Levitron Magnetic Top: spin stabilized magnetic levitation- this top will fly for about 3 minutes or more per launch with no batteries or circuits of any kind needed. The spin rate of the magnetic top must be just right for flight, not too fast or too slow. Air resistance and dissipative interactions between the magnets gradually slow the spin rate and the top then falls. Interestingly, trapping the top requires precision- the weight of the top must be adjusted (with adding or removing washers)