The Mathematician in Modern Physics

"The aim of the earlier thinkers, to reduce the whole of electrical science to one equation was now to be realized in a way that marks one of the most important epochs in the history of physical science; an epoch comparable only to that of Newton..."

"The peculiar feature of the ether, its permittance and permeability, were abolished and in their place appears the velocity and density of the electron, or charged particle. Electric fluid exists; magnetic fluid does not."

"When therefore the theory was universally accepted, it was already ripe for the modification, which Hertz himself actually began. The ether as Maxwell left it has two independent properties, specific inductive capacity and permeability, which may be regarded as associated in the velocity of the electromagnetic wave passing through it. But the equations apply only for a medium at rest or at least approximately at rest, to a quasi-stationary medium. It is fortunate that a very coarse approximation to rest suffices; otherwise the early workers would have lacked encouragement."

"In England... [Weber genre theories] were vigorously condemned. Thomson and Tate, T and T... anathematized them as all the more pernicious in proportion as they were beautiful. They were completely swept away by the profound originality and incisiveness of the Faraday-Maxwell hypothesis (1854). Maxwells great book (1873)... was looked at askance in Germany, Helmholtz alone excepted."

"While mathematics is easily able to cope with the problems of relativity, even in their most generalized aspects, since they never break with continuity, the questions are more menacing in the second class of the recent demands of experimental physics, which came to a crisis in certain straightforward experiments on radiation made at the Reichsanstalt (Lummer and Pringshen, 1899; Christianson, 1884) The question dates back to Kirchoffs (1859) in which emission and absorption are equal. Some time after came Stefans universal law of black body radiation (1879) and the theoretical verification on the part of Boltzmann in 1884."

"The new bodies, showing an inertia or virtual mass depending in a pronounced way on their speed, made havoc with Newtons laws and swept the classic dynamics mercilessly out of the field, as an arbiter of world phenomena."

"The equations of this celebrated , culminating in Einsteins famous addition theorem of velocities belonging to different systems—an ultimate break with the , where time has the same absolute value everywhere—have been the very focus of discussion for the last ten years."

"Lorentz then showed with consummate skill that the equations of the classic electromagnetics of Maxwell could be retained, that both the scaler potential and the vector-potential would retain their original form, would be invariant, so to speak, if the time-variable were belated by the interval consumed by light in passing from the source to the point of application in question."

"Hydrodynamics... profited and such beautiful researches as those of the Bjerknes (1863 et. seq.) father and son, were stimulated in proportion as they fitted into the electromagnetic scheme."

"As Maxwells equation contained no direct reference to the motion of the charged body, a first attempt... was made by Hertz (1890) to supply this deficiency; but it was not of permanent value."

"Of the Planck molecular oscillators... If operating continuously under the established electromagnetic laws they lead to the impossible distributions of energy in the spectrum investigated by Rayleigh and Jeans. But if emitting only, when their energy content is a whole number of energy elements, a case thus involving the entropy probability of Boltzmann, Wiens law and the numerical data referred to are deducible with astounding precision."

"The speed of the earth, regarded optically from axes fixed in the ether, is zero. The ether and the earth have no relative velocity. This is tantamount to a rejection of the ether. Judge the consternation!"