History of the Physical Sciences in India

In all early civilizations, the study of the physical sciences was neither formalized nor separated from other branches of knowledge. And at least initially, there were few conscious attempts to study the theory of science independently of the practical innovations and technologies that required some application of scientific principles. In most cases, technological discoveries took place without any knowledge of the underlying scientific principles, through hit and trial, and by experience. Sometimes there was a vague or approximate awareness of the science, but the predominant focus remained on the utilitarian aspects of the technique, on practical efficacy, as opposed to how and why something worked or didn't work.

In India, the earliest applications of chemistry took place in the context of medicine, metallurgy, construction technology (such as manufacture of cement and paints) and in textile production and dyeing. But in the process of understanding chemical processes, there also emerged a concomitant interest in attempting to describe the basic elements of matter - what they were composed of, and how they interacted with each other to produce new substances. Natural phenomenon were studied in the context of tides, rainfall, appearance of the sun, the moon and stellar formations, changes in season, weather patterns and agriculture. (For instance, Vedic literature mentions the condensation of water vapour from seas and oceans due to evaporation (caused by the sun's heat) and the subsequent formation of clouds and rain.) This naturally led to theories about physical processes and the forces of nature that are today studied as specific topics within the fields of chemistry and physics.

Philosophy and Physical Science

While it is hard to say which precedes which - theory or practice - clearly there is a dialectical relationship between both, and the neglect of either leads to the death of science. Religious beliefs, particularly religious taboos and irrational indoctrination towards mystical or magical phenomenon, or adherence to false superstitions can often pose as serious impediments to the advance of science, and play an important role in whether the why and the how of physical causes can be safely and usefully explored.

Societies that believed that only the "gods" knew the secrets of nature, and that it was futile for humans to attempt to unravel the mysteries of the universe were naturally incapable of making any substantial progress in the realm of the sciences. Even in societies where there were no formal religious taboos in understanding real-world phenomenon in a scientific way, the power and the influence of the priests could serve as an obstacle to scientific progress. For instance, in a society where ritual practices alone were considered sufficient in achieving desired goals, there would naturally be little scope for serious investigation into the properties and laws of nature.

While ancient India did not generally suffer from the first affliction (of religious opposition to science), it did suffer from the second (the proliferation of rituals and superstitions). The progress of science in India was thus inextricably linked to challenges to the domination of the priests, and resistance to the proliferation of rituals and sacrifices. It was necessary to at least argue that rituals alone were insufficient in producing desired results, and that some measure of rational observation of the world was necessary in shaping human destiny. It is therefore no accident that, by and large, developments in science and technology came in parallel with the advance of rational philosophy in India. (See Development of Philosophical Thought and Scientific Method).

In the earliest scientific texts such has those of the Vaisheshikas (6th C BC or possibly earlier), (see Philosophical Development from Upanishadic Theism to Scientific Realism), there was a rudimentary attempt at recording the physical properties of different types of plants and natural substances. There was also an attempt at summarizing and classifying the observations made about natural phenomenon. Intuitive formulations and approximate theories about the composition of matter and physical behavior followed. Thus, although the earliest applications of physics and chemistry in India (as in other ancient societies), took place without involving much theoretical knowledge or insight into these branches of science, there were elements of basic scientific investigation and scientific documentation in these early rational treatises. Primitive and tentative as these steps were, they were nevertheless crucial to humanity reaching it's present stage of knowledge in the fields of physics, chemistry, botany, biology and other physical sciences.

Particle Physics

Although particle physics is one of the most advanced and most complicated branches of modern physics, the earliest atomic theories are at least 2500 years old. In India, virtually every rational school of philosophy (whether Hindu, Buddhist or Jain - see Philosophical Development from Upanishadic Theism to Scientific Realism) had something to say on the nature of elementary particles, and various schools of thought promoted the idea that matter was composed of atoms that were indivisible and indestructible. Later philosophers further elaborated on this notion by positing that atoms could not only combine in pairs (dyads) but also in threes (triads) - and that the juxtaposition of dyads and triads determined the different physical properties of substances seen in nature. The Jains also postulated that the combinations of atoms required specific properties in the combining atoms, and also a separate "catalyst" atom. In this way, the earlier atomic theories became converted into a molecular theory of matter. While many details of these theories no longer stand the test of scientific validity, there was much in these formulations that was conceptually quite advanced and sophisticated for it's time.

{Although it may be just a coincidence, but the development of the Jain molecular theory appears to parallel practical developments in other fields such as medicine or metallurgy where the vital role of catalysts had been observed and carefully documented. Indian medical texts had postulated that proper human digestion and the successful absorption of medicinal pills and potions also required the presence of "catalytic" substances. The requirement of catalytic substances relating to the manufacture of acids and alkalis (relevant to medicinal and surgical applications) had also been documented, as had the role of suitable catalysts in metallurgical processes, and in the manufacture of color-fast dyes. (Today, much more is known about catalytic processes, as a variety of minerals, vitamins and enzymes have been identified as playing a key role (as catalysts) in a range of essential chemical processes that take place in our bodies, as do catalytic compounds in other physical processes).}

Atomic/molecular theories were also utilized in (albeit speculative) explanations of chemical changes caused by heat. Prasastapada proposed that the taijasa (heat) factor affected molecular groupings (vyuhas), thus causing chemical changes. Two competing theories attempted to provide a more detailed explanation of the process (as applied to the baking/coloring of a clay pot through firing): the Pilupakavada theory, as proposed by the Vaisesikas held that the application of heat (through fire, for instance) reduced the molecules of the earthen pot into atoms; and the continued application of heat caused the atoms to regroup creating new molecules and a different color. The Pitharapakavada theory offered by the Nyayikas (of the Nyaya school) disagreed, suggesting that the molecular changes/transformations took place without a breakdown of the original molecules into basic atoms, arguing that if that happened, there would also have to be a disintegration of the pot itself, which remained intact, but only changed color.

An intuitive understanding of kinetic energy appears in the texts of Prasastapada and the the Nyaya-Vaisesikas who believed that all atoms were in a state of constant activity. The concept of parispanda was propounded to describe such molecular/atomic motion, whether it be whirling, circling, or harmonic.

Optics and Sound

The earliest of the Indian rationalists also attempted to provide theories on the nature of light and sound. Like the ancient Greeks, the eye was assumed to be a source of light by the early Indian philosophers, and this error wasn't corrected until the 1st C AD when Susruta posited that it was light arriving from an external source at the retina that illuminated the world around us. (This was reiterated by Aryabhatta in the 5th C). In other respects, the earlier philosophers were more on the mark, with Cakrapani suggesting that both sound and light traveled in waves, but that light traveled at a much higher speed. Others like the Mimamsakas imagined light to comprise of minute particles (now understood to be photons) in constant motion and spreading through radiation and diffusion from the original source.

The wave character of sound was elaborated on by Prastapada who hypothesized that sound was borne by air in increasing circles, similar to the movement of ripples in water. Sound was understood to have its own reflection - pratidhvani (echo). Musical pitches (sruti) were seen as caused by the magnitude and frequency of vibrations. A svara (tone) was believed to consist of a sruti (fundamental tone) and some anuranana (partial tones or harmonics). Musical theory was elaborated on the basis of concepts such as jativyaktyoriva tadatamyam (genus and species of svara), parinama (change of fundamental frequency), vyanjana (manifestation of overtones), vivartana (reflection of sound), and karyakaranabhava (cause and effect of the sound).

In the 6th C. Varahamihira discussed reflection as being caused by light particles arriving on an object and then back-scattering (kiranavighattana, murcchana). Vatsyayana referred to this phenomenon as rasmiparavartana, and the concept was adapted to explain the occurrence of shadows and the opacity of materials. Refraction was understood to be caused by the ability of light to penetrate inner spaces of translucent or transparent materials and Uddyotakara drew a comparison with fluids moving through porous objects - tatra parispandah tiryaggamanam parisravah pata iti.

(Al Haytham (b, Basra, worked in Cairo, 10th C) who may have been familiar with the writings of Aryabhatta, expounded a more advanced theory of optics using light rays, diagrammatically explaining the concepts of reflection and refraction. He is particularly known for elucidating the laws of refraction and articulating that refraction was caused by light rays traveling at different speeds in different materials.)

Astronomy and Physics

Just as the study of Mathematics in India received an impetus from the study of astronomy, so did the study of Physics. As mentioned in the essay on mathematics, Aryabhatta (5th-6th C) made pioneering discoveries in the realm of planetary motion. This led to advances in the definition of space and time measuring units and better comprehension of concepts such as gravitation, motion and velocity.

{For instance, Yativrasabha's work Tiloyapannatti (6th C) gives various units for measuring distances and time and also describes a system of infinite time measures. More significantly, Vacaspati Misra (circa AD 840) anticipated solid (co-ordinate) geometry eight centuries before Descartes (AD 1644). In his Nyayasuchi-nibandha, he states that the position of a particle in space could be calculated by assuming it relative to another and measuring along three (imaginary) axes.

The study of astronomy also led to a great interest in quantifying very large and very small units of time and space. The solar day was considered to be made up of 1,944,000 ksana (units of time), according to the Nyaya-Vaisesikas. Each ksana thus correspnded to .044 seconds. The truti was defined as the smallest unit of time i.e. 2.9623*10-4. The Silpasastra records the smallest measure of length as the paramanu i.e. 1/349525 of an inch. This measurement corresponds to the smallest thickness of the Nyaya-Vaisesika school - the trasarenu, which was the size of the smallest mote visible on a sunbeam as it shone into a dark room. Varahamihira (circa AD sixth century) posited that 86 trasarenu were equal to one anguli i.e. three-fourths of an inch. He also suggested that 64 trasarenu were equal to the thickness of a hair.}

The Laws of Motion

Although the earliest attempts at classifying different types of motion were made by the Vaisesikas, Prasastapada took the study of the subject much further in the 7th C AD, and it appears from some of his definitions that at least some of the concepts he enunciated must have emerged from a study of planetary motion. In addition to linear motion, Prasastapada also described curvilinear motion (gamana), rotary motion (bhramana) and vibratory motion. He also differentiated motion that was initiated by some external action from that which took place as a result of gravity or fluidity.

He was also aware of motion that resulted from elasticity or momentum, or as an opposite reaction to an external force. He also noted that some types of actions result in like motion, and others in opposite motion, or no motion at all - the variations arising from the internal and inherent properties of the interacting objects.

Prasastapada also noted that at any given instance, a particle was capable of only a single motion (although a body such as a blowing leaf composed of multiple particles may experience a more complex pattern of motion due to different particles moving in different ways) - an important concept that was to facilitate in later quantifications of the laws of motion.

In the 10th C. Sridhara reiterated what had been observed by Prasastapada, and expanded on what he had documented. Bhaskaracharya (12th C), in his Siddhanta Siromani and Ganitadhyaya, took a crucial first step in quantification, and measured average velocity as v=s/t (where v is the average velocity, s is distance covered, and t is time).

For their time, Prasastapada's work, and Sridhara and Bhaskaracharya's later elaborations ought to be considered quite significant. However, one of the weaknesses of later Indian treatises was a failure to follow up with further attempts at quantification and conceptual elaboration. For instance, several types of motion had been earlier assigned to unseen causes. There was no subsequent attempts to solve these mysteries, nor was there the realization that the invisible cause behind various types of motion could be conceptually generalized and formally characterized and expressed in an abstract way, through a mathematical formula as was done by Newton a few centuries later.

Experimentation versus Intuition

In fact, the next major step in the study of motion was to take place in England, when the ground for scientific investigation was prepared by the likes of Roger Bacon (13th C) who described the great obstacles to learning as regard for authority, force of habit, theological prejudice and false concept of knowledge. A century later, Merton scholars at Oxford developed the concept of accelerated motion (an important precursor to the understanding that force=mass*acceleration) and took rudimentary but important steps in the measurement and quantification of heat in a rod. One of the hallmarks of British (and European) science thereafter was the fusion of theory and practice, unlike the generally intuitive approach followed by Indian scientists when investigating fields other than astronomy.

For instance, right up to the 16th C, Indian scientists continued to record useful scientific observations, but without serious attempts at quantification, or deeper investigation into the physical and chemical causes of what they observed. Magnetism is referred to by Bhoja (10th-11th C) as well as by Sankara Misra later. Udayana (10th-11th C) recognized solar heat as the heat-source of all chemical changes, and also that air had weight in a discussion of balloons in his Kiranawali. Vallabhacharya (13th C) in his Nyaya-lilavati pointed out the resistance of water to a sinking object, but did not go on to discuss the principle any further. Sankara Misra (15th-16th C) noted the phenomenon of electrostatic attraction after he had observed how grass and straw were attracted by amber. But the cause was deemed adrishta (unseen cause). He also recorded some awareness of the concept of kinetic energy and in his Upaskara dwelt on the properties of heat, and tried to relate the process of boiling to evaporation. In the same treatise, Sankara Misra also gave examples of capillary motion citing the ascent of sap from root to stem in a plant and the ability of liquids to penetrate porous vessels. He also wrote about surface tension, and posited sandrata (viscosity) as the cause behind the cohesion of water molecules and the smoothness of water itself.

The Social Milieu

Yet, unlike in astronomy, where many Indian scientists got very intensely involved, and were driven to work towards a considerable degree of accuracy, no such compulsions appeared to guide Indian scientists in other fields. Whereas Indian astronomers were compelled to develop useful mathematical formulae and explore the mysteries of the universe in greater depth - in other fields of scientific investigation, Indian scientists seemed to remain content with intuitive and general observations, tolerating a far greater degree of vagueness and imprecision. The answer to this apparent inconsistency may lie in the social milieu. The study of astronomy was triggered partly by practical considerations such as the need for accurate monsoon prediction and rainfall mapping, but perhaps even more so, by the growing demand for "good" astrologers. The obsession with astrological charts - both amongst the royalty and mercantile classes led to considerable state patronage of intellectuals who wished to pursue the study of astronomy. Patronage was also available for alchemists - for those attempting to discover the "elixir" of life. But support for modern scientific research as was beginning to take shape in 14th C Oxford was generally lacking.

The situation prevalent in 15th-16th C Italy was not significantly different, and Leonardo Da Vinci (1452-1519) was particularly frustrated that there was not sufficient interest in his many inventions and how those with means failed to distinguish genuine scientific activities from quackery and the work of charlatans. But Da Vinci was convinced that dedication to scientific truth would eventually prevail. "For nature, as it would seem, takes vengeance on such as would work miracles and they come to have less than other men who are more quiet. And those who wish to grow rich in a day shall live a long time in great poverty, as happens and will to all eternity happen to the alchemists, the would-be creators of gold and silver, and to the engineers who think to make dead water stir itself into life with perpetual motion, and to those supreme fools, the necromancer and the enchanter."

Although Raja Bhoja's Somarangana-sutradhara (circa AD 1100) describes many useful mechanical inventions, and the use of levers and pulleys is described in numerous other Urdu, Persian and Arabic texts in India and the Middle East, Da Vinci's notes on mechanics, the study of levers of different kinds, cantilevers, pulleys and gears in combination, varied gadgetry, bridges, and studies of flight were of a truly pioneering nature, and exceeded in complexity and breadth any civil and mechanical engineering treatise that had preceded him.

And even though in his time, Da Vinci's works were not especially appreciated, Western Europe was in the midst of a monumental change in it's attitude towards science and technology. A century later, the momentum towards the modern scientific era was to gather considerable pace, and eventually the European Renaissance created an environment where the ideas of Da Vinci and Francis Bacon (15-16th C England - who stressed the importance of the experimental method in science) were able to blossom and flourish.

But at the same time in India, several factors posed as hindrances to the development of modern science. In comparison to Europe, India enjoyed a relatively milder climate, and the production of necessities was deemed sufficient to satisfy the population of the time. The courts - whether Mughal or regional spent a good part of their rich treasuries on cultivating the fine arts and promoting the manufacture of luxury goods and decorative objects of exquisite beauty. Science and technology simply attracted little attention (except when it came to improving the tools of war).

The growing influence of religion - whether Quranic or Brahminical also had it's negative effect. While the Quran claimed that all the world's knowledge was already described in it, Brahminical orthodoxy created a sharp divide between the mental and the physical and thus prevented scientists from going beyond passive observation and intuition to practical experimentation, active theorizing and quantification. Whereas Akbar and Jehangir were not averse to science, and the latter took an active interest in books on botany and zoology, it appears from anecdotal accounts that Aurangzeb had a decidedly skeptical attitude towards the sciences. Although some patronage was available in the regional courts, (and outside the courts), alchemy, astrology, study of omens, numerology and other semi-rational and irrational traditions drew much more attention, and thus distracted from genuine scientific pursuits.

On the other hand, European scientists drew on the best works produced in the East - studying foreign documents with due diligence, often accepting little at face value - but instead verifying the results with apparatus and scientific measuring tools of their own creation. There was a time when such had also been the case in ancient India - but over time (due to both internal and external factors) - India's scientific spirit got eroded. Thus Europe was not only able to catch up with the knowledge of India and the East, it was able to rapidly surpass it.

Since independence, Indian scientists have been provided the opportunity of narrowing the gap, and in some fields have done especially well. However, the quality of science education for the masses still needs considerable improvement. On the one hand, the study of the physical sciences in India needs to be accompanied with practical demonstrations and more experimentation as is common practice in the West. In many instances, tools and apparatus used to demonstrate and quantify scientific phenomenon need to be modernized or improved. On the other hand, there also needs to be somewhat greater appreciation of the intuitive approach that has been the hallmark of ancient and medieval Indian science. The conceptual elegance of some earlier formulations, and the facility to inform and educate through analogy is also something that can be learned from the Indian tradition.

It may also be noted that in terms of pedagogy, the standard Western texts are not always as useful. Often, the teaching of physics and chemistry becomes too esoteric for the average student. There is excessive abstraction in most text books, and undue theoretical complexity is thrust upon relatively young students. In contrast, the Indian approach with it's stress on observation of natural phenomenon, and epistemological approach to understanding each field are much easier to grasp for beginners and intermediate students. Once the student understands the basics, and develops a good intuitive way of perceiving scientific phenomenon - the complexities and mathematical abstractions can follow - and the world of the physical sciences can be opened up to more than just the few who are able to transcend the complexities and difficulties that accompany the study of these branches of science today.