The evolution of science.
I am not a historian but I have lived long enough to have witnessed the evolution of some science. For example almost the whole of modern control theory has emerged since World War II. But where did science start? Certainly the Ancient Greeks had ideas that one might regard as the forerunners of science in their ideas of logic. However they had curious ideas about who should actually “do” logic. Typically they regarded arithmetic as wholly abstract and thought that its actual use was a task suitable only for slaves. They adopted a totally illogical position in saying dogmatically that when there was a conflict between logic and observation the observation must be wrong. That false position of the superiority of logic still echoes through the minds of men. There are claims for the evolution of science in the middle-east, the Indian subcontinent and so on. They may be correct but they came too early to have any parallel technological expertise to let science develop as it did subsequently in Europe.
It was not the men of science who designed and built steam engines for draining mines and for railways but practical men who by great good fortune had found an engine that would run and do useful work even though it was not understood nor well made. There can be no doubt that Newton and Bacon sowed the seeds of science and indeed took enormous strides to getting it started on a sound footing. Subsequently lots of gentlemen-scientists competed to explore what we now call physics and many of their names will never be forgotten in the English-speaking world. Unhappily this parallel development of technology by practical men and physics by theoreticians created a gulf of distrust that is in place to this day. It is sad but real.
When I was lecturing I set an examination paper in which I solved an equation by trial in three lines. When the external examiner returned the paper he had added four pages of detailed mathematics to find the same figure. He noted that it was not necessary to use a trial method. He must have had self-imposed rules that made him shy away from a trial solution yet we now know that it is the most powerful tool that we have when the trial is made instantly by a computer. Engineers find nothing wrong with a trial solution, mathematicians regard it as a failure of their mathematics. Yet Richard Feynman who started us along the road of quantum physics and played a major part during the Los Alamos nuclear bomb programme actually maintained and repaired the manual calculators that were worked to destruction solving differential equations by trial. But then he was also an engineer.
It becomes pertinent to ask whether there is a deep-rooted difference in the mind-sets of engineers and scientists. I think that there is. The gentlemen-scientists of the 19th century experimented to find simple mathematical laws to describe the observed behaviour of the natural things that were all around them. They produced simple laws relating temperature, pressure and volume for gases and for the elongation of metals under loads and a host of other similar examples. In the main they made little attempt to apply these laws in any practical way although William Thompson became wealthy from his work on telegraph cables and Davey is said to have invented the miner’s lamp. Horny-handed engineers made things and it is doubtful whether much of the output of the scientists impinged on the technological world. (Slaves did arithmetic!) Engineers could not wait for science to catch up, they had railways, bridges and ships to build and empirical experience to guide them.
A long time ago I read an account of an American scientist from space and aviation who wanted to design a sailing boat to travel at 40 knots. He noted that the designers of sailing craft seemed to be totally unaware of the developments in aeronautics during the first 60 years of the 20th century. Nothing has changed. Search the web for theory of sailing to see what I mean. The much-hyped warplanes designed between say 1935 and 1945 seem to have owed much more to the “can-do” men of industry than the aviation scientists employed by the governments. The can-do men could not wait because they were engineers who did not have the leisure to experiment systematically. Aeroplanes were needed immediately to fight a war not at some time in the future when some interesting theoretical problem had been solved.
The fundamental difference between the approach of scientists and engineers is that scientists have no goal because they are on a voyage of discovery whereas engineers do have a well-defined goal in the form of a bridge or a boiler or an aeroplane to design and build. They can use mathematics and physics just as a scientist does but they also have a goal that tells them that when the contribution from mathematics is exhausted or too time consuming or just not worth any more effort it is time to get designing.
One might argue for Euclid as a “scientist in the making” but his work gave us an fascinating tool to use and admire but not anything that might be regarded as a general principle. Galileo without doubt used deductions from observation to upset the dogmatic views of the established church on the structure of a planetary system. Francis Bacon made a major step forward when he said that the right way to build a science was to make observations and test them by experiment and to formulate the “laws” of nature as we go. He has been proved to be correct. Newton appears to have followed this idea and to have used abstract ideas to describe and explain the behaviour of real things in the natural world. The classic example of this is Newton’s statement of what are now known as “Newton’s laws of motion”.[1] The first and third of these laws can only be stated in words and they are complete as Newton expressed them. The second law is capable of being expressed in symbols, ie and then a system of mathematics is needed to apply this apparently simple statement to the motion of bodies in specified circumstances, eg when travelling in a circular path. If one cares to think of Newton as exploring the motion of bodies it becomes evident that he would not have made much progress without calculus. Of course he had to “invent” calculus, if that is the right word for discovering in the literal sense, something as useful as calculus that might also be regarded as innate to mathematics.[2]
Newton’s many contributions to the emergence of science are well known and it is clear that he belonged to a new school of thought where deductive reasoning about the physical world was tested against accurate observation. Perhaps Newton was one of the first to find out that if you look and observe and then attempt some rational analysis the next time you look you see more with a better understanding.
These ideas took root in European philosophy if nowhere else but science did not then emerge as a structured whole. It was like the six blind men and the elephant. Lots of people dabbled with bits of science and from time to time new unifying ideas came along each giving some coherence to a part of the whole. We now have a fairly coherent body of knowledge that usually works very well if used by someone who understands it. Unhappily when this knowledge is cherry picked it can be reconstructed to produce the most outrageous “theories” and the internet is full of them.
It is pertinent to ask where we are in the evolution of science. It seems to me that at the normal levels of science for everyday use by engineers we are finished except for tidying up some loose ends. We have explanations for most of the things that have sufficient order in their behaviour for us to quantify the behaviour. Even the weather is reasonably predictable for several days ahead.
However there seems to me to be one impediment to the application of science and that is the way that the internet is used. Often the outcome of science is a mass of useful data, e.g. the NACA data on aerofoils that is so good that it will never be superseded and the physical data for liquids gases and solids that has been gathered over many years. It is a very large data-base and it is an obvious next step to put all this data on the internet for use by anyone with a computer.[3] Unfortunately this data has cost money to gather and has become intellectual property and is available only if purchased. This means that a would-be user must weigh the direct cost of buying from the internet against the cost and effort needed for the acquisition of data by traditional methods. It makes the methods of science and engineering not as useful as it could be.
In the science of fluids both at rest and in motion we have sorted out good ways of predicting the things we want to know in many cases. We have two major groups of problems that resist our efforts. They are those for which the mechanical properties of the fluid cannot be quantified eg slurry, and those for which the boundaries cannot be quantified, eg the flow on watercourses. It is unlikely that these will ever yield.