THE NATURE OF MATTER
Some Reflections on Modern Scientific Concepts and Traditional Indian Thoughts
Jayant V. Narlikar
Against the background of some elementary knowledge about the many different streams of ancient thoughts, I have ventured to ask some questions vis--a-vis scientific ideas of modern times where I do know a little, perhaps just enough to gauge the extent of my ignorance. About our ancient traditions I do not even know the extent of my ignorance! So I had better begin with the modern scientific end. What does science say about the nature of matter on different physical scales?
Scales of Structure
A few years ago Professor Phillip Morrison had made a beautiful but short film entitled ‘Powers of Ten’. It started with a scene very common in the Western world, that of a couple picnicking in a city park. Then the camera zooms out showing the larger scale of the park, then zooms farther to show the city, then the state and so on. Each scene is followed by another with ten times larger scale. How far does this go on?
Taking 1 metre as the scale we measure our local distances in (— the picnicking couple occupied an area of a few square metres), the tenfold increases in length go on till about 1026 metres — that is, about a hundred million million million million metres! A few significant steps enroute to this gigantic scale are given in Table I below.
The largest scale in Table I is that of the large scale structure of the universe as we perceive it today. Our present cosmological theories tend to suggest that this is absolutely the largest scale we shall ever encounter. But the film does not end there! The second part of the film shows us how things look at small scale. By zooming in the camera takes us to scales smaller than 1 metre from the picnickers to their palms
Table I : Large Structures
|Linear Scale (metres)||Structure|
|1023||Clusters of Galaxies|
|1026||The observable universe|
and then inside the palms to human cells, molecules, atoms etc. Table II shows some important structures on these small scales. The limiting (smallest conceivable) scale in Table II is that of quantum gravity — representing a thousand-million-million-million-million-million-million-millionth part of a metre!Table II : Small Structures
|Linear Scale (metres)||Structure|
|10-29||Scales probed by present accelerators|
Below this small scale scientists can no longer trust the macroscopically familiar notions of space and time. Our laboratory experiments using the biggest manmade accelerators of particles, take us down to length scales 1016 (ten thousand million million) times this limit. To probe structures at still smaller scales demands accelerators far more complex and costly than can be built today. So tha human technology is lagging behind what human mind can conceive, by this large factor.
The main conclusion from the film is to tell us how matter exhibits structure on vastly different scales. Why does it exhibit structure? Is there any end to it? There are questions and puzzles. One puzzle relates to the large scale structure : is it fractal in nature? As an example of fracals, consider the map of a country’s coastline. It shows zig-zag patterns. It we use finer scale to examine a samller section in greater detail, we will still see the zig-zag pattern. The pattern keeps repeating at finer and finer levels, Likewise, analysis of large scale structure in the universe reveals a grouping at different length scales. Thus stars cluster in galaxies, galaxies in groups, groups in clusters and clusters in superclusters. There are claims that this tendency is of modern cosmology.
An allied puzzle facing cosmologists today is to understand why matter happens to be distributed in such a hierarchical and inhomogeneous way while radiation is so smooth. Here I refer to the radiation in microwaves pending the universe. This radiation is supposed to be the relic of the primordial creation event, the big bang which also produced matter. Why, if both matter and radiation were of primordial origin, did matter distribute itself in this clustered way while radiation remained extremely homogeneous?
A different kind of conceptual difficulty comes at the microscopic (subatomic) level. This arises from the quantum uncertainty principle. Its consequence is as follows. As we think of structures on smaller and smaller length scales, the masses of these structures keep on increasing in inverse proportion! Thus the smaller the system the larger the mass and energy it has. To reconcile this idea with our microscopic notion that mass of the whole is greater than mass of parts is indeed difficult. For example, three quarks make up a proton. Yet the mass of each quark is far more than that of the proton. Of course, the notion can be rationalized but this rationalization becomes more and more difficult as we probe deeper in our search for the ‘ultimate’ building block of matter.
Attempts at Unification
Scientists do not know the answers to puzzles like these which may call for radical rethinking. Indeed, howsoever objective they may call themselves, the practitioners of science tend to be reluctant to face new evidence that forces them to revise their ideas. Thus many of the puzzles are simply wished away. But science has a self correcting tendency that ultimately helps identify the correct path.
Sheldon Glashow, the Nobel Prize winning physicist likes to illustrate the cosmic puzzle with the figure of a snake swallowing its tail. The concept is of Indian origin, of Shesha Naga who is also portrayed in the tail-swallowing pose. Glashow’s snake has its tail pointing towards structure at the smallest scale (quantum gravity). As we progress towards the head we pass through structures on the larger and larger scales, with the head corresponding to the cosmological scale of 1026 metres. Thus we transverse 71 orders of magnitude from tail to head. Yet the bringing of the two ends symbolizes the link without which the picture remains incomplete. The snake is fully understood only if the two ends meet. In other words, the largest scale structures cannot be understood without reference to smallest scale ones and vice versa.
Considerable brainstorming is going on between cosmologists and particle theorists about this link. Many believe that the clue may come from the unification of all known physical forces in a single picture. There are four basic interactions that need to be united this way : the electromagnetic, the strong, the weak and the gravitational interactions. Whether this holy grail of unification will ever be attained reamins to be seen. Some physicists think that the end will be attained very soon.
I hold a pessimistic view that we will never discover the ultimate truth, although we may make progress in the right direction. Thus I disagree with those optimists who are confident that the ‘end’ of physics is at hand. And so, I do not think that attempts to demonstrate similarities between ancient traditional beliefs and the statements of modern science about nature are worthwhile. For the former are now frozen while the latter are evolving. To argue that the ancients knew about facts of nature that the scientists know today does not take account of the above situation.
To what level had the ancient understanding about nature progressed? Did our ancestors of the Puranik times have high technology? Examples of weapons used — the various saktis and astras of the Mahabharata War — are cited to demonstrate theat they did have advanced weaponry. However, advance technology has other effects on social structure. Questions arise. Why was a war with remote control missiles fought with chariots, elephants and infantry in a battlefield? And in descriptions of normal life of those days, why don’t we find references to such amenities as tap water and household electricity?
A proper claim for advanced technology in the past must be backed by a technical description involving quantitative statements. If there were aircrafts, do we have specifications of a working model? I searched through the Brihad-vimana-sastra without finding such details. It is of course possible to argue that such descriptions existed but were lost. But then a sceptic justifiably remains unconvinced. In this connection, I think Pushpa Bhargava and Chandana Chakrabarty have done, within their admittedly limited framework, a commendable exercise in sifting through the statements in life sciences and medicine. If they have drawn negative conclusions in some respects, specific counter-examples need to be produced to shoot them down. I hope their conclusions would generate fresh activity on this front and I am sure that they themselves would welcome any new evidence they might have missed.
I now make comments on another topic that had generated considerable argument during the seminar.
The question I wish to ask first is, how did the traditional knowledge that we see today in holistic form evolve with time? Science as we know it today has evolved through several processes, sometimes continuously while on ocassions through sudden jumps. Either way, the science of today is vastly different from that in Newton’s time, which in turn was vastly different from that in Aristotle’s time. Can we likewise see a thread of evolution running through the gems of our traditional knowledge?
This question leads to another. How far was our knowledge based on direct observations and experimentation? If these processes (common in modern science) did operate, did they lead to the modification or even abandonment of any existing line of reasoning? In this connection I may mention that at the time of Galileo, European scholars were in the habit of settling issues by philosophical debates rather than experimental demonstration. Galileo began the then new method of showing a particular claim to be wrong by explicit experimental proof. It was this new approach that heralded the new scientific era in Europe.
This brings me to the last but not the least of my questions about our scholastic history.
Why did our ancient scholastic tradition apparently come to a halt a few centuries ago, to be revived only with the advent of the British Raj? Why the astronomical tradition from Aryabhata to Bhaskara II did not continue beyond the twelfth century? For, during those seven centuries (500-1200 a.d.) India certainly compared favourably with Europe in astronomical know-how.
The question can be debated at length. I find one particular instance indicative of the state of affairs. I refer to the debate between Mandan Mishra and Shankaracharya. The story goes that when Shankara was searching for Mandan Mishra’s house he came across some women washing clothes. When he asked for directions to the house he was told :
I was very impressed when I first saw this shloka. Did it not indicate the scholarly atmosphere at the house of Mandan Mishra? And if even the parrots had picked up so much wisdom how wise must Mandan Mishra himself be? And didn’t the debate sound so similar to the modern cosmological controversy of ‘steady state’ vs ‘big-bang’?
But a careful examination brings out another aspect which is not so complimentary! Parrots pick up words and memorise them without understanding their meaning. They memorise them only when they hear the words recited repeatedly. That implies the practice of rote-learning. Were the students of Mandan Mishra simply memorising the argument as it was passed on to them by their Guru? As Narayan Rana told us in his talk, whatever the teacher told the students was uncritically accepted and memorised by them.
Even in Galileo’s time in Europe, Aristotle’s ideas were simply propagated through this uncritical process. When Galileo stepped in, he demonstrated by actual experiments why those ideas were wrong — experiments no one had bothered to perform since verbal arguments were considered sufficient.
[There is a similar sequel to the Shankara episode. When Mandan Mishra lost, his wife took up the debate on his behalf. Her questions demanded knowledge of sexual behaviour, which as a bachelor Shankara could not answer. So he asked for time, ‘entered’ the body of a married man to learn about the details. Whatever be the truth of the matter, here we see an example where experiment was called for to supplement knowledge!]
Thus rote learning and an unquestioning attitude may have been one of the contributory factors to the decline of science in India during 1200-1900 a.d.
I make these comments will all humility. I may also point out that conformity with the traditional dogma has always impeded the march of science. Even today most of the Western science is threatened with this danger. For scientifice research today calls for lots of financial support which is forthcoming only if peer-review is favourable. This guarantees conformism and makes it all the more difficult for new ideas to come in.
I began by discussing the manifestation of Bhutas — matter — on different scales. It took me on the one hand to larger and larger scales of interest to astronomers and cosmologists and on the other hand to smaller and smaller scales of interest to the particle physicist. There is the tantalizing possibility of linking the smallest structure with the largest one. How? We do not know yet! Perhaps we never will: for the quest of science is an unending one. And then I turned towards ancient knowledge; for our forefathers too had asked similar questions.
Here I have perhaps digressed too far from the subject of Bhutas and raised several questions about the nature and scope of ancient traditions. I would nevertheless be unfair to myself if I did not air these questions. One method of trying to understand these issues is by having interdisciplinary dialogue.
©1995 Indira Gandhi National Centre for the Arts, New Delhi