Did you know that a dowser, walking along divining for water, is actually sensing changes in the earth’s magnetic field? If you were able to shrink right down to miniature size and move across the surface of a common bipolar magnet, there would be no change in the magnetic field and it’s said to be uniform or “homogeneous”. Whereas, if you were able to walk across a Quadrapolar magnet, there would be large changes and the magnetic field is said to be non-uniform or “inhomogeneous” and produce magnetic field gradients.
One of the key factors in optimising static magnetic fields for therapeutic effects is incorporating magnetic field gradients which require multipolar magnets. See “How Q magnets work” for more details.
Dowser holding a divining rod while searching for underground water. (Illustration from Abbe´ de Vallemont’s
Treatise on the divining rod, Paris, 1693).