Over the weekend, the Haitian Student Association held an event for dowsers. It had two purposes. The first was to raise money for water filtration systems in Haiti. The second was to provide classes on dowsing (also known as divining or water witching). Playing with dowsing rods on Pembroke Green is one thing, but doing it in Haiti and other countries with problematic water supplies is another. Dowsing has repeatedly been shown to not work, and it should not be used in disaster areas where it has the potential to impede efforts that could actually help people. It's fine for a group to raise money for water filters, but they should not give implicit support to pseudoscientific practices along the way.
For those of you not familiar with dowsing, users claim that they can find water or pretty much anything else (gold, oil, etc.) with what's called a dowsing rod. At one point or another, you have probably seen a depiction in popular culture of someone using a traditional Y-shaped branch to look for underground water. Dowsers now use anything from bent coat hangers to pendulums.
The problem is that dowsing does not work. When subjected to scientific scrutiny, dowsers are unable to divine the location of objects hidden from their view. They are unable to find where to dig for wells unless they already know where the water is.
The James Randi Educational Foundation offers a million-dollar prize to anyone who can demonstrate a paranormal or supernatural ability under proper observing conditions. Randi has offered the prize since the 1960s (originally at only one thousand dollars) and no one has claimed the money yet. The Foundation has tested psychics, astrologers, and breatharians among others (look up breatharians, they're hilarious). However, dowsers are by far the most common applicants. Still, after all this time, not even one has passed the preliminary test. If dowsers want to help Haiti, they should win Randi's million-dollar prize with their paranormal abilities and donate it toward clean drinking water.
If dowsing doesn't work, then what is really happening? Dowsers move their rods through the ideomotor effect, a phenomenon where people make unconscious movements. The most familiar example of this is the Ouija board. It would appear that the planchette (a small wooden pointer) mysteriously moves around the board, spelling out words and answering questions. In reality, people are unconsciously pulling and pushing the indicator to the letter they want in order to spell out some word. If you blindfold the participants, the Ouija board no longer works. Without seeing the board, the participants can no longer unconsciously move the planchette to the correct locations.
The same thing happens in dowsing. If a dowser knows that there is a water pipe running along the street, the rods will cross to indicate the presence of water as the dowser passes the spot. If, however, the dowser has no knowledge of where the pipe is, he or she will be no more successful than random chance. The dowser might as well have walked to an arbitrary spot and proclaimed that water lies below.
The most disturbing application of dowsing is the detection of explosives and weapons. The Iraqi government has bought thousands of glorified dowsing rod devices for tens of thousands of dollars each. They use them at security checkpoints in an attempt to stop bombers from reaching their target. Unfortunately for the ensuing victims, dowsing rods detect bombs no better than they detect water.
But have no fear. Jim McCormick told the London Times that his company, which sells these devices, is making improvements: "We have been dealing with doubters for ten years. One of the problems we have is that the machine does look a little primitive. We are working on a new model that has flashing lights." They might not stop bombs, but at least they'll look cool. You'll be pleased to know that McCormick was arrested for fraud in January.
These devices are also used in the United States by law enforcement. Because they do not actually detect explosives — instead relying on the user's biases — they are perfect for disguising otherwise-unacceptable profiling. All the user needs to do is consciously or unconsciously move his or her wrist slightly and the device will flag someone the officer thinks is suspicious.
Pseudoscience is not harmless fun. No matter whether you have good intentions like the dowsers at last weekend's event or questionable ones like McCormick, dowsers are all operating in a world divorced from reality. The Haitian Student Association should have just stuck to raising money for the water filters. They should not be lending any credibility to demonstrably false claims, and they should not be tacitly encouraging dowsing in a disaster zone. Instead, the dowsers should have been told that if they really want to help Haiti, they should stick to effective efforts only.
David Sheffield '11 is a math-physics concentrator, whose subconscious refused to move the dowsing rods for him on Saturday. He can be contacted at david_sheffield (at) brown.edu
