The history of the zodiac
There is a predictable time in the year when the news cycle slows down and the same types of articles fill the blogosphere:
Did you know that your astrology sign is wrong?
Have you heard of the 13th sign?
Why You’re No Longer a Scorpio!
These brutal headlines are designed to attract clicks, upend mainstream knowledge of astrology and cast doubt on the age-old practice.
There’s just one problem: these ambitious traps aren’t revelations at all.
Many of the articles base their arguments on a phenomenon called “the precession of the equinoxes” – also known as old news repackaged as clickbait. But astrologers are not the ones who lag behind the state of the heavens; the journalists are. About 2000 years. So before you sadly fold up your “Virgo 4 Lyfe” T-shirt, let’s take a look precisely what these articles are wrong – and right – about how astrology works.
Time to get technical
First we need to understand the concept of the ecliptic. The ecliptic is the path that the sun appears to make through the sky over the course of the year. It is like a celestial superhighway where the sun, moon and planets appear to travel from our vantage point on Earth. “From our point of view” is a key phrase here: we generally write horoscopes for Earthlings, so we interpret heaven from Earth’s perspective.
So while Sol, Mercury, Venus and the rest move along this strip of airway at different speeds, their journeys have a stable background: the fixed stars. Unlike the planets, the relative positions of these stars do not appear to change. Their stability helps us locate the planets on their journey. The stars that shine along the ecliptic belong to the zodiac family star signs, groups of fixed stars identified by familiar names such as Aries, Taurus, Gemini, and so on. From our perspective, it appears that Sol takes one Earth year to transit all twelve constellations.
Would-be debunkers claim that your sun sign is indicated by the zodiac sign behind Sol at the time of your birth. If the zodiac sign Scorpio is lurking in the background of the sun when you are born, news media explain, you are a Scorpio. These writers add that, due to a phenomenon called the precession of the equinoxes, the sun no longer aligns with the same constellations as it did when the first astrologers observed it 2,000 years ago. So that means astrology is all nonsense, right?
Wrong.
To help you understand why, we need to explain the phenomenon of precession.
Precession of the equinoxes
It is common knowledge that the Earth rotates on its axis every 24 hours. This is how we work day and night. But the Earth’s axis itself also rotates, like a slowly spinning top, gradually completing its cycle, about once every 26,000 years. This secondary rotation creates a tilt, often called a “wobble” – in more scientific terms: precession.
Because of this imperceptible fluctuation, the constellation in which Sol rises at the equinox changes over time. It fluctuates by about one degree every 72 years – and about one sign every two millennia. Hence the name: “the precession of the equinoxes.” The relative positions of the fixed stars do not change, but the Sun will not always appear in the same place among the fixed stars on a given date. So if Sol no longer aligns with the Aries zodiac sign on March 21, the critics claim, it might be time to put away your signature Aries necklace and embrace your new identity as Pisces. Reasonable, right?
It would be – if it had anything to do with the past 2000 years of Western astrology. What these media outlets get wrong is that astrologers are well aware of precession and have developed multiple approaches to dealing with its effects.
Two ways to map the stars
To address the issue of precession, the ancients established two different zodiacs. One is the sidereal zodiac, the dominant system used in India today. The other is the tropical zodiacnow most common in North America and Europe.
By the 5th century BCE, the Mesopotamian astronomers-astrologers were standardizing the signs of the zodiac as twelve equal sky segments of 30 degrees, independent of the constellations themselves. Over time, astrologers began to mention this system the sidereal zodiac (from the Latin word sidereus, “of the stars or constellations”). This was the step that made astrology a primarily symbolic practice, rather than a purely empirical practice, because it does not reflect the exact positions of the stars in the sky.
Think of it this way: the night sky seems limitless, but what the human mind can conceptualize is not. Thanks to the ancient Mesopotamians, your astrological chart is evenly divided into twelve parts, representing twelve different signs. But in heaven the constellations are not so orderly. For example, the stars of Virgo span a large portion of the ecliptic, while other constellations, such as Cancer, span a relatively narrow portion.
But sidereal astrologers Doing consider the impact of precession and adjust the location of the signs so that they roughly align with the constellations. In other words, the so-called “new signs‘ in the tabloids are already used by sidereal astrologers around the world. To be clear, the system is still symbolic. Sidereal astrologers still argue that the Virgo zodiac sign does not take up a disproportionate share of the ecliptic real estate. But they adjust the degrees to account for the past 2,000 years of “wobble.”
So that’s one approach.
The second approach is to fix astrology on something that does not change: the equinox. The equinoxes are the two days a year when there is a perfect balance between daylight and darkness – wherever you are on Earth, and no matter when in history. Two millennia ago, when ancient astrologers had put everything in writing, the sun entered the constellation Aries at the northern hemisphere’s vernal equinox. So 0° Aries became the first degree of the tropical zodiac.
The ancient Greek astronomer Hipparchus, who discovered the phenomenon of precession, used the tropical zodiac system to stabilize his calculations. Hipparchus and other astronomers knew that Sol’s backdrop at the equinox would ultimately be a different constellation. But that didn’t bother them, since the zodiac has always been a symbolic representation of the heavens. For thousands of years, the tropical zodiac has reflected the steady rhythm of the seasons, not the slow progression of the constellations.
Which zodiac is more accurate?
Around the first century BC, the constellations and tropical zodiacs were roughly aligned, and the sun would begin to rise in Aries on the first day of spring in the Northern Hemisphere. Both zodiac systems were in use, so it can be difficult to distinguish between the two in early astrological texts. But as the effects of the precession became clearer, so did the unique strengths of each system. And in the second century BCE, Claudius Ptolemy – the famous mathematician, astronomer, astrologer and geographer – firmly favored the tropical zodiac over the sidereal zodiac in his writings.
So which system is better? Neither. Each system offers uniquely valuable wisdom, and what works best for you is a matter of personal preference. But it is important to note that astrologers were aware of the Earth’s wobble thousands of years ago, and they developed both zodiac systems in accordance with that knowledge.
Another crucial point: astrology may be symbolic, but that doesn’t mean it’s untrue. There are many fields in the world – including poetry, psychoanalysis and spirituality – whose secrets and powers cannot be explained in a laboratory report. Astrology’s relevance spans continental divides and millennia of profound cultural upheaval – and for good reason. As important as scientific research is, it is not always consistent with the art of astrology. And that’s not necessary; both disciplines are still valid. But it would be nice if the people publishing these tired headlines would do a little more research on their subject.
Do you want to know more about the signs in the zodiac? Click on the links below.
Ram | Taurus | Twin | Cancer | Lion | Virgin | Scale
Scorpion | Archer | Ibex | Aquarius | Fishing
Then download the CHANI app iOS or Android for extra lectures.
