The Optical Illusion that astrology is based upon

[Rohiniranjan]

Dear all,

The way astrological factors and phenomena are described, and sometimes learned without much critical thinking going into the process, there are some assumptions and misconceptions that enter the minds of even otherwise rational and intelligent people. Hopefully, I will be able to touch on a few.

The very basic axiom of astrology lies in there being an ecliptic belt in the sky that we call the bhachakra or zodiac, the belt of animals. This is the starry background created by earth as it wobbles and moves around the sun! due to the wobble of the earth, the sun seems to travel against a starry background (zodiac) and it does so with an apparent movement that spans a belt that is +28 to -28 degrees around the projected equator of the earth. If the earth were moving steadily without a wobble, which gives us the seasons, then that projected path of the sun would be the projected equator!

Confused, already? Anyway, this 56 degree belt gives the declination of the sun. It is entirely based on the wobble of the earth.

There is another 'wobble' that is created by the wobbles of other planets. That gives rise to what is known as latitude. Moon for instance, moves in an orbit that is at an angle to the axis of the earth, so moon sometimes goes north and sometimes south as it moves around the zodiac (longitude). If earth did not have a wobble, sun would not have a declination and any deflection of the planets away from the projected equator will be the latitude. There is a slight twist again: Declination in a sense is the displacement of a planet (due to earth's wobble) that is perpendicular to the sun's apparent path (earth's actually!). Latitude can be at an angle to the ecliptic equator (the imaginary path of the earth projected to the skies, if there were no wobble in earth. In other words if the north south axis of earth were vertical and not tilted at 23.3... degrees from vertical.

Because of these two variations on a straight theme, declination and latitude, phenomena such as eclipses which are based on visual/observed phenomena bring to our attention the FACT that often the things that are considered paramount in astrology (jyotish at least) such as longitude do not translate directly into astronomically observed phenomena!

Even though sun and moon may be at the same longitude, their declinations and latitudes may be such that they do not occlude each other (solar eclipse) or do not line up exactly on both sides of the earth (lunar eclipse).

Eclipses always coincide with full moon (lunar eclipse) and new moon (solar eclipse) but these two phenomena are based on longitudes whereas the eclipses are more dependent on the lat and decli, to create a partial or complete occultation of the lunar or solar disks.

Incidentally, this parallel matter of true vs mean nodes and their use in jyotish! Only at the point of eclipse can one map the true position of nodes because that is the moment when the imaginary mathematical points that nodes are (point of crossing of the lunar and solar/earth orbits) truly observed and measured and the intermediate points between the two true crossings are calculated or estimated, just like mean positions are! Over a large period of observations, the mathematical functions that represent the true motion of true nodes has been figured out, so it is not an entirely pulled out of a hat, value!

I am sorry if I am boring the august body here who know all this stuff which is pretty basic, anyway and the first thing that an aspiring astrologer must learn!

RR

[arian_1c]

that is wow, very interesting and informative rr ji...
thanks for that

the part about true and mean values of nodes was very interesting...
thanks for explaining the technical aspect of the nodes...however how and wht wud u use in making predictions or a chart...

it is obvious(as u mentioned) that the true values of the nodes is only apparent at the point of eclipse, and at any other time the true value is only an estimate worked out ofcourse from the sophisticated formulas......but then again, it brings us the question of true Vs mean...

[Rohiniranjan]

Since you have already arrived at the shore and watching as you rest [Sahil ;-)] the quest seems to be over for you, by your personal choosing {just teasing, okay? Please do not ban me!!!}

SERIOUSLY though -- the closer you can get to the 'true' value (and it is derived from myriads of eclipse data over time, hence is reliable), I would recommend using the TRUE values for nodes.

Even when an obvious paved path exists, and right in front of their eyes, there are individuals who prefer to go in the bushes in their quest to find short cuts and alternative paths. Nothing wrong with that, but if I am given the choice between:
a) waiting for them to get back and report to me the shorter or better route
b) or follow the paved path ahead of me, paved by reason and reasonably...

I shall choose (b) unless strong reasons prevail otherwise!

I do hope I am making pragmatic sense and I do hope that is still driving Jyotish and its true followers?

RR

[quote="arian_1c"]that is wow, very interesting and informative rr ji...
thanks for that

the part about true and mean values of nodes was very interesting...
thanks for explaining the technical aspect of the nodes...however how and wht wud u use in making predictions or a chart...

it is obvious(as u mentioned) that the true values of the nodes is only apparent at the point of eclipse, and at any other time the true value is only an estimate worked out ofcourse from the sophisticated formulas......but then again, it brings us the question of true Vs mean...[/quote]

[arian_1c]

thanks rr ji....
i thought that would be the right thing to do, using the true value...its strange as how many people use the mean value, and when i think of it now, i started studying astrology abt six years ago and i remember being told specifically not to use the true values and use the mean values....

it's been years since i made a chart by hand but i am guessing(can't remember) the almanacas also contain the mean value, no wonder so many horoscopes i've seen they've all had mean values of nodes used in them...

and my quest seems to add new dimensions every now and then so i am trying to hold on to and be true to the various dimensions of my quest...

regards, always
sahil

[Rohiniranjan]

Sahil,

You are right! But in today's day and age of software (as opposed to days bygone when ephemeris and proportional log tables reigned supreme) there is no excuse for cutting corners and making short-cuts sound like some religious gospel!

More dangerous is the practice of individuals just looking at rashi and jumping with joy when they see an exalted planet or even one in own house. A look at the shadbala and other strengths often gives insight into why the promise of an exalted planet did not get delivered in real lives. Lot of individuals for some reason, shy away from looking at charts and just keep quoting articles and texts -- even ancient ones all of which just give the rules but no basis for that or examples thereof!

RR

[quote="arian_1c"]thanks rr ji....
i thought that would be the right thing to do, using the true value...its strange as how many people use the mean value, and when i think of it now, i started studying astrology abt six years ago and i remember being told specifically not to use the true values and use the mean values....

it's been years since i made a chart by hand but i am guessing(can't remember) the almanacas also contain the mean value, no wonder so many horoscopes i've seen they've all had mean values of nodes used in them...

and my quest seems to add new dimensions every now and then so i am trying to hold on to and be true to the various dimensions of my quest...

regards, always
sahil[/quote]

[olusanya]

Incidentally, this parallel matter of true vs mean nodes and their use in jyotish! Only at the point of eclipse can one map the true position of nodes because that is the moment when the imaginary mathematical points that nodes are (point of crossing of the lunar and solar/earth orbits) truly observed and measured and the intermediate points between the two true crossings are calculated or estimated, just like mean positions are! Over a large period of observations, the mathematical functions that represent the true motion of true nodes has been figured out, so it is not an entirely pulled out of a hat, value!

Pranaam RR,

I was familiar with much of your initial discussion from an introduction to Vedic Astrology by Sanjay Rath, I thank you for putting it in such easy to understand language. My question is; Are you saying that due to the improvements in many of the Astrological software that we should use the true nodes instead of the mean, which is usually the default preference in the various programs?

[Rohiniranjan]

[quote="olusanya"][quote]Incidentally, this parallel matter of true vs mean nodes and their use in jyotish! Only at the point of eclipse can one map the true position of nodes because that is the moment when the imaginary mathematical points that nodes are (point of crossing of the lunar and solar/earth orbits) truly observed and measured and the intermediate points between the two true crossings are calculated or estimated, just like mean positions are! Over a large period of observations, the mathematical functions that represent the true motion of true nodes has been figured out, so it is not an entirely pulled out of a hat, value![/quote]
Pranaam RR,

I was familiar with much of your initial discussion from an introduction to Vedic Astrology by Sanjay Rath, I thank you for putting it in such easy to understand language. My question is; Are you saying that due to the improvements in many of the Astrological software that we should use the true nodes instead of the mean, which is usually the default preference in the various programs?[/quote]

Dear ... [you did not reveal your name!]

It is not so much the astrological software that have become sophisticated (far from true!) but the routines that they use. As far as I know most software utilize what are known as JPL routines. These stand for the Jet Propulsion laboratory, of NASA. Better routines improved by space research and astrophysics have been utilized by ephemeris makers and consequently by astro software. Even the software that uses built-in ephemeris (look up tables) as opposed to calculating values on the fly, utilizes the NASA figures.

As astrophysics and its research improved, the accuracy of the calculations we use has improved too. I know some people feel overly religious about this matter, but Indian panchaangs have been horribly imprecise and used to give values that varied over many degrees. I will stop there or I am sure someone may get offended. That was not the intention!

RR