Thanks Chris,

The last time I did this demo was for some friends using magnets
salvaged from some wedding corsage after a wedding I attended in
Holland. The florists had used small NiFeBn magnets taped to the flower
stem and another inside the lapel or dress to hold the flowers in place.
About 10mm diameter and 2mm thick, these were a nice fit in standard
copper tubing, 15mm?, and the increase in time taken to fall compared
to a non magnetic item was quite amazing. I grabbed all the unwanted
corsages and stripped the magnets, although they are not expensive these
days and readily available.

Christopher Tidy wrote:

David Billington wrote:

Another good way to demo this is using a cylindrical magnet and drop
it through a copper tube like used for plumbing. Re your sorting
method I believe this is similar to how many vending machines
validate that a coin is what it should be rather than a counterfeit.


Actually, this demo works okay with just about any NIB magnets, even
if they aren't cylindrical. Give it a go.

Chris