The British Caving Association

Dowsing and the Doctrine of Naive Analogy
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Author:  David Gibson [ Sat 08 Jun 2013 18:57 ]
Post subject:  Dowsing and the Doctrine of Naive Analogy

This 'Letter to the editor' is scheduled to appear in CREG journal 82, to be published in June 2013. See

Dowsing and the Doctrine of Naive Analogy

One of my earliest involvements with BCRA, over 20 years ago, was to listen to John Wilcock give a talk on dowsing. John prefaced his remarks by explaining that he approached the problem as a scientist, and maintained a healthy scientific scepticism. However, the recent article by Wilcock and Bagley [ref. 1] makes me doubt that the authors understand the scientific approach after all. They actively proclaim their professional qualifications, hoping we will be take them seriously as a result, and then they dream up ‘scientific’ explanations that, to quote a phrase from the famous physicist Niels Bohr are “not even wrong”!

John Newman [ref 2] quoted, in his comment on the article, Langmuir’s concept of ‘Pathological Science’. I have a similar description, which I have called the Doctrine of Naive Analogy. I have collected several examples of this, over the years, where the proponents of dubious scientific theories have clearly not understood the principles on which they base their assertions. A classic example of this doctrine is Hately’s crossed field antenna, for which (as he told me personally some years ago) he was thrown out of the IEE (now IET) – and rightly so!

Followers of the Doctrine (as Wilcock and Bagley clearly are) disregard several basic principles of science. They assert that ‘any hypothesis has value until disproved’, which is clearly Bad Science, and they do not obey the axiom quod supplantandum, prius bene sciendum, or ‘Whatever you hope to supplant, you will first know thoroughly’. Instead, they, produce hypotheses in ignorance of basic physics – the Naive Analogy.

I should say, at this point, that my objection to Wilcock and Bagley’s creed is not that ‘dowsing doesnt work’, it is that they are claiming to be scientists, but exposing themselves as fools. If we are to have a debate about dowsing, it has to be done on a scientific basis – quod supplantandum, prius bene sciendum. We do not have to limit ourselves to conventionally held wisdom – I am not afraid of the suggestion that dowsing may be paranormal – Im just saying that the Naive Analogies of Wilcock and Bagley should not be considered a good starting point.

John Newman listed a number of tell-tale signs of pathological science. To that list I would add: the use of overly complicated explanations that, on close inspection, do not actually make sense. Wilcock and Bagley’s spiral wavefront, ... modulating the Larmor frequency – quod supplantandum, prius bene sciendum. I struggled to understand and, for a while, I questioned my own detailed knowledge of this field. Then I re-read the article and noted this paragraph...

It should be pointed out that there is a certain philosophical ‘circularity’ in our experimental work because we used dowsing to investigate that which we are dowsing. Some people will use this to reject our results, but we decided we should ignore such an eventuality and press on, gaining understanding as we go.

In other words Wilcock and Bagley’s experiments amount to nothing, and this is why their ‘scientific’ explanation does not make sense – it is not based on any proper results, let alone on a proper understanding of electromagnetic theory.

So, how can they recover from their faux pas? Wilcock and Bagley do not appear to understand how proton precession at the Larmor frequency takes place – or at least, it is not clear, from their article that they are not simply making another Naive Analogy. Or, perhaps I’m being unfair, and they are just no good at explaining themselves? This matter is easily rectified without needing to do any dowsing. They both claim to be scientists; they both flaunt their credentials as members of a professional body for electronic engineers, so here’s a straightforward exercise for them – 1) Write down the magnetic moment of a bucket of water in which all the protons are precessing in the most favourable manner. 2) Explain how you would achieve this unusual state of affairs. 3) Calculate the magnetic field that results from this, and show how you would detect it using a small search coil and an amplifier.

This is a fundamental and very helpful exercise, which would give them the credence they need – quod supplantandum, prius bene sciendum. The next stage, of course is to build (or have built for them) the search coil / amplifier and use it to make the measurements. But this may not be necessary, because the real problem with Wilcock and Bagley’s hypotheses is that they have totally failed to understand signal to noise ratio. Just how is a very small electromagnetic signal supposed to travel through many metres of rock and then somehow be distinguishable in the human body from all the other background noise in that frequency band? Any hypothesis that it does so does not “stand until disproved” as Wilcock and Bagley would say, because it is a hypothesis of Naive Analogy. You may as well say that it is “valid” to hypothesise that dew is caused by the fairies watering the grass – does that “stand until disproved”?

Once again, let me state that this letter is not an attack on dowsing. It is an accusation of lax scientific principles from two people who claim to be scientists and ought to know better. If they are going to hypothesise that dowsing is explainable by an electromagnetic phenomenon then they really need to understand the principles more thoroughly than they have demonstrated. Alternatively, they need to ‘come clean’ and hypothesise that dowsing is paranormal. There is nothing inherently wrong with that approach – the British scientist Rupert Sheldrake has made a career by showing that the scientific method can be applied to such phenomena. Devising some Sheldrake-style experiments that truly tested dowsing would gain Wilcock and Bagley some needed respect. As it is, they do not do much to get dowsing accepted as a valid phenomenon (assuming it is) by inventing such dubious physics.


1. Wilcock, John and Geoff Bagley (2013), Why Won’t Dowsing Go Away?, CREGJ 79, pp4-8 (Sept 2012) & CREGJ 80, pp16-19 (Dec 2012)
2. Newman, John (2013), Letter: Dowsing – Maybe not?, CREGJ 81, p19 (March 2013)

Author:  David Gibson [ Mon 29 Jul 2013 16:39 ]
Post subject:  Re: Dowsing and the Doctrine of Naive Analogy

The previous post was written to fit on the letters page of the CREG journal, so I was not able to go into very much detail. But lets now look at Wilcock and Bagley’s ‘understanding’ of the Larmor frequency. This is the frequency at which the protons in the nuclei of the hydrogen atoms in the water molecules precess around the axis of a magnetic field. This is an aspect of ‘quantum spin’ and I should perhaps point out that the classical description of ‘spin’ is very much out of fashion now – the name has stuck, but you shouldnt take it too literally.

It is difficult to extract much sense from Wilcock and Bagley’s description. Im not sure if they think that water just ‘sits there’ and whistles at the Larmor frequency, or whether they think they can get it to do so by agitating it, but both suggestions are wrong. Left on its own, a bucket of water will emit no signal, because there is no coherent proton precession. The effect manifests itself, typically, when the protons are aligned by a strong external magnetic field, which is then suddenly collapsed. The residual field due to the earth’s magnetism then causes a transitory effect, whereby the protons exhibit a decaying precession about the magnetic field axis, which lasts for a few seconds until they lose their coherence.

So we come to Wilcock and Bagley’s bizarre experiment where they introduce a vortex into a bucket of water and claim to detect an effect. They seem to be saying that they can shake up the water and cause the protons to precess, emitting a signal at the Larmor frequency. Do they think that their vortex somehow ‘spins’ the protons? This is to misunderstand the origin of the effect since the ‘spin’ involved is not a classical, 'physical' spin, it is a quantum effect. And it only arises when the protons are all aligned in the same direction because otherwise any effects would simply cancel out. Simply taking a macroscopic sample of water and rotating it in a vortex is not going to achieve this. Or to put it another way - if spinning a (non ferromagnetic) substance at these (moderate) speeds caused it to manifest a detectable signal, somebody would have noticed by now! If Wilcock and Bagley are the first to notice this, surely this is Nobel prize material?

The effect I have described can be analysed by some straightforward mathematics. This can give you not only the frequency of the signal but its magnitude. And this brings me to my main criticism: the effect is tiny! How is it supposed to be transmitted through many metres of rock and still be detected? Wilcock and Bagley clearly have no concept of signal-to-noise ratio which is a staggering, if not somewhat shameful omission on their part.

And yet they claim to have detected a signal! Im not sure what they mean by a ‘spiral wavefront’ since Im fairly sure that no electromagnetic effect could possibility result in such an unusual phenomenon. But this is where it gets interesting – have Wilcock and Bagley actually detected something? There are two conclusions. Either ...

a) there is no effect and they have completely imagined it – they have convinced themselves that they have detected what they expected to find. We laugh at their antics! One of them sets up an experiment and says “I think we’ll see a spiral wavefront here” and the other waves his dowsing–fingers and agrees. Its just like Hamlet and Polonius – “Do you see yonder wavefront that’s almost in the shape of a spiral?”. And, of course, Hamlet was not entirely in touch with reality, and Polonius was a bit of a buffoon.

or b) there is an effect, and as expert dowsers they have detected it, but it is unexplainable by known physics - well done! - and I mean that most sincerely. Unfortunately, the evidence for this is far less than the evidence that they are just sloppy scientists who have performed the most basic errors in experimentation and created a load of mumbo-jumbo to attempt to explain results which cannot be independently verified because ...bizarrely ... they rely on dowsing itself to confirm them.

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