude and promissors without, thinking they were following Ptolemy, but actually studying something that never actually existed in practice and then thinking something doesn't work because they didn't understand what was going on. A list in chronological order would be helpful if it is not explicitly stated in your text. I will have to crack it open again.

Life would be much easier if the New software lists directions as :
P2S - Promissor to signifactor
S2P - Signifactor to Promissor.

If it is all by primary motion and and. P2S square has the same notion as S2P. then confusion of terminology can be avoided altogether.


PD

Martin Gansten wrote:... there is no necessary correlation between house division and method of direction. (...) Makransky invented a directional method based on the Alcabitius house system, but that was entirely untraditional. (Plantiko, for those who read German, did the same.)

This reminds me of the discussion some time ago,
http://www.skyscript.co.uk/forums/viewt ... c0dbc1cd3e page 4 of that thread.

Martin Gansten wrote:

Ed F wrote:This statement confuses me. Various circles of position (various definitions, depending on domification model) and proportional semiarc positions give different results for directions.

The phrase depending on domification model rather begs the question. There are any number of house systems, but only two historically practised methods of (full-blown) primary direction; and before the 15th century there was only one in common use, namely, Ptolemy's semi-arc method (later to become the basis of the Placidus house system). Ptolemy's method was used by generations of astrologers who simultaneously employed whole-sign houses, equal houses, Porphyry houses and/or Alcabitius houses as their 'domification model'. The idea that house system and method of directions should be somehow related was apparently alien to them.

zoidsoft wrote:If the arc of direction is the same in both directions, then how is the measurement going to be different? I'm defining here that point A arcs to point B, to measure from B to A should be the same. If latitude changes, then the points change.

Perhaps the following example will clarify the difference a bit.

Natal chart
Marseille, France 5?24?E, 43?18?N -
1 january 2000, 0:00. Universal Time 23:00 (31 dec 1999).
Sidereal Time 6h01m18s.
Source www.astro.com ? free chart selection.

Secondary motion of the planets isn?t taken into account in this example, nor is latitude.

Imagine Venus and Jupiter being positioned as follows:
Venus on cusp XII ? 4?42? Virgo
Jupiter on cusp XI ? 4?22? Leo

Considering the following four situations.
Forwards in time after birth:
1- Jupiter directed to cusp IX gives a ?Placidian? in zodiaco square to cusp XII and thus to Venus.
2- Venus directed to cusp VIII gives a ?Placidian? in zodiaco square to cusp XI and thus to Jupiter.

Backwards in time before birth:
3- Jupiter directed backwards to cusp III gives a ?Placidian? in zodiaco square to cusp XII and thus to Venus.
4- Venus directed backwards to cusp II gives a ?Placidian? in zodiaco square to cusp XI and thus to Jupiter.

The questions are when these positions will take or took place.
1- When cusp IX is at 4?22? Leo.
2- When cusp VIII is at 4?42? Virgo
3- When cusp III was at 4?22? Leo.
4- When cusp II was at 4?42? Virgo.

With a bit trial and error typing different times the following sidereal times! are found.
hh:mm:ss
1- 10:52:18 (04:50:13 West European Time = UT+1)
2- 14:51:09 (08:48:25 WET)
3- 22:01:19 (16:01:20 WET, 31 December 1999)
4- 02:01:18 (20:00:40 WET, 31 Dec)

Expressed in equatorial degrees the sidereal times are (rounded off to the nearest minute):
1- 163?45?
2- 222?47?
3- 330?20?
4- 30?20?

for the natal sidereal time we get 90?20?
So for the mutual differences in sidereal time degrees we get:
1- 73?25?
2- 132?47?
3- 120?00?
4- 60?00?
These are considered as years according to Ptolemy?s key.

Conclusion: If forwards in time would give the same result as backwards in time, then 1 would be equal to 4 and 2 equal to 3. This isn?t the case because the semi arcs of the planets are different when expressed in equatorial degrees (Sun in 4?Leo gives a longer day than Sun in 4?Virgo)and therefore the results in time are different. When expressed in distances between cusps they are similar (just like days with the Sun in 4?Leo and in 4?Virgo both are 12 'seasonal' hours in length).

Eddy wrote:

zoidsoft wrote:If the arc of direction is the same in both directions, then how is the measurement going to be different? I'm defining here that point A arcs to point B, to measure from B to A should be the same. If latitude changes, then the points change.

Perhaps the following example will clarify the difference a bit.


Conclusion: If forwards in time would give the same result as backwards in time, then 1 would be equal to 4 and 2 equal to 3. This isn?t the case because the semi arcs of the planets are different when expressed in equatorial degrees (Sun in 4?Leo gives a longer day than Sun in 4?Virgo)and therefore the results in time are different.

I agree with Eddy.

This is very easy to understand according Cieloeterra algorithm for semi-arc directions, in my opinion.

Planets are in different positions, and their position is given by their hourly distance (distance from meridian in hours). Their speed is given by their temporal hour (1/6 of their semiarc).

If A goes to B, A moves with A's temporal hour (ie with A semiarc), but if B goes to A, B moves with its speed, ie B's temporal hour.

The distance between the points don't change, but one can be a tortoise and another a hare. They have different speed....

margherita

margherita wrote:

Eddy wrote:

zoidsoft wrote:If the arc of direction is the same in both directions, then how is the measurement going to be different? I'm defining here that point A arcs to point B, to measure from B to A should be the same. If latitude changes, then the points change.

Perhaps the following example will clarify the difference a bit.


Conclusion: If forwards in time would give the same result as backwards in time, then 1 would be equal to 4 and 2 equal to 3. This isn?t the case because the semi arcs of the planets are different when expressed in equatorial degrees (Sun in 4?Leo gives a longer day than Sun in 4?Virgo)and therefore the results in time are different.

I agree with Eddy.

This is very easy to understand according Cieloeterra algorithm for semi-arc directions, in my opinion.

Planets are in different positions, and their position is given by their hourly distance (distance from meridian in hours). Their speed is given by their temporal hour (1/6 of their semiarc).

If A goes to B, A moves with A's temporal hour (ie with A semiarc), but if B goes to A, B moves with its speed, ie B's temporal hour.

The distance between the points don't change, but one can be a tortoise and another a hare. They have different speed....

margherita

I think that they have to be different arcs though. In one case the arc is drawn from A to B and they have different declination usually and this accounts for the time difference. If B is drawn to A while maintaining the arc parallel to the equator which will almost certainly be either above or below the other planet, but considered conjunct according to the projection circle that is canonical for the measurement of the direction, then the arc is actually from a higher/lower declination. Otherwise I can't see how the arcs can be the same. I've drawn a crude illustration of what I'm trying to say here:
This image is viewing the equator edge on. Note that point A and Point B are near the ecliptic, but the declination if B is slightly south and the declination of A is north. The arc of direction has to go in the direction of primary motion which is parallel to the equator and is measured to a conjunction either above or below the other point. They never actually meet in the sky, so the definition of "conjunction" depends upon the frame of reference. Both A and B trace out different arcs which are small circles. The closer to the pole, the smaller the circle. So B which is closest to the equator as measured to A should be longer than A measured toward B. Therefore they are not the same arc of direction.