Heinrich Hertz

HERTZ, Heinrich (1857–1894), one of the greatest German physicists. Upon graduating from his higher education institution, Hertz was an assistant to Professor Helmholtz, and later a professor in Kiel, Karlsruhe, and Bonn. Hertz's work touched upon a whole range of problems in physics. He is credited with classical research in the field of photoelectricity and the study of the effect of ultraviolet rays on a spark. Furthermore, he provided a remarkably complete study of the collision of elastic spheres, in which oscillations occur under the influence of elasticity. Finally, he authored a remarkable course on mechanics, in which he presented a completely new point of view on the fundamental principles of this science. But the largest and most important part of his work was the research undertaken on the propagation of electromagnetic oscillations and waves in the ether. In these studies, Hertz pointed out the possibility of constructing such devices (vibrators) in which high-frequency currents arise, creating a variable electromagnetic field around the vibrators. Such a field propagates in space at the speed of light and exhibits all the phenomena observed during the propagation of light: rays of electric force, or, as they are called now, electromagnetic waves, can be concentrated with the help of mirrors; they can be refracted, reflected, and show double refraction; electromagnetic waves are, therefore, a process identical to light waves, differing from the latter by a greater wavelength. Hertzian waves have a wavelength of about 1 m, while light waves are, on average, 500 mµ. These studies by Hertz were the first substantiation of Maxwell's ideas regarding the identity of the nature of light rays and electromagnetic processes. Furthermore, Hertz is credited with profound theoretical studies of the electromagnetic field and the electrodynamics of stationary and moving bodies. Hertz's work was valued extremely highly even during his lifetime: as a young man, he was invited to Berlin to occupy Helmholtz's chair, which Hertz, however, declined so as not to engage in the heavy organizational work associated with staying in Berlin. Helmholtz characterizes him in one remarkable letter (1888) to the mathematician Lipschitz as one of the most talented physicists in Germany. Among Hertz's students, one must point out the famous German physicist Philipp Lenard, to whom science owes many studies in the field of cathode rays. Hertz's main works: "Uber die Beziehungen zwischen Licht u. Elektrizität" (Leipzig, 1894); "Untersuchungen über die Ausbreitung der elektrischen Kraft" (Leipzig, 1894); "Die Prinzipien der Mechanik in neuem Zusammenhange dargestellt" (Leipzig, 1894); Collected Works, Vol. I–III (Leipzig, 1894). The work "On the Relation Between Light and Electricity" (St. Petersburg, 1890) was published in Russian.