When metals with this property are placed in a magnetic field they repel the field demonstrating perfect diamagnetism, which can be seen in the levitation of a magnet above them.
The tunneling of electrons between objects displaying this property separated by an insulator is described in the Josephson effect. When metals with this property are placed in a magnetic field they repel the field demonstrating perfect diamagnetism, which can be seen in the levitation of a magnet above them. That effect postulated by Ochsenfeld and Meissner is described in a theory of it stating that this arises from the condensation of electron pairs. That BCS theory states this phenomenon is linked with the formation of Cooper pairs, allowing for increased electric flow. For 10 points, name this property characterized by zero resistance in very cold metals.
The tunneling of electrons between objects displaying this property separated by an insulator is described in the Josephson effect.
 superconductivity [or superconductor]