The Not-So-Scientific Scientific History Of Astrology

Living with a love of both astrology and astronomy is a little like being a Creationist science teacher: certainly possible, but probably not advisable. Still, magic is just a language for ordering the world. And, believing — perhaps against all reason — in the unknowable doesn’t have to mean refuting the known. For some people, religion offers a map with which to chart the course of their lives; for others, it’s the architecture of the universe itself that provides the tools for navigation. I believe in astrology not so much for its ability to tell fortunes, but for its narrative structure — the way it asks me to look at the events of my life as part of a larger pattern of cycles and deaths and rebirths. Astrology belongs in the land of the mythical, but it’s a mythology I’ve chosen, and one that keeps me connected to something larger and more beautiful than myself.

Astrology — in general, the idea that celestial events have some influence on our lives and fates — is a system nearly as old as human civilization. It crosses cultures, centuries, and continents, and persists to this day despite the fact that it has no roots whatsoever in scientific fact. While today we think of astrology as predicting or describing events that affect individual lives, ancient cultures used astronomical observations to develop elaborate systems of augury. The ancient Babylonians, for example, believed that the constellations were literally gods, and connected them to events like eclipses, catastrophic floods, and other disasters. The Maya — the most advanced astronomers of the pre-Colombian world, who correctly calculated the phases of Mercury, Venus, and Mars — likely used astrology to plan crop planting and warfare.

Western astrology — what you’re using when you look up your horoscope — has its roots in the system developed by Ptolemy in the second century, A.D. Ptolemy described the universe as a set of concentric spheres with the earth at its center. His magnum opus, the Almagest, would go on to influence astronomers and mathematicians in the Western world until Copernicus shook up the status quo in 1543 by creating a model of the universe with the sun, not the Earth, at its center. Astrology and astronomy were considered largely inseparable sciences until the end of the 17th century; even Johannes Kepler, who discovered the laws of planetary motion, had a side career casting horoscopes for the Emperor Rudolph II.

With the rise of the Enlightenment in the 1700s, astrology fell out of fashion and soon lost any legitimacy as a science — with good reason. The Western astrological system divides the sky into twelve 30-degree sections; each is named after a major constellation within its boundaries. This system charts the influences of the planets, the sun, and the moon as they move through each segment of the heavens. But, as astronomers have been pointing out for decades, the precession of the Earth’s axis is enough to have altered the position of the astrological sun signs, though astrology has yet to adjust accordingly. There’s no scientific basis whatsoever for astrology; since the 1970s, researchers have conducted studies that have proven (repeatedly) that astrological predictions have no bearing on actual events. In short, there’s no earthly — or heavenly — reason to take seriously the idea that space rocks have any power over our lives. But, all the same, I know I’m not the only science nerd waiting with bated breath for my Susan Miller horoscope each month.

And, while few astronomers on this planet would be caught dead defending the dark art of planetary divination, I’m not alone in my (Gemini) willingness to live in both worlds at the same time. A collective of scientists and artists recently created the Scientific Tarot Deck, in which each card links a scientific discovery to a potential personal meaning (stellar expansion, for example, reflects entering a stage of maturity).

In the end, we’re all looking for ways to narrate the sequence of our lives. I don’t think astrology is by any means the worst of them. It gets people looking skyward; maybe they’ll next be obsessed with the mechanics behind the stars' movements. Because, if you think astrology is cool, just wait until you check out cosmology. Or, we can all just go by the "wisdom" that clergyman Richard Carpenter doled out in his 1657 sermon: “Astrology proved harmless, useful, pious.”