Is the pendulum accurate? What the tests show

1. What the tests show

   For several decades, dowsers and water diviners have agreed to controlled trials: finding water under one of several pipes, the right envelope, the right card. At Kassel, in 1990, about thirty dowsers did not exceed chance, according to James Randi’s account. In Munich, the experiments led by Hans-Dieter Betz concluded there was an effect, which their authors defend; James T. Enright, in analyses published in 1995 and 1999, sees chance fluctuations. When no one knows the answer, the other trials stay at the level of chance.

2. Where the movement comes from

   In 1833, in a letter to André-Marie Ampère, the chemist Michel-Eugène Chevreul describes his trials with a hand-held pendulum. He observes that the movement weakens when his arm is supported and that it depends on what he sees and expects. He concludes that imperceptible muscle movements, guided by thought, are responsible. In 1854, he returns to the question in a book devoted to the rod, the pendulum, and table-turning.

3. Why so many people rely on it

   The movement is real, visible, and it does come from the person holding the chain: that is what makes it unsettling. It can bring out a still-vague preference, a fear, a wish. Many practitioners say so themselves: the answer matters less than the way it affects you. Seen this way, the pendulum becomes a mirror rather than an oracle.

4. Checking it yourself

   Versana’s blind test takes up the spirit of these experiments, without equipment: the site hides an answer, you look for it with the pendulum, and the comparison with chance is made at the end of the series. Ten tries are enough to discover the exercise; twenty give a steadier idea. The result passes no judgment on you: it only says where your score falls.

Blind tests have done no better than chance: the movement is thought to come from small involuntary movements of the hand. Never ask a pendulum a question about health, money, or the law: see a professional.