Kuhn says leading physicists accepted Newton's theory of gravitation before astronomical measurements were accurate enough to decide the issue ["Structure of Scientific Revolutions" 1962]. Other than this aged example, is there any case in which physicists accepted a new or modified basic theory of physics based on a mathematical derivation from well-accepted theories, before direct empirical evidence was available? The Higgs boson and cosmic inflation have something of this flavor: these theories had substantial credibility before empirical evidence was available because they explained phenomena that were left unexplained by existing theories, but they were not fully accepted in the canon of physics.