Max Planck

“ The dynamics of the electron is not only testable by the deflection of Becquerel rays. Abraham has alluded to the need of attributung to the Lorentz-electron a special internal energy. That difficulty seems greater to me than the deviation from Kaufmann's measurements. Against Einstein's theory of relativity certain objections can be raised. He uses Maxwell's equations, but ignores that certain conditions are not met, namely the validity of the divergence theorem of electrical force. ”

“ As to the question of principle formulated by Planck, I would suspect that the gentlemen under 40 years prefer the electrodynamic postulate, that those over 40 years prefer the mechanical-relativistic postulate. I prefer the electrodynamic. (Laughter.)
Kaufmann: To the postulate-question I would like to say that the epistemological value of the postulate of relative motion is, however, not very large, as it is only useful for uniform translation. As soon as we take into account rotation and irregular motions, we don't get along with it. ”

“ Therefore, one may say that within the currently executable measurements, the electrical deflectability of such a ray is in the relative theory always greater than in the sphere theory, and the difference is the greater, the smaller the discharge potential is.
For P = 0 (β = β' = 0) there is especially:
. Simultaneous measurements of the discharge potentials, magnetic and electrical deflectability of the cathode rays have been known to be performed by H. Starke [10] . Maybe they can already be used for an examination of the two theories. ”

“ For u = 0 (magnetic deflection is zero) we have:
. For u = ∞ (magnetic deflection equal to infinity) we have:
. Because an experimental decision between the two theories is the more likely, the more their results differ, we can assume that measurements of the electrical deflectability, which should lead to a decision between the theories, is more appropriate to conduct with cathode rays than with Becquerel rays.
§ 8. Difference between the theories for cathode rays of a certain discharge potential. ”

“ The electric field strength is zero between the diaphragm and the photographic plate, and constant between the capacitor plates at a proper distance from the edges. As Kaufmann, we connect the field strength to its value in the homogeneous part of the field and take it as unity, calling the field strength measured in this way. ”

“ The fourth and sixth column contain the values of calculated from u according to (24) and (25) , the fifth and seventh column contain the values of following from (18) , where the required φ' and φ2 are taken from (17) and (11) ”

“ Table VII, p. 529) , and from which u is calculated by using Kaufmann's equations (14) and (17 ) , determining the corresponding according to each of the two theories, and then pass to y' by using Kaufmann's equation (18) . Then is given by Kaufmann's equation (12) . For this calculation, Kaufmann's constants A and B are of course not the "constants of curve" but the "constants of apparatus", which were measured independently of the deflection experiments. ”