Dowsing and skating

On Sunday, a small group of people from the St. Louis Atheist group went ice skating at a local ice rink at Forest Park in St. Louis.

As per usual, conversation ranged from arranging us in descending order based on the number of times we fell on our asses, to whether or not one should come out as an atheist during a time in which one is receiving prayers from everyone due to a planned hospital visit.

One of the things we talked about briefly is dowsing.

I have this idea to hold a Skeptical Society of St. Louis workshop in which each member gets to make their own pair of dowsing rods. During this workshop each skeptic can learn just how much truth there is to the claim that when a dowser is holding a pair of dowsing rods, he or she has “no control” over the direction they turn. I think I’ll have people make their choice of dowsing equipment: either a pair of dowsing rods or a pendulum, and then we will perform all sorts of dowsing experiments in and around the building.

There are a lot of ways to dowse for things, but there are three devices that are most popular. You can either use a forked stick, two rods bent at 90 degree angles, or a pendulum. Dowsers claim that dowsing can be used to find all sorts of things, including water running underground, playing cards, or immaterial future events.

The James Randi Educational Foundation has had several dowsers try out for the million dollar challenge, and none of them have made it through the preliminary trials. The Wikipedia article also cites several references to studies done on dowsing.

My theory and the theory of most skeptics is that dowsing relies on confirmation bias and the ideomotor effect. You’ll note that all dowsing devices are always held in the hands. We never see dowsers asking psychic questions while the rods are mounted 5 feet away on a stand, away from any human touch.

(yes, I know the video covers up my sidebar. There isn’t anything I can do about this)