Usually, the boundary between science and science fiction is as distinct as the difference between the 6 o'clock news and "The Simpsons." Wherever the line blurs, you're bound to find contentious debates. One of the longest-running of these disagreements centers on dowsing, a supposed sixth sense that enables people to find underground water using a forked branch, pendulum or pair of bent wires. There is no scientific reason why dowsing should work. Yet, it apparently works well enough and reliably enough to keep the practice alive.
The success of dowsers doesn't surprise the people who know the most about finding underground water, hydrogeologists for the United States Geological Survey (USGS). They point out that the United States is so water-rich you can get wet drilling just about anywhere, if you drill deep enough. Far harsher criticism of dowsing and dowsers comes from outside the mainstream scientific community. Two organizations, the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP), http://www.csicop.org/si, and the James Randi Educational Foundation (JREF), http://www.randi.org, are actually working to discourage the practice, which they both dismiss as paranormal nonsense. To make their point that dowsing is a sham each has staged demonstrations in which dowsers were asked to find buried pipes. Dowsers did no better than the laws of chance predict. JREF is so confident of its position it promises to pay $1.1 million to anyone who can "prove" dowsing works.
Yet Dowsers Flourish
Like bees unaware they are too aerodynamically challenged to fly, dowsers don't let the skeptics get them down. In fact, the ranks of dowsers have been steadily growing. Forty years ago, about 50 dowsers and curiosity seekers were drawn to Danville, Vt., for a 1-day National Dowsing Convention. That get-together led to the creation of the American Society of Dowsers (ASD), www.newhampshire.com/dowsers.org, which now counts about 4200 members. Lest you dismiss dowsing's popularity as just another New Age fad, take a close look at the 16th century drawing to the left. The men wearing traditional miners' clothing are holding the same type of forked stick in use by many dowsers today.
Now comes a massive set of data that suggests there may be some validity to dowsers' claims. The encouraging words are contained in a study financed by the German government and published in the Journal Of Scientific Exploration, http://www.jse.com/betz_toc.html, which is a peer-reviewed scientific journal published at Stanford University.
The project was conducted by the Deutsche Gesellschaft fur Technische Zusammenarbeit in the hope of finding cheaper and more reliable ways of locating drinking water supplies in Third World countries.
Researchers analyzed the successes and failures of dowsers in attempting to locate water at more than 2000 sites in arid regions of Sri Lanka, Zaire, Kenya, Namibia and Yemen over a 10-year period. To do this, researchers teamed geological experts with experienced dowsers and then set up a scientific study group to evaluate the results. Drill crews guided by dowsers didn't hit water every time, but their success rate was impressive. In Sri Lanka, for example, they drilled 691 holes and had an overall success rate of 96 percent.
"In hundreds of cases the dowsers were able to predict the depth of the water source and the yield of the well to within 10 percent or 20 percent," says Hans-Dieter Betz, a physicist at the University of Munich, who headed the research group.
"We carefully considered the statistics of these correlations, and they far exceeded lucky guesses," he says. What's more, virtually all of the sites in Sri Lanka were in regions where the odds of finding water by random drilling were extremely low. As for a USGS notion that dowsers get subtle clues from the landscape and geology, Betz points out that the underground sources were often more than 100 ft. deep and so narrow that misplacing the drill only a few feet would mean digging a dry hole.
As impressive as this success rate may seem, it doesn't do much to change the minds of skeptics. Their preference is to test dowsing under more controlled conditions. Back To The Lab
Anticipating this criticism, the German researchers matched their field work with laboratory experiments in which they had dowsers attempt to locate water-filled pipes inside a building. The tests were similar to those conducted by CSICOP and JREF, and similarly discouraging. Skeptics see the poor showing as evidence of failure. Betz sees the discrepancy as an important clue. He says that subtle electromagnetic gradients may result when natural fissures and water flows create changes in the electrical properties of rock and soil. Dowsers, he theorizes, somehow sense these gradients and unconsciously respond by wagging their forked sticks, pendulums or bent wires.
Low-Energy Sensor
There is ample evidence that humans can detect small amounts of energy. All creatures with eyes can detect extremely small amounts of electromagnetic energy at visible light wavelengths. Some researchers believe the dark-adapted human eye can detect a single photon, the smallest measurable quantity of energy. Biologists also have found nonvisual electric and magnetic sensing organs in creatures from bacteria to sharks, fish and birds. Physiologists, however, have yet to find comparable structures in humans.
Betz offers no theories of how dowsers come by their skill and prefers to confine his speculation to his data. "There are two things that I am certain of after 10 years of field research," he says. "A combination of dowsing and modern techniques can be both more successful, and far less expensive, than we had thought."