Pushing the boundaries
Science is a wonderful thing and has made tremendous strides in the lifetimes of most of us, but there’s one message which keeps being reinforced: the more you know, the more you realise how limited your understanding really is. Scientific knowledge today is vast in extent, but constantly changing, usually incrementally but occasionally in quantum leaps. Just as one field of study seems essentially complete, new areas open up or, in some cases, the received wisdom is found wanting.
What we think of as knowledge is a hodgepodge of evidence, interpretation and theory. According to Karl Popper, science progresses by testing hypotheses against the evidence. As long as all the evidence is consistent with the hypothesis, this is taken as the current best explanation and may, over time, achieve the status of theory: never 100% proven, but as good an account of the facts as we believe is possible.
But the essence of Popper’s philosophy is twofold: that any hypothesis can be tested against evidence (that is, it is falsifiable) and that if any conflicting evidence is found, then the hypothesis must be revised or abandoned. While this may be a picture of an idealised way of doing science, the reality is often much messier.
The alternative philosophy of science, put forward by Thomas Kuhn, is that an accepted paradigm is formed and only replaced by another when sufficient evidence has accumulated for there to be a collective change of mind. In the words of Max Planck “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather because its opponents eventually die, and a new generation grows up that is familiar with it.” Or, to use a rather blunter paraphrase “science advances one funeral at a time”.
Whereas it was possible for a Lavoisier or Newton to make major discoveries as individuals with few resources beyond their own intellects, modern science is of a very different ilk. A range of specialities has been developed, in which researchers have deep but very specialised knowledge. The days of physicists and biologists having a good degree of comprehension of the other’s discipline are long gone and even connections between specialised silos in the same general area are often rather tenuous.
Because of this, much of today’s science advances incrementally in the way that Popper described, by proposing a hypothesis and testing it by experiment. But step changes in understanding are also still possible. Often, these still require years of painstaking work to provide the necessary supporting evidence, but the key ideas are often individual ones. Albert Szent-Gyorgyi (hardly a household name, but the winner of a Nobel Prize in 1937 for the discovery of Vitamin C) put it very succinctly: “Discovery consists of seeing what everybody has seen and thinking what nobody has thought.”
This independence of thought is what should be most cherished about science, but it takes courage for individuals to put their heads above the parapet on controversial issues. It is often said that journals are very eager to publish the work of some iconoclast, but in practice there is an inbuilt conservatism in major areas of science as in any sphere of work. Editors of major journals – and the reviewers of submitted papers – are part of the same Establishment which awards grants for research. Competition in academia is fierce these days, and there is rarely any funding available for work which questions some of the primary shared understanding of the scientific community. Being on-message greatly increases the chances of getting grants.
Despite its claim to represent rational thought and draw conclusions based on evidence, science is still to some extent a set of shared beliefs, some of which get overturned or supplanted over time. This can happen with or without conflict. A perfect example of how even the best science is to some extent provisional and incomplete is Newtonian mechanics.
Newton’s laws of motion perfectly encapsulate the behaviour of objects on a human scale. However, at cosmic scale and at speeds approaching the speed of light, this apparently cast-iron set of rules breaks down, and Einstein’s relativistic mechanics comes into play. His formulation of first the special and later the general theory of relativity has been found to be consistent with all the evidence gathered in the century since they were proposed. But relativistic mechanics do not replace Newton’s laws; they simply apply in different circumstances.
There are also plenty of examples of how basic understanding has changed completely, in conflict with prevailing belief; nowhere more so than in medicine. In the 17th Century, van Leeuwenhoek’s invention of the microscope showed the presence of what we now call microorganisms in water. Despite that, it was two centuries before the concept of germs as causes of disease was put forward and gradually accepted by doctors.
Until then, many diseases were believed to be transmitted by a ‘miasma’ of bad air (hence also, malaria, associated with the bad air of swamps rather than a mosquito-borne parasite). Personal cleanliness and sterilisation of surgical instruments, both of which we now take for granted as basic precautions to prevent the spread of illness, were at one time largely foreign concepts. Doubtless our great grandchildren will look back with horror on our primitive present-day understanding of disease and treatment.
These sorts of breakthroughs come sometimes because the area is seen as a fruitful one by the scientific community, but at other times it is the insight of a loner willing to question the received wisdom which catalyses the breakthrough. This attitude is one which we should encourage, particularly among young scientists. But it applies similarly to the general public.
We should all come to our own decisions based on the evidence we see, rather than simply take the word of an expert. The Royal Society’s motto is Nullius in verba, normally translated as ‘take no-one’s word for it’. Unfortunately, the Royal Society is the science Establishment, and prone to the usual inherent conservatism, despite the excellent work done by many of its Fellows. Nevertheless, both scientists and others would do well to adopt their motto and try to push the boundaries more, rather than simply be constrained by them.