A Meta-History of India’s Space Science

IN THE EARLY part of Kalidasa’s narrative-verse called Meghadutam (the Cloud Messenger), a certain lovelorn yaksha (a demigod) asks the passing clouds to carry a series of messages for his wife in the celestial city of Alakapuri, where she awaited his return. The clouds become companions to the yaksha’s loneliness as well as an apostrophic plot device in the hands of an expert poet. In his messages, the yaksha describes the geographies of ancient India with his florid similes and tender exaggerations, yet his entreaties also were an exile’s quest to impose meaning on the strange new world that he found himself in. A world brimming with humans and festivals, gods and forests, tumultuous rivers and adulterous loves. What follows in the composition are some of the most wondrous lines in Sanskrit—a confection of sounds and rhythm. What is often missed in this cornucopia of Sanskrit poetry is that there is also ensconced in the narrative another voice: a more sceptical voice, one that is a stand-in for both the reader and, perhaps, even Kalidasa himself. This voice wonders within the poem about the absurdity of speaking to a cloud. The unnamed narrator of the poem asks how can the clouds, which are nothing but a concatenation of vapour, water and wind (‘dhuma jyotih salila marutam’), an assemblage of non-sentience, carry any message, far less become a messenger of complex imageries uttered by the yaksha. It is as if the poet acknowledged the thin ice upon which the narrative was premised and shrewdly defanged any putative criticism about the lack of reality by offering up a minor note of protest on behalf of empiricism in the poetic imaginary that was to unfold.

In much of traditional Indian texts, this contrasting duality—the empirical and the imaginative—is often a standard move, a readymade device to inject narrative tension. It reveals either as subtly as in Meghadutam or more explicitly in plays with prescribed roles for the vidushaka (the jester, a proto-Shakespearean fool who injects philosophical pessimism in the name of reality in contrast to the preening hero). A millennium before Kalidasa wrote his text, as David Shulman writes and translates, in the Vedic sacrifices we see such contrasts formalised in ritual: the officiating priest ‘thinks’ the ritual (tad yat kim cemani bhutani mansa sankalpayanti tesam eva sa krith—whatever these living beings imagine in their minds is performed) while others in the priestly order go about the ritual of the sacrifice. In old Tamil imagination, this duality emerges as a way to contrast the poet’s inner temple (akakkoyil) with the king’s outer temple (purakkoyil). Kalidasa, when viewed in this wider context, was merely borrowing and reiterating a traditional way of conceptualising any reality as a totality rather than as a mere assemblage of discrete parts. A totality that in 1953 was described by CP Snow, in language we now recognise, as comprising two cultures: the sciences and the humanities.

It is this commingling of empiricism and the poetic that makes the writing of the history of India’s long abiding fascination, reverence and fear of the skies, astral objects and space—in essence, the history of India’s astronomical sciences—particularly difficult. A priori, such a history faces a (seemingly) contradictory challenge. Unlike in the West where the sciences and materialist thought shared an uneasy coexistence with the Church, in ancient India the distinctions are subtler. A historical retelling of ancient Indian sciences must distinguish between histories of Indian materialist thought—which had little use for analytical or mathematical techniques and were often philosophical in nature—versus the histories of Hindu religious practice and thought—which developed analytical techniques to construct theological claims to impose order upon the world. Trying to parse the lineaments of this complex landscape where religious claims, astronomical speculations, mathematical techniques and historical borrowings come together to make unified claims is tricky business. A simple example suffices to show the challenges involved.

The Shatapatha Brahmana—a text brimming with chants, spells, incantations and stipulations—describes that speech (vaak) congeals into a physical presence as 36,000 fires. Why 36,000? The answer is linked to the incipient use of calendars: every year was assumed to be 360 days and every fully lived human life comprised 100 years—thus, 100×360 days. Each day of a fully lived life was therefore meant to be animated by a specific fire, a particular manifestation of human mind that expressed itself through speech. One could very well be satisfied with this sort of explanation. But a deeper question stares back: why did ancient Indians arrive at the idea of 360 days per year? Some like the scholar David Pingree have argued that early Vedic calendars and astronomy were entirely borrowed from Mesopotamia on the basis of a single, incompletely available recension of an older text called Yavanajataka. Subsequent scholarship, led by the scholars KS Shukla and Harry Falk, demonstrated that this claim was due to misreadings and force-fitting evidence to arguments proffered by old scholarship. More recently, the historian Bill Mak demonstrated that the historical truth of this claim of borrowings—like Dharma—is subtle and ultimately more study was needed to address this question. To make matters more complex, there also follows the question of why did some other religious texts believe in adding a 13th month in a five-year cycle to arrive at an average of 366 days per year (5×360+30=1,830 days divided by 5 years). Finding the answer requires both imagination and a patient reading of obscured texts and tablets. What this simple example reveals is the complexity of trying to discern the fundamentals of how Indian scientific thought came about.

Irrespective of such controversies in relatively arcane corners of scholarship, what is almost a foundational article of faith is that the history of Indian sciences is also a history of influences between schools and individuals within India, as well as a give-and-take across cultures—Greeks, Mesopotamians and Persians. But the record of these influences is often only available in commentaries, digests and expositions which were written centuries later. Before long, like Alice down a rabbit hole, any historian finds himself chasing ancient calendars, conjecturing on the migration patterns of ideas, translating algorithms deployed into modern vocabulary—all of these in languages underscored by inflections and innuendoes that are by now largely foreign even to scholars.

DESPITE ALL THESE challenges, the history of India’s upward gaze into the skies is also a history of imposing theoretical frameworks to make the infinity of space more manageable. Nowhere is this seen more frequently than in our astronomically informed calendar. Time was typically cleaved into twos—the nycthemeron was divided into night and day, the month into two phases of the moon (shuklapaksha and krishnapaksha), the year into two journeys of the sun (uttarayana and dakshinayana)—even as discourse developed on both ends: the small time frames of muhurtas, naadi, tithi, praana versus the vast and cyclical epochs that ran into millions of years. The five main schools involved were the Brahma, the Arya, the Ardharaatrika, the Saura and the Ganesha: the main difference between them was the estimated rotations of planets within each vast cyclical enclosure of time and creation called kalpa and, therefore, the difference between parameters used in specific models. Loosely speaking, all astral bodies were subject to two calculations: a ‘theoretical’ (mean) estimate and the empirically observed (anomalous) location. It was deemed that the reason planets drifted from their theoretically calculated mean paths was because of ‘demons’ who pulled these astral objects by cords of wind. What is important to recognise is that even by the high Vedic period, around 600 BCE to 400 BCE, an elaborate analytical infrastructure that involved recursive computations, error minimisation algorithms, parametric drifts was in place. These calculations were used to compute time of festivals, temporal frames of auspiciousness, cast horoscopes and, more fundamentally, enable continuity in locating one’s place in a world that still largely comprised forests, darkness and the unknown.

In the absence of writing as a technology, much of the early part of this increasingly complex enterprise relied on memory to transmit knowledge across generations. But memory’s fickleness resulted in an elaborate formalisation of mnemotechnics that relied on unbroken recitations, rules to model the structure of sound and ultimately a careful arrangement of euphony itself. A simple example from the Agnicayana rituals (courtesy Frits Staal) makes some basic mnemotechnics more vivid for present purposes. A standalone fragment like agnih nah yajnam upa vetu (Agni, may he come to our ritual) is transformed at the boundaries of each word to sound like agnir no yajnam upa vetu. By transposing agnir for 1, no for 2 and so on, one recitation algorithm may be ‘1 2 2 1 1 2 3 3 2 1 1 2 3’. Thus, we get a recitation that sounds like agnir no no’gnir agnir no yajnam and so on. The result of such a mnemotechnic is an increased reliance on abstraction and developing a metacognition about how to modify certain parameters to arrive at newer incantations. What follows is less focus on the content of the utterance than on the aural shapes they acquire. (The great Austrian philosopher of language Ludwig Wittgenstein wrote in the 20th century, ‘You might say that certain words are only pegs to hang intonations on.’) Whereas Romans used techniques of ‘memory palace’ (about which the great Frances Yates has written evocatively) which relied on association between objects and words, in the Vedic ritual narrations—recorded in associated texts called pratisaakhya—what also acquired importance was the relationships, movements and dynamics of sounds. Like learning to adjust the parameters in sinusoidal calculations (called manda-jya and sighra-jya) through practice and labour, these mnemotechnics had an element of the counterintuitive that could only be mastered by long practice. The upshot of such techniques is that they acted as a template for knowledge dissemination—where newer material could be tacked on preexisting formats. Anomalies lay not in new content but in failure to comply with extant structures of memorialisation.

AMONG THE EARLIEST of such evidence of transposition and borrowings is seen in Lagadha’s Vedangajyotisha, composed around the time of the Achaemenid Empire in Gandhara. Certain stylistic innovations within it are similar to Pingala’s Chhandahsutra which uses nakshatras (star clusters) as markers within the text. This technique of using astronomical markers to annotate texts has a surprisingly long history and is worthy of a historical survey by itself. Perhaps nowhere is this technique of recording dates seen better than in the text of mathematical astronomy called Tantrasamgraha by Nilakantha Somayaji from 16th century Kerala. In the latter text, two Sanskrit phrases he vishno nihitam krtsnam and lakshmisanihitadhyanaih act as beginnings and endings of the mathematical treatise. An unsuspecting reader would think of these fragments as merely religious invocations that marked many such texts in the 16th century. However, thanks to the mathematician Sankara Variyar in the 16th century, we learn that upon using the Katapayadi schema (words are transposed to numbers) these phrases annotate the kali-ahargana (the number of days since the Kali Yuga commenced). Thus, we learn that the Tantrasamgraha was composed between 1,680,548 and 1,680,553 days after the Kali Yuga began, which translates to March 22nd, 1500, and March 27th, 1500—a stunningly short period to compose a text of mathematical astronomy.

But we are often not lucky to have dates explicitly spelt out by the text. The time span between Lagadha’s Rig Vedic recension of Vedangajyotisha and Nilakantha’s Tantrasamgraha was nearly two millennia, during which religions like Buddhism rose and fell, Islam arrived in India along with the Arabian breeze and as whirlwinds through the Khyber, and intellectual thought underwent extraordinary ferment. To tell a fully fleshed history of Indian sciences is thus intimately linked not just to the history of transmissions—oral or textual—but also to the history of evolving complexity of topics under investigation. Concurrently, the history of Indian sciences is also a history of extraordinary gaps (in contrast to the ongoing project called History of Philosophy Without Any Gaps). The great scholar of ancient astronomy Kripa Shankar Shukla writes, ‘Practically no scientific work of intervening period ranging from c 500 BCE to c 500 CE is available.’ Those that survived, as mentioned, were often religious texts in which we find analytical techniques. Yet mysteriously, as if the goddess Saraswati had decided to throw a lifeline to future historians of science, around 500 CE there appeared the singular figure of Varahamihira, who was an extraordinary compiler of analytical techniques that now allow us a glimpse into the scientific mind around the age of the Gupta dynasties. For reasons not fully understood, it led to an efflorescence of textual learning. Various types of texts, including the siddhantas which were often algorithms to compute theoretical paths, the karanas which included more localised calculation around the time of composition and koshthakas which were tabular summaries, appear. Some like the siddhantas were models of economy and algorithmic terseness, others like koshthakas had distant ancestors in the star catalogues we first see nearly a millenium earlier in Mesopotamia such as the Three Stars Each tablets which spoke of the water god Ea, the sky god Anu and the wind Enlil. What Varahamihira does—an extraordinary service to all posterity—is he summarises the five siddhantas of his time into a treatise called Panchasiddhantika. Among these were included the Romaka and Saura siddhantas which, according to KS Shukla, ‘bear traces of the Greek influence’. If Varahamihira played the role of a diligent compiler that provided ballast to the renaissance of Hindu astronomy, Aryabhata I was its most luminous expression. He left behind not just treatises, but also inspired subsequent generations (Bhaskara I and others) to either modify his work or set the stage for others (Brahmagupta and others) to devise entirely different methods of modifying parametric constants relevant for mean calculations. Perhaps, Aryabhata I’s longest surviving contribution was the nearly hundred-year long research agenda that his work inspired, which found its most original expression in the trigonometric power series devised by the Kerala school of mathematics before Newton and Leibnitz.

All of this may lead one to think the histories of Indian science are merely a matter of listing names, studying their texts and attempting to draw some linkages. Yet, the reality of such seemingly ‘humble’ goals is imperiled by confounding factors. Recensions abound of a single text across geographies and the construction of critical editions and bibliographies requires great knowledge accompanied by a detective’s skill to unearth obscure linkages. Some texts are no longer preserved or available in Sanskrit, rather only commentaries about them survive in languages that are in medieval versions of modern-day languages (the mathematical text by Jyeshtadeva called Ganita Yuktibhasha, translated as Rationales in Mathematical Astronomy, is in the Malayalam of the 16th century and with the pioneering translations of KV Sarma and annotations by K Ramasubramanian, MD Srinivas and MS Sriram). Often, abject disregard for autobiographical detail adds to the challenge of dating texts, even ones that were ostensibly written closer to our times (the Karana-paddhati of Putumana Somayaji is even today described as being written sometime between the 15th and 17th centuries). More perverse, from a modern perspective, is the method of naming texts solely by eponymous means that references ancestral homes, gotra of the writer, lineage of a writer and so on—which makes mockery of any modern conceit that a text can be reduced to singular authorship. In the absence of well-informed local histories, any attempt to contextualise with details about the social environs in which these texts appeared remains a forbidding challenge. To round up this litany of seeming insurmountables, there is also the saturnine reputation of astrology that a modern scholar must learn to overcome to study and understand ancient astronomy itself. The economist John Maynard Keynes wrote of Isaac Newton, who was a more fervent alchemist than perhaps a mathematician, that: ‘Newton was not the first of the age of reason. He was the last of the magicians, the last of the Babylonians and Sumerians.’ Similarly, almost all of our ancient masters of analytical techniques were also proficient users of astrology and other occult. To study ancient mathematical astronomy and write the history of Indian science inevitably also means studying variations in astrological terminologies and descriptions on one hand alongside with techniques from modern spherical astronomy such as occultation of stars by the moons. This demand on scholarship is not an Indian problem but rather a problem of studying antiquity and medieval science. The great Austro-American scholar of Babylonian mathematics Otto Neugebauer wrote many years ago: ‘No Arabic astronomer can be fully understood without a thorough knowledge of astrological concepts.’

These difficulties notwithstanding, two other great unknowns face any retelling. One is to understand the absence of drawings in most manuscripts. Unlike Hellenistic Greeks or later Latin Church Fathers, Indian sciences relied extraordinarily on formulae and hypothesis and rarely on diagrammatics. Perhaps this has to do with lack of paper or parchment for writing and the difficulties of using palm leaves to record writings. Or, it was perhaps because the art of drawing structures belonged to the domain of experts in the field of carpentry, masonry and architecture and thus the provenance of a different set of practitioners. The other is more consequential for the history of Indian science: the lack of experimental devices or automatons or tools to aid observations. As KS Shukla writes, ‘The Hindu astronomers did not possess the telescope.’ This is however not to be understood as that Indians merely engaged with theory and had no history of mechanised instruments. On the contrary, there are well recorded instances of objects like ghatika—a time-keeping device from 4th CE—which was described by Aryabhata I in his Aryabhatasiddhanta and used by astronomers and common folk alike. In it, we also find mentions of yantravalaya, ‘a spherical instrument’, that may have aided observations as well. Likewise, Varahamihira’s Panchasiddhantika also describes astronomical instruments. Mentions of clever automatons (yantras) abound and much of these were intricate arrangements of pulleys and presses that used water as a source of kinetic energy. In a landmark survey by the scholar V Raghavan, we learn about a bewildering assortment of water presses, war machines, water horses, talking dolls, fountains, etcetera which were in due course classified and their lore spread into popular narrative. Be it in the works of Dandin the playwright or King Bhoja of the Paramaras in the city of Dhara, early medieval literature often spoke about a variety of machines, automatons and labour-saving devices. Bhoja, according to the scholar Daud Ali, goes on to classify machines as those which are self-driving (svayamvahaka), need periodic propulsion (sakrtprerya), are invisibly driven (antaritavaahyam) and far travelling (vaahyam duratah). Despite this demotic culture of technology that seemingly thrived well into 10-11th centuries—there seems to be an element of play in these texts, a quality of tinkering with contraptions no different than the early phases of the Industrial Revolution—it was not until 1651 that the first telescope is recorded as being used for scientific purposes in India to observe the transit of Mercury out of Surat. For a culture that was quite open up to the 11th-12th centuries in scientific, astronomical and astrological exchanges with the Persian and Arab worlds, a remarkable decline begins in the centuries thereafter. Enclaves like the Kerala school of mathematics survived by refining and inventing new techniques for computation and mathematics, but after Bhaskara II wrote his Siddhantasiromani in 12th CE, astronomical sciences slowly decline. It is as if the maximal extent of our skygazing by the naked eye was exhausted—perhaps ownig to the lack of telescopes or artisans involved in lenses and glasses. Any history of Indian science thus has to also try to discern how a technical and scientific culture began to withdraw, look inwards instead of growing and expanding its prowess. What social constraints—caste, language, patronage, political upheaval—led to this quiescence of Indian sciences?

There are other challenges as well. Any history of Indian science up to the advent of colonisation runs the risk of portraying the whole enterprise as an organised, coherent exercise where progress was incrementally achieved. In parts, our ability to interpret the growth of scientific knowledge is influenced by a certain form of triumphalist narratives that abound in the traditional description of the Scientific Revolution in Europe upon which a tyranny of coherence is imposed. (In more recent years, the pendulum has swung the other way and now the entire scientific enterprise of the early modern Europe is interpreted as merely a set of ‘cultural practices’ to control the natural world.) How are we to understand the age that followed Aryabhata I to Bhaskara II—nearly 600 years of technical refinements, cross pollination of ideas and clusters of knowledge centre? As a revolution, a renaissance or merely an archipelago of loosely connected innovations on which we now force fit a narrative shape?

IRRESPECTIVE OF HOW we choose to describe this period of our scientific history, the reality of it is that we still know very little of our scientific past. In a recent lecture, an economist and eminent translator of Sanskrit estimated that over 40 million manuscripts lay about in various archives and private libraries of which 95 per cent remain untranslated; of the 5 per cent which have been translated, only a few have been annotated to the standards of modern scholarship. If we assume that only 0.5 per cent of those 40 million are related to scientific and technical matters, this translates to 200,000 manuscripts, an amount that should leave a few generations of scholars actively occupied. As David Pingree writes, ‘The exploration of the millions of surviving Sanskrit and vernacular manuscripts copied in a dozen different scripts would probably reveal a number of other Madhavas whose work deserves the attention of historians and philosophers of science.’ In fact, in many senses we are like the British in the 19th century who discovered Sankara Varma’s 1823 trigonometric work called Sadratnamala and didn’t know what to make of such works. Our social, intellectual and cultural establishment, barring a handful of scholars, no longer knows how to study such works.

None of these potential discoveries however helps address the more fundamental questions of how to think about our scientific past and the actors who were involved in it. Who were these people who went about stargazing, constructing algorithms, painstakingly calculating figures to construct calendars? What were their inner lives like? To an extent, much of this is unknowable and we enter the world of poetic imagination. The great Irish novelist John Banville wrote a tetralogy of scientifically fascinating and psychologically intricate novels where Copernicus, Kepler, Newton and Dr Faustus are the protagonists and struggle in the face of self-doubt as they wage battles to retrieve universal laws from the skies. Few Indian literary minds however have attempted a deeply imagined novel about Varahamihira or Aryabhata or Madhava. In parts, this reluctance to head down this path is due to the mathematical ignorance of our literary class and lack of adequate material for non-specialists; but there are also deeper psychological wounds in Indians as a people that can only express itself as malignant neglect or as witless triumphalism when faced with the history of Indian science. The role of novelists, of imagination in preparing the groundwork for an entire culture to take its past seriously, to study it more rigorously cannot be understated. If there is any lesson to learn from the lives of Aryabhata or Nilakantha, as distant as they are to our sensibilities, it is the need to recognise that knowledge which survives across generations is born from mastering the grammar of the discipline while still subjecting it to empirical verification. What will then follow is the ability to make imaginative leaps. For us, separated as we are by centuries, the challenge is to ask more rigorous questions about how we should write about this practice of knowledge production—an activity that survived and thrived over generations. To do so, we will need to put aside the sociopolitical needs of the present so that we may intuit the shadows of a long forgotten past as truthfully as we can.

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