The other day I was waiting for my gas tank to get filled (I live in Oregon where the citizens are not considered sufficient competent to pump their own gas), when I noticed a landscaping project being conducted at the church on the opposite corner. The grass had been sprayed out (dead), a couple of dump piles of topsoil here and there. But what caught my eye were the two guys wandering back and forth over the dead grass – They were “dowsing” presumably to locate the underground irrigation pipes.
One guy held two bent L-shaped metal rods, one in each hand; the other had a can of orange spray paint. The guy with the metal rods paced a few steps forward then backward. He would then direct the guy with the spray paint to mark the ground in front of his feet. These guys then wandered to another area of the dead grass and repeated the dousing – each time the dower was satisfied there was an irrigation pipe under his feet, the spray paint guy would mark it.
Had I the time I really would have loved to stop and talk with the guys and have them demonstrate for me their dowsing “skill”; unfortunately I had other time constraints. As I watching them dowsing and marking, the thought occurred to me that I would fully expect to find irrigation lines under a previously planted lawn. So what’s the surprise here?
Dowsing is among the more thoroughly debunked psychic phenomena. Most dowsers will provide enthusiastic confirmation that dowsing works. This is because they usually find water (or whatever they are dowsing for) where they expect to find it. This type of fallacious conclusions is called “post hoc” reasoning. Dowsers often will also misinterpret statistical results of their dowsing success. For example, a dowser may feel that if they successfully find water in 2 or 3 out of 10 tries, this is confirmation of their dowsing success. Of course such results are less than what one would expect from random chance.
Controlled scientific tests have been conducted on dowsers; not surprisingly, their success is never better random chance. Dowsers don’t just attempt to detect hidden water; dowsers claim they can find oil, gold or treasure or even detect illicit drugs. Modern dowsers have even tried to sell bogus dousing equipment to the US Military… to dowse for roadside bombs. Considering such dangers, unscientific bunk such as this tips the scale from the realm of silliness to being outright deadly.
I drove by the church landscaping project a few days later, there were holes dug up randomly all over the dead lawn. Perhaps they were just experiencing an invasion of over-sized gophers. Their psychic should have warned them about that.