Dowsing, sometimes called doodlebugging, divining or water witching, is a practice whereby dowsers attempt to locate hidden water wells, buried metals, gemstones, or other objects as well as currents of earth radiation without the use of scientific apparatus. A Y- or L-shaped twig or rod is sometimes used during dowsing, although some dowsers use other equipment or no equipment at all.
Dowsing has been in use since ancient times and is still widely practiced, despite scientific evidence disproving its efficacy.
Dowsing as practiced today may have originated in Germany during the 15th century, when it was used to find metals. The technique spread to England with German miners who went there to work in the coal mines. During the Middle Ages dowsing was associated with the Devil. In 1662 dowsing was declared to be "superstitious, or rather satanic" by a Jesuit, Gaspar Schott, though he later noted that he wasn't sure that the devil was always responsible for the movement of the rod. In 1701 the Inquisition stopped the use of dowsing rod in trials.
In the late 1960s during the Vietnam War, some United States Marines used dowsing to attempt to locate weapons and tunnels. An extensive book on the history of dowsing was published by Christopher Bird in 1979 under the title of The Divining Hand. James Randi’s 1982 book Flim-Flam! devotes 19 pages to comprehensive double-blind tests done in Italy which yielded chance results.
Many dowsers today use a pair of simple L-shaped metal rods, and some use bent wire coat hangers. One rod is held in each hand, with the short part of the L held upright, and the long part pointing forward. Some dowsers claim best success with rods made of particular metals, such as brass.
Pendulums such as a crystal or a metal weight suspended on a chain are sometimes used in divination and dowsing, particularly in remote or "map dowsing". In one approach, the user first determines which direction (left-right, up-down) will indicate "yes" and which "no," before proceeding to ask the pendulum specific questions. In another form of divination, the pendulum is used with a pad or cloth that has "yes" and "no" written on it, and perhaps other words, written in a circle in the latter case. The person holding the pendulum aims to hold it as steadily as possible over the center. An interviewer may pose questions to the person holding the pendulum, and it swings by minute unconscious bodily movement in the direction of the answer. In the practice of radiesthesia, a pendulum is used for medical diagnosis.
In a scientific study in Munich 1987-1988 by Hans-Dieter Betz and other scientists, 500 dowsers were initially tested for their "skill", and the experimenters selected the best 43 among them. These 43 were then tested the following way. On the ground floor of a two-story barn, water was pumped through a pipe. Before each test, the pipe was moved in a direction perpendicular to the water flow. On the upper floor, each dowser was asked to determine the position of the pipe. Over two years, the 43 dowsers performed 843 such tests. Of the 43 pre-selected and extensively tested candidates, at least 37 of them showed no dowsing ability. The results from the remaining 6 were said to be better than chance, resulting in the experimenters' conclusion that some dowsers "in particular tasks, showed an extraordinarily high rate of success, which can scarcely if at all be explained as due to chance ... a real core of dowser-phenomena can be regarded as empirically proven"
Five years after the Munich study was published, scientist Jim T. Enright contended that these results are merely consistent with statistical fluctuations and do not demonstrate any real ability. He noted that the best tester was on average 4 millimeters out of 10 meters closer to a mid-line guess, an advantage of 0.0004%. The study's authors responded but Enright remains unconvinced.
More recently, a study was undertaken in Kassel, Germany, under the direction of the Gesellschaft zur Wissenschaftlichen Untersuchung von Parawissenschaften (GWUP) [Society for the Scientific Investigation of the Parasciences]. The three-day test of some 30 dowsers involved plastic pipes through which a large flow of water could be controlled and directed. The pipes were buried 50 centimeters under a level field. On the surface, the position of each pipe was marked with a colored stripe, so all the dowsers had to do was tell whether there was water running through the pipe. All the dowsers signed a statement agreeing this was a fair test of their abilities and that they expected a 100 percent success rate. However, the results were no better than what would have been expected by chance.
Some researchers have investigated possible physical or geophysical explanations for dowsing abilities. For example, Soviet geologists have made claims for the abilities of dowsers, which are difficult to account for in terms of the reception of normal sensory cues. Some authors suggest that these abilities may be explained by postulating human sensitivity to small magnetic field gradient changes.
One study concludes that dowsers "respond" to a 60 Hz electromagnetic field, but this response does not occur if the kidney area or head are shielded.
A review of archaeological studies in Iowa suggests that dowsing is ineffective at finding unmarked human burials.