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Levitating Frogs amongst other things!

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Offy
847418.  Sat Sep 17, 2011 9:11 am Reply with quote

Can it be true, a levitating frog? Well infact it is, using the interesting principle of diamagnetic levitation.

'Diamagnetism is the property of an object which causes it to create a magnetic field in opposition to an externally applied magnetic field, thus causing a repulsive effect. Specifically, an external magnetic field alters the orbital velocity of electrons around their nuclei, thus changing the magnetic dipole moment. According to Lenz's law, these electrons will oppose the magnetic field changes provided by the applied field, preventing them from building up. The result is that lines of magnetic flux curve away from the material. In most materials, diamagnetism is a weak effect, but under conditions of superconductivity, which only some materials may obtain, a strong quantum effect can emerge wherein the lines are completely blocked, excluding a very thin layer at the material's surface. Diamagnets are materials with a magnetic permeability less than μ0 (a relative permeability less than 1).' (1)

In the case of the frog, the orbiting electrons of the atoms when placed in a magnetic field shift/alter in a manner to oppose the external magnetic force. The distrupted electrons create their own little magnetic field thus it can be said that they are acting as mini magnets pointing in the opposite direction of the applied external force.

In this said field, the atoms within the frog are creating a field of about 2 Gauss (although very small, such a field can still be detected by a compass). The force, which is directed upwards, appears to be strong enough to compensate the force of gravity that also acts on every single atom of the frog. So, the frog’s atoms do not feel any force at all, thus i give you a levitating frog! (2)

Here is a youtube video of this in action:

http://www.youtube.com/watch?v=A1vyB-O5i6E

No frogs were harmed in the making of this post!

It is not only frogs which can be levitated, there are many materials/objects in which this principle applies. For example, strawberries, some woods, water, etc.

Sources:

(1) http://en.wikipedia.org/wiki/Diamagnetism
(2) http://www.physics.org/facts/frog-really.asp

 
Jenny
847549.  Sat Sep 17, 2011 2:06 pm Reply with quote

Great stuff! Welcome, Offy :-)

 
Moosh
847592.  Sat Sep 17, 2011 5:09 pm Reply with quote

Prof. Andre Geim won an Ig Nobel prize in 2000 for his work in levitating frogs, he went on to win a Nobel prize in 2010 for his work with graphene, becoming the first person to win both.

 

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