Astrology
From RationalWiki
| Looking good is good enough |
| Pseudosciences |
| Popular pseudosciences |
| Random examples |
| Resources |
Astrology is the belief that huge balls of rocks, liquids, gases, and nuclear fusion reactions millions or billions of miles away from Earth can affect the financial, sexual, and employment situations of individual carbon-based life forms on one specific planet.
This widely believed idea has never produced any worthwhile and conclusive predictions, in spite of having several different formulations across disparate cultures. As all the "evidence" that it is true is only anecdotal, selectively reported or made up, it is an excellent example of a woo explanation for something quite mundane.
Contents |
[edit] The scientific point of view
The scientific view, in the most candid form, is that astrology is a load of nonsense perpetrated by ignorant fools or those wishing to exploit others. It is, for lack of a better word, crap. In the interest of being factual, honest, and accurate rather than merely rhetorical, the scientific point of view will be spread out in more detail below, but will come to the same conclusion: astrology = crap.
[edit] Potential forces
There is no known mechanism whereby a person could be significantly influenced by distant celestial bodies. A psychological explanation - where pretty shapes in the sky sub-consciously alter people's moods, perceptions or desires, like an accidental form of advertising or brainwashing - is unlikely as stars and celestial objects don't tend to be visible during the day and, with the exception of very dramatic events such as eclipses, all look the same to the untrained eye. In addition, viewing the stars (in order to be psychologically influenced by them) isn't a prerequisite for astrology, as a predictive mechanism, working.
More "physical" explanations are equally unlikely - this requires briefly looking into the physics that could possibly be behind it. The fundamental natural forces in nature are the strong and weak nuclear forces, the electromagnetic force, and the gravitational force. The strong and weak forces are nuclear forces are not applicable to interactions between people and objects such as planets or stars - their strengths tail off so dramatically that they barely have any effect outside the nucleus of an atom, yet alone at the macroscopic scale. Similarly, the electrostatic force - while acting at greater distances than nuclear forces - becomes completely negligible at modest distance, and does not act in any way over astronomical distance.
This leaves us with the one remaining "long distance" force; gravity. However, despite working over far vaster distances than other forces, it is still practically impossible for planets to influence actions on Earth. Gravity follows the inverse square law, that is, that gravitational strength is proportional to the inverse of the square of the distance. As distance increases, gravitational pull decreases very dramatically; something that moves to twice as far away exerts a quarter of the gravitational pull, something three times further away exerts a ninth of the gravitational pull. Newton's law of gravitation can be used to show that, at its closest approach to Earth, the planet Mars exerts approximately the same gravitational force on a person as a 50 ton fully-loaded big rig placed 15 yards from that same person. The star Alpha Centauri A has a mass of 1.1 solar masses and is one of the three stars closest to Earth, yet its gravitational pull on a person is comparable to that of a 100 gram cellphone at 9 meters. The moon and sun, being closer, exert more force on the earth and result in the changing of tides (although this system is a little more complex than "the moon pulls water towards it"). Astrology is often not limited to just these two objects with the highest degree of gravitational interference and even so, these should - like with water in the tides - affect everyone equally.[1]
Whatever the mysterious force may be that astrologists claim causes the effects of the positions and movements of celestial bodies on human physiology, it is not backed up by any current knowledge or research and certainly isn't natural. If there is a force, it can't be detected, and woo pushers tend to like that sort of thing - but this raises an important question; if it can't be detected in any way, shape or form, then how can it actually affect anything? However, we can still be open to so-called "supernatural" explanations and only look at the efficacy of astrology.
[edit] Astrological predictions
Predictions made by astrologers vary wildly from the vague to the specific (most often they are extremely vague). The more vague a prediction, the higher the chance it has of coming true; or more accurately, the higher the chance that it can be interpreted as having been true. This can be seen most easily in the form of astrology that most people are familiar with; the horoscope. A horoscope is a prediction or advice based only on someone's date of birth, or more commonly (in newspapers and magazines, for instance) their zodiac sign, of which there are 12. Given that there are more than 6 billion people on Earth, at least one horoscope in every publication applies to more than 500 million people from the pigeonhole principle.[2] This gives more than enough room for even specific predictions to come true for a large number of people purely by accident. It is a clear fact that half a billion people do not have the same experiences each day, so the power of these predictions cannot be as widely and universally applied as is claimed.
James Randi once replicated an experiment to demonstrate how people can basically be "tricked" into thinking a horoscope is accurate. A number of students were asked their zodiac and given the appropriate horoscope to read. They were then asked to grade how accurate they felt the horoscope was regarding their selves and a significant number, if not the majority, gave their horoscopes scores ranging from 4 to 5 (the maximum). Later they were asked to pass along their personal horoscope to the person behind them where the "trick" was revealed; they had all been given the same horoscope. This is a demonstration of the Forer effect and how the language used in horoscopes can be vague and widely applicable to many people yet still give the illusion of being very specific. With a careful selection of language, phrases and tone, it is almost impossible for a horoscope to not to be applicable to someone.[3]
In most studies, astrological predictions work no better than mere guesses.[4] Sometimes they're right just by playing the odds, sometimes by cold reading but almost always, the positive and supportive results are reported while the negative results are not. This selective reporting gives the illusion that the technique works.
[edit] Value to science
Like many protosciences, astrology provided the original foundation of the modern science of astronomy. As natural scientists started trying to understand what the bright things we see in the sky are, where they are, and their relationship to each other, astrology was able to provide some thousands of years of observations to develop hypotheses from. After all, mystics spent enough time gazing at the sky that it was inevitable that some useful information would slip into human knowledge.
To a lesser extent, horoscopes - which would include fairly accurate astronomical data - of figures in the past and clear mentions of what were then "astrological" events may help modern historians with efforts to assign accurate dates to the past.
[edit] Quote mining
| “ | What utter madness in these astrologers, in considering the effect of the vast, slow movements and change in the heavens, to assume that wind and rain have no effect at birth! | ” |
| —Marcus Tullius Cicero, 44 B.C.E | ||
[edit] See also
[edit] Completely bullshit external links
None of these links are endorsed by RationalWiki but are presented (for your amusement only) as examples of the genre.
- The Book of World Horoscopes - Horoscopes for every country in the world
[edit] Footnotes
- ↑ Scientific American - Lunacy and the Full Moon
- ↑ Barring any birth timing irregularities, on average every horoscope should be applicable to around 500 million people.
- ↑ http://www.youtube.com/watch?v=3Dp2Zqk8vHw
- ↑ A description of one double blind study into astrology.

