Levitation explained


Leaving science fiction aside, science does know different ways to levitate things. For instance, a helicopter can be considered as a very impressive levitation device that uses a stream of air to keep floating.

Scientists have also found many ways to levitate things without any noise or the need for petrol or air, by using electromagnetic fields. Levitating trains and levitating displays are but two examples of electromagnetic levitation. However, a source of energy (an engine or a battery at least) is always required to keep an object afloat. Remove the battery and the levitation inevitably stops.

Real levitation

Today's science knows only one way to achieve real levitation, such that no energy input is required and the levitation can last forever. This levitation makes use of diamagnetism, the ability  of many materials to expel a portion of an external magnetic field. Electrons in such materials rearrange their orbits slightly so that they expel the external field. As a result, diamagnetic materials repel and are repelled by strong magnetic fields.

Three basic schemes using various aspects of diamagnetism allow the true levitation:

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Superconducting levitation


Superconductors are ideal diamagnetics and completely expel magnetic field at low temperatures. The picture shows a sumo wrestler standing on a levitating magnet platform that floats above a high-temperature superconductor. The superconductor is cooled by liquid air and hidden below the platform.

Levitating Frog

Diamagnetic levitation

Normal things, even humans, can levitate if they are placed in a strong magnetic field. Although the majority of ordinary materials, such as wood or plastic, seem to be non-magnetic, they all exhibit very weak diamagnetism. Such materials can be levitated using magnetic fields of about 10 Tesla.

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Diamagnetically stablised levitation

Very low temperatures (such that air turns liquid) and powerful magnets (such that cooking pans are drawn from a distance of several meters) are not what you are likely to have at home to be able to watch the superconducting or diamagnetic levitation. Now, there is a way - at last - to have miniature levitating devices that you can make.