Archive for August, 2009

A universal history of astronomy as an educational aid

Posted in Blogs (Articles) on August 31st, 2009 by Rajesh Kochhar – Be the first to comment


Rajesh Kochhar

Invited  talk delivered at XXVII General Assembly of International Astronomical Union  Special Session 4: Astronomy Education between Past and Future, Rio de Janeiro 6 August 2009

A man is wise with the wisdom of his age only,

and ignorant with its ignorance.    -Henry David Thoreau

History is an exercise in constructing the past carried out in the present with an eye on the future. Thus, paradoxical as it may seem , history converts the past into a bridge between the present and the future. As our perception of today and expectations from tomorrow change, our interpretation of yesterday must also accordingly change.

Human beings are an astronomical species. Ever since they learnt to walk upright they have looked at the sky and wondered. The sky has remained the same, but not its meaning. Astronomy is thus simultaneously a state-of-art intellectual enquiry as well as a symbol of the collectivity and continuity of humankind’s endeavours to come to terms with their cosmic environment. This collectivity can be conveniently discussed in terms of a three-phase model comprising (i) propitiatory phase; (ii) negotiatory phase; and (iii) the modern, curiosity-driven, impersonal phase.

To begin with, sky was home to divinities who were to be feared and appeased. As time progressed, human beings felt more secure and became intellectually more alert. Earlier awe made way for curiosity. Sky was now seen as a phenomenon which could be described The knowledge thus gained was employed to renegotiate the equation with celestial bodies. (iii) The third phase nominally began with Copernicus but took off with Galileo. Sky was now the abode of laws of nature which could be discovered and tested. Earlier astronomy had measured angles; now it could ascertain distances. The sky had acquired depth literally as well as figuratively. It is the transition from phase 2 to phase 3 which concerns us here.

Cultural Copernicanism

Post- world war II decades have ushered in an age which we may call the age of Cultural Copernicanism . In analogy with the cosmological principle that the universe has no preferred location or direction, principle of Cultural Copernicanism would assert that no cultural or geographical area or ethnic or social group can be deemed to constitute a superior entity or a benchmark for judging or evaluating others. This principle argues for a Trans-Cultural Civilizational Perspective whereby modern astronomy (or science in general) is seen not as a western brand but as the current phase of human cultural cumulus to which contributions at different times have come from different parts of the world.

This framework however is a recent development. Historiography developed in the long 19th century consciously projected modern science ( including modern astronomy) as a characteristic produce of western civilization, decoupled from and superior to its antecedents, with the implication that all material and ideological benefits arising from it ( and modern technology) were reserved for its authors.

As a reaction to this, the orientalized east has often tended to view modern astronomy as western astronomy , and sought to defend, protect and reinvent its “own” heritage. This defensive mindset works against the propagation of modern astronomy in many non-western countries.

It also warps their own accounts of their history. Those who act can retract, but those who react continue doing so.

Those to whom evil is done

Do evil in return. – W.H. Auden

If we wish to create enthusiasm for (modern) astronomy and teach it effectively, especially in geographical areas which have memories of their astronomical past, we must create links to the past and situate modern astronomy in a more extended evolutionary sequence.

Even for researchers, educators and students in astronomically advanced countries, a universal history of astronomy would be professionally beneficial and culturally satisfying. It will bring home the important lesson that at all times, including today, scientific breakthroughs have taken place only when inputs are received from diverse sources.

19th century historiography:Suggested correctives

There are two aspects to be considered: (A) How Europe constructed its own history of astronomy and (B) how it described earlier developments especially in India and the Muslim cultural zone (MCZ). (I am unable to say any thing about developments , e.g., in China.)

Greek science

My own assessment is that science in Europe would have developed exactly the way it did even if Greek science did not exist. This is because of the dynamism created by maritime voyages and the exorbitant profits therefrom. Europe however took its science’s roots back to ancient Greece. And stopped there. It refused to go into the antecedents of Greek science itself . Hellenic and Hellenistic periods were presented as a monolith so that by association Homer and Aristarchus would reinforce each other.

Greek science could arise only after Alexander. His conquests brought Greeks to the older civilizations of Egypt and Iraq, which had large surplus economies, vast geographical extent, higher levels of practical knowledge and technological advancements. These, when combined classical Greece’s intellectual prowess, gave rise to “Greek science”. But it did not suit Europe of the time to give any credit to Africa or Asia.

Terms like Hindu astronomy and Arab astronomy are isolationist and were intended as such. Moreover they are misleading. The word Hindu was not in use in 500 CE. And .as Ibn – Khaldoon pointed out , “ most Muslim scholars both in the religious and in the intellectual sciences have been non-Arabs”. Unfortunately, these terms continue to be used by sheer force of habit. They should be discarded in favour of purely descriptive terms like Siddhantic astronomy and Zij astronomy.

More generally, serious thought needs to be applied to the vocabulary employed. Words do not have any intrinsic meaning; they carry the meaning given to them. Some terms may appear innocuous to astronomers, but they may carry their own baggage from other area studies.

With reference to earlier epochs, terms like pre-scientific or ascientific astronomy have been employed even in serious literature. In contrast , ethno-astronomy or cultural astronomy may appear more acceptable , but they have their own shortcomings. They appear to be patronizing and an exercise in exoticism. ( All human activity including the modern scientific is cultural)

I have seen the use of term rational astronomy to refer to the modem phase. This seems to suggest that in earlier phases people made a distinction between the rational and the irrational and deliberately chose the irrational!

May be terms like solsticial (equinoctial) astronomy or colure astronomy or cardinal point astronomy can be used, because they are purely descriptive and not tainted by any association.

Incidentally, we routinely use geographical terms like India, China, and Egypt while discussing their antiquity. But an exception is made in case of Iraq which is invariably described in such difficult-to-comprehend terms like Mesopotamia, Babylonia, Chaldea, etc. This tends to decouple modern Iraq from its rich heritage. Why is this so?

Copernicus

Greek science was one of the big bangs for 19th century Euro-centric historiography; Copernicus was another. Some of the earlier accounts give the impression that he was not a product of his time at all , but was merely  taking sides in the  old dispute between Aristarchus’ heliocentrism and Ptolemy’s geocentrism.

Al-Tusi

The common use of a term like Arabic numerals raises the hackles of Indians who consider it to be a case of mis-branding. (This is true. ( Arabic/Persian call them Hind-se’, from India.) But terms like Arabic numerals and Algorithm, after Al-Khwarizmi, draw attention to an important historical fact , namely, arrival of intellectual inputs from MCZ into Europe.

What did Europe do with these inputs? More specifically, did they go into the making of Copernicus? Whether Al-Tusi deserves to be elevated from a lowly , early 19th century, footnote to the 21st century main text needs to engage the attention of present-day scholars, in a non-parochial context.

A universal history of astronomy would transcend patriotisms of all kinds.

Buddhists and Arabs

Arabs were  dismissively told that there role had been no more than as librarians and archivists for preserving  Greek science till Europe was in a position to take its heritage back. And yet, when Indians in their own context pointed out that in earlier times the Buddhists had  worked extensively  on health-related  chemistry , they were told with a straight face that  when their ancient texts mention Buddhist , they probably meant Arabs! Surely Arabs would have liked to hear that. But it was not considered necessary to inform them.

From about 500 CE till Kepler’s time , Indian astronomers were probably the only ones in the world who could calculate an eclipse with any reasonable accuracy. Disdainfully they were told that there was nothing original in their astronomy; it was a tame imitation of the Greeks. Indians did not retort that the only way to build an intellectual tradition is to absorb extant knowledge and build on it. Instead they weakly argued that the Greek borrowing was in astrology and not in astronomy, as if the distinction would have made any sense 2000 years ago.

Indians take pride in the appreciation earned by Indian texts in Baghdad, but are themselves less than liberal in acknowledging the role of Greco-Babylonian inputs around 1st century CE in revitalizing their Vedic astronomical tradition.

Since racial purity is an absolute no-no now , great emphasis is being placed on cultural purity. It is like discovering therapeutic virtues in distilled water.

Unlike the MCZ, Indian astronomical developments did not impinge Europe directly. The main concern of Siddhantic astronomers was the computation of planetary orbits. In the process they solved many equations which as formal mathematics caught Europe’s interest much later. Should they be the concern of only Indian historians?

History of astronomy functions at two levels. At one level we are interested in tracing the historical trajectory which leads to recent developments. But examination of high points that do not lie on the trajectory is also a legitimate field of enquiry. To put it attractively, if history has its compulsions, it also has its romances.

Thomas Godfrey’s 1730 invention of sextant in Philadelphia a year before Hadley invented it “ independently” the next year in England is an example of romance of history . Similarly European pre-history of telescope before Hans Lippershey’s commercial invention in 1608 is a fascinating subject. This line of enquiry should be extended to include similar episodes from other culture areas as well.

To sum up

Astronomy as a modern scientific discipline stands apart from most others in the sense that iy is collaborative rather than competitive. No person howsoever important, no nation howsoever powerful, no observatory howsoever well equipped is permitted a view of the whole celestial sphere.

It is a significant arrangement by nature that to know where you are located on the earth you must take the help of the sky ( stars/satellites).There is a rather obscure theorem in applied mathematics, known as Lichtenstein’s theorem, which tells you that for a rotating body like the earth the distinction between north and south along with the existence of equator is a mathematical fact , but the distinction between east and west is completely arbitrary.

We are all committed to the world-wide propagation of astronomical sciences. I have argued that to facilitate the task we must construct a universal history of astronomy so that every one feels they have contributed to it in the past and must do in the present and future as well.

Even otherwise an inclusive history is good for the world’s general wellness.

Scientist in exile [ Subramanya Chandrasekhar]

Posted in Blogs (Articles) on August 28th, 2009 by Rajesh Kochhar – Be the first to comment

Sunday Times of India, 14 July 1991

Rajesh Kochhar

[This essay reviews Kameshwar C. Wali’s authorized biography of Subramanya Chandrasekhar, titled Chandra. The review was written when Chandrasekhar was still alive. I sent him a copy. His response makes interesting reading. He wrote in a personal letter dated 5 Aug 1991: “It is always interesting to read upon aspects of the book different reviewers select to comment. In this instance, there seems to be systematic difference between the reviewers in the “West” [his quotes]. When the biography came out in paperback, the blurb carried excerpt from this review. Subsequently I published two newspaper articles on Chandrasekhar, which may be seen as companion pieces:

R. Kochhar (1995) Transcending the limits: Chandrasekhar’s stellar contribution. Times of India, 19 Oct.]

R. Kochhar (1999) India-born U.S. astrophysicist. Chandra Observatory: Tribute to a legend. The Tribune, 27 Jul. {Cited in Wikipedia}

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Chandrasekhar symbolises the practice of science at its noblest. A man of integrity, modesty, and exceptionally high standards, he is “the kind of person for whom and through whom the university existed”. His personality, like his mathematics, is self-consistent; there are no kinks, aberrations or loose ends. It is difficult to decide whether his research is an extension of his personality or whether his personality has been mounded by his research.Perhaps there has been a symbiotic relationship between the two.

Chandra’s life story by his compatriot Kameshwar C. Wali, himself a physics professor in the USA, is a labour of love. The biographer has reconstructed Chandra’s life mainly from material supplied by Chandra himself and has added his own comments and notes, at the end, which provide useful background material.

The best part of book starts after the author’s description of Chandra’s life. Entitled ‘Conversation with Chandra’, it describes in Chandra’s own words his thoughts on himself, his colleagues and his times. The book comes alive in these pages through Chandra’s sensitivity and honesty. Of special interest to Indian readers will be his views on men and matters in India.

This is not a scientific biography. As the author says, “it is biography of an individual whom I admired from a distance for many years.” It provides a splendid insight into the working of a great contemporary mind, and can be read with profit by lay persons for enlightenment, and by scientists for introspection.

Chandra – as he is universally known – wrote his first research paper in 1929 when he was an 18-year-old under -graduate at Presidency College, Madras. His uninterrupted research career, spanning six decades and three continents, has been marked by mathematical rigor and elegance. The award of a Nobel Prize in 1983 made him into science’s show boy and he found this rather unbecoming.

Chandra come of age a a time when western education had taken root in India; when modern physics was being founded in Europe; when the Imperial government in India has developed a mild sense of noblesse oblige; and when nationalism was assert in in self.

In 1930, when he was travelling from Delhi to Madras by first class (his father worked for the Railways), an English memsahib loudly expressed her disgust at having to share the compartment with a native, but added that at least he was in European dress. Chandra promptly left the compartment and returned in the typical south Indian dress of shirt and veshti.

Then again, Chandra once missed classes to go and listen to Jawaharlal Nehru who was visiting Madras. The principal, shocked to find Chandra among the “culprits”, exclaimed: ‘you too!’ But this did not prevent the college from creating a special scholarship to enable their brilliant student to go to England. Not surprisingly while the government did not hesitate to create a special scholarship to send Chandra to Cambridge for his PhD it would not create a job for him in India when he wanted to return.

In 1933 Chandra got his PhD and also the Fellowship of Trinity College which, 16 years previously, had been held by another Indian, Srinivasa Ramanujam. He now returned to the important question: what happens to a star once it is has burnt all its nuclear fuel? The leading lights of the day claimed that they already knew the answer: All stars finally retired as earth-sized white dwarfs.

Chandra was the first one to apply the theory of special relativity to understand the behaviour of stars. In his 1930 voyage out of India, he had done preliminary work on the topic and to remove all doubts about the results, he now got down to working out a complete, rigorous mathematical theory without taking any short-cuts.

Chandra found that all stars do not end up as white dwarfs, only low mass ones do. As to what happens to bigger stars, Chandra’s answer must rank as the understatement of the century: “. . . one is left speculating on other possibilities”. No white dwarf can be bigger than the Chandrasekhar mass limite, that is 1.4 times the mass of the sun. The “other possibilities” are the neutron star and the black hole, as even a school student knows today.

In January 1935, Chandra presented his results at the London meeting of the Royal Astronomical Society. He was hoping to be warmly received by the astronomical community for his path-breaking research, little realising what he was in for. Sir Arthur Eddington, the most influential astronomer of the time, stood up to present his own results and tore Chandra to pieces, not by pointing out mistakes in his analysis but by ridiculing him, not by logic but by rhetoric. Sir Arthur did not believe in black holes. With a haughtiness one associates with Viceroys rather than scientists, he declared, “I think there should be a law of nature to prevent a star from behaving in this absurd manner.”

Sir Arthur was blinded by his self-righteousness; the others by the glare of his self-righteousness; the others by the glare of his personality. It was not that one hypothesis was competing with another.It was an exact mathematical theory that was pitted against a refusal to listen. A desperate Chandra tried to enlist support form among the international community of astronomers and physicists. There was however no one who had the time or the courage to sit down with paper and pencil and see through the hollowness of Eddington’s arguments. After four long frustrating years Chandra gave up.

Having pitted himself against the dons of Cambridge and Oxford, young Chandra had no chance of a job in Britain or even Europe. The United States of America offered to take him in: “Out there, we don’t believe in Eddington”. Chandra left Sir Arthur’s England as well as the white dwarfs and headed for the University of Chicago in 1937 where he has remained ever since. He was the first non-white on the faculty of the university, which was, he puts it, “30 years ahead of its time”.

A lesser man would have been traumatized by the experience. But Chandra confronted the situation stoically and raarranged his thoughts. For one, he decided to never become an Eddington himself. He would retain a “certain modesty of approach”, and an open-mindedness. (In 1984, when I wrote to Chandra pointing out a mistake in one of his papers, his reply was warm and prompt; “Publish your results”) The second lesson Chandra learnt from the episode was even more momentous. He would never again try to canvass support for his work. He would let it speak for itself. Mathematics would be his only ally, and time his judge.

In a book that is now a classic, Chandra put down what he knew about white dwarfs and closed the topic. In his never-ending “quest for perspectives”, he would take up a new topic, work on it for a number of years, write a monograph, and move on.

All his work carries a uniform stamp of scholarship. And his later work tends to be the last word on the subject, unlike his early work on the white dwarfs, which was the first word. The first word took a long time to sink in. Chandra has won a number of prestigious awards, but for a long time there was no reference to his white dwarf work. In fact it was only in 1974, 40 years after the work, that a prize mentioned this work.

The belated Nobel Prize in 1983 tried to set things right. His citation refers to the work on white dwarfs “accomplished when he was in his 20s”. As if to compress the intervening time, the citation also mentions two pieces of later work on the relativistic instability of stars done in the ’60s.

It is futile to speculate what course Chandra’s life would have taken if the had won Sir Arthur’s support in 1935. There is, however, no doubt that Sir Arthur’s obduracy delayed the development of the subject by a generation. The recent work on neutron stars and black holes would certainly have been done in the late 30s and 40s as a natural extension of Chandra’s pioneering work.

Chandra has been good for American science. He would drive 100 miles, week after week, to teach a class of two American-Chinese students, both of whom went on to win the 1957 Nobel Prize. He has trained many generations of students and researchers, and taken extraordinary pains to set the standards for astronomical research journals.

Chandra has always kept in touch with India. It was his efforts that brought to light Srinivasa Ramanujan’s passport photograph, the basis for all later photographs, etchings and sculpture. As Chandra says, finding Ramanujan’s photograph has been one of his important discoveries.

From an Indian point of view, it is unfortunate that the country of his birth was not the theatre of his activities. Unlike Har Gobind Khurana who required sophisticated laboratories for his work, all Chandra has ever needed is a library and students. It is not that he did not try, or that India didn’t. He tried before independence, and India afterwards.

The first jog offer to Chandra came from Sir C.V. Raman, Chandra’s father’s younger brother and the director of the Tatas-sponsored Indian Institute of Science (IIS) Bangalore. He was offered an assistant professorship. Chandra’s father’s response was electric: “ My advice is keep out of his orbit.” Having an overbearing uncle in the family was enough of strain. Having him as boss would have been impossible. Not only did Chandra not want a job in his uncle’s institute, he also did not wand it through his influence.

In 1935 Chandra was interested in a mathematics professorship at Government College, Lahore (his birth place). But he withdrew when he came to know about the candidacy of S. Chowla, a personal friend “whose work and abilities I greatly admire”.

Chandra’s election as a Fellow of the Royal Society in 1944 (for which he was supported by Eddington) enhanced his job prospects in India. He was offered the directorship of the Kodaikanal Observatory, for which he was ill equipped. He could not do observational work and did not want to do administrative work. He asked for a comparable post where he would do his theoretical research. Nothing came of it, just as his earlier attempts to find reader’s post at a university had yielded nothing. While sending Chandra to Cambridge was good for Cambridge, creating a job for him in India would have been good for the Indians but Imperial Government was not interested.

A positive offer came from Dr Homi Bhabha in 1951 when he was building the Tata Institute of Fundamental Research (TIFR) Bombay. Chandra was tempted, but not strongly enough. Soon after, he became a US citizen, and conditions changed drastically. In 1961 the CSIR, on instructions from Jawaharlal Nehru, offered him a national professorship, provided he relinquished his foreign citizenship.

Again, in 1963 when Dr Bhabha died, the government, forgetting that Chandra was no longer an Indian citizen, offered him the chairmanship of the Atomic Energy Commission. Of all the offers Chandra received, the most attractive was Dr Bhabha’s Looking back, he now feels that perhaps he should have accepted it, but at the time he was not quite sure whether he would fit in.

Chandra had had a ringside view of Indian science, first as Sir Raman’s nephew and then in his own right, and he did not like what he saw. The Trimurti of Indian physics: Raman, Meghnad Saha, and S.N. Bose, especially the first two, were always at each other’s throats. K.S. Krishnan, who worked with Raman but did not share the Noble Prize, was Chandra’s friend. (Chandra later obtained a copy of his diary for the Royal Society.)

Chandra liked Dr Bhabha and his cosmopolitanism but was dismayed by his autocracy. Once when Wolfgang Pauli and other foreign scientists came to India, they were transported in a bus. Dr Bhabha followed them in his limousine. An enraged Wolfgang Pauli left the country the next day.

Chandra did not want administrative power, but was not sure whether he would be academically free if he did not occupy the top slot himself. Raman’s advice was blunt: “Don’t play second fiddle”. The very fact that the concept of “first or second fiddle” existed put Chandra off.

The Chandra of British India had to leave his country for the sake of science. And the tragedy of independent India lies in the fact that if a Chandra, who wants academic freedom without administrative power or interference, were to appear today, he would still have to go into exile.

Was Raja Jai Singh a plagiarist ?

Posted in Blogs (Articles) on August 28th, 2009 by Rajesh Kochhar – Be the first to comment

The Tribune , Chandigarh, 7 January 1999

Rajesh Kochhar

The name Jantar Mantar, sounding like hocus-pocus, would have pained Raja Sawai Jai Singh. The quaintly shaped buildings at Delhi and Jaipur that would have intrigued many a passer-by are in fact scientific instruments improvised and built, at least as wax models, by Jai Singh himself in the 1720s and 1730s.

Jai Singh was not a sovereign ruler. He was a high-level mansabdar (official) in the Mughal administration, paid for his services by the allotment of his vatan (native) jagir retrospectively called Jaipur and other transferable jagirs. He was a key player in the politics and intrigue of his turbulent times. He was also a skilled astronomer. Astronomy was his passion and, one suspects, his refuge. The Delhi observatory commemorates, in a way, the restoration of order if not leadership under emperor Muhammed Shah. Jaipur with its observatory symbolises Jai Singh’s dreams of making personal peace with the menacing Mahrattas and carving out a bigger niche for himself. Jai Singh was thwarted in his political ambitions. It now turns out that history’s verdict on his astronomical enterprise may not be any the less harsh.

Historically, the most outstanding feature of Jai Singh’s astronomy is its anachronism. Though he came on the scene a hundred years after Galileo and 50 years after the setting up of the Paris and Greenwich observatories, his role model was the 15th century king-astronomer Ulugh Beg, the more revered for being a collateral ancestor of the Mughal dynasty. Jai Singh came to know about the telescope, but did not view it as a revolutionary break with the past that is was. To him the modern astronomers were Europe’s Ulugh Begs with whom he wished to interact and compare notes.

In 1732, after the more- or- less completion of his masonry observatories Jai Singh received a valuable gift from the king of Portugal. It was a copy of the 1702 astronomical tables prepared in Latin at Paris by Phillipe de La Hire. Jai Singh brought out his own set of tables, or Zij. In his preface dedicating it to the emperor, Jai Singh declared that he had found that La Hire’s tables did not agree with his own observation and that his own tables were an attempt to “arrive as near as possible at the truth”.

Contemporaneous accounts cast aspersion on the validity of Jai Singh’s claims to originality.A French astronomer, Joseph Dubois, employed at the Jaipur observatory, was asked to prepare a copy of La Hire’s tables. In his preface to the tables, also written in Latin, he noted that Jai Singh had got La Hire’s tables “transcribed in his own script” and that he had “ordered all his astronomers to make calculations by them”.

A more explicit statement came from the Jesuit father Francis Pons who spent some years in Jaipur. He wrote in 1740 that “The Tables of M. de La Hire, under the name of this Prince, will be in use every where”.

The actual comparison of Jai Singh’s Zij with La Hire’s tables had to wait for another 250 years. An astronomical table is an intricate mix of observations, available data and tedious calculations. If two tables are independently prepared, their entries will be unrelated to each other. Recently, a British historian of astronomy, Raymond Mercier, has shown that the entries in the two tables are not un-correlated.

Take a number quoted by La Hire for the position of, say , the sun or moon. Now carry out a two-step mathematical transformation: change the epoch from 1 January 1 to 20 February 1719, the nominal date of ascension of Muhammad Shah to the throne. In the second step, change the longitude from that of Paris to the longitude of Jaipur. You obtain the corresponding number listed in Jai Singh’s Zij!! Obviously, as a homage to Jai Singh’s own pet city, the calculations were carried out for Jaipur; but as a concession to the empire’s city they were listed as if the actual observations had been made at Delhi.

Jai Singh died in 1743. The Delhi observatory was ransacked by the Jat leader Suraj Mal’s son Javahar Singh. Perhaps the most telling comment on Jai Singh’s anachronistic astronomical efforts comes from the rather disconcerting fact that his grandson at Jaipur used the ancestral 400 kg brass astrolabe for target practice.

The story can be summed up simply: A part rajah-part scientist creates a scientific facility with great fanfare. But then takes the easy way out and borrows data from abroad. His successors abandon the facility altogether, creating a ruin.

What makes the story rather unsettling is that it does not merely describe the India of the early 18th century but perhaps also the India of the later 20th century.