The gemstone slowly begins to swing ... flow. Dowsing has a long history. Its roots can be traced back to Africa some 6,000 to 8,000 years ago. People have used a forked twig, a pendulum, or ...

The change in direction of the swinging brass ball hanging from a steel cable is almost indiscernible. Called a Foucault (pronounced “foo-KOH”) pendulum after its designer, French physicist ...