Babylonian sidereal zodiac

[ismaelcavada-max]

when will the Babylonian sidereal zodiac be introduced, the Babylonian sky culture (MUL.APIN)

[gzotti]

If you read the description of the later Babylonian sky culture, you will hopefully understand why we don't show a Zodiac in the older. Tell us more about the "Babylonian Sidereal Zodiac" please.

[ismaelcavada-max]

Here's a good website on the subject.
https://oastrologovedico-com.translate.goog/como-a-arqueologia-revelou-a-astrologia-sideral-dos-babilonios/?srsltid&_x_tr_sl=pt&_x_tr_tl=en&_x_tr_hl=pt-BR&_x_tr_pto=wapp

[gzotti]

@sushoff are these anchor stars still current state of knowledge? Is there a need to change anything?

[ismaelcavada-max]

https://sumerianastrology.com/babylonian-zodiac-original-sidereal-zodiac/
https://adsabs.harvard.edu/full/2007JHA....38..443S
https://sevenstarsastrology.com/babylonian-zodiac/
Some websites I found on the subject should have more.

[sushoff]

The first zodiac system was created in Ancient Mesopotamia, specifically by the Babylonians, around the first millennium BC (especially between the 7th and 5th centuries BC).

Although earlier civilizations, such as the Sumerians, had already observed the stars, it was the Babylonians who structured what we know today as the 12-sign zodiac.

The System Used: The Babylonian Sidereal Zodiac The original Babylonian system was a celestial coordinate system based on the ecliptic (the apparent path the Sun travels in the sky during the year).

The main characteristics of this system were:

Mathematical Division: They divided the ecliptic into 12 equal segments of 30 degrees each. This was a crucial mathematical innovation, as the actual constellations in the sky have different sizes, but the zodiac system standardized these divisions to facilitate calculations.

Basis in the Calendar: The division into 12 parts was made to correspond to the 12 lunar months of the Babylonian calendar. Practical Use (Astronomy and Omens): Initially, the system was not used for "individual horoscopes" as it is today. It served to:

Mark the time: Act as an agricultural and religious calendar.

Locate planets: Serve as a map to record the position of the Moon and planets.

Royal Omens: Predict events that would affect the king or the nation (wars, harvests, floods), and not the personality of ordinary people.

The Transition to the Current System

The system most of us use today (the Tropical Zodiac) was later refined by the Greeks, such as Ptolemy, who associated the signs with the seasons in the Northern Hemisphere, fixing the beginning of the zodiac (Aries) at the Spring Equinox. The first Babylonian zodiac was a sidereal zodiac.

This means it was based on the actual position of the fixed stars and constellations in the sky, not on the seasons (like the tropical zodiac we use today in Western astrology).

Here are the details on how this system worked:

1. Based on the Stars (Sidereal)
   The Babylonians created the zodiac to serve as a reference map. Because the stars appeared "fixed" relative to each other, they used them as landmarks to measure the movement of the planets and the Moon.

They selected specific stars to mark the beginning of each of the 12 30-degree signs.

Unlike the current system, their sign of Aries began where the constellation of Aries actually was in the sky.

2. The Initial "Confusion"
   At that time (around 500 BC), the point of the spring equinox (the beginning of spring in the Northern Hemisphere) coincided almost perfectly with the constellation Aries. Because of this, for the Babylonians, the system was simultaneously sidereal (linked to the stars) and tropical (aligned with the seasons).

They did not know, however, about the Precession of the Equinoxes—a slow movement of the Earth that causes the point of the equinox to change position relative to the stars over the centuries (about 1 degree every 72 years).

3. The Separation
   The distinction between the two systems only became clear centuries later:

The Sidereal Zodiac (Babylonian/Vedic): Continued to follow the stars. Today, it is about 24 degrees "behind" the Western zodiac.

The Tropical (Western) Zodiac: It was formalized by Greeks like Ptolemy (2nd century AD). He decided to fix 0° Aries on the exact day of the spring equinox, regardless of where the stars were. That is why, today, when the Sun enters the "sign" of Aries on March 21st, it is astronomically passing through the "constellation" of Pisces.

What is the source for the statement that the first zodiac system was created b. 7-5 c. BCE?
The currently displayed research opinion is that the equidistantly divided zodiac was invented around 410 BCE (Britton 2010).

Why do you think the original system is based on the "path that the Sun travels". MUL.APIN explicitely states the "path of the Moon" and not the Sun. This text dates before 1000 BCE and has no zodiac. However, it does have a coordinate system (equivalent to our right ascensions but, of course, phrased differently). MUL.APIN is fundamental for the entire first millennium.

It is definitely not right that "the transition to the current system" (as you call it) was made by Ptolemy (2nd c. CE). That has been an evolution over centuries. The link between signs and seasons already exists in Aratus and in contemporary Babylonian sources. There is a whole genre of texts of mathematical astronomy called "Anaphora" that is found in Babylonian as well as in Greek literature. The Babylonian mathematics for this is found in Greek literature since the 2nd c. BCE.

Ecliptic longitudes were used in mathematical Bab. astral science at least in the Seleucid epoch (half a millennium before Ptolemy). Normal star texts are probably what you mean with "based on actual position f the fixed stars ...".

A statement like ", the point of the spring equinox (...)coincided almost perfectly with the constellation..." does not make any sense mathematically. A constellation is an area, a point can be inside this area but that would last some centuries or even millennia (depending on the size of the constellation). "Aries" did not exist around 500 BCE. The Bab. const. in that area, "Hired Man", covered a larger area. So, the equinox point might have been inside that constellation around 500 and alsoo around 700 and around 300 BCE...

It is incorrect that "Ptolemy fixed the tropical zodiac" in the 2nd c. CE. The tropical zodiac is already used in Hipparchus (2nd c. BCE), Aratus and Eudoxus (4th. c. BCE), and in Babylonian texts of the time there are various computation systems with variants of putting the origin of the coordinate system to either the first degree of Aries (number zero did not exist, even in Ptolemy's time!), the eighth or the fifteenth: see Ossendrijver (2012) as a compendium on mathematical procedures discussing the Babylonian variants, and Hoffmann (2017) "Hipparchs Himmelsglobus" for the various Babylonian and Greek flavours.

[sushoff]

This explains the text flood. The anchor stars are the new info (for me) here. When Hipparcos was the one to discover the drift, we can assume the Babylonians did not realize the need to differentiate. If you want to experiment, simply use the User Guide or see how a Sidereal zodiac is linked in the Indian SCs. You will only need one of the stars. (One will fit accurately, the rest might be close.) Please add the actual publication titles from Huber or Powell so we can evaluate this interpretation and decide further actions.

nobody knows who discovered precession!

It could have been the Babylonians (Schnabel 1923) or anybody else