Crossword clues for superconductivity
superconductivity
Longman Dictionary of Contemporary English
Wiktionary
n. (context physics English) The property of a material whereby it has no resistance to the flow of an electric current.
WordNet
n. the disappearance of electrical resistance at very low temperatures
Wikipedia
Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic flux fields occurring in certain materials when cooled below a characteristic critical temperature. It was discovered by Dutch physicist Heike Kamerlingh Onnes on April 8, 1911 in Leiden. Like ferromagnetism and atomic spectral lines, superconductivity is a quantum mechanical phenomenon. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The occurrence of the Meissner effect indicates that superconductivity cannot be understood simply as the idealization of perfect conductivity in classical physics.
The electrical resistance of a metallic conductor decreases gradually as temperature is lowered. In ordinary conductors, such as copper or silver, this decrease is limited by impurities and other defects. Even near absolute zero, a real sample of a normal conductor shows some resistance. In a superconductor, the resistance drops abruptly to zero when the material is cooled below its critical temperature. An electric current flowing through a loop of superconducting wire can persist indefinitely with no power source.
In 1986, it was discovered that some cuprate- perovskite ceramic materials have a critical temperature above . Such a high transition temperature is theoretically impossible for a conventional superconductor, leading the materials to be termed high-temperature superconductors. Liquid nitrogen boils at 77 K, and superconduction at higher temperatures than this facilitates many experiments and applications that are less practical at lower temperatures.
Usage examples of "superconductivity".
Anderson, an expert in superconductivity and solid-state physics, was visiting Cambridge for the year while on sabbatical from his position at Bell Laboratories.
Luckily, that volume has already been written, following in great detail the path from the Egyptians to modern times, including the strange effects of Meissner fields, superconductivity, and magnetism.
Once upon a time, superconductivity had been associated only with utter cold, near absolute zero.
She treats the roiling, surging channels of superconductivity far below as she formerly did the highways and byways of the Net, as yet another domain to rule by proxy, by subroutine, by force of will.
Today we understand superconductivity to be an intrusion of quantum mechanics into our everyday, macroscopic world.
Instead, superconductivity relies on a subtle mechanism that prods the electrons to join in pairs, at which point they become bosons and lose all inhibition.
As of this writing, the physical basis for high-temperature superconductivity remains an enigma.
Even in its original low-temperature form, superconductivity always offered great economic and energy-saving promise.
That was one reason why the discovery of high-temperature superconductivity caused such a stir: The critical temperatures could now be reached by cooling with liquid nitrogen, which is both cheap and abundant.
Yet Josephson seemed to be suggesting he understood the theory of superconductivity better than its creator did.
His entry to the field came when he began collaborating with Peter Hadley, a graduate student at Stanford University, and his adviser Mac Beasley, an expert on superconductivity, who had already realized that nonlinear dynamics should have something to offer to the analysis of Josephson arrays.
Kreef managed to perfect room-temperature superconductivity, Spock said, the Joy Machine is clearly big enough to perform almost any function necessary.
Luckily, that volume has already been written, following in great detail the path from the Egyptians to modern times, including the strange effects of Meissner fields, superconductivity, and magnetism.
Not the parlor magic stuff of superconductivity, but a real low-cost system that would negate mass and resistance.
Until late 1986, superconductivity was a phenomenon never encountered at temperatures above 23 K, and usually at just a couple of degrees Kelvin.