R. A. Millikan’s Struggle with the Meaning of Planck’s Constant

Abstract

In 1916 R. A. Millikan published his experimental determination of the value of Planck’s constant, with remarkable precision. It was later cited as part of his Nobel Prize award. But as a study of that paper together with Millikan’s subsequent comments over the years reveal, he initially refused to accept the interpretation of the theoretical meaning of his work, as seen from the perspective of a present-day physicist. Yet, over time, Millikan adjusted his view retroactively to accept the meaning of what he had done — namely to provide crucial support for Einstein’s heuristic point of view on the quantum theory of light (1905). This case also serves as a test whether scientists, as is now often alleged, as a rule arrange to obtain their results in the light of their own beliefs.