b"Divination: A geophysicist's viewFeaturepotential (SP) surveys show anomalies of the order of tens of millivolts associated with water movement, typically positive at outflows. It eludes me as to how a divining rod, either wood or metal, could be substituted for a voltmeter and non-polarizing electrodes set in-ground to register the small anomalous electrical field. Possibly the diviner has sensitive feet, even with shoes on, and as the operator paces up or down across the equipotential lines, with gradients of a few mV/m, the subtle difference in potential is registered between the feet, passed through the trunk of the body (containing sensitive anatomical parts) thence to the brain for subconscious interpretation?The Ideomotor ResponseIMRHow then can we explain the continual use of a puzzling Figure 13.Induced electromotive force charge separation in a conductive rodtechnique with a dubious record? Suggestion can be a powerful(length l) moving with velocity (v) to the right in a magnetic field (B) is as shown.influence. For 200 years some scientists (e.g. the famous Michael The magnetic field is directed orthogonally into the plane of the diagram (X).Faraday 1791-1867), medicos, and psychologists have believed The potential difference between the rod ends in Blv (volts) [think of the right- that ideas can cause a reflex action in a body, analogous to a hand rule]. body acting automatically to pain. They postulate that thoughts and beliefs give rise to reflex muscular movements of often rod no. 8 (l= 0.57 m) in an area with a 50 000 nT magneticsmall, but significant amplitude. This is the subconscious field (B = 5 x 10 5 T, inclination -90) and maintaining a leisurelyideomotor response, IMR. [ ones own, motus movement]. pace of about one footstep per second (v 1 m/s). The voltageThus is explained automatic writing, table turning, Ouija boards, potential difference between the ends of the rod will be ~ 3 xand divining with rod or twig. In such phenomena the activity 10 5 V i.e. 30 V. Could the dowser sense this tiny difference,is posited as due to mental states, not to esoteric energies, with clenched hands presenting a contact resistance of a fewspirit/sprite involvement, or the paranormal continuum. Quite megohm between hand and copper? The answer is no, neitherreasonable persons can exhibit muscular actions or spasms in quantitatively nor qualitatively, for normal human bodies. If theline with their expectations.magnetic field changes to, say, 100 000 nT owing to a subsurface feature further along the traverse then the potential differenceConcluding remarkswould be ~ 60 V. Neither this nor the difference between the two zones (indicating some sort of contact anomaly) would beWhat is the basis for the use of divining and the activities of detectable by a person without sophisticated instrumentation. dowsers? It seems to me to involve the centuries old belief that a sought substances intrinsic vigour releases essential vapours So one cannot really believe that a dowser with any sort ofcarrying corpuscles of the substance that rise to the surface divining device would be sensitive to magnetic anomalies.there to be intercepted by the artful dowser with a divining Unless, of course, pigeon-like, there are, arrayed in the dowsersrod. The emanations are absorbed by a porous wood rod, or brain, magnetic particles that somehow communicate theadsorbed onto a metal rod, which is consequently caused to magnetic ambience to the gifted persons mental apparatus,dip down towards the source. Such vapours have yet to be irrespective of the rod used. observed and documented by conventional scientific means. We could go on through all the conceivable physical methodsThe effects are claimed to be enhanced by the undefined radiometrics [radioactive bodies actually do emanate a partqualities gifted to the dowser, and by a sympathy or affinity of their essence]; - acoustics [could the dowsers diaphragmbetween a particular wood or metal and the sought substance. act as source and receiver of infrasound, via the rod, and byThese are extraordinary claims; they require extraordinary which the subsurface is assessed?]; - electromagnetics [couldevidence to secure validity. After thousands of years this the dowsers chest, arms, hands, linked to the rod, form a typeevidence is yet to be provided, despite widespread interest.of flesh-wood coil somehow to be electrically energised toIn terms of physics I cannot fathom the principles, if any, of generate a primary magnetic field to probe the subsurface anddivining nor the peculiar personal power, if any, ascribed to then somehow to receive a secondary (phase and amplitudedowsers. Perhaps it all has to do with the supernatural and with shifted) magnetic field to be interpreted by the brain?]; - andfaith, a strong emotion, being a feeling rather than a cognition. so on Space does not permit a detailed speculative analysis.The faith of the able, intelligent fathers of the early Christian However, there is one other phenomenon of interest that will bechurch seemed irrational to pagans. But the clergy have always discussed: streaming potentials. Reports of UK water authoritieshad a vested interest in the supernatural, their jobs depended using divining, to locate leaks, indicate that the water dowserson it. Credo quia absurdum: I believe because it is unreasonable, claim to be able to locate underground streams is still takenand certum est quia impossibile: its certain because it is seriously. Rushing underground streams of popular imaginationimpossible, are only a couple of expressions they used to do not exist except in water mains leaks, and in caverns in karstdefiantly defend their faith when questioned on the mysteries or tubed volcanic terrain after rain. Groundwater, in confined orof miracles, transubstantiation, the Trinity etc. They saw no unconfined aquifers, under natural hydraulic gradients, movesreal need for understanding. Such lines of thought continue usually very slowly with water velocities of the order of a fewto be widespread to this day in the minds of decent, otherwise m/day, if that. However, locally, as geophysicists know, waterreasonable, people. It is certainly manifest in divining and the seeping downhill, or leaking from dams, will generate streamingdowser. This is an observation, not a criticism, as such people potentials positive in the flow direction. In studies of dams, selfwere and are entitled to their viewpoint, especially in our own DECEMBER 2020 PREVIEW 56"