The birth of quantum mechanics from the spirit of radiation theory

This paper starts from the observation that the major hallmarks in the history of quantum mechanics centrally involved light and radiation. Consequently, we ask how precisely did concepts and ideas from radiation theory define the creation of quantum mechanics? And why was it a quantum theory of mechanics and not a quantum theory of electrodynamics that was crafted in the years 1925/26? Following these questions, this paper provides a reading of the history of the old quantum theory from the perspective of radiation. We argue that both wave and matrix mechanics, while emerging from widely different trajectories, emerged as spin-offs from nascent, ultimately unsuccessful quantum theories of radiation. We discuss the epistemological implications of this development for the historical and philosophical analysis of quantum mechanics and quantum field theory.