Discuss the BCS Theory

http://hsc.csu.edu.au/physics/core/implementation/9_4_4/944net.html#net2
· The BCS theory (after is proponents US physicists John Bardeen, Leon Cooper and John Schrieffer) explains superconductivity in terms of electron pairs and packets of sound waves related to lattice vibrations (called phonons).
· At temperatures below the critical temperature for particular metals (or metal alloys), the movement of electrons is enhanced by lattice vibrations (phonons) which cause electric field effects resulting in electron pairing (by overcoming what would normally be strong repulsive forces between like charges) and an assisted passage through the lattice with negligible energy loss.
· At temperatures below the critical temperature for the particular conductor, the cooper pairs (as the electron pairs are called) stay together. Because resistance is effectively zero...