i2
PHYSICS OF THE IMPOSSIBLE
substances are cooled to below 20 R above absolute zero, all electrical
resistance is lost. Usually when we cool down the temperature of a
metal, its resistance decreases gradually. (This is because random vibrations of the atom impede the flow of electrons in a wire. By reducing the temperature, these random motions are reduced, and hence
electricity flows with less resistance.) But much to Onnes's surprise, he
found that the resistance of certain materials fell abruptly to zero at a
critical temperature.
Physicists immediately recognized the importance of this result.
Power lines lose a significant amount of energy by transporting electricity across long distances. But if all resistance could be eliminated,
electrical power could be transmitted almost for free. In fact, if electricity were made to circulate in a coil of wire, the electricity would
circulate for millions of years, without any reduction in energy. Furthermore, magnets of incredible power could be made with little effort
from these enormous electric currents. With these magnets, one could
lift huge loads with ease.
Despite all these miraculous powers, the problem with superconductivity is that it is very expensive to immerse large magnets in vats
of supercooled liquid. Huge refrigeration plants are required to keep
liquids supercooled, making superconducting magnets prohibitively
expensive.
But one day physicists may be able to create a "room-temperature
superconductor," the holy grail of solid-state physicists. The invention
of room-temperature superconductors in the laboratory would spark a
second industrial revolution. Powerful magnetic fields capable of lifting cars and trains would become so cheap that hover cars might become economically feasible. With room-temperature superconductors,
the fantastic flying cars seen in Back to the Future, Minority Report,
and Star Wars might become a reality.
In principle, one might be able to wear a belt made of superconducting magnets that would enable one to effortlessly levitate off the
ground. With such a belt, one could fly in the air like Superman.
Room-temperature superconductors are so remarkable that they ap-
PHYSICS OF THE IMPOSSIBLE
substances are cooled to below 20 R above absolute zero, all electrical
resistance is lost. Usually when we cool down the temperature of a
metal, its resistance decreases gradually. (This is because random vibrations of the atom impede the flow of electrons in a wire. By reducing the temperature, these random motions are reduced, and hence
electricity flows with less resistance.) But much to Onnes's surprise, he
found that the resistance of certain materials fell abruptly to zero at a
critical temperature.
Physicists immediately recognized the importance of this result.
Power lines lose a significant amount of energy by transporting electricity across long distances. But if all resistance could be eliminated,
electrical power could be transmitted almost for free. In fact, if electricity were made to circulate in a coil of wire, the electricity would
circulate for millions of years, without any reduction in energy. Furthermore, magnets of incredible power could be made with little effort
from these enormous electric currents. With these magnets, one could
lift huge loads with ease.
Despite all these miraculous powers, the problem with superconductivity is that it is very expensive to immerse large magnets in vats
of supercooled liquid. Huge refrigeration plants are required to keep
liquids supercooled, making superconducting magnets prohibitively
expensive.
But one day physicists may be able to create a "room-temperature
superconductor," the holy grail of solid-state physicists. The invention
of room-temperature superconductors in the laboratory would spark a
second industrial revolution. Powerful magnetic fields capable of lifting cars and trains would become so cheap that hover cars might become economically feasible. With room-temperature superconductors,
the fantastic flying cars seen in Back to the Future, Minority Report,
and Star Wars might become a reality.
In principle, one might be able to wear a belt made of superconducting magnets that would enable one to effortlessly levitate off the
ground. With such a belt, one could fly in the air like Superman.
Room-temperature superconductors are so remarkable that they ap-