Showing posts with label Jayant Narlikar. Show all posts
Showing posts with label Jayant Narlikar. Show all posts

Thursday, 20 December 2012

Signs in the Sky: The Irrationality of Astrology




With the New Year just around the corner, most people will now be taking stock of their performance in the current year and will be busy making fresh resolutions for the New Year. Anxious to perform better than in the past, they hope to foresee their future. Instead of making a rational assessment and prediction, many people fall back upon superstitions. Making an accurate assessment of this situation and exploiting the weakness of the gullible to the hilt, astrologers do a flourishing business in making horoscopes. Millions of copies horoscopes are printed and sold every year in our country. Bookstalls in railway stations and bus stands and airports display them prominently.


In our continuing effort to debunk this nonsense of astrology, we publish an essay by the eminent astrophysicist, Jayant V Narlikar. This essay was first published almost two decades back in The Times of India (January 1, 1994). We have left out the last paragraph of the original essay as it is not relevant today.



‘The fault, dear Brutus, lies not in our stars but in ourselves…’ Thus wrote the Bard of Avon in his classic, Julius Caesar. William Shakespeare belonged to the 16th century and Julius Caesar pre-dated him by about 17 centuries. The statement denies any power to heavenly bodies in shaping human destiny.  In the modern age of science when the astrophysicists have solved the mystery of what the stars are made of and what makes them shine, how does the above statement sound?

Imagine the following scenario.  The time is early afternoon, yet the ever-busy city of Bombay is at a standstill, its streets empty, the BEST buses parked in rows long the pavements, shops with shutters drawn. Why? Is it one of those bandhs which have (sadly) become part of our life?  Has the plague been rampant? Have there been bombs going of everywhere? Or is the city deserted because of the threat of an imminent air attack?

Well, the scenario is not imaginary.  It actually took place but not because of any of the above causes which, though unpleasant, are at least rational.  The cause was irrational; its source, the star nearest to us – our sun. The day was February 16, 1980, when a total solar eclipse was visible from certain parts of India. For Bombay, which claims to be the most advance city in India, a partial cover of the sun was, however, enough to drive practically everyone indoors.

Science Models

Schools texts tell us how and why the solar and lunar eclipses take place. Models are made to demonstrate how the earth’s shadow (in the sun’s light) falling on the moon causes the lunar eclipse and how the moon blocking the view of the sun from the earth causes a solar eclipse.  The geometry of the earth-moon-sun system tells us that the eclipses of the sun are considerably rarer than the eclipses of the moon.  Even the Indian astronomer, Aryabhata, back in the fifth century knew all this. Yet, the spectacle of a shining ball of light disappearing, if only for a few minutes, causing momentary darkness is impressive, and can even be frightening if you do not know its case.  Thus our ancient forefathers may be excused for reacting to the phenomenon with wonder and far. It is not surprising that legends grew up around the eclipse phenomena, legends that inspired rituals. The transient darkness and the serpentine shadow bands were considered harmful.

The fear, the legends, the rituals continue to dominate the minds of many to this day, even though science has given a rational explanation for the phenomena.  This irrationality which drove even a city like Bombay behind doors, has its roots in a deeply-imagined belief that the fate of any individual here on the earth is governed by the heavenly bodies.  Let us see what hard scientific evidence has to say on this belief.  To what extent do starts govern our condition?

The existence and sustenance of life here on the earth has been possible because our planet goes around a star (the sun) at a ‘reasonable’  distance; that is not too close to be burnt out by the sun’s heat and not too far as to freeze to death.  The sun provides energy that is needed for all life forms out here.  Our own building blocks – the elements we are made of - were mostly manufacture deep in the cores of other stars through the process of thermonuclear fusion and ejected through stellar explosions. The stars are essential for our existence.  But this statement is a far cry from the claim that your birth chart of horoscope determines your future or that an eclipse or a comet will bring disaster.  Scientific temper requires that such claim be examines in the first instance by the usual techniques that scientists use to test the validity of empirical relationships. What has been the outcome of such tests?

Birth Charts

Take, for example, the belief that for a happy and sustained married life the birth charts of the couple must be compatible.  Compatibility here means a matching as per astrological criteria. To test this hypothesis studies have been conducted for couples of kinds, those whose marriages were happy and sustained and those whose marriages did not last. The birth charts of couples from both groups were given to astrologers (who were not told to which group they belonged) to sort out which coupes and compatible birth charts and which did not.  Their classification tuned out to have co correlation whatsoever with the actual groups; In other words, compatibility of birth charts has no bearing on compatibility of marriage. This is just one of the many ways in which astrological predictions have been tested by scientists using objective criteria and statistical methods of inference employed successfully in other fields for testing empirical hypotheses.  In all cases the results have been negative; that is, astrological statements have shown no scientifically predictive power.

In the ancient times of Julius Caesar, the motions of planets were known to be irregular, not fitting in the same circular pattern in which stars appeared to move. The Greek word ‘planet’ itself means ‘wanderer’.  Did the planets wander because they moved at will?  Did they possess extraordinary powers? Did they exercise them on humans here on the earth?  Affirmative replies to these questions partly, if not fully, account for belief in astrology.

The work by Kepler and Newton in the 17th century, however, has put the planets in their place, in orbits round the sun with motion, far from being irregular, but entirely calculable.  Today computer programs are available with whose help even a secondary school student can tell where Mars or Jupiter will be at any given time on any day.  Spacecrafts are launched to the moon and the planets with trajectories of split-second accuracy, thanks to the entirely predictable nature of scientific laws – the same laws that so graphically and accurately predicted the collision of Comet Shoemaker-Levy with Jupiter.

Astrology Flourishing

Why then even today we find astrology still flourishing?  For reasons one must look to that part of the human brain that is subjective, not rational.  Belief in astrology may provide solace to the frustrated and hold out hope when by all objective assessment there none.  For the stars (that is, the planets, which in astrological jargon also include the moon and the eclipse nodes) may then provide excuses for human failing and inaction and raise expectations that they will override human control.

While an individual may find mental solace in such beliefs, they are hardly beneficial to society. Think of marriage proposal between otherwise well-suited couples being turned down because their horoscopes don’t match. Or important decision like launching welfare programmes or forming cabinets put of to ‘more auspicious times’.  Or relaxing efforts in the success of an enterprise because ‘stars are favorable’.  I have hopes that in the highly competitive age of science and technology the long battle against superstitions will eventually be won.

Wednesday, 23 May 2012

Were Our Ancient Ancestors Scientifically Advanced?




[This essay, written by the eminent Cosmologist Jayant V Narlikar, first appeared in the April 1985 issue of Science Age, a magazine now defunct, brought out by Nehru Centre, Bombay. Though the essay is almost three decades old, it continues to be as relevant as most of the criticisms on pseudoscience are.

While recommending books debunking pseudoscience,  MassimoPigliucci says in his influential book Nonsense on Stilts - How to Tell Science from Bunk that though the books he recommends are old, one need not worry as pseudoscience never progress. Since the purveyors of pseudoscience almost always recycle the same stale arguments, the criticism raised earlier also continues to be valid. This is true of promoters of pseudoscience in India as well - especially those who make outrageous claims about the so-called "Vedic Sciences"]

Dr Jayant V Narlikar
Image Courtesy:
http://scientistsinformation.blogspot.in/
“Astronomical Vedic Science” by J Arunachalam (Science Age, March 1985) tries to show that the Vedas contain extraordinary scientific knowledge.  Others believe our puranas contain descriptions of things which re scientific and technological inventions of the most sophisticated order.  Was Sanjay in the Mahabharata the first TV commentator?  Were the Kaurava princes test-tube babies?  Were the battles in our mythology fought with guided missiles? Was the Pushpak Viman a helicopter?  These are examples of technology.  But were our Vedic ancestors scientifically advanced?  Did they or their immediate successors employ high technology?  If you believe that the answers to these questions are n the affirmative, you must prove it with scientific evidence.

Let me clarify what I mean by scientific evidence.  For someone to argue that an apple falls down from an apple tree (when it ripens, say, and gets disconnected from the branch) because there is a force of gravity acting on it and pulling it towards the Earth, is not enough.  Not even Newton could have convinced his fellow scientists of the law of gravitation with just that observation.  The law of gravitation has behind it Kepler’s meticulous analysis of observations of planetary motion, Newton’s law of motion, the mathematics of calculus; it has following it such predictions as Halley’s Comet and the discovery of Neptune.  Science, in other words, is not a collection of vague qualitative statements: it rests upon detailed experiments and mathematical foundations.  What is technology?  It is not a folklore of extraordinary objects: it is made of detailed manuals specifying in minute details all the components that go to make such objects.  Scientific evidence should produce such detailed descriptions.

Take the Greek epicyclic theory.  Wrong though it turned out to be, it can be judged as a scientific theory even to day by examining, say, Ptolemy’s Almagest. Detailed geometrical constructions are given the aim of which was to reproduce the observed positions of planets on the sky and to predict where to find them in future. 

Mr Arunachalam complains that “a majority of Indian scientists who know a great deal of Greek science are thoroughly ignorant of Indian science”.  Since he talks of Vedic science, he presumably means that there exists Vedic science in such quantitative details as the above example of Greek science.  Unfortunately, to date, no such detailed description has emerged.

Science makes unambiguous statements based on precisely stated assumptions. Unfortunately, Sanskrit (a language which I know a little and admire a lot) is not a suitable medium for describing science.  It has flexibility of syntax and meaning that can lead to many interpretations being given to the same statement.  A classic example is Aryabhata’s sloka implying that the Earth revolves around an axis against a background of fixed stars.  Since at the time he made the statement, and in the centuries that followed, the geocentric theory held sway, Aryabhata’s successors interpreted this sloka differently.

This being the drawback of Sanskrit, statements in that language depend very much on who chooses to interpret them.  Scientific conclusions are by contrast objective.  When Einstein writes a paper it does not require different interpreters to say what he meant. If he wrote a paper in such ambiguous terms it would not be accepted for publication in any scientific journal.

Arunachalm’s examples from ancient writings are such that they depend very much on the interpreter.  Take for example his translation of the answer to where the Sun gets its energy: “the Sun gets its power from a gas, which is in unlimited quantity.”  Now if modern science had found the Kelvin-Helmholtz hypothesis of gravitational energy (of contractions) as the correct answer to solar energy, this statement could be cited in support of it.  This hypothesis is, however, incorrect and so the same statement could be cited (as Arunachalm presumably intends) as supporting thermonuclear energy.  Further, what does the adjective “unlimited” mean?  The Sun has a large but finite mass. Is this what is implied?  If so, the interpretations are contrived at best. The relationship of the time span of manvantara (300,000,000 years) to the modern estimate of the Sun’s orbital period round the Galaxy is equally farfetched unless the Sun’s motion round the Galaxy is so stated explicitly somewhere.

The Viman-shastra which I had once studied failed to satisfy me on either of the two counts.  In terms of science, it did not give (even qualitatively) the theory of aerodynamic lift that motivates all modern planes.  It did not give any alternative scientific explanation as to why planes fly.  An in terms of technology it did not give a manual on how to make a plane.

It is wrong to read “science” into descriptions that are not scientific texts in the first place. The Ramayana and Kumarasambhava are literary masterpieces. Let us not confuse them with such things as Principia Mathematica or Review of Modern Physics.  As for the Vedas, as Arunachalam says, “traditions hold that even to misspell a word by a single letter is sin” – that is hardly the spirit of science!  Had science followed such a tradition our school children or college graduates would today be reciting Alagest word for word.

In the end I wish to clarify that there have been scientific text in India. The Charaka and Sushruta Samhitas give medical science as known and understood and practiced in ancient India.  The works of Aryabhata and Bhaskara are examples of astronomy text which exhibit clarity (in spite of Sanskrit!).  Leelavatis is an excellent example of a text in arithmetic, algebra and geometry.  Thus it is not necessary to go to Western science per se for examples of ancient science writing.

This makes it all the more important to find scientifically written texts of Vedic times.  Until such text are found, I regret that my answers to questions in my title cannot be in the affirmative.

Share

Twitter Delicious Facebook Digg Stumbleupon Favorites More