A popular-science review of all aspects of magnetic levitation, from flying frogs to maglev trains.
James D. Livingston
Humankind has long been fascinated by the prospect of defying gravity, and our fiction is full of heros capable of flying - from Peter Pan to Harry Potter. Levitation has also been a popular illusion for professional magicians such as David Copperfield and David Blaine. We discuss levitation in fiction and magic, the levitation of saints, and non-magnetic means of combating gravity, but the focus of this book is the use of upward magnetic forces to oppose the ubiquitous downward force of gravity. In toys like the Levitron and floating globes, the major goal is the aesthetic effect. But much of modern science and technology uses magnetic levitation for very practical reasons, usually to reduce friction and achieve faster, smoother, quieter, more efficient motion, as in the maglev airport shuttle at Shanghai that achieves speeds up to 270 mph. Does gravity get you down? Magnets can lift you up! Does friction slow you down? Magnets can speed you up! Fighting the forces of gravity and friction is one of the things that magnets do best.
It may take many years before we eventually decide to build an intercity maglev line whisking us along at speeds over 300 mph, as envisioned by Emile Bachelet back in 1912. But the overall use of maglev in other applications is likely to continue to grow, both with increasing use of old applications, like magnetic bearings in rotating machinery, and the appearance of new applications, like blood pumps, haptics technology, photolithography, and superconducting bearings. The aesthetic appeal, pizzazz, and practicality of magnetic levitation in “fighting friction by fighting gravity” will retain its magic for many years to come.