Quantum mechanics: A historical-linguistic perspective

Quantum mechanics would not be quantum mechanics without the many technical terms which emerged a century ago but are still found in modern textbooks. The theory was mainly created by German-speaking physicists, which is reflected in German–English hybrid words such as “eigenvalue” and “eigenstate.” While “eigenvalue” was a neologism—such as was “quantum mechanics” itself—other terms in the quantum lexicon were metaphors adopted from everyday language, e.g., “spin” and “tunneling.” Conversely, a few of the specialized quantum terms were later reused in common language with new meanings. In today's parlance, to make a “quantum jump” has a meaning entirely different from the one in which the expression originated. This paper examines various linguistic aspects associated with the early development of quantum mechanics and its predecessor, the old quantum theory. For example, all physicists are familiar with the quantum concept of degeneracy. But the same term has also been employed to denote certain groups of people as “degenerate.” Is there any historical connection between the two widely different connotations?