The Nature of Science
I was at a conference last week-end where we were considering the future of grammar school education. During a meal, a professor who is director of a university Institute of Education said to me that he thought that within perhaps another generation the demand for scientists would increase so greatly that 90% of boys and girls in sixth-forms would be specialising in science and only 10% in such subjects as English, History, Languages, Art. At first this prospect seemed alarming, for there was something in our habitual ways of thinking that made us take it for granted that science was an inadequate subject from the cultural point of view, and could not provide the material or experience of a true all-round education. Often we do take it for granted that English or History are cultural subjects, whatever that may mean, and that science is not. Perhaps we mean that English or History are likely to provide a more human study, a more complete introduction to human thought and activity and that science would tend to narrowness. But when we thought a bit more about it we wondered whether this was necessarily true. Any subject could be dealt with in a way that made it narrowing, academic, unrelated to life and uninspired – a student of History or English or Classics could be every bit as narrow, as blinkered as a student of Physics. On the other hand, science could be handled in such a way as to make it as inspiring, as humanly revealing a subject, as stimulating to the imagination as any of the subjects listed under “Arts”. But are there any tendencies prevalent in science teaching or in the attitude of scientists that make a widespread increase in the number of students a danger? I think there are.
One of the chief tendencies is the inclination to think that science is above all other subjects the one that seeks and discovers the truth. Science, it is often thought, is the supreme “de-bunker”, it dispels the mist of prejudice and tradition, gets rid of long established superstition and shows us the indisputable facts, the naked truth. The conviction that science does this, rests largely on the fact that science has waged a battle with religious notions about the origin of life and the world and has won the battle without any doubt
So now we have this tendency to think that science is steadily filling in the map of truth and that there will come a time when that map is complete. The scientists will then be able to sit back and say “The job is done; we have all the answers.” If this sounds ridiculous to you, I can quote Fred Hoyle, who at the end of his latest book, a most fascinating and lively one, refers to his work as being directed towards “a complete understanding of the universe.”
It is not surprising that this assumption about truth rises up in the mind of the scientist, because science has to work on the assumption that a more complete understanding can be obtained. But I want to show that there is a paradox underlying all this. What in fact happens is that the more the scientist understands, the more he finds that has yet to be understood. For every question he answers, two new questions appear. The more he delves into mystery, the more mystery there is to be investigated. So instead of reducing the remaining problems as they become fewer and fewer, with a possible end in sight, he in fact opens up an ever-increasing field of study. The prospect before science now is indeed vast, immeasurably greater than it could ever have been imagined a hundred years ago. I might add, as an aside, that this is precisely what makes science so exciting. There is no end to it!
Less than a hundred years ago the battle was fought out between those who believed in the Creation as described in Genesis, and those who understood and accepted Darwin’s “Origin of Species.”
I am sure there must be many people who, when the scientists had won the day, sat back and said “Now we know the truth; what more is there to be said?” But do we? We see that “natural selection” gets to work on the many variations, that appear in a group of animals, or in the offspring of a pair of parents. The stronger, more adaptable ones, survive and give rise to a line of animals that have these qualities making them fitter to survive. But now we have to ask “Why do variations appear, why are the offspring a little different from the parents? Why do these surprising variations called “mutations” appear. We penetrate into the minute structure of cells with our microscopes. We discover chromosomes and genes. But where does our next step take us? Out into the enormous inter-stellar spaces through which stream the cosmic rays, rays that, coming from millions upon millions of miles away, penetrate our testicles and ovaries and may there be the cause of the variations. So the problem, far from narrowing down, steadily enlarges, far from becoming simpler, leads us into unforeseen complications.
Let us think now of the origin of the Earth, how science has worked on that problem. We no longer think – unless we belong to some curious “fundamentalist” sect – that the account in Genesis is the literal truth. We think of it as pietry (sic) and symbolism. The scientists of the last century substituted a molten sun, flinging off a molten earth, and both of them cooling. The earth formed a crust through which volcanoes burst and belched as in Walt Disney’s “Fantasia.” H.G.Wells gave us a moving picture of the gradual cooling of a steaming earth till it reached a temperature when life could begin in the sea and carried it on till we saw a frozen, lifeless earth slowly moving nearer and nearer to a vast dull red sun. In more recent years we have found that the earth is not cooling down but is kept warm by the energy of the radioactive substances in its surface. Three or four years ago a new theory of its origin appeared; together with the other planets it was a wisp of matter left behind by an exploding twin star that once circled our Sun – a supernova. Already that theory has gone – to be replaced by a new one, but also involving a supernova explosion. We are no longer allowed to think of a molten mass slowly cooling, but of the earth as formed by an aggregation of cold particles, crushing towards each other as they spun and producing warmth that raised the temperature of the whole mass. Fred Hoyle’s description of this process –as he conceives it to have happened - reads like a great poetic phantasy. Until recently we thought that perhaps the great underground lakes of petroleum that we tap for our oil supplies were formed from the decaying vegetation or sea life of previous ages. But now scientists have found traces of hydrocarbons in meteorites. So perhaps when the cold particles began crowding together to from our earth, warming each other up until they became partly fluid the hydrocarbons in each were squeezed towards the surface of the globe, forming the lakes we know. And it may be that our fears of the exhaustion of our oils supplies are quite unfounded; for perhaps great quantities of oil are still being squeezed out of the lower layers of the earth’s surface.
How complicated, how fanciful and incredible the statements of modern science would seem to the medieval mind. In the time of Dante, the picture that men held in their minds of the universe was so simple and finite, so unchanging, so secure. The earth was its centre, the planets revolved on accurately timed crystal spheres, beyond the outermost sphere lay the Empyrean Heaven. There was no need for speculation about infinite space for the universe was neatly arranged and securely bounded. It was as firmly circumscribed by its spheres as a medieval city by its walls. Then with Copernicus and Newton the universe burst open into endlessness and unfathomable space.
In our own time we have been challenges by such powerful thoughts as the curvature of space, universe that is “finite yet unbounded” a universe that is expanding at a tremendous rate, blowing up like an enormous balloon: so that the spiral nebulae are rushing away from each other at [no value entered] miles a second.
In the last four hundred years we have changed from an ancient homely picture of the universe to a concept of it as expanding both in magnitude and in the number of problems that it sets us, a universe in which – unless we are convinced of a loving God – we are, surely, utterly, dwarfed and homeless.
Now let us go in the other direction – to the world of the infinitely small – the world of the atom. When I was a schoolboy Rutherford had just done his work: he had given us the first modern picture of the atom. In the sixth form we drank in what our chemistry teacher told us, marvelling at the beauty and simplicity of the Rutherford atom. Here is the story of how the picture dawned on Rutherford himself.
“Geiger and a colleague, Marsden, set to work. They used thin films of gold which is almost “transparent” to alpha rays, but they found that a considerable proportion of the rays were deflected at an angle of 90 degrees. Rutherford was flabbergasted. ‘It’s as though a 15 inch shell were being bounced off a sheet of tissue paper.’ He said.
“Alpha rays were not easily deflected in this way. In experiments an enormous electric field was needed to turn them through an angle of 90°. How could such an electric field exist in such a thin piece of foil? It was baffling, and for days, Rutherford went around the laboratory humming dolefully ‘Fight the good fight’ – a sure sign he was unhappily perplexed. Then one day he bounced into the laboratory humming ‘Onward Christian Soldiers’ –a sure sign that he was in great good humour. ‘Geiger.’ He cried, ‘I now know why your particles are kicked around and what an atom looks like!’
“This was how he had reasoned on the facts available; the particles fired by an exploding radio-active atom travelled in straight lines (like the buck-shot from the gun). These alpha particles passed through matter, not by pushing the atoms aside nor by swerving to avoid them, but by passing through the atoms themselves. Therefore atoms could not be solid as the prevailing idea was then. ‘So,’ argued Rutherford, ‘they must be like solar systems – not solid spheres.’ The invading alpha particles would thus be able to traverse the empty space between the central sun and the planets of this system. This system would be held together by the fact that the ‘planets’ would be negatively charged electrons and the ‘sun’ a positively charged nucleus. This nucleus would contain most of the mass of the atom, but it would be a relatively small part of its volume as contained by the circumference of the electrons in their orbits. The strong central field which would thus be created would account for the bending of the alpha rays, since the positively charges alpha particles (helium nuclei in fact) would be violently repelled if they came near the positively charged nucleus.”
How truly simple. Only two fundamental particles to explain the whole world of matter. That was in the days of the first World war. The particles have multiplied since. We now have, as well as protons and electrons, neutrons, µ-mesons, җ-mesons, positrons, negative protons, neutrinos, as well as particles of short duration such as taus, chis, lamdas and thetas. The world of atomic physics, so apparently successful in its outward, practical achievements, is in its theory in a very queer state, not a state of confusion perhaps, but a state of some perplexity, certainly not one of simplicity. It contrasts so startlingly with the atomic outlook of the last century, when atoms were as real and hard as billiard balls. Now when we look for them they vanish and we are left only with an algebraic equation. What a shock some of the scientists of the 19th Century would have if they woke up to our present world. The 19th Century was so much a century of hard fact. There are few facts that are “hard” now to a scientist, even size is relative. According to the Lorents principle when a train is moving it is slightly shorter than when it is standing still. If it moved with the speed of light it would have no length at all. Our century is certainly a century of tremendous upheaval, in which uncertainties seem to be increasing, mystery deepening and questions multiplying almost overwhelmingly.
Now let us go back to the original question – what are we to do about the education of scientists. Certainly we must prevent them from becoming “flat minded” people who think that they can “get everything taped,” who think that mystery and the wonder it generates are only a temporary experience from which we shall soon emerge, One thing we must do – and that is to stop people worshipping text-books, for that is all to(sic) apt to kill the eager, imaginative approach to science that is so necessary to its life. The text-book is but the corpse when the life has departed. Science is the living experience in the laboratory and the active mind. Corpses are useful to the student. Dissect them, find out all you can from them and then do as the medical student does, put the bits back in a box and give them a decent funeral. Then return to the study of the living, active thing that is science, always ready to discover that the text-book is wrong.
You must recognize too that science is not just a plodding, rational logical process, remorselessly churning out of its own nature, fact, generalisation and theory. All the usual descriptions of scientific method are post-mortems, they cannot fully analyse the creative, complex activity in the mind of the scientific genius. Those who would be discoverers and innovators must keep their imaginations well nourished, so that their minds respond to observations with a lively flow of ideas and images – as did Lord Rutherford’s in the account I read. The scientist at his best comes very near to the poet and the artist and the creative writer, These are all people who can imagine the things that do not occur to duller minds, whose thoughts can leap where others move only in a slow pedestrian fashion.
To be an artist, a poet, a writer, a musician, or a creative scientist, you must be able to dream dreams and see visions. If you are a scientist the dreams must not be wholly within science. Often the dreams that prove the most fertile, draw their energy from experiences far removed from science itself. So do not be scornful of these other activities of mankind – those activities that seem so unscientific. Your scientific thought may be enriched and fertilised by some of their dreams and images. I am not afraid of a multitude of scientists, so long as they do not become proud and cocksure. Their work requires that they have humility. If they have humility not only in their science but in their approach to all the other activities of mankind, they will not only do no harm to “culture,” but they will also enrich it.
Archive reference PP/KCB 3/7/3 Document 16