Hermann von Helmholtz

Name	Hermann von Helmholtz
Image width	225px
Birth date	August 31, 1821
Birth place	Potsdam, Kingdom of Prussia
Residence	Germany
Nationality	Germany
Death date	September 08, 1894
Death place	Charlottenburg, German Empire
Field	Physics and physiology
Work institution	University of Königsberg University of Bonn University of Heidelberg University of Berlin
Alma mater	Royal Friedrich-Wilhelm Institute
Doctoral advisor	Johannes Peter Müller
Notable students	Henry Augustus Rowland Wilhelm Wundt
Known for	Conservation of energy Helmholtz free energy

Hermann Ludwig Ferdinand von Helmholtz (August 31, 1821 – September 8, 1894) was a German physician and physicist who made significant contributions to several widely varied areas of modern science. In physiology and psychology, he is known for his mathematics of the eye, theories of vision, ideas on the visual perception of space, color vision research, and on the sensation of tone, perception of sound, and empiricism. In physics, he is known for his theories on the conservation of energy, work in electrodynamics, chemical thermodynamics, and on a mechanical foundation of thermodynamics. As a philosopher, he is known for his philosophy of science, ideas on the relation between the laws of perception and the laws of nature, the science of aesthetics, and ideas on the civilizing power of science. A large German association of research institutions, the Helmholtz Association, is named after him.

Biography

Early years

Helmholtz was the son of the Potsdam Gymnasium headmaster, Ferdinand Helmholtz, who had studied classical philology and philosophy, and who was a close friend of the publisher and philosopher Immanuel Hermann Fichte. Helmholtz's work is influenced by the philosophy of Fichte and Kant. He tried to trace their theories in empirical matters like physiology.

As a young man, Helmholtz was interested in natural science, but his father wanted him to study medicine at the Charité because there was financial support for medical students.

Helmholtz wrote about many topics ranging from the age of the Earth to the origin of the solar system.

Career

Mechanics

His first important scientific achievement, an 1847 physics treatise on the conservation of energy was written in the context of his medical studies and philosophical background. He discovered the principle of conservation of energy while studying muscle metabolism. He tried to demonstrate that no energy is lost in muscle movement, motivated by the implication that there were no vital forces necessary to move a muscle. This was a rejection of the speculative tradition of Naturphilosophie which was at that time a dominant philosophical paradigm in German physiology.

Drawing on the earlier work of Sadi Carnot, Émile Clapeyron and James Prescott Joule, he postulated a relationship between mechanics, heat, light, electricity and magnetism by treating them all as manifestations of a single force (energy in modern terms). He published his theories in his book Über die Erhaltung der Kraft (On the Conservation of Force, 1847). Whether or not Helmholtz knew of Julius Robert von Mayer's discovery of the law of conservation of energy in the beginning of the 1840s is a point of controversy. Helmholtz did not quote Mayer in his work and was accused by contemporaries of plagiarism.

In the 1850s and 60s, building on the publications of William Thomson, Helmholtz and William Rankine popularized the idea of the heat death of the universe.

Sensory physiology

The sensory physiology of Helmholtz was the basis of the work of Wilhelm Wundt, a student of Helmholtz, who is considered one of the founders of experimental psychology. He, more explicitly than Helmholtz, 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 of Naturphilosophie, stressed the importance of materialism, and was focusing more on the unity of "mind" and body.

Ophthalmic optics

In 1851, Helmholtz revolutionized the field of ophthalmology with the invention of the ophthalmoscope; an instrument used to examine the inside of the human 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, entitled Handbuch der Physiologischen Optik (Handbook of Physiological Optics), provided empirical theories on spatial vision, color vision, and motion perception, and became the fundamental reference work in his field during the second half of the nineteenth century. It was first translated into English under the editorship of James P. C. Southall on behalf of the Optical Society of America in 1924-5. His theory of accommodation 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 with Ewald Hering who held opposite views on spatial and color vision. This dispute divided the discipline of physiology during the second half of the 1800s.

Acoustics and aesthetics

In 1863 Helmholtz published Die Lehre von den Tonempfindungen als physiologische Grundlage für die Theorie der Musik (On the Sensations of Tone as a Physiological Basis for the Theory of Music), once again demonstrating his interest in the physics of perception. This book influenced musicologists into the twentieth century. Helmholtz invented the Helmholtz resonator to identify the various frequencies or "tones" present in musical and other sounds containing by multiple tones. Alexander Graham Bell in particular was interested in how Helmholtz used resonators to mimic vowel sounds. Due to not being able to read German, Bell misconstrued Helmholtz' diagrams as meaning that Helmholtz had transmitted vowel sounds over a wire, whereas Helmholtz was merely using electrical stimulation to keep his resonators in motion without manual intervention. Bell reasoned that if vowels could be transmitted, then consonants also should be possible. He tried, and failed, to reproduce what he thought had already been done by Helmholtz. However, Bell was later to say that if he had been able to read German he would probably have given up the task as impossible, but in the event, went on to invent the telephone using the harmonic telegraph as the basis.

The book was translated by Alexander J. Ellis in 1885 (first English edition from third German edition completed June 1885, and second English edition from fourth German edition completed July 1885; see external links for download).

Electromagnetism

Helmholtz studied the phenomena of electrical oscillations from 1869 to 1871, and in a lecture delivered to the Nat. Hist. Med. Ver. at Heidelberg on April 30, 1869 titled On Electrical Oscillations he indicated that the perceptible damped electrical oscillations in a coil joined up with a Leyden jar were about 1/50th of a second in duration. In 1871 he announced that the velocity of the propagation of electromagnetic induction was about 314,000 meters per second.

In 1871 Helmholtz moved from Heidelberg to Berlin to become a professor in physics. He became interested in electromagnetism and the Helmholtz equation is named for him. Although he did not make major contributions to this field, his student Heinrich Rudolf Hertz became famous as the first to demonstrate electromagnetic radiation. Oliver Heaviside criticised Helmholtz's electromagnetic theory because it allowed the existence of longitudinal waves. Based on work on Maxwell'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.

Quotations

Whoever in the pursuit of science, seeks after immediate practical utility may rest assured that he seeks in vain. --Academic Discourse (Heidelberg 1862)

Students and associates

Other students and research associates of Helmholtz at Berlin included Max Planck, Heinrich Kayser, Eugen Goldstein, Wilhelm Wien, Arthur König, Henry Augustus Rowland, A. A. Michelson, Wilhelm Wundt, and Michael I. Pupin. Leo Koenigsberger, who studied at Berlin while Helmholtz was there, wrote the definitive biography of him in 1902.

Bibliography

1971. Selected Writings of Hermann von Helmholtz. Kahl, Russell, ed. Wesleyan Uni. Press.

1977. Helmholtz: Epistemological Writings. Cohen, Robert, and Wartofsky, Marx, eds. and trans. Reidel.

Ewald, William B., ed., 1996. From Kant to Hilbert: A Source Book in the Foundations of Mathematics, 2 vols. Oxford Uni. Press.

*1876. "The origin and meaning of geometrical axioms," 663–88.

*1878. "The facts in perception," 698–726.

*1887. "Numbering and measuring from an epistemological viewpoint," 727–52.

Jackson, Myles W. Harmonious Triads: Physicists, Musicians, and Instrument Makers in Nineteenth-Century Germany (MIT Press, 2006).

Koenigsberger, Leo. Hermann von Helmholtz, translated by Frances A. Welby (Dover, 1965)

See also

Helmholtz free energy

Helmholtz coil

Helmholtz pitch notation

Helmholtz resonance

Helmholtz theorem

Helmholtz decomposition

Helmholtz equation

Helmholtz machine

Kelvin–Helmholtz instability

Young–Helmholtz theory, about the trichromatic colour vision

References

Further reading

David Cahan (Ed.): Hermann von Helmholtz and the Foundations of Nineteenth-Century Science. Univ. California, Berkeley 1994, ISBN 978-0520083349.

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, ISBN 978-1-4020-5629-1.

Franz Werner: Hermann Helmholtz´ Heidelberger Jahre (1858–1871). (= Sonderveröffentlichungen des Stadtarchivs Heidelberg 8). Mit 52 Abbildungen. Berlin / Heidelberg (Springer) 1997.

External links

"Hermann von Helmholtz" (Obituary). Royal Society (Great Britain). (1894). Proceedings of the Royal Society of London. London: Printed by Taylor and Francis.

"Hermann von Helmholtz" by Leo Koenigsberger (Oxford: Clarendon press, 1906) from Internet Archive

"Hermann von Helmholtz" article by Lydia Patton, Stanford Encyclopedia of Philosophy

J. G. McKendrick Hermann Ludwig Ferdinand von Helmholtz (London : Unwin, 1899)

On the Conservation of Force Introduction to a Series of Lectures Delivered at Carlsruhe in the Winter of 1862–1863, English translation

On the Sensations of Tone as a Physiological Basis for the Theory of Music (downloadable from Google Books) Fourth Edition, By Hermann von Helmholtz, Alexander John Ellis, Published by Longmans, Green, 1912, 575 pages

Treatise on Physiological Optics 1910, three volumes. English translation by Optical Society of America (1924–5).

Popular lectures on scientific subjects 1885

Popular lectures on scientific subjects second series, 1908

Biography, bibliography and access to digital sources in the Virtual Laboratory of the Max Planck Institute for the History of Science

Category:1821 births Category:1894 deaths Category:People from Potsdam Category:Biophysicists Category:Color scientists Category:German nobility Category:German ophthalmologists Category:German physicists Category:History of neuroscience Category:Members of the Prussian Academy of Sciences Category:Members of the Royal Swedish Academy of Sciences Category:People from the Province of Brandenburg Category:Recipients of the Copley Medal Category:Thermodynamicists Category:University of Königsberg faculty Category:University of Bonn faculty Category:University of Heidelberg faculty Category:Humboldt University of Berlin faculty Category:Faraday Lecturers Category:19th-century scientists Category:Foreign Members of the Royal Society