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? Editor's note: Such a specialized field as quantum mechanics naturally uses many specialized terms. Words such as "spin," "degeneracy," and "quantum jump," have come out of a variety of contexts, and some have even taken on new meanings in the general public. This paper discusses the origins and linguistic history of quantum terminology. Readers will especially enjoy learning how certain words came to be the dominant, established, terms in the field. For example, why do we talk about "eigenvalues" today when we could be speaking of "proper values" or "eigenwerts?" [ABSTRACT FROM AUTHOR]