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Water companies use dowsing to find leaks

Today's Daily Mirror reports that an engineer working for the Severn Trent water company used dowsing to search for a leak at a property. The property owners' daughter, who is studying for a Ph.D in evolutionary biology at Oxford University, contacted the water company; they confirmed that some of their engineers practise dowsing and they have no objection. She then wrote to other water companies and found that nine of them used dowsing.

Dowsing is generally regarded as pseudo-science. Wikipedia lists a number of scientific studies of the practice that have been conducted since the early twentieth century; they have almost uniformly found the results were no better than chance.

A number of homeopaths use dowsing, usually with a pendulum, to choose their medicines. In the 1980s, when I was a physician at The Royal London Homeopathic Hospital (now The Royal London Hospital for Integrated Medicine), I contacted a dowsers' society to ask if their members were willing to take part in a trial to see if they could distinguish real homeopathic medicines from placebos. They agreed to do this and I started to set up the trial, but unfortunately they then backed out.

The priesthood of public health

Richard Lehman has a blog about medical research at; extracts from this appear as Research Update each week in the BMJ.

On 16 July 2016 Dr Lehman had a nice comment on a recent JAMA article on "the theology of eating fat", in which he referred to diet pundits as "the priestbood of public health". The occasion was a recently published large-scale study of nurses and doctors in the USA, which concluded that saturated fat is bad for you.and polyunsaturated fat is good. Lehman's comment is that it "doesn't provide the priestbood with very much to preach about in my opinion".


There's a good piece by Jim Davies called 'Academic Obfuscations: The Psychological Attraction of Postmodern Nonsense' which you can read at the Skeptic Society's Lectures site.

Davies discusses why people read obscure passages in academic articles that make little if any sense. In essence, his answer is that because readers have to work hard to extract meaning from the obscurity they value the meaning they think they have found all the more.

So what is the pull of obscure writing, of which some postmodern writing happens to be an example? I argue that some prefer it because each reader has to do so much work to get any meaning out of it, and when we have to work hard for something, we really value it. We can mistake obscurity for profundity.

I'm sure this is correct. And the unfortunate corollary is that writing that is clear and easy to understand is less likely to gain acceptance for ideas that the reader doesn't agree with already.

Still, I remain an advocate of clear writing. In this I agree with the late F.L. Lucas, whose book Style has been my guide for how to write for many years. Lucas valued clarity above everything else and was scornful of writers who sought to dazzle their readers with pseudo-profundity. Here are a few quotes from his book.

I draw the conclusion that it is wiser to use one's mind as telescope, or microscope, or magic crystal, than as a looking-glass; and I would suggest that it is foolish to take singing-lessons from peacocks.

Many writers, especially of an academic or aesthetic kind (and never more than today), seem to me to stultify themselves because they are neither clever enough to be brilliant, nor honest enough to be simple.

A clear word is like a finger-post pointing straight at its object; but our abstract terms are too often like signposts with many arms, some broken, some twisted, some half-effaced, pointing into a fog.

Those who chase originality... are more likely to find they have caught instead her ugly sister eccentricity...

Book review: Paleofantasy, by Marlene Zuk

There is a widespread belief that many of our modern ills, physical and mental, result from a mismatch between our genes and the artificial environment that we have created for ourselves. Books, magazine articles, TV programmes, and numerous websites popularise the view that we were shaped over many thousands or millions of years to live a hunter-gatherer existence in small groups, yet now we live in huge cities with millions of inhabitants. In this 'unnatural' environment we encounter an abundant supply of food and drink of kinds that we are not evolutionarily adapted for. A critical point in our path to all this was the adoption of agriculture a 'mere' ten thousand years or so ago. The path to salvation lies in returning to the habits and diets of our palaeolithic ancestors.

This is an intuitively appealing story, but is it true? According to Marlene Zuk many of the assumptions on which it is based are questionable. While not rejecting the importance of evolution in shaping us - quite the opposite - Zuk picks the presuppositions of the 'paleofantasists' to pieces and shows how ill-founded many of their ideas are. In me, this prompted the thought that the current enthusiasm for life in the palaeolithic really a modern version of the myth of the Noble Savage or a secular version of the legend of the Garden of Eden. [More]

Precognitive dream?

Opening today's Independent I read an article about a surf-boarder in Australia who had two fingers bitten off by a shark. I then remembered that last night I had dreamt of a man who had his nose bitten off by a shark.

There have been numerous claims for precognition in dreams. Mine would appear to be an example and I have had similar dreams in the past. But are they really precognitive? The usual counter-argument is that millions of people in Britain dream every night and by chance there will sometimes be some dreams that coincide with events. I think this must be the right explanation.

At a more trivial level, I sometimes have the radio on when I'm at the computer, and from time to time I find myself typing a word at the exact moment I hear the same word spoken on the radio. Sometimes this has been a very unusual word. These coinidences are obviously just that - concidences - and I think the same must be true of apparently precognitive dreams.

We find this difficult to accept because we tend to attach significance to dreams, even if we are not Jungians. For many dreams, like this one, there has been no identifiable precipitating event in the previous day and this makes the coincidence seem more spooky. But if I could identify some trigger for the dream in something I had experienced or read during the day, the spookiness would largely disappear. Such a trigger presumably does exist; it's just that I don't know what it is.

Telomeres - the latest "scientific"(?) way to tell your fortune

Today's Independent has a piece about having your telomeres measured. These sequences at the ends of chromosomes are alleged to give an indication of how far your biological age differs from your chonological age. The longer they are, the longer you are likely to live. The test is now available commercially; it's still expensive but is forecast to become increasingly cheaper in coming years, to the point where everyone will be able to afford it.

The one prediction I'm prepared to make is that it will be a money-spinner for the Spanish company that markets it. Professor Carol Greider, who won a Nobel Prize for her work on telomeres in 2009, is sceptical about the value of the test but that won't prevent many thousand or millions of people from taking it. Another egregious example of useless screening. Plenty more about this in my blog - search for "screening" with the search button on the right for links.

Looking forward to the end of the world (Mayan calendar)

I'm looking forward with pleasurable anticipation to next Friday, 21 December, to see how people who believe that the world will end then, courtesy of the Mayan calendar, will react when nothing happens. Judging by historical precedents offered by previous unfulfilled predictions of the kind, few believers will admit to having been fooled and ways of reconciling fact and faith will be found.

Scepticism, homeopathy, and the Swiss Government report

For some reason the fact that the Swiss Government had produced a favourable report on homeopathy had escaped my notice until today, but when I learnt of it I looked it up on the net. This brought me to the Quackometer site, which has a discussion of the report called The Swizz report on homeopathy.

Well, of course, you'd expect the Quackometer to be critical of a report that supports homeopathy, but fortunately their piece contains some quotations from the Swiss article which help us to make up our own minds..

The current thinking and research of mainstream medicine are influenced mainly by Newton’s mechanistic and strictly causal-analytical physics (classical reductionist biomedical model), which ignores the more complex phenomena of nature, the organism’s systemic correlations, its life processes and overall regulation, and life as a whole, as well as qualitative experiences and the phenomena of spiritual science.

This passage is a complete give-away, particularly the reference to spiritual science. This will no doubt puzzle many readers, but anyone who knows anything about Anthroposophy, the so-called "Spiritual Science" founded by the philosopher and mystic Rudolf Steiner in the first half of the twentieth century, will recognise the term at once. It seems certain that Anthroposophical influences helped to shape the authors' conclusions.

So Newton is outmoded and a waste of time but science is not a total washout, it seems. Further on, predictably, we are told that homeopathy is supported by quantum physics.

Modern physics with its theory of relativity and quantum physics has long overtaken Newtonian mechanics and is paving the way for an understanding of the homeopathic mechanism of action.

Since few of us who are not trained physicists have any deep understanding of quantum mechanics or relativity we mostly have to rely on non-mathematical descriptions of these things written for readers like us. Some of these are very good, but physicists assure us that verbal accounts cannot give an in-depth understanding of the matter. Quantum mechanics is often invoked to explain the action of highly dilute homeopathic medicines. Often, I think, this amounts to little more than asserting that quantum mechanics and homeopathy are both mysterious, so they ought work in the same way. Moreover, if science can tolerate the paradoxes of quantum mechanics, why baulk at homeopathy?

Just to round off, I should point out that we even get the long-discredited idea of the vital force.

The vital force, just as vitality in general, cannot be measured and quantified by science, but it exists as a phenomenon.

I admit I haven't read the whole of this (long) report and perhaps some parts of it are better. But at least it seems clear that its authors are hostile to the values of the Enlightenment, which is enough to move it a long way down my reading list.

Getting away with it: Jimmy Savile, Laurens van der Post, and Eric Gill

The current furore over the unmasking of the late Jimmy Savile as a paedophile reminds me of two other once-revered figures who also 'got away with it' by dying before their misdemeanours came to light.

One was Sir Laurens van der Post (1906-96). Storyteller, J.D.F. Jones's biography of this erstwhile guru, informs us that his numerous sexual liasons were conducted with little apparent regard for the feelings of the women concerned. More than once, it seems, an unwanted pregnancy was the signal for Laurens to decamp hurriedly and disappear. But the most startling episode of the kind occurred when, at the age of 43, he seduced and made pregnant a 14-year-old South African girl who had been placed in his care. This event, which would have ruined Laurens if it had become known in his lifetime, was not revealed until after his death.

The other figure was Eric Gill (1882-1940). He was a renowned sculptor and designer, a group of whose sculptures can be seen on the front of BBC Broadcasting House in London. Like Savile, he was a Roman Catholic. He was deeply religious but his personal diaries recount repeated episodes, not merely of paedophilia, but of incest. As his entry in Wikipedia states, 'Gill sexually abused his own children, had an incestuous relationship with his sister and performed sexual acts on his dog. This aspect of Gill's life was little known until publication of the 1989 biography by Fiona MacCarthy. The earlier biography by Robert Speaight mentioned none of it.'

The Tibetans, it is said, hold that you should not expect a guru to be a guru all the time. Instead, you should recognise that all gurus are flawed and should try to catch the guru when he is being a guru. This may be true, but these three individuals do seem to have taken matters to extremes.

Note added 24 February 2020: The disclosure of sexual abuse of women over many years by Jean Vanier, the founder of L'Arche, an international federation of communities spread over 37 countries for people with developmental disabilities and those who assist them, should he mentioned here. Vanier, who died in 2019, had been praised for his work by Pope Francis and was revered as a spiritual adviser by many; he might even have seemed a possible candidate for sainthood. Unlike the other two people I refer to in this post, Vanier was confronted by one of the women involved shortly before his death, but the full extent of his activities didn't come to light until later.

A full account of this affair has been published by L'Arche International and is available online. See the Wikipedia article on Vanier for more details and links.

Nice iconoclastic article in BMJ

This week's BMJ (10 Sept 2011) has a nice article by Nigel Hawkes expressing doubt about the validity of much of the dietary advice we are so often regaled with.

The lesson we should have learnt by now is that laying down dietary guidelines that are based on the evidence of the day is a task to be undertaken with humility, Almost every nutritional 'fact' is in reality an opinion, often based on poor quality evidence.

Hawkes is making the same point as Gary Taubes in The Diet Delusion. Both repay reading by anyone of a sceptical turn of mind.

End of the world on my birthday?

An American preacher, Harold Camping of Oakland, California, is predicting the Second Coming and the 'rapture' for tomorrow, 21 May. As this is my birthday I suppose you could say this will be an unexpected birthday present for me, except that, as a non-believer, I don't think I shall be among the two per cent of the population who qualifies for immediate translation to heaven. Oh well ...

Did the ancients know about the precession of the equinoxes?

The "precession of the equinoxes" refers to the slow shift in the Earth's axis of rotation, which produces a gradual change in the positions of the constellations. The axis of rotation of the Earth is wobbling, like a spinning top. A complete revolution of the axis takes approximately 26,000 years. This is known to astrologers as the Platonic Great Year.

I was listening today to the BBC programme Start The Week, in which the astrophysicist Jocelyn Bell Burnell was talking about the current Internet flap concerning a Mayan prophecy of the end of the world on 21 December next year. She did a good job of showing this up as an egregious example of pseudoscience, which of course it is. She is due to give the Faraday Lecture on the subject at the Royal Society.

But she also mentioned that the Mayans, along with a number of other ancient peoples, including the Babylonians and Sumerians, all knew about this 26,000 year cycle. But did they?

According to Gary D. Thompson, whose scholarly website on ancient astronomy is the place to go for information about such questions, the idea of ancient Mesopotamian knowledge of the cycle is a myth. In his extensive discussion, The Myth of Babylonian Knowledge of Precession, he writes:

"The hypothesis that the Babylonians knew precession can be confidently dismissed. The hypothesis has been adequately refuted by the studies of the astronomer and Assyriologist Franz Kugler, the mathematician Otto Neugebauer, and the Assyriologist Abraham Sachs."

Wikipedia is equally dismissive of claims for knowledge of precession on the part of the Babylonians and ancient Egyptians, and indeed the Mayans. "There has been speculation that the Mesoamerican Long Count calendar is somehow calibrated against the precession, but this view is not held by professional scholars of Mayan civilization."

Dr Bell is a most eminent scientist, who discovered the first radio pulsar as a postgraduate student (although, controversially, she was not listed as a co-recipient for the subsequent award of a Nobel Prize). Perhaps she has information about the Mayans and others that I don't know of, but I thjnk that in this case she has not been sufficiently sceptical.

I'm interested in the question because I was myself taken in at one time by pseudo-scholarship about ancient knowledge of the precession. I was drawing on a strange book, Hamlet's Mill, by de Santillana and von Dechend. I included their ideas in my own book The Assassins of Alamut. Thanks largely to Thompson, I now know that those authors' claims are invalid, and I deleted the discussion from my book.


A recent New Scientist article by Laura Spinney (16 November 2010) says that the chances are that, as a reader of the magazine, I am "western, educated, industrialised, rich and democratic, aka WEIRD." In this respect it appears, I am in a minority: seven out of ten of the world's population think differently. Analytic thinking, psychological research suggests, is a minority pursuit.

The serious message for psychologists is that they need to expand their subject pool before they start drawing conclusions about human psychology, or else restrict those conclusions to the subpopulation whose members they have recruited for their study. As for you, the next time you watch a documentary about the San people or Amazonian foragers, try to remember that you're the exotic one.

I don't find this idea surprising, because I've often thought something of the kind, but I do find it disturbing. This way of thinking became dominant in the West as a result of the Enlightenment movement and it is probably essential for science to work. It also underpins the rejection of religion, which, again, is an unusual feature of modern life, at least in Western Europe.

An important difference between WEIRD individuals and those in other societies is how they think about individuality. Westerners typically attach a lot of importance to individual autonomy, whereas people in east Asia seem to think of themselves more as members of a community. I certainly recognise this trait in myself. For example, I have little interest in any team games, whereas I enjoy watching tennis and boxing.

The article seems to assume that these differences are culturally determined; "all humans have the same kind of brain." But do they? in What's New? Matthew D. Lieberman has an interesting discussion of why certain ideas, such as mind-body dualism, seem to be so deeply ingrained in our consciousness. He suggests that the answer may be found in Terrence Deacon's important hypothesis about the way languages are transmitted. Deacon believes they have evolved to be easily grasped by the human brain, especially the brains of children. In the same way, Lieberman suggests, "Big Ideas" correspond to brain structure and function and evolve over time to fit even better.

Lieberman goes on to show that there may be genetic differences between East and West in the way such ideas are taken up by the brain. Eastern cultures tend to favour ideas of the interrelatedness of individuals in society, whereas the West inclines more towards individualism. This difference may not be purely cultural in origin but may be connected with genetic differences in the regulatory portion of the serotonin transporter gene. People in the East tend to have a version of the gene that makes them more dependent on a social framework of mental health; if the framework is lacking they become depressed. Westerners, in contrast, mostly have a different genetic make-up which renders them less dependent on social and family support. Lieberman concludes that differences of this kind may help to account for differences in religion.

I can't escape from the way I see the world and I don't want to. I'm a passionate advocate of the values of the Enlightenment. But I am willing to admit that I'm in a minority, and I also think that even in the West we are witnessing a reaction against those values. They are not guaranteed to endure for all time.

Correcting the error in retinal design

I still remember how surprised I was as a medical student when I learnt that the mammalian eye is designed back to front. I thought I must have misunderstood. The fibres of the optic nerve are placed in front of the photoreceptors (rods and cones) instead of behind them, so that the light has to traverse the fibres before it reaches the light-sensitive area. This arrangement also produces the blind spot, where the optic nerve leaves the eye.

My surprise was of course based on a misunderstanding about evolution. Natural selection has no foresight and the structure of the eye wasn't planned; it was simply cobbled together bit by bit. According to today's New Scientist (8 May), however, the mammalian eye was later modified to compensate for this. The Müller cells support and nourish the overlying cells in the retina but also collect, filter and refocus the light to give a clearer image. So evolution first botched the design and then took steps to put things right.

What this puts me in mind of is the Hubble space telescope. Initially this was sent into space with a design fault, which had to be corrected later by a mission from earth. In that case there were of course human designers behind the telescope. If creationists wish to apply the same logic to the eye to infer the existence of a Creator they must also conclude that said Creator was as fallible as were the telescope designers. At most, this would be evidence, not for an omniscient Creator in the Christian sense, but for a Platonic demiurge - a superhuman being who did his best with what he found to hand but made a bit of a mess of things. The suggestion that this world is a computer simulation by a superhuman civilisation would also fit the facts for anyone who wishes to reject Darwinian natural selection.

Book review: The Diet Delusion, by Gary Taubes

I've just posted my review of Gary Taubes's book The Diet Delusion. This is an in-depth critical examination of the received wisdom about diet. Taubes makes a good case for rejecting the alleged link between dietary fat and heart disease and instead attributes obesity to carbohydrates. It's an excellent piece of science writing - strongly recommended.