The Unnatural Nature of Science Read online

  The mechanics of building again illustrates the independence of technology and science until recent times. Statics, the science of the forces acting on a body at rest, like an arch or a bridge, was founded by Archimedes when he devised formulae for the equilibrium of simple levers and for determining the centres of gravity of simple objects. It was not until some 1,800 years later that further progress was made, by the Dutch mathematician Simon Steven, who, in the sixteenth century, showed how to analyse more complex combinations of forces. How to calculate correctly the forces acting on a structure became clear in the eighteenth and nineteenth centuries, but this knowledge began to be applied to building structures only in the nineteenth century: none of the buildings constructed before that time made use of any scientific principles that are used in modern engineering. They probably did make use of what may be thought of as ‘The Five Minutes Theorem’: if a structure was built and remained standing for five minutes after the supports had been removed, it was assumed it would stand up forever.

  All the beautiful cathedrals with their great domes and high naves were built by engineers who based their buildings on practical experience, not on science. The early iron bridges were also constructed on a purely empirical basis. So the bridge designed in the 1850s by Robert Stephenson and William Fairbairn to span the Menai Strait in North Wales – the first box-girder bridge – was based on experiments. A series of models was used to establish the design. The theory which could have provided an analytical approach to designing the structure had been published a few years earlier, but it was ignored. Technology may well have used a series of ad hoc hypotheses and conjectures, but these were entirely directed to practical ends and not to understanding. There was no attempt at generality

  Science by contrast has always been heavily dependent on the available technology, both for ideas and for apparatus. Technology has had a profound influence on science, whereas the converse has seldom been the case until quite recently.

  The invention of the steam engine, pendulum clock and navigational techniques requires special examination, since science did play a role here, but not necessarily in terms of understanding. However, the very rarity of such special cases underlines and strengthens the main thesis.

  The origin of the steam engine can be thought of as owing more to the blacksmith’s world than to the Royal Society and its scientists. James Watts’s steam engine of 1775 was a major modification of the Newcomen engine (1712) which had been in wide use for sixty years. Newcomen’s engine was based on the condensation of steam in a cylinder – this caused a partial vacuum, and atmospheric pressure then forced a piston down into the cylinder. Thus the working stroke involved the piston moving into the cylinder, whereas in Watts’s steam engine the pressure of the steam drove the piston outwards. Scientists had for centuries been fascinated by the very idea of a vacuum. In the 1690s Denis Papin, a French scientist, had devised a machine for making a vacuum in a cylinder containing a piston, based on the condensation of steam. He realized that the condensation process could be used to provide useful work. What is unclear is whether or not Newcomen, an ironmonger, was aware of Papin’s work and current ideas about atmospheric pressure. Even if he was, his engine was very different from Papin’s simple cylinder and piston. More important, his engine was not based on any theoretical consideration; rather, the apparatus used for a scientific experiment may have formed the basis for a technological invention.

  Another area where it might reasonably be thought that science did have an impact on technology is timekeeping and navigation. Galileo introduced the pendulum to clocks. The story goes that, at the age of nineteen, he had noticed that a swinging altar lamp always took the same time to move from one side to the other, no matter whether the swing was large or small. He did not have to understand why this was so in order to recognize its value in timekeeping, but this does come very close to science affecting technology. Similarly, I have to recognize that, before there was an accurate clock that could be carried on board a ship, navigators needed some training in mathematics: to find longitude at sea required precise observations on the moon and quite subtle calculations.

  The motivations behind technology and science are very different. The final product of science is an idea, or information, probably in a scientific paper; the final product of technology is an artefact – the clock or the electric motor, say. Unlike science, the product of technology is measured not against nature but in terms of its novelty and the value that a particular culture puts on it. Whether or not it is true, statements such as that of Karl Marx to the effect that inventions since 1830 could be thought of as being ‘for the sole purpose of supplying capital with weapons against the revolts of the working class’ could not conceivably be made about scientific ideas.

  A more interesting general question is: what drives technological and scientific advance? For technology it is the demands of the market-place or advancing technology ‘making’ the need. Inventive activity is, it seems, governed by the expected value of the invention – inventions peak when investments peak – and patents also illustrate a clear difference between science and technology, for one cannot patent scientific discoveries or ideas. Oliver Lodge disliked the idea of patenting his ideas on radio waves, as patenting is the antithesis of the openness which scientists want. The reward for the inventor is money; for the scientist it is esteem. In earlier times, the ethos of the craftsmen was like that of a guild: learning was by apprenticeship, outsiders were excluded and secrecy was essential. In this, too, it differed from science, for which openness, controversy and public access to knowledge are characteristic features. Yet another difference lies in the selection criteria that determine success: for technology, success is related to wants and needs; for science, success depends on correspondence with reality.

  Technology has its own evolutionary history. The historian of technology George Basalla has adopted a biological approach to technology, reviewing its history in evolutionary terms. An artefact is regarded as the fundamental unit, and continuity prevails – different versions result from modification of the original object. By contrast, ideas, not artefacts, are the fundamental units in science. A key feature in the evolution of technology is diversity, which is conventionally ascribed to necessity and utility. But the variety is astonishing, and even Marx was surprised to learn that 500 different kinds of hammer were produced in Birmingham in 1867. Was this diversity really necessary and useful? In general terms, Basalla argues that technology does not always exist primarily to supply humanity with its needs; rather, the need often develops only after the invention. For example, the invention of the internal-combustion engine gave rise to the necessity for motor transportation.

  The story of the wheel illustrates his point. Only some thousands of years old (compared to the one and a half million for the making of fire), the wheel probably developed from the rollers that were used to move heavy objects. Evidence that wagons were used for transport dates from round 2000 BC, about one thousand years after the wheel’s first appearance in Europe and Asia. In the Americas and southern Africa, for example, the wheel did not appear until modern times. The puzzle is Central America: wheeled transport arrived only with the Spaniards, in the sixteenth century, but long before, from the fourth to the fifteenth centuries, small figurative sculptures were fitted with axles and wheels to make them mobile. An explanation as to why this invention of the wheel was not developed for transport is that there was no need since, except in Peru, there were no roads, and there were also no large domesticated animals to pull heavy loads. Again, between the third and seventh centuries the camel performed the role of wheeled vehicles in the Near East and North Africa. The wheel is not a universal need.

  The interaction between science and technology in recent times has been illuminated by Basalla’s discussion of the history of radio communication. Electromagnetic waves had their origin not in experiment but in the equations which James Clerk Maxwell developed in the second half of the nineteenth
century. His equations initially dealt with all that was known about electricity and magnetism, but for mathematical consistency he introduced a new term that effectively implied the propagation, with the speed of light, of electromagnetic waves. He made no effort to verify the existence of such waves, however. His theory essentially put Michael Faraday’s ideas about electricity and magnetism in a mathematical form, and at the same time provided a completely new conception of electromagnetism by considering how Faraday’s lines of force were produced and what medium they required for their propagation. In spite of the highly mathematical nature of his analysis, he presented the theory in terms of physical models that related to the technology of the time – so much so that the French mathematician Henri Poincaré remarked that ‘one seemed to be reading the description of a workshop with gearing, with rods transmitting motion and bending under the effort, with wheels, belts and governors’. It is ironic that Maxwell’s new ideas were visualized in terms of the rather old-fashioned technology of his age.

  Heinrich Hertz’s contribution, in 1888, was to demonstrate the propagation of electromagnetic waves. Yet is was not Hertz but Oliver Lodge, who was doing similar experiments, who recognized their importance for telegraphy. His interest was rather reluctant, and it was left to Marconi to pursue the commercial exploitation of Hertzian waves. Just before Marconi’s invention, the English scientist Karl Pearson had, in 1892, written in his book The Logic of Science that he regarded electromagnetic waves as having no useful application.

  The very natures of scientific and technological thinking are dissimilar. Many aspects of technology are visual and non-verbal, which is quite unlike scientific thinking. It is not that scientists do not visualize structures, concepts and mechanisms, but exposition is fundamental to science and the images must be translated into language and symbols, particularly mathematics. Unencumbered by verbalized theories, the designers of technology bring together, in their minds, different elements in new combinations. In contrast to science, technological knowledge from the Renaissance until the nineteenth century was carried in books which were dominated by illustrations – the information was largely carried in pictorial form. Many of the books carried numerous illustrations of mechanical linkages, assemblies of gears and cams, and machines themselves, such as pumps. Curiously, there were claims that all these mechanical arts rested on the firm foundation of mathematics, but quite the contrary was true: there is no evidence for the use of either geometry or arithmetic in the design of the machines. It seems that it was true even then, as now, that claims that designs were based on science gave them greater respectability. Visual thinking also dominated industrial design. Science offered no guidance to the early designers of motorcycles, for example – it could not tell them where to put the engine, battery and fuel tank in relation to one another.

  Engineering, even today, should not just be construed as merely applied science. The relationship between science, technology and industrial success in modern societies is complex. Many have puzzled as to why Japanese industry should have been so successful. It has been suggested that its success is based not on science but on its ability to apply science. The transistor, invented in the United States and the basis of modern electronics, was initially perceived as a replacement of the old thermionic valve; the idea of an integrated circuit developed only slowly. There is no doubt that the invention of the transistor depended on science, but its exploitation was rather different: the Japanese showed that a strong scientific base was not necessary for a successful manufacturing industry.

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  Thales’s Leap: West and East

  The peculiar nature of science is responsible for the fact that, unlike technology or religion, science originated only once in history, in Greece. Most scholars are agreed that science had its origin in Greece, though those that equate science with technology would argue differently. This unique origin is important for understanding the nature of science, since it makes science quite different from so many other human activities, for no other society independently developed a scientific mode of thought, and all later developments in science can be traced back to the Greeks. It is my intention not to try to account for this single origin but to emphasize how rare science is in human cultural history and also to use its origin to illuminate some of the special characteristics of scientific inquiry.

  Thales of Miletos, who lived in about 600 BC, was the first we know of who tried to explain the world not in terms of myths but in more concrete terms, terms that might be subject to verification. What, he wondered, might the world be made of? His unexpected answer was: water. Water could clearly change its form from solid to liquid to gas and back again; clouds and rivers were in essence watery; and water was essential for life. His suggestion was fantastical perhaps, but such unnatural thoughts – contrary to common sense – are often the essence of science. But more important than his answer was his explicit attempt to find a fundamental unity in nature. It expressed the belief that, underlying all the varied forms and substances in the world, a unifying principle could be found. The possibility of objective and critical thinking about nature had begun. Never before had someone put forward general ideas about the nature of the world that might be universal, ideas that tried to explain the nature of the world in a way quite unlike the explanations provided by all-pervasive myths. For the first time there was a conviction that there were laws controlling nature, and that these laws were discoverable. Together with an emphasis on rationality, such ideas were to be crucial to the success of science and its survival later in the West. This was one of the most exciting and important ideas in the entire history of mankind. But, even more important, this idea was open for discussion and debate. It was a wonderful leap that was to free thinking from the strait-jacket of mythology and the grip of relating everything to man. Here, too, for the first time, attention was focused on the nature of the world with no immediate relevance to humankind. Human curiosity had hitherto been entirely devoted to man’s relation to nature, and not to nature itself. It is with the Greeks that man and nature are for the first time no longer perceived as inextricably linked and there begins a distanced curiosity about the world itself.

  While giving the honour of being effectively the first scientist to Thales of Miletos, one recognizes that Thales was himself a philosopher and heir to an intellectual tradition whose origins are obscure. He cannot have been totally unaware of the achievements of the Egyptians and particularly the Babylonians with respect to the use of mathematics. Miletos, where Thales lived, was the main harbour and the richest market of Ionia, trading with Phoenicia, Egypt and many other countries. This would have provided a rich and varied environment. In addition, the Ionians were colonists and may perhaps be assumed to have the intellectual vigour and the freedom from well-established ideas that characterize many immigrant communities. The Greeks, unlike the Jews, had no dogmas like the Old Testament to constrain their thinking, though they did have plenty of myths.

  It was also Thales who established mathematics as a science, irrespective of how much he might have learned from the Babylonians and Egyptians, who had established arithmetic procedures and the elements of geometry for their practical needs. The Babylonians knew elements of geometry as early as 1700 BC, and had tables listing the sides of right-angled triangles – they thus must have been aware of the key features of Pythagoras’s theorem which states that the square of the hypotenuse is the sum of the squares of the other two sides. Egypt contributed little to the advancement of mathematics, but used it for practical problems of measurement. Thales, by contrast, turned these tools of measurement into a science. He put forward a number of basic propositions: that a circle is bisected by its diameter; that, if two straight lines cut each other, the opposite angles are equal; and that the angle inscribed in a semicircle is a right angle. Here, for the first time, were general statements about lines and circles – statements of a kind never made before. They were general statements that applied to all circles and lines
everywhere, and that is the generality to which science aspires. The Greeks transformed a varied collection of empirical rules for calculation into an ordered abstract system. Mathematics was no longer merely a tool used for practical problems: it became a science.

  Thales’s contemporary in Miletos, Anaximander, did not find Thales’s ideas about water persuasive. To Anaximander it seemed that air was a much better candidate for being the primary substance of which all things were made. And so began the sort of claim and counterclaim for the understanding of nature which eventually gave rise to modern science. There was, even so, a crucial ingredient still lacking: experimental method.

  With Thales and the later Greeks there came the transition from explanations by means of myths to explanations which were self-consistent and open to critical analysis. This constituted a very big change. While myths do provide explanations to questions about ‘how’ and ‘why’, they are defective from at least two points of view: the problem being addressed may not be explicit, and the proposed solution may rest on arbitrary assumptions whose applicability is not specified. For example, the circumstances under which the Babylonians believed that Marduk split the primeval water goddess Tiamat to make the sky and its celestial waters on one side and the ‘great abode’ on the other are not made explicit. Similarly, the Egyptian explanation that the movement of the sun is due to the god Ra rowing a boat across the sky is a story, not an explanation in scientific terms: it is neither verifiable nor falsifiable. By contrast, Aristotle’s discussions about the shape and position of the earth and its movement, even though they were wrong, belonged to a quite different class. Together with these new kinds of explanation came a critical appreciation of the nature of explanation itself, and the requirement for logical consistency. It was no longer acceptable to suggest that the earth does not move because it is supported by, say, air or water; for what, in turn, supports that?