Levitation with Space Age Materials - Mini-Lab

Magnetic Levitation

Few materials can be made to magnetically levitate stably above the magnetic field from a permanent magnet. Although you can obviously and easily achieve magnetic repulsion between any two magnets, the shape of the field causes the upper magnet to push off sideways, rather than remaining supported, rendering stable levitation “impossible” for magnetic objects (see Earnshaw's Theorem). Strongly diamagnetic materials, however, can levitate above powerful magnets.

(Note:  water is in fact also mildly diamagnetic – for a fun demonstration of this effect, please check here to see a frog levitated above an approx. 16 Tesla magnet).

With the availability of rare earth permanent magnets in recent years, the strong diamagnetism of pyrolytic carbon makes it a suitable demonstration material for this effect.

The kit includes all the materials needed to perform the levitation:

• Two pieces of pyrolytic graphite - measuring 10 mm x 10 mm x 0.75 mm (one needed plus an extra)
• Four neodymium “N52” super strong permanent magnets – measuring 1 cm³ (pull force 3 kg each) 
• One straight-forward set of instructions to perform the levitation       

Note:  “N52” is the strongest grade of neodymium magnet but are also very fragile.  The magnets are triple-plated in nickel-copper-nickel to protect them, but please note you must handle them with care.

The instructions are not very complicated.  In brief, the key is to arrange the magnets firmly together in a square (alternating North/South works well), and then simply float the piece of pyrolytic graphite on top!

Recommended for Age 12 & Up (with adult supervision)