To the Editors of the Washington Post:
I happened to miss an event your website hosted last week, but as your Twitter feed was still promoting it this morning, it seemed still relevant to write to you. This event was an hour-long conversation with astrologer Susan Miller “to celebrate the arrival of Jupiter, giver of gifts and luck, in Cancer for the first time in twelve years.” As a writer dedicated to bringing the understanding of science to the general public, I feel it is irresponsible for your newspaper to promote something as thoroughly discredited as astrology under your imprimatur.
Astrology, as I’m sure you’re aware, is the notion that human lives are affected by the relative positions of the Sun, the Moon, and planets in the Solar System to each other and to the stars. It’s a venerable notion, with versions from many different ancient cultures. Modern astrology is a mishmash of these, but one thing all the versions have in common is their basis in a premodern view of the Solar System.
Today, we know that planets are worlds like Earth, orbiting the Sun in predictable ways thanks to the action of gravity. Stars are very distant spheres of plasma, driven by nuclear fusion deep in their cores. Constellations are random associations that our brains organize into arbitrary patterns, such that stars appearing close together in the sky may be very far apart when we consider their distances from Earth. There’s no way for (say) the position of Jupiter relative to the stars in the constellation Cancer to have any bearing on life on Earth. From physics and biology, we know there are no forces that can act on us that strongly over such vast distances.
I realize that astrology is popular in the United States, and that the Post — like most newspapers in the US — runs a daily horoscope, alongside the comics section and advice columns. As such, protesting the presence of a horoscope is a losing battle. However, young-Earth Creationism is also relatively popular, despite its clearly incorrect assertion that Earth is less than 10,000 years old. Shall the Post hold a discussion with leading Creationists? I’m sure they’d be happy to participate.
If you’re interested in understanding why astrology is frankly wrong, please read below my signature, or follow up with Phil Plait’s thorough debunking. However, you may think that promoting an astrologer does no harm, even if astrology is unscientific. I couldn’t disagree more. In this era when scientists are under attack for studying humanity’s role in climate change and when basic science like evolution is still considered “controversial” in public school classrooms, it’s more important than ever that the media do not give credence to pseudo-scientific and anti-scientific ideas.
Given that the Post employs good science writers and runs excellent scientific content, it’s all the more shameful that you should undermine the work your own newspaper does by giving an astrologer such a prominent platform. I hope you will follow your own example in the future. I’m sure your own science writers would be happy to have a similar platform talk about real science — including Jupiter and the stars.
Astrology vs. common sense
Even Saint Augustine of Hippo (354-450 AD) recognized that astrology fails a basic test: when comparing the lives of identical twins who follow different paths.
I then turned my thoughts to those that are born twins, who generally come out of the womb so near the one to the other that the short interval between them— whatever importance they may ascribe to it in the nature of things — cannot be noted by human observation or expressed in those tables which the astrologer uses to examine when he undertakes to pronounce the truth. But such pronouncements cannot be true. For looking into the same horoscopes, he must have foretold the same future for Esau and Jacob, to 33:20. whereas the same future did not turn out for them. He must therefore speak falsely. If he is to speak truly, then he must read contrary predictions into the same horoscopes. But this would mean that it was not by art, but by chance, that he would speak truly. (from Confessions)
Augustine was hardly a modern scientist, but he was right. From the astrological point of view, two people born the same hour of the same day should have very similar destinies, but direct experience contradicts that.
However, the situation gets even worse when you examine the astrological claim of Jupiter entering Cancer. Jupiter is a planet that, like Earth, orbits the Sun in a predictable way. Its period of orbit — the Jupiter year, the time it takes to make one full orbit around the Sun, returning to the same position — is slightly less than 12 Earth years, which so far is consistent with the astrologer’s claims above. Cancer is a constellation, a region of the sky that ancient Greeks associated with the crab that bit Hercules on the foot. Cancer is also one of the constellations of the Zodiac, a region of the sky through which the Sun and the planets in the Solar System regularly pass.
The problem, as you can see from the star chart at right, is that Jupiter isn’t in Cancer at all.
The Zodiac used by most astrologers in the US is based on the constellations as they were about 3,000 years ago, when ancient Babylonians developed their system. While Babylonian astrology influenced astronomy that came later — the 360 degrees in a circle is due to them, for example — a lot has changed in 3,000 years. In particular, Earth’s axis precessed: it points in a different position today than it did thousands of years ago. Polaris is the North Star today, but it wasn’t back then, and the Sun no longer moves through the constellations of the Zodiac at the same times of the year as it used to. Think you’re a Cancer? You’re not: the Sun was actually in Gemini when you were born. Update: As the commenter below notes, astrology abandoned the connection between the houses of the Zodiac and the constellations that originally gave them their names. Obviously this has no bearing on astrology’s claims to truth, since planets’ positions don’t affect your life either way.
Astrology has no connection with your destiny (whatever that even means), and no basis in measurable phenomena. We might as well cut open birds and read their entrails, or throw bones to divine events. Personally, I find that liberating: I don’t need to consult an astrologer for the right time to do things. Also, Jupiter is much more fascinating to me as a planet than it is as a giver of gifts and bringer of luck. It’s a complex world, center of its own system of moons and rings, and shaper of the paths of asteroids. Understanding Jupiter’s structure and history is a way for us to understand the origins and evolution of our Solar System — and thereby our own origins. No horoscope can promise the same.