Dowsing is one of those difficult subjects that bring out the worst in people: the mystically inclined get carried away by spiritual energies while otherwise sober and rational scientists rant with rabid, even evangelical fervour against the mere mention of the idea. Ley lines fare little better, with historians also keen to offer dubious theories that keep the pot boiling. So when I choose to tell you about my own experience of dowsing a ley line and the events which surrounded it, I trust you will forgive me. But it needs to be said, if only to honour the man who developed the first truly rational and scientific theory as to how it all works.
Anthony Hopwood, Tony to his friends, was a highly intelligent and imaginative scientist who unfortunately suffered from severe dyslexia and dyspraxia - inabilities with spelling and numbers. Consequently he could never tackle higher mathematics, write a serious scientific paper, or cope well with computers. He was forced to work, unqualified and unsupported, outside the mainstream. But he was as sharp as a razor, understood electricity and magnetism better than anyone I have ever met and could wield a soldering iron with the greatest ingenuity and effect. Sadly he died a few days ago on 26 June 2014, so this essay stands as my epitaph to a great man.
I first met him when he appeared in my parents' garden many years ago, dashing about enthusiastically with his dowsing rods and demonstrating how he could do it blindfold. There he found a ley line, cutting diagonally across the garden wherever a lack of trees and overhead pylons allowed him to dowse it through. I tried his dowsing rods, and it worked! I closed my eyes and it still worked. We stuck in a line of thin posts and took a compass bearing. Afterwards over tea, Tony explained how in conditions of poor visibility, such as in fog or at night, a dowser would naturally follow a ley to avoid getting lost. Old trackways would then equally naturally be found along them. There was also often a curious pattern of repetition near them, which led to a kind of grid of subsidiary lines emanating from the main one, some parallel and some across it. In fact, I had watched while Tony found our ley by working from one to another of these in the direction of increasing strength. These subsidiary lines might in turn lead to the creation of parallel local tracks. We should also expect to find archaeological features scattered along the track, again easy to find in the dark. I got out a large-scale map and we plotted the line through our garden. There they were! It ran from Little Malvern Priory on the Malvern Hills, parallel with many a straight stretch of our winding local lanes and right along one of them, through a good number of old farmsteads and across the river Severn - smack where the old ferry lay disused. Near the Eastern bank sat Towbury Hill, an old Iron Age earthwork fort, one side parallel to the river and a nearby brook and one inexplicably askew. That skew side lay along the line. Beyond there it faded off into the Vale of Evesham.
Of course! Imagine you are a shaman or similar, asked where to put the new mill or whatever. You work up your ritual, take hold of your hazel twigs or whatever and trot off along the river bank. When you reach the ley, bingo! the twig twists in your hands - where else could be more auspicious than a spot chosen by the Gods?
Except, Tony did not believe in such Gods and neither did I. There had to be a more mundane reason why the ancients were so frequently able to recognise ley lines. An idea mooted at the time was that the human nervous system could pick up stray magnetic signals from the air and somehow amplify them into visible movement, especially if they were tensed in an awkward position holding a twig or a couple of dowsing rods, or perhaps holding a pendulum. This was his starting point, although the technical case for magnetism as such was pretty shaky and he wanted to explore other electromagnetic fields.
He began working on experiments to nail down the signal, looking for electromagnetic energies in the air that might affect the human nervous system. He would come back to our garden from time to time with this or that lashed-up frequency generator to see if it affected the ley line. He was not above risking a few minutes' unlicensed upset to the Royal Signals Research Establishment as it then was, a few miles away over the open fields. I think Defford may have still been active then too, more or less in line of sight across the river. Thankfully, nobody ever came knocking at the door. When he did finally ferret out the answer it was both simple and subtle. First, the dowsing sense:
First he confirmed that magnetism didn't do it. Radio waves at any reasonable frequency didn't do it either. But then he turned to another field which permeates the outdoor air around us, a natural electrostatic field between the ground and the sky. The air acts as an insulator between above and below, and when it breaks down we call the spectacular result lightning. The field is enormous, around a thousand volts per metre. You can release a lot of energy when that short-circuits, perhaps you could release enough to affect a nerve fibre just by disturbing it. Could dowsing be an ability to detect disturbances, local variations, in this powerful field?
And so it proved. He put up a metal bar overhead. With the bar earthed he could dowse it in an under-the-trees kind of way. He made a high-voltage generator and attached it to the bar. With the generator at full whack the bar stood out against the background sky and he could dowse that too, with his rods swinging the opposite way. But when he turned the generator down a little so that the field strength under the bar exactly matched the field strength in the free air all around, an amazing thing happened: he could no longer dowse it. It had somehow become invisible to his dowsing sense, merging like a chameleon into the background field. This seemed to be the secret to dowsing, it all made sense and the test was repeatable.
But what about ley lines? They too were thought to be magnetic in nature. Earth currents flow through the ground, generated by lightning strikes and other forces. Any current flow creates a magnetic field around it. Where such a current meets a geological fault line its flow is disturbed and so too is its magnetic field. The current cannot change size but it can - and must - change course. Surely such a fault line would leave its stamp in the magnetic field above ground. But experiments attempting to correlate the properties of such magnetic fields with dowsing had repeatedly failed, allowing the sceptics to crow with delight and the mystics to hold their faith.
Tony however recalled his basic physics, that wherever there is a changing magnetic field there must also be a changing electric field. Where an Earth current changes, its magnetic field changes and the associated change in electric field would affect the ambient electrostatic field. Could we be sensing not the changing Earth current but the change in the electrostatic field near it? That would explain why things like running water, trees and power lines mess up the detection of ley lines - they all in their different ways affect the electrostatic field between ground and sky. A few more experiments with his test rig seemed to confirm his suspicions.
The only thing he did not tell me was whether he thought the subsidiary grid was down to additional cracking in the geology or some kind of resonance in our ability to dowse. But really, that is not important to the basic principle. To all intents and purposes, it was a wrap.
But Science with a capital S was not convinced. And quite rightly so, for like every result in science it needed independent verification. And here, sadly, Science did not acquit itself well - or at least not if the journalist who reported it was accurate. The experiment is described in the journal New Scientist, 22 October 1981. Its designers were illustrious enough: Denys Parsons, CSICOP, Prof. Bernard Watson and television personality Prof. Heinz Wolff. The idea was that Tony would try repeatedly to dowse a high-voltage cable strung above his head without knowing if it was switched on or off. Wolff was to sit nearby, calling out each test in a long series. When he arrived on the day, Tony immediately saw a fatal flaw in the setup. The experiment was to be conducted indoors, inside a large lecture hall. The hall had plenty of metal in the roof or ceiling, both structural and in the mains wiring strung through it for the lighting. It must have been just like his attempts to conduct experiments in my parents' apple orchard - hopeless. He told them firmly that any result would be meaningless, but they prevailed on his good nature to give it a try. With much warning of the futility of this, he nevertheless was good-natured enough to accede. The result was of course negative. He persuaded them at least to let him change the test voltage on the off chance that this might improve matters, but it did not.
As a result of Tony's vociferous protests they eventually condescended to move the experiment to an outside courtyard and try again. Tony told me several times how the courtyard was itself far from clear of overhead wires, steel-reinforced walls towering high all around and other electrically disturbing objects. The vertical field would have been almost as badly messed up as indoors and he did not stint in saying so. They prevailed on him once more and, usurprisingly, it proved as negative as the indoor runs.
Let me now explain why I regard the whole experiment as a sham and its conduct a farce bordering on dishonesty. But first my credentials. I spent some years as an electromagnetics engineer, typically specialising in compliance (EMC) testing and troubleshooting. On occasion I was trusted to travel the world sorting out one thing or another. I developed some of the discipline's early digital test concepts and methods during the transition from analogue to digital instrumentation (though not in the public domain, so put Google down and read on). As anybody in that field will tell you, electromagnetism is mardy stuff. Everything is an antenna, a conductor or a dielectric, or quite likely all three; nothing is solely what you designed it to be. And the energy does not go where you fondly expect, it goes where it wants according to Maxwell's equations (whether for far- or near-fields or that grey hinterland between the two, note), and you have to just go figure. It is a real black art. So I pass judgement on Hopwood and this experiment with more than usual authority.
Back to the CSICOP brigade. Remarkably, every man jack of them was a biologists interested only in the physiological response; none of them had a clue about electromagnetism. Not one! For that they relied wholly on Tony, despite the fact that it was the central variable of the experiment and he himself was also the experimental subject. Despite going to modest lengths to ensure that he had no idea of what he was dowsing on each test, they failed to establish in the slightest that they had any better idea! Recall that his theory assumed an ambient vertical E-field of around a thousand volts per metre and this was what his overhead electrode was disturbing. But here there was no calibration measurement of the ambient vertical field strength, no clue how the overhead cable related to it, in other words, no idea of the disturbance they were actually inducing or even what they were inducing it in. In actual fact, the metalwork would have reduced the indoor E-field to as near zero as makes no difference, much like walking under a canopy of wet trees. The residual field would have been anything but uniform or vertical, and walking along through it would produce arbitrary and unpredictable dowsing results. Then, from the electromagnetics perspective, Tony was acting as a human measuring instrument, intended to detect possibly quite small changes in the strength of a large and directed field. In any sensible experiment such instruments are carefully calibrated against known inputs before the experiment begins, then equally carefully checked again afterwards. One does not take an instrument formerly used within a certain operating range, throw at it an unknown and arbitrary environment and there rely on it to give accurate readings. Yet this was exactly what they did with Tony. Each test was carried out under arbitrary, unknown and highly sensitive conditions, yet they expected consistent results. And when the only electromagnetics expert in the room explained it all to them, they ignored him and pressed on regardless.
Then again, New Scientist states that this was a double-blind experiment. This is a standard precaution for such experiments, however as described it was not in fact double-blind. Wolff is said to have read the test number aloud while himself setting the on/off switch accordingly. But this is not double-blind. For that, the speaker of the number should not have known whether the device was to be switched on or off. He should have called out his anonymous number to, say, a hidden technician who operated the switch according to their own list which the speaker had not seen. In this way, Wolff would not have known when he read out each number what the field would be. This would have avoided any risk of his tone of voice or body language either aiding or confusing Tony. As it was, he reportedly knew in each case and consequently the trial was not conducted correctly.
Unless New Scientist was mistaken, those responsible showed staggering lapses of rigour in both its design and execution. As a piece of science the experiment appears to have been both badly conceived and ineptly executed. To add insult to injury Tony was not listened to but was for the most part brushed aside. He was offered only a couple of token but patently inadequate gestures, before his reputation was trashed.
It might strike you as a fine irony that a theory intended to banish the psychic mumbo-jumbo from dowsing was avidly attacked by a bunch of established psychic debunkers; had they allowed Hopwood's theory space, they would have advanced their own cause. I am going to stick my neck out here and suggest that they were so purblind in their hatred of all things psychic that the mere word "dowsing" stopped them cold. They would not countenance it, it was a crack in the doorway for the psychics, it had to be held firmly closed regardless. In short, they were not rational sceptics, they were what is becoming known as pseudosceptics – dogmatic evangelists of a Cause who use scientific scepticism as a pretext for their self-justification. Because they were certainly not being scientific here. To anybody with the slightest pretensions to science, their farcical nonsense so beggars belief that regarding it as innocent also does; they had set Tony up to knock him down, and were determined to do so at any cost. Disgusting is an understatement; something I would expect of CSICOP and its brand of smartass showmanship, but Wolff should have known to behave better, even if he did not know his electormagnetism any better.
I am sorry, but I saw with my own eyes the careful and methodical electromagnetics work which led to Tony's results, I discussed with him the theories that he discarded along the way, I watched the electrostatic theory grow through his highly innovative equipment design and his accounts of solid experimental technique. He was forced to invent novel electrostatic detectors, which would go on to create a minor revolution in their own right; nowadays they are widely used for 24/7 monitoring of the sky for meteor trails as they puncture the ionosphere, at the time possible only visually on a clear night. This was truly a man of methodical science and engineering, of deep electromagnetics insight and carefully reasoned thinking. His personal library of rare and important scientific texts would put any Professor to shame and many a whole Faculty. Both Hopwood and Wolff are now dead. So maybe it's time to even the score a little and expose Wolff for the ignorant pseudosceptic he was.
Some modest anecdotal support for Hopwood's theory has since come from a short piece carried by The Irish Times in 2000, noting that "[some] experimenters claim that dowsers respond to anomalous electrical fields in the vicinity, which they say affect their blood pressure and their pulse rates." (But others are taking to throwing about electric fields and charges with the usual fruitloop disdain for sanity, be warned).
Now, I am not claiming that Tony was necessarily right about dowsing or ley lines. It may be that he deluded both himself and me with unconscious thoroughness, I will be the first to accept the truth of the matter when it is properly confirmed. And do remember that I have been discussing a controversy between two scientific views, with no psychic forces or suchlike in the picture anywhere. But one thing is abundantly clear, and that is that the case against Hopwood is at best unproven and needs to be re-examined. If nothing else, Tony's memory deserves it.
On 23 July 2015 I wrote an email to New Scientist on the question of, "Was Hopwood doing good science?":
Dear Opinion Editor,
New Scientist has twice reported on the electrostatic theory of dowsing and ley lines proposed by Tony Hopwood. The first account was Hopwood's own. The second was of an experiment, involving among others SCICOP (sic) and Heinz Wolff, which purported to falsify his claims. Hopwood died recently and I was moved to revisit the story. In short order I was further moved to debunk the debunkers. If New Scientist's account is to be believed there were serious flaws in both the conception and execution of the independently-run experiment. It was, frankly, worthless.
Hopwood's theory remains unverified either way. As a sometime electromagnetic test engineer and before that a confidant of his during its development, I found it to be far the most rational of any that I encountered. Both in the name of Science and in the memory of Tony, I would make so bold as to ask New Scientist to once more bring the matter to public attention.
 Hopwood, A.; "Dowsing, ley lines and the electromagnetic link", New Scientist 20/27 December 1979, pp. 948-9
 Charfas, J.; "No better than chance", New Scientist 22 October 1981, p. 262
 Inchbald, G.; "Dowsing, ley lines and Tony Hopwood", http://www.steelpillow.com/blocki/philosophy/DowsingTony.html
I did not receive so much as an acknowledgement in reply. Do ask them if they ever read it.
Perhaps I have been a little hard on the sceptics, but I still believe they deserve it.
Radiesthesia may be described as "The faculty and study of certain reflexive physical responses of living tissue to various radiations ... resulting in displacement currents and other inductive effects in living tissues." Wise practitioners, such as Cecil Maby, distinguish it sharply from any psychic phenomena, believing that the observed phenomena must have some basis in purely material physics. Nevertheless, no such physical mechanism has ever been demonstrated to the satisfaction of the mainstream. Moreover, practitioners typically use dowsing equipment to try and detect these radiations, and when you meet such a dowser they maye have no considered view on whether they are dowsing a physical or a psychic phenomenon. Perhaps unsurprisingly, mainstream science assumes radiesthesia to be as much pseudoscience as its psychic brethren.
It is immediately obvious that Hopwood's theory can be seen as an attempt to demonstrate just such a physical mechanism for radiesthesia. There is perhaps a genuine sceptical case to be answered.
And here, Third Millennium science shows signs of coming to the rescue. Historically, up until a century ago, the mainstream accepted such fringe phenomena. That led to too much credulity. Twentieth-century atheistic materialism, and its ultimate expression in philosophical positivism, swung the world the other way, dissing anything and everything outside the realm of known physics. That led to too much pseudoscepticism, and in particular to a blindness to global warming. This latter has finally brought itself home to us with such force in the new millennium, that we are horrified at that purblind scepticism and prejudice, and are revisiting all that the materialists rejected, in a mindset of re-evaluation and recovering what was lost (this is true also in matters as diverse as spirituality and the secondhand market, but that is going off-topic).
The case in point here is the secret life of plants. All that stuff about musical tastes and plant sentience gave it a bad name back in the day. But plants do communicate chemically, and that means electrochemically. Now, in 2023, biologists are discovering that they can be sensitive to electromagnetism (I read of this once again in New Scientist). It is early days yet and, if past experience is anything to go by, researchers will make a right hash of understanding the electromagnetics side of things. But still, progress is progress and we now have mainstream biologists prepared to accept that electromagnetic phenomena in the environment can affect and even direct living metabolisms. A scientific basis for radiesthesia is showing signs of emerging, and that old last-millennium blanket pseudoscepticism is no longer a showstopper.
It really is time to re-evaluate Hopwood's theory and put it to the test under the aegis of an experienced electromagnetics test engineer.
 Charfas, J.; "No better than chance", New Scientist 22 October 1981, p. 262. See also Hopwood's own account of his key experiments in "Dowsing, ley lines and the electromagnetic link", New Scientist 20/27 December 1979, pp. 948-9.
 Brendan McWilliams; "Scientific theories to explain dowser's art", The Irish Times, 16 Feb 2000.
 I am no longer a practising electromagnetics test engineer and my past friendship with Tony must also place a question mark over my objectivity. I therefore feel that it is not appropriate for me to present such a re-examination. But that doesn't stop me calling for it.
Updated 19 May 2023