Ochsenfeld robert (1 risultati)
Editore: Julius Springer, Berlin 1933
- Prima edizione
Da: Atticus Rare Books, West Branch, IA, U.S.A.Atticus Rare Books
Contatta il venditoreVenditore con 5 stelleCondizione: Usato
EUR 444,99
EUR 8,21 spedizioneSpedito in U.S.A.Quantità: 1 disponibili
1st Edition. FIRST EDITION, FULL VOLUME, OF MEISSNER & OCHSENFELD'S CONSEQUENTIAL 1933 DISCOVERY OF THE MEISSNER EFFECT: "SUPERCONDUCTORS EXPEL MAGNETIC FIELDS" (Brandt, Harvest of the Century, 362). "Superconductivity [is] one of the most spectacular phenomena of physics, [arising] when a superconducting material is cooled to a… low critical temperature. Suddenly, an electric current can flow with no resistance whatsoever" (Nobel Prize Press Release]. Simultaneously, the Meissner effect occurs. Meissner and Ochsenfeld's â??unexpected' discovery that superconductors exclude magnetic fields from their interior "had important experimental and theoretical consequences" (Brandt). While superconductivity was first observed by Onnes in 1911, M & O's observation took the first step toward explaining it; their work led as well to the pioneering theories of Fritz and Heinz London who were able to provide a theoretical description of the electrodynamics of superconductivity not only consistent with the Meissner effect but that could also be used with Maxwell's electrodynamical equations to predict how magnetic field and surface current varies with distance from the surface of a superconductor. The Meissner effect is a phenomenon in which a superconductor negates all magnetic fields inside of the superconducting material. It does this by creating small currents along the surface of the superconductor that then cancel out all magnetic fields that would come in contact with the material. When "superconducting materials within a magnetic field become cold enough to become superconductors, the superconducting materials expel the magnetic field and are no longer magnetic. The phenomenon of a magnet levitating above a superconductor is a spectacular demonstration of the Meissner effect (Stiles, UAnews, Dec. 17, 2008). While studying the resistance of metals at low temperatures, the Dutch physicist Onnes was the first to observe the phenomenon of superconductivity, the absence of electrical resistance. "Onnes and his team discovered that the electrical resistance of mercury goes to zero below 4.2" -- meaning, electrical resistance disappears in certain materials at very low temperatures. "Of all the discoveries in condensed matter physics during the 20th century, some might call superconductivity the "â??crown jewel'" (CERN; PW 24, April 2011, 18). M & O's work went further, showing that "when materials were cooled below their critical temperatures and became superconductors, they excluded magnetic [and ]became diamagnetic. They found that this happened both when the substances were cooled to below their critical temperatures in the presence of a magnetic field, and when the magnetic field was applied after they were cooled" (Eisberg, Quantum Physics, 525). The Meissner effect demonstrates that "magnetic fields cannot penetrate into the interiors of superconductors but instead remain confined in a thin surface layer" (History of Physics: The Wenner Collection). The phenomenon is the result of electric currents "circulating at the surface of the superconductor, [there generating] magnetic fields that are exactly equal and opposite to the applied field" (Watson, The Quantum Quark, 309). When operating within the effect, the "superconductor creates a mirror image of the magnetic field that repels the magnetic field. The cancellation of [that] field creates currents that persist indefinitely without resistance" (Wenner). CONDITION & DETAILS: Complete 4to. 904 pp. Very small institutional stamp on the title and front flyleaf; no other markings. Handsomely bound in faux alligator over brown cloth, spine is gilt lettered. Slight rubbing at edge tips, bright and clean throughout. Near fine.
