The Evolvement and Its Dynamics of High-Resolution-Power Spectroscopes in Studying the Fine Structure of Hydrogen Spectrum: 1920s-1930s

Experiments in studying the fine-structure of hydrogen spectrum played an important role in physics development in 1920s-1930s. As core apparatus, the evolvement of high-resolution-power spectroscopes in use largely reflects how these experiments developed. Focusing on these experiments, we describes how spectroscopes evolved from old apparatus, Lummer-Gehrcke plates and echelons, to new ones, Fabry-Perot interferometers. In 1920s, new apparatus were noticed that they could simplify error handling and thus were introduced into these experiments, although initial measurements of them were not as accurate as those of the old ones. In 1930s, new apparatus significantly improved their measurement accuracy with a better usage, winning the competition against old ones. Meanwhile, some research concerns for such experiments changed. With new concerns, old apparatus were replaced without further competition, even though they were potentially as capable as the new ones to face these concerns.

Previous narratives of this history mainly focused on the controversies between the results or conclusions of concurrent experiments. As complementary perspectives, we take spectroscope evolvement as a clue to reveal the consistency and continuity of these experiments and analyze the dynamics behind the spectroscope evolvement by showing the effect of another accumulative consensus different from experimental results or conclusions.