Dowsing

Dowsing is a type of divination employed in attempts to locate ground water, buried metals or ores, gemstones, oil, claimed radiations (radiesthesia), gravesites, malign "earth vibrations" and many other objects and materials without the use of a scientific apparatus. It is also known as divining (especially in water divining), doodlebugging (particularly in the United States, in searching for petroleum or treasure) or water finding, or water witching (in the United States).

A Y-shaped twig or rod, or two L-shaped ones, called dowsing rods or divining rods are normally used, and the motion of these are said to reveal the location of the target material. The motion of such dowsing devices is generally attributed to random movement, or to the ideomotor phenomenon, a psychological response where a subject makes motions unconsciously.

The scientific evidence shows that dowsing is no more effective than random chance. It is therefore regarded as a pseudoscience. Provided by Wikipedia