As aphilosopher, he is known for hisphilosophy of science, ideas on the relation between the laws of perception and thelaws of nature, the science ofaesthetics, and ideas on the civilizing power of science. By the late nineteenth century, Helmholtz's development of a broadly Kantian methodology, including thea priori determination of the manifold of possible orientations in perceptual space, had inspired new readings of Kant[4] and contributed to the late modernneo-Kantianism movement in philosophy.[5]
As a young man, Helmholtz was interested in natural science, but his father wanted him to study medicine. Helmholtz earned amedical doctorate at Medizinisch-chirurgisches Friedrich-Wilhelm-Institute in 1842 and served a one-year internship at theCharité hospital[6] (because there was financial support for medical students).
Trained primarily in physiology, Helmholtz wrote on many other topics, ranging from theoretical physics to theage of the Earth, and to the origin of theSolar System.
Helmholtz's first academic position was as a teacher of anatomy at the Academy of Arts in Berlin in 1848.[7] He then moved to take a post of associate professor of physiology at the PrussianUniversity of Königsberg, where he was appointed in 1849. In 1855 he accepted a full professorship of anatomy and physiology at theUniversity of Bonn. He was not particularly happy in Bonn, however, and three years later he transferred to theUniversity of Heidelberg, inBaden, where he served as professor of physiology. In 1871 he accepted his final university position, as professor of physics at theFriedrich Wilhelm University in Berlin.
His first important scientific achievement, an 1847 treatise on theconservation of energy, was written in the context of his medical studies and philosophical background. His work on energy conservation came about while studyingmusclemetabolism. He tried to demonstrate that no energy is lost in muscle movement, motivated by the implication that there were novital forces necessary to move a muscle. This was a rejection of the speculative tradition ofNaturphilosophie andvitalism which was at that time a dominant philosophical paradigm in German physiology. He was working against the argument, promoted by some vitalists, that "living force" can power a machine indefinitely.[4]
Helmholtz was a pioneer in the scientific study of human vision and audition. Inspired bypsychophysics, he was interested in the relationships between measurable physical stimuli and their correspondent human perceptions. For example, the amplitude of a sound wave can be varied, causing the sound to appear louder or softer, but a linear step in sound pressure amplitude does not result in a linear step in perceived loudness. The physical sound needs to be increased exponentially in order for equal steps to seem linear, a fact that is used in current electronic devices to control volume. Helmholtz paved the way in experimental studies on the relationship between the physical energy (physics) and its appreciation (psychology), with the goal in mind to develop "psychophysical laws".
The sensory physiology of Helmholtz was the basis of the work ofWilhelm Wundt, Helmholtz's student, who is considered one of the founders of experimentalpsychology. More explicitly than Helmholtz, Wundt described his research as a form of empirical philosophy and as a study of the mind as something separate. Helmholtz had, in his early repudiation ofNaturphilosophie, stressed the importance ofmaterialism, and was focusing more on the unity of "mind" and body.[9]
In 1851, Helmholtz revolutionized the field ofophthalmology with the invention of theophthalmoscope; an instrument used to examine the inside of thehuman eye. This made him world-famous overnight. Helmholtz's interests at that time were increasingly focused on the physiology of the senses. His main publication, titledHandbuch der Physiologischen Optik (Handbook of Physiological Optics orTreatise on Physiological Optics; English translation of the 3rd volumehere), provided empirical theories ondepth perception,colour vision, andmotion perception, and became the fundamental reference work in his field during the second half of the nineteenth century. In the third and final volume, published in 1867, Helmholtz described the importance ofunconscious inferences for perception. TheHandbuch was first translated into English under the editorship ofJames P. C. Southall on behalf of theOptical Society of America in 1924–5. His theory ofaccommodation went unchallenged until the final decade of the 20th century.
Helmholtz continued to work for several decades on several editions of the handbook, frequently updating his work because of his dispute withEwald Hering who held opposite views on spatial and colour vision. This dispute divided the discipline of physiology during the second half of the 1800s.
In 1849, while at Königsberg, Helmholtz measured the speed at which the signal is carried along a nerve fibre. At that time most people believed that nerve signals passed along nerves immeasurably fast.[10] He used a recently dissected sciatic nerve of a frog and the calf muscle to which it attached. He used agalvanometer as a sensitive timing device, attaching a mirror to the needle to reflect a light beam across the room to a scale which gave much greater sensitivity.[10] Helmholtz reported[11][12] transmission speeds in the range of 24.6 – 38.4 meters per second.[10]
Helmholtz showed that different combinations of resonators could mimicvowel sounds:Alexander Graham Bell in particular was interested in this but, not being able to read German, misconstrued Helmholtz's diagrams as meaning that Helmholtz had transmitted multiple frequencies by wire—which would allow multiplexing of telegraph signals—whereas, in reality, electrical power was used only to keep the resonators in motion. Bell failed to reproduce what he thought Helmholtz had done but later said that, had he been able to read German, he would not have gone on to invent the telephone on theharmonic telegraph principle.[14][15][16][17]
The translation byAlexander J. Ellis was first published in 1875 (the first English edition was from the 1870 third German edition; Ellis's second English edition from the 1877 fourth German edition was published in 1885; the 1895 and 1912 third and fourth English editions were reprints of the second).[18]
Helmholtz studied electrical oscillations from 1869 to 1871, and in a lecture delivered to the Naturhistorisch-medizinischen Verein zu Heidelberg (Natural History and Medical Association of Heidelberg) on 30 April 1869, titledOn Electrical Oscillations, he indicated that the perceptible damped electrical oscillations in a coil connected to aLeyden jar were about1⁄50 second in duration.[19]
In 1871, Helmholtz moved from Heidelberg to Berlin to become a professor of physics. He became interested inelectromagnetism, and theHelmholtz equation is named for him. Although he made no major contributions to this field, his studentHeinrich Rudolf Hertz became famous as the first to demonstrateelectromagnetic radiation.Oliver Heaviside criticised Helmholtz's electromagnetic theory because it allowed the existence oflongitudinal waves. Based on work onMaxwell's equations, Heaviside pronounced that longitudinal waves could not exist in a vacuum or a homogeneous medium. Heaviside did not note, however, that longitudinal electromagnetic waves can exist at a boundary or in an enclosed space.[20]
Helmholtz's scientific work in physiology and mechanics occasioned much that he is known for inphilosophy of science, including ideas on the relation between the laws of perception and thelaws of nature and his rejection of the exclusive use ofEuclidean geometry.[21]
His philosophy of science wavered between some version ofempiricism andtranscendentalism.[22] Despite the speculative associations of the latter, his philosophy of science is thoroughly indebted to his use of mathematical physics to supplant vitalism and articulate the general conservation of energy principle.[4]
His rejection of Euclidean geometry as the only possible science of space is central to understanding his appropriation of Kant's philosophy of space, which ostensibly requires Euclidean geometry to be that exclusivea priori science ofphysical space. Helmholtz introduced a new conception of thea priori in space: that of the determination of the manifold of possible orientations in perceptual space. These developments inspired new readings of Kant[4] and contributed to the rise of late modernneo-Kantianism movement in philosophy.
On 10 November 1881, he was awarded theLégion d'honneur: au grade de Commandeur, or Level 3 – a senior grade. (No. 2173).
In 1883, Professor Helmholtz was honoured by the Emperor, being raised to the nobility, orAdel. TheAdelung meant that he and his family were now styled:von Helmholtz. The distinction was not a peerage or title, but it was hereditary and conferred a certain social cachet.
^Heis, Jeremy (2018)."Neo-Kantianism".Stanford Encyclopedia of Philosophy. Retrieved6 October 2024.This movement drew inspiration from a diverse cast of philosophers—principally, Kuno Fischer (Fischer 1860), Hermann von Helmholtz (Helmholtz 1867, 1878), Friedrich Lange (Lange 1866), Otto Liebmann (Liebmann 1865), and Eduard Zeller (Zeller 1862))—who in the middle of the nineteenth century were calling for a return to Kant's philosophy as an alternative to both speculative metaphysics and materialism (Beiser 2014b).
^R. S. Turner,In the Eye's Mind: Vision and the Helmholtz-Hering Controversy, Princeton University Press, 2014, p. 36.
^English translation published inScientific memoirs, selected from the transactions of foreign academies of science, and from foreign journals: Natural philosophy (1853), p. 114; trans. by John Tyndall.Google Books,HathiTrust
^abcGlynn, Ian (2010).Elegance in Science. Oxford: Oxford University Press. pp. 147–150.ISBN978-0-19-957862-7.
^Helmholtz, Hermann von (1850).Vorläufiger Bericht über die Fortpflanzungs-Geschwindigkeit der Nervenreizung. In: Archiv für Anatomie, Physiologie und wissenschaftliche Medicin. Veit & Comp., pp. 71–73.MPIWG Berlin
^Helmholtz, Hermann von (1850).Messungen über den zeitlichen Verlauf der Zuckung animalischer Muskeln und die Fortpflanzungsgeschwindigkeit der Reizung in den Nerven. In: Archiv für Anatomie, Physiologie und wissenschaftliche Medicin. Veit & Comp., pp. 276–364.MPIWG Berlin
David Cahan:Helmholtz: A Life in Science (University of Chicago, 2018).ISBN978-0-226-48114-2
Steven Shapin, "A Theorist of (Not Quite) Everything" (review of David Cahan,Helmholtz: A Life in Science, University of Chicago Press, 2018,ISBN978-0-226-48114-2, 937 pp.),The New York Review of Books, vol. 66, no. 15 (10 October 2019), pp. 29–31.
David Cahan (Ed.):Hermann von Helmholtz and the Foundations of Nineteenth-Century Science. Univ. California, Berkeley 1994,ISBN978-0-520-08334-9.
Gregor Schiemann:Hermann von Helmholtz's Mechanism: The Loss of Certainty. A Study on the Transition from Classical to Modern Philosophy of Nature. Dordrecht: Springer 2009,ISBN978-1-4020-5629-1.
Franz Werner:Hermann Helmholtz´ Heidelberger Jahre (1858–1871). (= Sonderveröffentlichungen des Stadtarchivs Heidelberg 8). Mit 52 Abbildungen. Berlin / Heidelberg (Springer) 1997.
"Hermann von Helmholtz" (Obituary). Royal Society (Great Britain). (1894).Proceedings of the Royal Society of London. London: Printed by Taylor and Francis. p. xvii.
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