著者

安孫子 誠也

出版者

日本科学史学会

雑誌

科学史研究 (ISSN:21887535)

巻号頁・発行日

vol.27, no.168, pp.193-206, 1988 (Released:2021-09-01)

---

While the formation of special relativity is usually described as an event in the particle-dynamical tradition, the present study asserts that it really derived from the chemico-thermal origin, in which A.Einstein participated at the start of his scientific career. Firstly, the student-life of A. Einstein is briefly sketched, discussing how he was studying writings of Helmholtz, Kirchhoff, Hertz and Boltzmann, independently of his university's course, and was considering about the light-velocity within the transparent moving materials. Nextly, commentary is made of Einstein's each paper up to 1905, in which is made clear how he was studying dissociation, diffusion and fluctuation, both thermodynamically and statistical-thermodynamically, paying much attention to the connection between macroscopic- and microscopic-aspects of matter. Thirdly, the motivation of his writing of "On the electrodynamics of moving bodies" is presented. It is pointed out that, in his Ph. D dissertation written early in 1905, he estimated viscosity-coefficient of liquid solution, by way of solving the hydrodynamical equation in the coordinate system of the soluteparticle at rest. Then, led by the analogical considerations, in order to estimate radiational friction coefficient of a body moving within the black-body radiation, he needed at that time the electromagnetic equation in the coordinate system of the gas-particle or the suspended small mirror at rest. It is also pointed out that the principle of relativity might have been suggested by the analogy with the Galileian invarince of the hydrodynamical equation, as well as by the energetic considerations on the relative motion of a conductor and a magnet. And, the constancy of light velocity might be the result of that principle applied to the Maxwelfs equation, and might be the extention to include the case of light quantum which does not obey the Maxwell's equation Lastly, a comment is made about the most important contributions of chemico-thermal origin to Einstein's formation of the special relativity They are :the reinterpretation of length and time as observable physical quantities, and the reconception of time, from absolutely defined mechanical time independent of the coordinate systems, to thermodynamical time. The latter is based on the signal-velocity of light in vacuum, i.e.the speed of dissipation into vacuum of the free energy preserved in the lightsource, and on the motion of needles in the windup-spring watches, which is also a process of dissipation of the free energy stored in the wound springs.