James Dewar and the vanishing electrical resistance at absolute zero temperature

Abstract

History of science is full of surprises and there is no end to instances where experimental observations or theoretical predictions come to overthrow intuitive expectations. But it is one thing to be faced with what for the specific period is considered counterintuitive, and it is another to deal with results whose mere description cannot be realized within the descriptive framework that contemporary theories allow. Of these events we do not have too many. There is, however, one area – low temperature physics – that has offered a plenitude of such events. From the observation of zero electrical resistance of mercury at helium temperatures to the phenomena of superfluid helium, low temperature physics has generously provided us with “counterintuitive” instances: the “unreasonable” effectiveness of the Gorter-Casimir thermodynamic calculations, the “unexpected” results of the Meissner-Ochenfeld experiment, the “unique” macroscopic wave function proposed by Fritz London, the “mysterious” case of the measurement of viscosity of liquid helium below 2 ◦K with two different yet perfectly equivalent ways and the difference of 100 000 in the measured values, the “phantasmagoric” fountain effect as well as the creeping film of liquid helium, these and more, became the trademark of low temperature physics. The “birth date” of all these phenomena, was the discovery of suFigure 1 Variation of electrical resistance of mercury at liquid oxygen temperatures. The dotted part represents the extrapolated expected values (from [7]).