Eur. Phys. J. H 39, 263–281 (2014)
https://doi.org/10.1140/epjh/e2014-50007-7

The names of physics: plasma, fission, photon

Centre for Science Studies, Department of Mathematics, Aarhus University, 8000 Aarhus, Denmark

^a e-mail: helge.kragh@css.au.dk

Received: 24 January 2014
Received in final form: 10 July 2014
Published online: 5 September 2014

Abstract

The study of the origin and dissemination of names used in science is a useful but largely uncultivated historiographical method. What I call the etymological approach to the history of science is here illustrated by an examination of three important terms that originated in the 1920s and 1930s and are today as popular as ever. The names “plasma” and “fission” were introduced in physics in 1928 and 1939, respectively, in both cases by borrowing a name that was already firmly established in the biological sciences. The etymology of “photon” is different and more complex. Although it was quickly understood as just a synonym for Einstein’s light quantum going back to 1905, when it was originally introduced it was with a different meaning. It can be traced back to 1916, when it was proposed as a unit for the illumination of the retina, and ten years later the name was revived in still another non-Einsteinian context. Apart from examining how the three words first entered physics, I also look at how the physics community initially responded to them.