Superconductivity

"SUPERCONDUCTIVITY"

9-20-05

SUPERCONDUCTIVITY

Superconductivity is an obscure and relatively new phenomenon that has puzzled scientists and physicists for years. Until relatively recently not much was known about superconductivity, but great progress has been made to better under stand this marvel of science since it was first discovered over 90 years ago. Superconductivity is basically a phenomenon that occurs when a conductor is super-cooled to a point where its resistance reaches zero. In other words, electricity is passing through the material without any loss of energy. This is significant because when electricity passes through a normal, conductor energy is lost.

It was believed for many years that a material reaching zero resistance was impossible. That was until a Dutch physicist by the name of Omens discovered this amazing possibility by cooling "normal conductors" to super-cold temperatures (approaching 0 Kelvin). It was quickly realized by Onnes as well as others what an important discovery this was due the fact that electricity is such an important and expensive commodity. He subsequently won the Nobel Prize for his groundbreaking work in 1913.

In 1933 a couple of researchers named Meissner and Ocshenfeld discovered another phenomenal property of superconductors. They found that superconductors have the ability to exclude a magnetic field (Plakida 94). In other words, a superconductor will propel a magnetic field around it, rather than allow the magnetic field to penetrate it as all other materials are known to do. Today this is known as the Meissner effect. This property of superconductors, is demonstrated when a small but strong magnet is placed on a superconductor. Because the superconductor does not allow the magnetic field of the magnet to penetrate its surface, it will actually cause the magnet to levitate up off the surface of the superconductor. This amazing physical property also was recognized to have much potential, especially in applications where there is energy lost through frictional forces. Because there is no contact between the magnet and the superconductor, there is little or no friction, hence no waste of energy.

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