How do you judge historical science?

All kinds of claims are being made about the scientific achievements of our ancestors and a huge variability of the period in which they lived is routinely proposed. No one on either side of the argument was present at the time when the claimed events occurred or did not occur. So how do you distinguish between truth and fabrication? 

This is easier than most people would imagine. The most common approach is that of direct dating of the archaeological remains of residues of human activity. This kind of study will tell you that the anatomically modern human arose about a million years ago and then, about one lakh years ago the humans spread to different parts of the world, gradually dominating all the landscapes. The accuracy of the numbers depends on how far back you are going. The best evidence for human entry into the Indian subcontinent is around seventy thousand years ago. We continue to come across sites where humans made various tools and left behind other residues and they show a gradual increase in sophistication with time. By about seven to ten thousand years ago, they begin to take up farming in a serious way and settle down. At this stage they begin to build the large stone structures in all parts of the Indian subcontinent. The best evidence of horse bones in India comes around a thousand to fifteen hundred years ago. This story is fairly incontrovertible except for a few fine points here and there.

However, the entire evidence for the early habitation by Sanskrit speakers in India is literary and there are few, if any archaeological sites that can be associated with early Sanskrit speakers. In this case therefore, there is a fair scope for error. However, two criteria are used to date them. One is that languages are not constant and consistent. After all, my own grandfather had a completely different vocabulary compared to mine – if you don’t believe me, pay attention to the agonising updates that the Oxford English Dictionary goes through every year. Since language evolves, it is also possible to date ancient documents. For example, if I see an English essay that uses “Though” or “Thine” it is certainly several decades, and probably hundreds of years old. The other method is to look for records of astronomical events, internal dating of family trees etc. as well as description of animals and flora and fauna to pin down the place where the writing occurred and the period during which it happens. This can also be reconfirmed with the description of technology and other knowledge, say of medicinal plants, description of various technologies etc. 

In recent decades, the genetics of humans, animals and plants have proved invaluable in understanding the movement and mixing of people and their migratory pattern. Here, the genetics of languages can also provide other supporting evidence. 

From the Ashokan period, we get monuments that can be dated by the above method and they provide direct evidence of human behaviour in the historic period. 

However, when extreme claims are made, there are a host of arguments that can be brought to bear upon the matter under discussion. Most importantly, no field of science today has arisen in isolation. To reach quantum mechanics, we had to learn about thermodynamics, atomic physics and electromagnetic theory in its full mathematical complexity to realise that the problem of stability of atom required a new kind of physical law. Similarly, to get to the stage of flying an aeroplane, we needed to understand the dynamics of air and wind, its movement, measure air pressure and its difference when it went over a curved surface compared to a flat surface. Bernoulli’s principle did not arise in vacuum and Wright brothers could not have even imagined an aircraft without a hundred years of industrial revolution and deep understanding of metal, internal combustion engine and so on. Interplanetary travel required first the understanding of distances between planets, a firmly established heliocentric idea of the organisation of the solar system. Extremely powerful engines that could lift objects out of the gravity of the Earth (and hence a good understanding of gravity itself) and a basic mathematical foundation in calculus to get there. Experimental facilities, test facilities, manufacturing facilities all go hand in hand for this kind of a capability to arise. 

Similarly, for genetic engineering, we need to understand life at the molecular level. For this you have to know that the smallest objects are molecules made of atoms. We need to know that there are only a handful of atoms that provide the entire variety of the universe. We need to understand atomic physics for which we need X-ray, optical and infrared devices and photographic plates that can take spectra of lights from atoms and allow us to create a mathematical theory about how biology works. This needs to be further supported by microscopy and other devices to understand and create molecules of various complexity and the manner in which they interact. We need to understand the centrality of carbon in life and so on. After a century or more of such studies can one begin to realise that heredity is based on the information provided to a foetus through the very process of conception. We then need to isolate these cells in extremely clean and low temperature environment and then study and manipulate them. Only several decades of such studies can give us the basic rules of genetics. And manipulating these genes to make composite life forms is an order of magnitude more complex. We need to first understand how genetic information is actually read and executed. We need to understand the consequences of removing or replacing some genes from one animal into the life cycle of another life form. This again requires unbelievable amount of resources and time, not to mention a rigorous educational system. 

Similarly, nuclear weapons arose after we had understood the uniqueness of atoms, interaction of atoms and the nature of energy coming from unstable nuclei. We needed a whole host of technologies to isolate atoms of specific material in prolific quantities. Even then, pure uranium will not instantly give you an atom bomb since the neutrons emitted by a uranium atom may or may not go and hit another uranium atom. To achieve this, the core uranium has to be compressed in a specialised compression technology to make an atom bomb. This requires highly evolved metallurgy and other infrastructure not to mention complex mathematics. And atom bombs are certainly not light enough to be put on an arrow head. 

So when one talks of whether a particular technology was known to our ancestors, one must sit back and take a pause. Consider the amount of other knowledge that led to a particular insight into the working of nature and satisfy yourself and convince others that this entire scaffolding of knowledge existed at the period being mentioned. The evidence can be in the form of reliable documents in appropriate language, evidence of experimental facilities, evidence of technological competence and mathematical competence. Without this evidence, all claims are simply fantasies of an untrained mind. Patriotism is the last refuge of a scoundrel. It is worth bearing in mind that none of these claimants of the technology of the past have made a single prediction stating that such and such a technology will be the next one to be found and that the ancient literature defines how to reach this unattained technology. 

Also, implicit to all this is that electricity is crucial to the entire working. It provides the most convenient and versatile source of energy which can be converted into other forms. There is absolutely no evidence that our ancients knew how to generate and use electricity.

So the next time you read a claim of the powers of our ancients, pause and think, don’t just get carried away.