The Science of Scepticism

June 1999 No. 138

Graham Marett takes up our challenge over PK with sketches inspired by Anna Marett.

On the night of October 11th 1492 Christopher Columbus “prayed mightily to the Lord” for divine intervention. The crews of the three ships in his expedition to find the Orient by sailing West were close to mutiny, and the captains of his two companion ships Niña and Pinta had begged him to turn back. History might have been different if Columbus had bowed to their entreaties, but whether by divine intervention or not his prayers were answered when at two o’clock in the morning the lookout on the Pinta sighted land in the moonlight.

They made landfall on an island of the Bahamas which Columbus named San Salvador, since it had provided their salvation. Until his dying day Columbus was not aware that he had failed to reach the Orient, and the precise location of his island of salvation has been a hotly debated issue ever since. Today there is general consensus that he landed at Watling island (which now bears the name San Salvador), but there is precious little in the way of hard evidence.

This story may seem to have little bearing on the issue of scepticism in science, but questions of theory, belief, speculation and truth are not restricted to the scientific domain and we can use this example from history to illustrate several points.

Leaving aside the question of ‘divine intervention’ we can ask ourselves what was the truth of the matter regarding Columbus’s precise landing site, and how it relates to the evidence and the beliefs of those who have researched the subject (even on the present-day San Salvador there are a number of different sites vying for the honour of being the actual place of landing.) The ‘truth’ will probably never be known: We have ‘facts’, such as Columbus’s log giving his description of their journey and the topography of the island, and a pitifully small collection of archaeological artefacts providing evidence for goods of Spanish origin. We have theories (at least half a dozen other islands have been proposed, with varying degrees of evidence), and we have beliefs in abundance (the local inhabitants will argue strongly in favour of the merits of their own favoured site).

What is the interested layman to make of this? He can read the copious literature which has been written on the subject, he can even visit the various locations and form his own opinion if he is so inclined. But what he cannot do is refer to some infallible, absolute source of information for a definitive answer, because no such source exists. The same can be said for all branches of knowledge, and in particular for scientific knowledge.

We have facts (observations and the results of experiment), we have theories (intellectual ideas linking together and explaining the observed phenomena), and each of us has our own personal set of beliefs (facts or theories which we accept as being true). But, as Pontius Pilate famously responded to Christ when he claimed to bear witness to the truth, ‘what is truth?’ (John, 18:38). In science as in all other branches of knowledge we do not have an absolute source of infallible truth to which we can refer, which is of course why science can be at the same time so fascinating and so frustrating.

Since we lack access to a source of absolute truth we have to rely on the next best thing, which is our own set of personal beliefs based on our assessment of the evidence and theories. If truth and belief are not the same thing, it is perhaps prudent to consider all our beliefs as provisional, and to dust them off and examine them with a critical eye from time to time. ‘Facts’ have a habit of changing over time (perhaps as new observations are made or as scientific methods become more sophisticated), and theories evolve as new intellects are brought to bear on the issues. Consider the following list of ‘truths’, and your own ‘belief status’ regarding each:-

When I started to prepare this list I imagined that I could list the items in descending order of credibility, so that readers would be able to pin-point their own ‘cut-off point’. I soon realised that this was impossible! Theological matters will divide people into atheists and believers of various faiths in a different way to issues of a scientific nature such as black holes or cold fusion, and non-scientists who are sceptical about the big issues of science may be convinced of the veracity of fortune tellers. Nevertheless, most people would accept certain items as ‘true’ to a very high degree of certainty (perhaps that the earth is round, for example), others as flagrantly false (the Elvis Presley myth?), and still others on which they would not like to commit themselves either way.

What would it take to make you change your mind on any particular belief? Perhaps you would be taken aback to meet Elvis face-to-face in your local supermarket (as was featured in a recent advertisement), but you would probably conclude that it was you who had been hoaxed rather than the world at large. On scientific issues which were outside of your own particular field of expertise you would perhaps consider the views of acknowledged experts in the field, and look out for comment from others whose views you respected (you may for example prefer to base your judgements on science columns in the serious broadsheets or science journals, and not on lurid headlines in the tabloid press).

It is often suggested that scientists have closed minds regarding matters on which they have already made up their minds (that is to say formed their beliefs), and are not open to suggestions that they may be wrong. This is especially the case with issues of a paranormal nature, which many scientists are said to dismiss out of hand. How, we might ask, can a scientist justify his belief in outlandish and untestable ideas such as a universe which originated with a ‘big bang’ billions of years ago, or the outrageous idea that human beings are just another kind of animal with no preordained special status in the greater scheme of things, when that same scientist chooses not to believe in paranormal phenomena which many people seem to experience regularly and which should be easy to put to the test?

This is a question which many scientists find hard to answer, since the way they formulate their beliefs depends on the subtle interplay between the nature of scientific investigation, observations, and theories. Scientific knowledge is built up over long periods, often measured in centuries or even millennia, and is based on careful, critical analysis of many observations and experimental results, coupled with clear and logical thinking. Occasionally, a great leap forward is made by the deep intuitive insight of a brilliant mind, but these insights are never accepted at face value by the scientific community as a whole but must themselves undergo rigorous analysis and testing by sceptical peer groups.

It is often the case that sceptics of the paranormal are challenged to explain particular psychic phenomena, and if they fail to do so it is taken as evidence that the phenomena must have a paranormal explanation. The scientists are then accused of burying their heads in the sand and ignoring the reality of the evidence. Is such criticism of working scientists valid? An important part of a scientist’s work includes publication of new results and findings so that data and new theoretical proposals are opened up to critical analysis by peer groups. This process is never plain sailing, and in all branches of science new findings are discussed and criticised in depth, often in heated debate, and often with the debate polarised by the views of non-scientists (the BSE saga and the current furore over genetically modified foods spring to mind!)

Gaining acceptance for new ideas has always been a difficult and challenging enterprise, and this continues to be the case today. Of the many examples which could be cited I will briefly mention three, one from the 17th century, one from early in our own century, and one very recent.

Galileo

In 1633 Galileo was placed on trial, condemned, and imprisoned after his grilling by the Inquisition for his support of the Copernican system, which placed the Sun rather than the Earth at the centre of the solar system. Although the new heliocentric view of the solar system quickly gained almost universal acceptance it was only as recently as 1992 that Pope John Paul II conceded on behalf of the Catholic Church that Galileo had been unjustly treated. On a related theme, I imagine that no readers of this magazine would claim to support the views of the Flat Earth Society (or will I be proved wrong by a flood of letters?), yet a quick check on the Internet revealed that the society is alive and well and busy denouncing almost all scientific advances since the Middle Ages (interested readers can check out the latest misdemeanours of science on http://www.talkorigins.org/faqs/flatearth.html).

Albert Einstein

Albert Einstein published his seminal work on Special Relativity in 1905, and his most famous and important work on General Relativity in 1915. His theories were triumphs of logical reasoning, and his theory of gravity has been described as, the most aesthetically beautiful creation in the history of physics. The predictions of the theory have passed every test with flying colours, and today his revolutionary ideas form the heart of modern physics and cosmology. Yet when Einstein was awarded the Nobel Prize for physics in 1921 it was for his work on the photoelectric effect, a major contribution to the fledgling new branch of physics known as Quantum Mechanics, and not for his revolutionary work on relativity, which was then considered too speculative and radical.

Even today there are many who do not accept Einstein’s theories. I am sometimes told that, just as Einstein’s theories were the death knell of Newtonian physics, so Einstein would be overthrown in the not too distant future. Such views indicate a lack of understanding of the progressive nature of scientific advances, and are not expressed by those who have taken the trouble to study the foundations and implications of relativity theory.

Cold Fusion

In 1989 spontaneous ‘cold fusion’ of deuterium (in the form of ‘heavy water’) was reported to have taken place at modest temperatures under laboratory conditions. These findings were controversial, and have been the result of intense research in many laboratories in the subsequent decade. So far the findings have not been duplicated, and there is widespread doubt in the scientific community about the validity of the original experiments. Yet the proponents of cold fusion battle on against the odds, and who knows? Perhaps the next Millennium will see the advent of an unlimited free source of energy from tap water!

Close scrutiny by peer groups and others is the fate of any new finding in science, and many more examples of scientific advances which have either flourished or fallen on fallow ground could be cited. But when evidence of psychic phenomena consistently fails to pass the rigorous tests of sceptical analysis scientists are routinely accused of bias or a lack of openness to new ideas. It is certainly true that most scientists are wary of devoting their efforts to research into the paranormal, but this is usually due more to the dismal success record of such endeavours in the past than to any lack of interest in the subject. I have not heard of any big lottery winner claiming that (previously acknowledged) psychic powers helped with the selection of the numbers (or are those with paranormal powers too public spirited to use their endowments to their own advantage?), and property vendors are not yet obliged to refund the purchaser’s money if the house they sell proves to be haunted (as reported in a recent news item). Nor is government policy, as far as I am aware, influenced by astrological predictions regarding the future of the economy.

Critics of science sometimes claim that psychic phenomena, like religious faith, lie ‘outside’ of science and cannot be subjected to the same kinds of analysis or verification. This has always seemed to me to be a rather spurious argument, since science purports to concern itself with the totality of phenomena which make up our universe – how can any phenomenon be exempt from such an all-encompassing endeavour?

It is also often suggested (and has been in this magazine) that sceptics who fail to acknowledge the reality of paranormal manifestations are living in the dark ages, and should take note of the many errors of judgement made by scientists of earlier generations. In particular, it is often stated that if all scientists had been so obtuse we would still believe in a flat Earth and a universe centred on the Earth. This too is a spurious argument, ignoring the fact that the Copernican revolution (and any other major advance in science, for that matter) had nothing to do with open-mindedness about the paranormal but everything to do with careful observation of natural phenomena, clear and logical thought, and the construction of theories which made specific predictions which could be rigorously tested by experiment.

Research into psychic or paranormal phenomena is fraught with difficulties, since the true believer is rarely persuaded by the results of scientific tests, however convincing they may be. As an example of the power of entrenched beliefs consider the case of the Turin Shroud, venerated for centuries as the linen shroud described in the Gospel of St Mark, and in which the body of Christ was wrapped after it was taken down from the cross. The authenticity of religious relics has always been a touchy subject, and scientific analysis is often deemed inappropriate in such a context. However in 1988, after intense historical scholarship and renewed scientific interest in the subject, the keepers of the shroud released small portions for radiocarbon dating. The results were devastating: the shroud was revealed to date from no earlier than the Middle Ages, and although its precise origin could not be established it was almost certainly an elaborate forgery.

This I imagined would be the end of the matter, and certainly enthusiastic believers in the shroud’s authenticity were crestfallen and subdued for a number of years. Today, however, millions are said to venerate the shroud, and it is claimed that the samples tested were ‘unrepresentative’. The Church has recalled all outstanding samples and declined to sanction further tests. In science new ideas can never be cut off from further study in this way, and the work of any scientist is always open to critical scrutiny

The true sceptic recognises that the boundaries between religion, science and pseudoscience will always be fuzzy, but he also acknowledges that the power of the scientific method must always take precedence over preconceived ideas and prejudices. It is right and proper that the exponents of the paranormal should face a steep uphill battle to gain respectability for their claims: after all, it is the same uphill battle which scientists in all fields must fight to gain acceptance for new ideas.