May 302010

In fact, it is possible to magnetically levitate every material and every living creature on the earth due to the always present molecular magnetism. The molecular magnetism is very weak (millions times weaker than ferromagnetism) and usually remains unnoticed in everyday life, thereby producing the wrong impression that materials around us are mainly nonmagnetic. But they are all magnetic.

Seeing is believing:

A little frog (alive !) and a water ball levitate inside a Ø32mm vertical bore of a Bitter solenoid in a magnetic field of about 16 Tesla at the Nijmegen High Field Magnet Laboratory.

Video of the levitating frog:

High Field Magnetic Laboratory Home Page:

Why does the frog fly?

(this explanation is written in response to numerous inquiries from children who have not studied physics yet … or even do not want to study it at all)

As you might well know, all matter in the universe consists of small particles called atoms and each atom contains electrons that circle around a nucleus. This is how the world is made. 
If one places an atom (or a large piece of a matter containing billions and billions of atoms) in a magnetic field, electrons doing their circles inside do not like this very much. They alter their motion in such a way as to oppose this external influence. 
Incidentally, this is the most general principle of Nature: whenever one tries to change something settled and quiet, the reaction is always negative (you can easily check out that this principle also applies to the interaction between you and your parents). So, according to this principle, the disturbed electrons create their own magnetic field and as a result the atoms behave as little magnetic needles pointing in the direction opposite to the applied field*.

As you probably saw many times when playing with magnets, magnets push each other away if you try to bring together their like poles, for example, two north or two south poles. Similarly, the north pole of the external field will try to push away the “north poles” of magnetized atoms. 
Our magnet creates a very large magnetic field (about 100 to 1000 times larger than school or household magnets). 
In this field, all the atoms inside the frog act as very small magnets creating a field of about 2 Gauss (although very small, such a field can still be detected by a compass). One may say that the frog is now built up of these tiny magnets all of which are repelled by the large magnet. The force, which is directed upwards, appears to be strong enough to compensate the force of gravity (directed downwards) that also acts on every single atom of the frog. So, the frog’s atoms do not feel any force at all and the frog floats as if it were in a spacecraft.

Intuition Failure

 Posted by at 4:43 pm

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