A long-term technological holy grail is room-temperature superconductivity. Normal electrical conductors have resistance, and convert part of the electrical energy that flows through them to heat, which is lost. Superconductivity, a consequence of quantum mechanics, allows an electrical current to flow without any resistance at all, and would allow efficient transmission of electricity over long distances, more efficient motors, and magnetic levitation for devices such as high speed vehicles.
Superconductivity was discovered experimentally in 1911, but was not explained theoretically until 1957 by Bardeen, Cooper, and Schrieffer, who shared the 1972 Nobel Prize in physics for their theory. The early superconductors required very low temperatures to operate: on the order of the temperature of liquid helium (around 4° K). It is very expensive to produce liquid helium and keep it liquid: while liquid nitrogen costs about as much as milk; liquid helium costs as much as Scotch whisky.... [Read More]