Young’s theory of interference and its application

Abstract

Most historians have believed that Young’s case for the principle of interference of light was strong.¹ A few scholars, however, have concluded that his observations were too crude, some of his explanations were erroneous, and others overburdened with hypotheses.² Since neither of these opinions seems well documented, the question remains open. I intend to defend another view of Young’s theory of periodical colors, which I will call the “theory of interference.” It will be shown that, 1) Young constructed the theory of interference as a mathematical theory; 2) to support his theory, he presented observations of his own and of others, of such number and precision as he considered sufficient for periodical colors ; 3) all his mathematical derivations and all his experiments (except for one) were accurate ; 4) the presentation of his theory lacked mathematical details and a discussion of fundamental physical concepts ; and 5) some of Young’s alleged “mistakes” were caused by a miscomprehension of his works. My discussion will be based on a study of all of Young’s works on interference of light written between 1801 and 1817.