A colleague in the physics department received from his granddaughter a toy
called Euler's disk. He described it to me over the phone thusly: A small
steel disk is spun on its edge on a concave mirrored surface, much as you
would spin a quarter on a tabletop. Apparently the concave surface keeps
it centered. If the surfaces are clean, the disk will spin for 75-80
seconds. My colleague doesn't have access to computer e-mail (he's
retired) and wants to know if anyone out there can point him to any
reference that might describe this kind of motion. He spent some time on
the library search system but had no luck. Incidentally, the toy is
marketed by Tangent Toy Company in Sausalito, California.
Since I will be gone for two weeks starting Friday, you can reply to this
message to
harp@physics.purdue.edu
and he will pass it along to our colleague.
Thanks so much.
Van E. Neie
Dept of Physics 157 Ivy Hill Drive
1396 Phys Bldg W. Lafayette, IN 47906-4865
Purdue University (765) 463-5022
W. Lafayette, IN 47907-1396
(765) 494-5511 FAX (765) 494-0706
"Consider how hard it is to change yourself and you'll understand what
little chance you have of trying to change others." -- Jacob M. Braude