I dug a one-meter square test pit outside an 18th century ruined cottage. A “dowser” invited to test his powers stood beside the pit dangling a bob on a string. It swung from side to side. He declared, “There’s nothing in there.”
“Nothing all the way to China?” I asked. He grunted and went away. I’m not a fan.
Many or most dowsers claim they have no influence over the response of their implement, be it Y-twigs or L-rods. I sought to test this and made an isolating device consisting of a board of MDF approximately 1″ x 4″ x 12″ into which I drilled two channels, into which I fitted a tube of Perspex with the bottom blanked off. I then placed L-rods into the channels. I call it ‘HI’, for hand isolator.
I invited putative dowsers to ply their trade holding the HI. These were people who had tried L-rods and professed that they “worked”, meaning they had mysteriously crossed over at certain survey points.
In the HI, the L-rods form an unstable system when the short piece of the rod is held vertically; in other words they swing about uncontrollably. The only way they can be controlled is by gravity and tilting the board very slightly forward, which makes them point forward in parallel. The practitioners can then walk carefully, watching the rods and trying to keep them stable. No cross-overs appear. They can’t. Any movement is governed by gravity; the most that can be hoped for is that they swing in parallel to the left or right, or if the user has the upright section exactly vertical, the rods swing uncontrollably.
I had a colleague who was convinced she had dowsed successfully in finding graves in a cemetery in Turkey. I thought about this and the reports of dowsers finding underground streams. I also knew an electrical engineer who swore by dowsing to find underground cables. My MDF HI board showed (to my satisfaction) that, free of hand influence, the dowsers were unable to obtain any positive responses. So what, if anything, could the influence of hands do?
Great cats, when stalking, hold their heads perfectly level, no matter what the terrain. They concentrate on the prey to the exclusion of all distractions. The human fist is not naturally held vertically, i.e. as with a candle held upright. Relax the hand and the fist will rotate inwards (try it). L-rods detect this minute rotation and turn inwards to cross. Holding them vertically and still takes great concentration and effort, like lions hunting, to the exclusion of all outside influences. When moving forward, any change in the level of the ground will impact on the sensory balance, resulting in a distraction. At that instant, the concentration on the hands is lost and they relax, albeit imperceptibly. They rotate inwards and the L-rods cross. The change in surface level need not be large: even stepping on a pebble will have the effect. It will also be repeatable if the dowser retraces steps and tries again. The HI board eliminates these movements.
From James Randi’s Swift (vol. 2 No. 3/4, Jan., 1999), “The matter of dowsing”:
The Ideomotor Effect
We are witnessing here a very powerful psychological phenomenon known as the “ideomotor effect.” This is defined as, “an involuntary body movement evoked by an idea or thought process rather than by sensory stimulation.” The dowser is unknowingly moving the device of choice, exerting a small shaking, tilt or pressure to it, enough to disturb its state of balance.â€
IÂ suggest the sensory stimulation of balance receptors distract the eye-concentration sufficiently to allow momentary relaxing of the hands, causing the device to be unstable. This of course only applies where surface level changes are the source of the anomaly.Â
Graves sink through time. Trenches with buried cables do likewise. I suspect underground streams or pools cause some sinking of the ground surface. Anywhere there is a change in surface level is probably sufficient to cause a distraction which relaxes the hands and causes the L-rods to cross.
The same theory can be applied to the twig. The hands hold the unstable fork under tension until the hands relax and the fork bifurcates to a new stable position, twitching upwards or downwards.
So there is a logical explanation. Dowsing may sometimes appear to “work” but not for the paranormal reasons commonly put forward.
Ray Kidd is a retired telecoms engineer.