Re: Snake Oil

[Andy Dougherty <doughera@LAFAYETTE.EDU>]

On Sun, 9 Jan 2000, Raymond A. Rogoway wrote:

> classroom. Does anyone have any data that supports magnetic therapy?
>
> Comments???

At the APS Centennial meeting last March in Atlanta, there was a session
on junk science and related matters, with Bob Park, James Randi, and one
other presenter whose name escapes me at the moment.  One of them
(I'm pretty sure it was Bob Park) talked quite a bit about "Magnet
therapy" and I know it's been featured in several of the What's New
newsletters.

Here's roughly what I recall:

The speaker purchased one of these "Magnetic Therapy" items.  It appeared
to be essentially a refrigerator magnet wrapped in a nice soft enclosure.
Refrigerator magnets are usually set up with closely-alternating poles so
that the field lines don't go too far from the magnet itself.  The net
effect is that most of the field never gets outside the nice soft
enclosure to make it to the body.  If you try to do things like pick up
paper clips with the "Magnetic Therapy" device, you'll find the field is
so weak that it is difficult to imagine it could possibly have any
therapeutic effect.

--
    Andy Dougherty              doughera@lafayette.edu
    Dept. of Physics
    Lafayette College, Easton PA 18042