Meissner effect

1933 Meissner effect

The book of science

Tom Sharp

Walther Meissner, Robert Ochsenfeld electromagnetism Meissner effect

Meissner effect

Meissner and Ochsenfeld discovered that superconducting materials present the illusion of perfect diamagnetism. When they cooled their samples below their transition temperatures the samples perfectly repelled an external magnetic field so none of the magnetic flux was lost, which is called conservation of the flux. If the same effect were true for visible light and you cooled a superconductor below its transition temperature, it would disappear.

Surface effects

A superconductor responds to a magnetic field by generating persistent electric currents near its surface. * Lightwaves don’t actually bounce from mirrors but cause small secondary lightwaves that interfere and add up to the angle of reflection. * Molecules of a liquid pull together so they are under tension at their surfaces. * A superfluid is inviscid. Is magnetic flux a superfluid?

Ways to tell

If you pinch yourself and don’t wake up you can tell you’re not dreaming. * If you pinch me and I say “ouch,” you can tell I’m not Italian. * If you throw a stone into a pit and you don’t hear it hit bottom, you can tell it’s bottomless or you’ve lost your hearing. * If your material levitates, you can tell you have found a room-temperature superconductor or an anti-gravitational principle. * If it walks like a duck, and it quacks like a duck, you can tell it’s at least a good imitation of a duck. * If you don’t see your reflection in a mirror, you can tell you have no soul. * If you can’t see through me, you can tell I might be teasing you.

Although it is also called superdiamagnetism, the Miessner effect is the result of a different physical mechanism than diamagnetism in normal materials, in which atoms become temporarily aligned throughout the material.

See also in The book of science:

Readings on wikipedia: