When you unpack this incredible device, you see a shiny gold-plated, rectangular solid floating in air! Predicted by Braunbek in 1939 and demonstrated by Boerdijk in 1956, it is finally available for the science classroom! The gold-plated NdFeB magnet is seen hovering between two blocks of graphite, one of the most strongly diamagnetic substances in the world. (Note: a diamagnetic substance repels both the north and south poles of a magnet. The ceramic top magnets are adjusted to compensate for the gravitational pull on the hovering neodymium magnet. The secure cover can be removed with a tool.
Included are materials and suggestions for further experimentation. Stands approximately 5 inches tall.
About Diamagnetism
All materials are weakly diamagnetic - they repel magnets. This is thought to be due to paired electrons in orbitals. Usually, the property of diamagnetism is so weak that it is difficult to demonstrate. However, in 1939 Braunbek predicted that using a strong magnetic field and strongly diamagnetic materials, it would be possible to create stable regions for levitation. The availability of neodymium magnets and graphite blocks now make this possible.
See: The Physics Teacher, Vol. 39, December 2001 pages 556 to 558
Thanks to Martin Simon for the information on the contributions of Braunbek and Boerdijk.