Hermann von Helmholtz

Hermann von Helmholtz (1821-1894) was amongst the last of the great polymaths. He made significant contributions to all of the sciences as well as to philosophy and the arts, his enormous contribution to acoustics being just one of his many outputs. The Whipple's collection contains several items relating to his work, including his apparatus for the synthesis of sound and his iconic resonators.

Early life

Helmholtz was born in 1821 in Potsdam, Prussia, the only son of a school teacher. He had wanted to study physics but his father could not afford to sponsor him in that costly pursuit. However, the Prussian government offered bursaries for the study of medicine for anyone who would sign up for military service and so Helmholtz enrolled at a medical institute in Berlin after which he was assigned a post with a guards regiment in Potsdam. As a promising medical doctor he was given space to set up his own laboratory where he began a series of important experiments in optics and nerve impulses. In addition, and despite a full-time position as an army surgeon, he was able to devote attention to establishing a firm mathematical basis for the principle of the conservation of energy. The brilliance of Helmholtz's work led to a cancellation of his remaining years of army service and to his appointment as Professor of physiology at Koenigsberg. He then quit medicine and focused exclusively on physiology and physics.

Acoustical work

Helmholtz began his work on acoustics in 1856, which culminated in the groundbreaking publication of On the Sensation of Tone as a Physiological Basis for the Theory of Music in 1863. Helmholtz applied the mathematical ideas of François Fourier (1772-1837) to the question of tonal quality, or timbre. Fourier had invented a type of mathematical analysis that demonstrated that any periodic sound wave can be represented as the sum of sine waves having the appropriate amplitude, frequency and phase. This led the way to Helmholtz's reductionist ideas about sound, whereby all complex sounds are composed of simple tones. Helmholtz further applied these ideas to the human perception of sound, arguing that our ears analyze sounds in a similar way to his resonators, with vibrations of different frequencies being extracted from the sound and sent to different nerve endings.