Young-Helmholtz: Trichromatic Theory

Young-Helmholtz: Trichromatic Theory

Introduction

Helmholtz was born on Aug. 31, 1821, in Potsdam, where his father, a teacher at the gymnasium, taught him languages and the scientific thinking of the time. In 1838 he entered the Friedrich Wilhelm Medical Institute in Berlin. There the renowned physiologist Johannes Muller (1801-58) grounded him in the prevailing Kantian approach to “nature philosophy,” which held that vital or nonphysical forces imperceptible to the senses accounted for physiological functions. Opposing this theory, Helmholtz soon came to believe that physiological forces as well as forces of inorganic nature could be perceived by the senses. Helmholtz became further convinced that such forces could be mechanically measured and understood; this belief carried through the rest of his life and led him to his later investigations and contributions (Abney 2003).

Helmholtz next examined the sciatic nerves of frogs, becoming the first to measure the velocity of nerve impulses. From 1856 to 1866, as a professor of anatomy primarily at the University of Heidelberg, he researched the eye, which vitalists of the time considered the organ that best illustrated the workings of nonmaterial forces. The result of this extensive research was his multivolume Physiological Optics, a work that remained for many decades the definitive study on the physiology and physics of vision. During these studies Helmholtz also invented the ophthalmoscope (an instrument used to view the interior of the eye) and developed a theory of color vision (Mollon 2003).

Next, studying the ear, Helmholtz formulated the resonance theory of hearing, in which certain organs of the inner ear were believed to function as tuned resonators. In 1863, with the publication of On the Sensation of Tone as a Physiological Basis for the Theory of Music, Helmholtz further refuted the vitalists by demonstrating that the aesthetics of music were a function of the ear's mechanical ability to pick up wave motions of musical sounds.

By the time of his death in Berlin on Sept. 8, 1894, the explanation of the physical world in terms of classical mechanics was nearly played out. The revolution in physics brought on by the discovery of X rays and radioactivity and the development of relativity theory soon replaced the considerable advances that Helmholtz made during his century (Schwartz 2009).

Interest in Color

Scientific interest in color began in the latter part of the seventeenth century with the research of Newton on light and colors. Of historical significance was his discovery that white (or grey) and all other colors are, in fact, reproducible with a mixture of two or more kinds of homogeneous light. During the eighteenth century some physicists expressed the opinion that a minimum of three elementary or primary colors were necessary to reproduce all the known colors. Experimenting with mixtures of colored pigments they concluded that red, yellow, and blue were the primary colors, green being excluded since it was obtainable with mixtures of yellow and blue substances. Wunsch, experimenting with mixtures of spectral lights, concluded that red, green, and violet were the primary ...