Is astrology "bunkum" because it uses outdated planetary models?


 Several articles on astrology appeared recently in Sri Lankan news media, pointing out that astrology is "bunkum" or "pseudoscience". These articles are topical at election times when "Astrologers  Royal" make or break their reputations. Unfortunately, astrology has been "debunked" in some of these articles for the   incorrect reasons, e.g., for its geocentric model (that the planets go around the earth), and that it does not include all the known planetary objects etc. However, these are NOT the reasons why astrology is wrong.  We reject astrology as "bunkum" because of its unsubstantiated  premise that there is a  direct relationship between planetary configurations and events in the life and "destiny" of  individuals, or groups of individuals.  Indeed, astrology assumes that the earth stays at rest, while the "nine planets" (nava garayaho) which include the sun and the moon move around the earth. There are many planetary objects recognized by science, but not included in astrological  predictions. Two of the "grahayo", namely, "Raahu" and "Kehethu" are not physical objects found in the sky.

 Although the physical model is wrong, the geocentric model is a good "calculational model", for the purposes of Astrology. Since the relative positions of the planets in the sky at the time of  birth of a person on earth are needed,  geocentric calculations are appropriate, while  a heliocentric calculation will give the same answer. In fact, calculations relative to the earth, relative to the sun, or relative to a rocket are equally valid. Astrology still uses  the astronomy used till about the 17th century, and sanctioned by the Church as well as Chinese and Indian belief systems. This astronomy was remarkably accurate. Chinese and Hindu texts (e.g., those of Varaha Mihira) on astrology contain Greek terms, showing that just as "western science" is the pan-science of today, the ancient world also had its pan-science, cutting across geo-cultural differences, debunking the socio-relativist  interpretations of philosophers like Kuhn and Latour. Such relativism of knowledge has been echoed even in Sri Lanka, e.g.,  by individuals like Dr. Nalin de Silva. The latter’s discussions of astrology etc.,  may be read in articles that appeared in the  Island newspaper and the Lankaweb (e.g., 13-05-2013 and other dates).

Of course it is well known that planetary objects influence each other ‘s motion by their "gravitational fields". Even if the physical nature of the gravitational field may be open to interpretation, the phenomenon of gravity is not disputed.  Even if it is proposed that planets affect humans by some unknown "astrological force field", no  characteristics (e.g., the sex at birth), nor events in the life of individuals  that can be unambiguously linked to astrological forces have ever been confirmed. Astrology divides the sky into 12 parts (houses) corresponding to the 12 zodiacal signs, and  locates the planets in them at a given moment. Hence the calculational accuracy needed is quite rough (within two hours, i.e., plus or minus one hour). However, there are sharp transitions between houses and different astrologers use different ad hoc schemes for handling these "cusps".

Anyone with some knowledge of physics and elementary astronomy can do the calculations and cast a "horoscope" in a short time. I suggest that physics teachers in high schools should teach this  to take the mystery out of it. The teacher can use the opportunity to explain "standard clock time", local time, daylight-saving time, sidereal time,  etc.,  and the lack of any scientific evidence for astrology. If you wish to predict where a bunch of runners would be at any given moment, you need their initial positions, speeds, or equivalent details. It is such details for the planets that are provided by the "Ephemeris", or the "Almanac".

Most ephemeris publications also give details of converting local clock time to sidereal time, and charts to locate planetary positions.  Thus given an "Almanac", drawing up a horoscope is a trivial matter. Most almanacs use the geocentric system, and this is NOT an error. The fact that astrology ignores the "minor planets" and other planetary objects is no serious indictment. However, astrology ignores more important natural forces right here on earth, like microbes, tsunamis, genetics etc., and the fact that one’s destiny may simply be in the hands of others. Thus, should the astrologer read the horoscopes of a person and all his associates (and theirs too) to carry out valid predictions? Of course, the parents need to provide the astrologer with the "time of birth" of a child to cast a horoscope. What does one mean by the time of birth? Is it the moment when labour contractions began? Is it the moment when one end of the baby emerged from the mother’s uterus etc? However, an error of plus or minus one hour may be tolerated using various "ad hoc" schemes since the sky is divided into 12 parts, each equal to 2 hours of time. The astrologer often deliberately adjusts the time to fit his prediction of the sex of the child to what it actually is, and this is called "kaala shudhdhiiya" (time correction). This is "needed" because it is known that "blind" predictions of the sex of new born babies using astrology are  simply true or false on a 50% "by-chance" basis. This was found in experiments done in  hospitals, in collaboration with astrologers, in India,  California and elsewhere with different socio-cultural settings.

The failure to predict the sex of an infant from its horoscope is a clear contradiction of  the main premise of astrology. A good example of the web of belief that goes into astrological predictions,  developed by  Brahmins in India may be seen in a recent article, published on Dec 14, 2014 by a Sri Lankan  astrologer living in Canada (  He suggests that a competent astrologer should cast not one, but at least 16 planetary charts for one individual,  using the CORRECTED Date, Time and Place of Birth.

The astrologer would then examine the Running Dasas (Planetary Periods) first, applicable Power Yogas (configurations) second, Ashtaka Vargas (Directional Strength) of planets third, Varshapal (Solar return) Chart fourth and then examine the "time-tested vital Double Transit of Jupiter and Saturn". On the basis of these, benefic and malefic points are given according to ad hoc prescriptions,  and various conjugations are said to determine health, career, marriage etc. This provides an infinite number of templates for the astrologer to weave out an elaborate story, often incorporating known facts from the life of the person who is seeking astrological predictions. Thus, credulous individuals are ready with anecdotal evidence of how astrologers or palm readers divined their past and predicted the future.

The "ola  leaf" astrologers of India are even said to pull out your pre-made horoscope when you arrive for consultations, and give your full name and many other details of your life even if you did not tell them those details! Just as there are optical illusions, there are also auditory illusions. You  hear exactly what you wish to hear, while a recording of what the Jothishyaachaari said seems very mumbled and unclear  when the recording is played back. Although government all over the world are spending large sums of money on scientific research, the public are not ready to give up their cherished beliefs that go against science. The vast majority of tobacco smokers know that tobacco is bad for their health, but many prefer to blame environmental pollution or Monsanto for their health problems. Many believers in astrology and astrologically "auspicious times" may deny  serious belief in astrology if pressed. But the belief will exist and even take control when  the stakes at issue become significant.


Chandre Dharmawardana,

Ottawa, Canada

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