On the theory of light and colours

This landmark scientific lecture investigates the nature of light and the origins of colour through a careful union of observation, experiment, and mathematical reasoning. Rather than relying on speculation, it seeks simple, consistent principles capable of explaining a wide range of apparently unrelated phenomena, with particular attention to the striking colours seen in thin plates and finely striated substances.

Drawing on the optical work of Newton and the earlier ideas of Hooke, Huygens, Euler, and others, the discussion revisits long-standing debates about whether light behaves as particles or waves. Detailed analyses show how subtle changes in structure and thickness can produce vivid, shifting colours, while the accompanying figures clarify the geometrical relationships involved. Historically important and intellectually engaging, this compact work offers listeners a glimpse into the development of modern physical theory and the patient reasoning behind a major explanation of nature.