🚀 go-pugleaf

This should be very interesting to subject to further tests. It's well
known that such an object, made if iron, can be magnetized by being held
aligned to the earth's field, then struck sharp blows, as with a hammer.
Usually an iron rod is used. The magnetization is weak. Is it enough to
make the object into a compass needle if it is hung by a suitably
flexible suspension? Try it.

Try the original coat hanger, the one which seemed to work, hung from
diferent places in the room and see if it consistently points the right
direction, or if the one case you mentioned was a statistical fluke.
Also, there are three distinct ways the hanger can be conveniently hung. Try
all three. Any differences?

Test the original coat hanger for residual magnetization with a compass
needle. If you find any, such a magnetization event may have occured on
the coat hanger. Or maybe the students were playing in your lab with a
strong magnet and a coat hanger and inadvertently magnetized the hanger.
Maybe it wasn't inadvertent, as the time we, back in the 50's, pulled
this trick on our high school physics teacher. He never did catch on that
we did it deliberately. But then, they made better coat hangers then.

And if that coat hanger happens to be non-ferrous, your observed result
would be *very* hard to believe. That, of course, is easy to check.

Next they will ask you if dull razor blades placed actually placed under
a paper or plastic pyramid will become sharper. (They will, but the
pyramid has nothing to do with it, and the difference will be hard to
test without a microscope.)

        -- Donald

On Thu, 16 Mar 1995 Namkcihp@AOL.COM wrote:

> Friends!
> One of my ninth grade studenst raised her hand right at the end of class.
> When she started with "Is it true that....." I thought that it would be
> something like UFO's or anyhting to get us off the subject of magnetostatics.
> But, I was pleasantly surprized. She asked "Is it true that a metal coat
> hanger hung from a string and undisturbed will align itself north-south?" In
> 20 years I had never heard this one so, I said lets find out!
> Fortunately we had a coat hanger left over from the "spin-the-
> penney-in-a-circle" demonstration and I hung it in the center of the
> classroom by a thread on its hook. The bell rang and they all left. When I
> returned to lock up the room, sure enough it was pointing N-S.
> I tried it at home and it did not work. Has anyone seem this written up in
> the literature?
> Paul
>