Dowsing is a type of divination that has been used to locate ground water, metals, ores, gemstones, oil, gravesites etc., and currents of earth radiation or Ley lines. Dowsing is also known as divining, doodlebugging (USA), or, when searching for water, water finding or water witching. Dowsing appears to have originated in Germany during a 15th century Renaissance of magic when it was used to find metals. In 1518 Martin Luther declared that dowsing for metals broke the first commandment, as he considered it to be practising occultism. In 1662 Gaspar Schott, a Jesuit, decided dowsing was "superstitious, or rather satanic", later he stated that he wasn't sure that the devil was always responsible for the movement of the rod. In early 19th century New England the use of divining rods was considered a branch of folk magic; nevertheless the early leaders of Mormonism used them for revelatory purposes. This divine gift, a means in which to learn the "mysteries of God" was later known as "the gift of Aaron", for Moses' brother Aaron used a rod in the Old Testament. More recently, United States Marines tried dowsing during the 1960’s Vietnam War in an attempt to locate weapon hoards and tunnels.
Originally a Y or L shaped twig or rod was used but nowadays a variety of materials including metal rods are used as a dowsing tool. Dowsers have their own favourite wood, and some prefer freshly cut branches, Hazel is traditionally chosen in Europe and witch-hazel, willow or peach in the United States. Some dowsers prefer rods made of particular metals, glass or plastic, even fashioned from wire coat hangers, others think the material is irrelevant as it is the human body that does the detecting consequently some practioners use nothing at all.
When using a Y shaped twig, each hand holds one of the forked ends with the stem of the Y pointing ahead. The dowser walks slowly over the search area and the dowsing rod supposedly dips, inclines or twitches when a discovery is made. When using modern L-shaped metal rods, a rod is held in each hand with the long arm pointing forward. When something is found, the rods cross over one another making an "X" over the found object. If the object is long and straight, such as a water pipe, the rods will point in opposite directions, along its orientation.
When divining rods are used as revelatory devices; a rod is held up in the air, and the rodman asks a question. If the rod moves, the answer is "yes", if not, the answer is "no". The information acquired is believed to come from magical spirits or god.
A pendulum of crystal, metal or other materials suspended on a chain is sometimes used both in divination and dowsing. One way of doing this is for the user, or another person, to determine which direction of movement will indicate "yes" and which "no" then the pendulum will be asked specific questions. Alternatively the pendulum is held over a pad or cloth with “yes" and "no" written on it, sometimes other words are written in a circle. The person holding the pendulum holds it as still as possible over the centre of the pad and its movements are believed to indicate answers to the questions.
In the practice of radiesthesia, a pendulum is used for medical diagnosis.
Attempts to scientifically explain dowsing range from emanations from substances of interest affecting the rod, to being explained by sensory cues, expectancy effects and probability, (Nature, 1986). Sceptics believe that dowsing rods have no power but merely amplify slight movements of the hands caused by a phenomenon known as the ideomotor effect: where people's subconscious minds autonomically influence their bodies, thus making the dowsing rods a conduit for the diviner's subconscious knowledge or perception.
A 1948 study tested 58 dowsers' ability to detect water but none were proven to be more reliable than by chance. A controlled experiment in 1979 into dowsing for water found that none of the practitioners showed better than chance results. In 1987-1988 a study in Munich by Hans-Dieter Betz and other scientists tested the abilities of 500 dowsers then ran further tests on the 43 who performed the best. On the ground floor of a two-storey barn they pumped water through a pipe which was moved before each test. From the upper floor each dowser was asked locate the position of the pipe. 843 tests were performed over two years; of the 43 dowsers 37 showed no dowsing ability, the remaining 6 had results that were better than chance. The conclusion was that when performing some particular tasks some dowsers showed an extraordinarily high rate of success that could not be explained as chance. Some dowsers say that this is proof that dowsing works.
Five years later Jim T. Enright, professor of physiology and sceptic, suggested that the study's results were merely consistent with statistical fluctuations and not significant. Examining the results using his own method of data analysis he noted that the best dowser was on average 4 millimetres out of 10 meters closer to a mid-line guess, an advantage of 0.0004%. The study's authors questioned his methods of analysis. A paper by German psychologist Dr. S. Ertel confirmed the findings of the Munich study.
A more recent three-day study took place in Kassel, Germany under the direction of the Gesellschaft zur Wissenschaftlichen Untersuchung von Parawissenschaften (GWUP) [Society for the Scientific Investigation of the Parasciences] where plastic pipes through which water flow could be controlled and directed were buried 50 centimetres under a level field, the position of each pipe was marked on the surface with a coloured strip. The dowsers had to determine which pipes had water was running through them. The results were no better than chance.
Some researchers have investigated possible physical or geophysical explanations for alleged dowsing abilities. One study concluded that dowsers "respond" to a 60 Hz electromagnetic field, but this response does not occur if the kidney area or head are shielded.
There is no scientific rationale for the concept of dowsing and no scientific evidence that it works. In all cases, the device is in a state of unstable equilibrium from which slight movements may be amplified.