View source for Hermann von Helmholtz

{{short description|German physicist and physiologist (1821–1894)}}
{{redirect|Helmholtz|other uses|Helmholtz (disambiguation)}}
{{Use dmy dates|date=August 2023}}
{{Infobox scientist
| honorific_suffix  = {{post-nominals|country=GBR|size=100%|ForMemRS}}
| image             = Hermann von Helmholtz.jpg
| birth_name        = Hermann Ludwig Ferdinand Helmholtz
| birth_date        = {{birth date|df=y|1821|8|31}}
| birth_place       = [[Potsdam]], [[Province of Brandenburg]], [[Kingdom of Prussia]], [[German Confederation]]
| death_date        = {{death date and age|1894|df=y|9|8|1821|8|31}}
| death_place       = [[Charlottenburg]], Kingdom of Prussia, [[German Empire]]
| education         = {{ill|Medizinisch-chirurgisches Friedrich-Wilhelm-Institut|de}} ([[Doctor of Medicine|MD]], 1842)
| known_for         = {{collapsible list|title={{nobold|''See list''}}
|Studies in the [[conservation of energy]]
|[[Helmholtz theorem (classical mechanics)|Helmholtz classical theorem]]
|[[Helmholtz coil]]
|[[Helmholtz condition]]
|[[Helmholtz decomposition]]
|[[Helmholtz equation]]
|[[Helmholtz free energy]]
|[[Free entropy#Massieu potential / Helmholtz free entropy|Helmholtz free entropy]]
|[[Helmholtz layer]]
|[[Helmholtz minimum dissipation theorem]]
|[[Violin acoustics#Helmholtz motion|Helmholtz motion]]
|[[Helmholtz pitch notation]]
|[[Helmholtz reciprocity]]
|[[Helmholtz resonance]]
|[[Helmholtz temperament]]
|[[Helmholtz's theorems]]
|[[Helmholtz–Kohlrausch effect]]
|[[Helmholtz-Smoluchowski equation|Helmholtz–Smoluchowski equation]]
|[[Helmholtz-Ellis notation|Helmholtz–Ellis notation]]
|[[Helmholtz–Thévenin theorem]]
|[[Gibbs–Helmholtz equation]]
|[[Kelvin–Helmholtz instability]]
|[[Smith–Helmholtz invariant]]
|[[Kelvin–Helmholtz mechanism]]
|[[Young–Helmholtz theory]]
|[[Additive synthesis]]
|[[Efference copy]]
|[[Entoptic phenomenon]]
|[[Heat death paradox]]
|[[Hydrodynamic stability]]
|[[Keratometer]]
|[[Ophthalmoscopy]]
|[[Place theory (hearing)|Place theory]]|
[[Prism adaptation]]|[[Pure tone]]
|[[Unconscious inference]]
|[[Vortex ring]]
}}
| spouse            = {{marriage|[[Anna von Mohl]]|1861}}
| children          = 3
| relatives         = [[Anna Augusta Von Helmholtz-Phelan]] (grand-niece)
| awards            = {{ublist|[[Fellow of the Royal Society#Foreign member|ForMemRS]] (1860)|[[Croonian Medal]] (1864)|[[Matteucci Medal]] (1868)|[[Copley Medal]] (1873)|[[Pour le Mérite#Civil class|''Pour le Mérite'']] (1873)|[[Faraday Lectureship Prize]] (1881)|[[Albert Medal (Royal Society of Arts)|Albert Medal]] (1888)}}
| fields            = [[Physics]]<br>[[Physiology]]
| work_institutions = {{plainlist|
*[[University of Königsberg]] (1849–1855)
*[[University of Bonn]] (1855–1858)
*[[University of Heidelberg]] (1858–1871)
*{{nowrap|[[University of Berlin]] (1871–1888)}}
}}
| thesis_title      = De fabrica systematis nervosi evertebratorum
| thesis_url        = http://archiv.ub.uni-heidelberg.de/volltextserver/13299/
| thesis_year       = 1842
| doctoral_advisor  = [[Johannes Peter Müller]]
| doctoral_students = {{ubl|[[Loránd Eötvös]]|[[Heinrich Hertz]]|[[Gabriel Lippmann]]|[[Otto Lummer]]|[[Albert A. Michelson]]|[[Max Planck]]|[[Mihajlo Pupin]]|[[Friedrich Schottky]]|[[Arthur Gordon Webster]]|[[Max Wien]]|[[Wilhelm Wien]]}}
| notable_students  = {{ubl|[[Émile Boutroux]]|[[Johannes von Kries]]<ref>{{cite book | title=Hermann Von Helmholtz and the Foundations of Nineteenth-Century Science | author = David Cahan | publisher = University of California Press | year = 1993 | page = 198 | isbn = 978-0-520-08334-9 | url = https://books.google.com/books?id=Gx-ZGgeF2EwC&q=%22Johannes+von+Kries%22+psychologist&pg=PA198 }}</ref>|[[Edward Leamington Nichols|Edward Nichols]]|[[Henry Augustus Rowland]]|[[Wilhelm Wundt]]}}
| signature         = Hermann.von.Helmholtz.Signature.png
}}
{{Thermodynamics}}
[[File:Helmholtz's polyphonic siren, Hunterian Museum, Glasgow.jpg|thumb|Helmholtz's polyphonic siren, Hunterian Museum, Glasgow]]

'''Hermann Ludwig Ferdinand von Helmholtz''' ({{IPAc-en|ˈ|h|ɛ|l|m| |h|oʊ|l|t|s}}; {{IPA|de|ˈhɛʁman fɔn ˈhɛlmˌhɔlts|lang}}; 31 August 1821 – 8 September 1894; "von" since 1883) was a German  [[physicist]] and [[physician]] who made significant contributions in several scientific fields, particularly [[hydrodynamic stability]].<ref>{{Cite thesis |title=Robust flow stability: Theory, computations and experiments in near-wall turbulence |url=https://ui.adsabs.harvard.edu/abs/2004PhDT.......158B |date=1 January 2004 |first=Kumar Manoj |last=Bobba|bibcode=2004PhDT.......158B }}</ref> The [[Helmholtz Association of German Research Centres|Helmholtz Association]], the largest German association of [[research institution]]s, was named in his honour.<ref name="Gemeinschaft">{{Cite web |title=The polymath with a sense of practice |url=https://www.helmholtz.de/en/about-us/who-we-are/history/hermann-von-helmholtz/ |access-date=2024-10-04 |website=Helmholtz-Gemeinschaft Deutscher Forschungszentren}}</ref>

In the fields of [[physiology]] and [[psychology]], Helmholtz is known for his mathematics concerning the [[Human eye|eye]], [[Theory of vision|theories of vision]], ideas on the [[visual perception]] of space, [[colour vision]] research, the sensation of tone, perceptions of sound, and [[empiricism]] in the physiology of perception. In [[physics]], he is known for his theories on the conservation of [[energy]] and on the electrical [[Double layer (surface science)|double layer]], work in [[electrodynamics]], [[chemical thermodynamics]], and on a [[Mechanics|mechanical]] foundation of [[thermodynamics]]. Although credit is shared with [[Julius von Mayer]], [[James Joule]], and [[Daniel Bernoulli]]—among others—for the energy conservation principles that eventually led to the [[first law of thermodynamics]], he is credited with the first formulation of the energy conservation principle in its maximally general form.<ref name="Patton"/>

As a [[philosopher]], he is known for his [[philosophy of science]], ideas on the relation between the laws of perception and the [[physical law|laws of nature]], the science of [[aesthetics]], and ideas on the civilizing power of science. By the late nineteenth century, Helmholtz's development of a broadly Kantian methodology, including the ''a priori'' determination of the manifold of possible orientations in perceptual space, had inspired new readings of Kant<ref name="Patton"/> and contributed to the late modern [[neo-Kantianism]] movement in philosophy.<ref>{{cite web |url=https://plato.stanford.edu/entrieS/neo-kantianism/ |title=Neo-Kantianism |last=Heis |first=Jeremy |date=2018 |website=Stanford Encyclopedia of Philosophy |access-date=6 October 2024 |quote=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).}}</ref>

== Biography ==

===Early years===

Helmholtz was born in [[Potsdam]], the son of the local [[Gymnasium (school)|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 was influenced by the philosophy of [[Johann Gottlieb Fichte]] and [[Immanuel 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. Helmholtz earned a [[medical doctorate]] at Medizinisch-chirurgisches Friedrich-Wilhelm-Institute in 1842 and served a one-year internship at the [[Charité]] hospital<ref>R. S. Turner, ''In the Eye's Mind: Vision and the Helmholtz-Hering Controversy'', Princeton University Press, 2014, p. 36.</ref> (because there was financial support for medical students).

Trained primarily in physiology, Helmholtz wrote on many other topics, ranging from theoretical physics to the [[age of the Earth]], and to the origin of the [[Solar System]].

===University posts===

Helmholtz's first academic position was as a teacher of anatomy at the Academy of Arts in Berlin in 1848.<ref>{{cite book|title=Biographical Index of Former Fellows of the Royal Society of Edinburgh 1783–2002|date=July 2006|publisher=The Royal Society of Edinburgh|isbn=0-902198-84-X|url=https://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf|access-date=21 October 2016|archive-date=24 January 2013|archive-url=https://web.archive.org/web/20130124115814/http://www.royalsoced.org.uk/cms/files/fellows/biographical_index/fells_indexp1.pdf|url-status=dead}}</ref> He then moved to take a post of associate professor of physiology at the Prussian [[University of Königsberg]], where he was appointed in 1849. In 1855 he accepted a full professorship of anatomy and physiology at the [[University of Bonn]]. He was not particularly happy in Bonn, however, and three years later he transferred to the [[University of Heidelberg]], in [[Baden]], where he served as professor of physiology. In 1871 he accepted his final university position, as professor of physics at the [[Humboldt University of Berlin|Friedrich Wilhelm University]] in Berlin.

== Research ==

[[File:Helmholtz 1848.jpg|thumb|upright|Helmholtz in 1848]]

===Mechanics===

His first important scientific achievement, an 1847 treatise on the [[conservation of energy]], was written in the context of his medical studies and philosophical background. His work on energy conservation came about 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]]'' and [[vitalism]] 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.<ref name="Patton">[https://plato.stanford.edu/entries/hermann-helmholtz/?simple=True Patton, Lydia. "Hermann von Helmholtz." (2008), Stanford Encyclopedia of Philosophy.]</ref>

Drawing on the earlier work of [[Nicolas Léonard Sadi Carnot|Sadi Carnot]], [[Benoît Paul 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'', or [[energy]] in today's terminology. He published his theories in his book ''Über die Erhaltung der Kraft'' (''On the Conservation of Force'', 1847).<ref>English translation published in ''Scientific memoirs, selected from the transactions of foreign academies of science, and from foreign journals: Natural philosophy'' (1853), p. 114; trans. by John Tyndall. [https://books.google.com/books?id=C1i4AAAAIAAJ&pg=PA114 Google Books], [http://hdl.handle.net/2027/uc1.b4252190?urlappend=%3Bseq=124 HathiTrust]</ref>

In the 1850s and 60s, building on the publications of [[William Thomson, 1st Baron Kelvin|William Thomson]], Helmholtz and [[William Rankine]] helped popularize the idea of the [[heat death of the universe]].

In fluid dynamics, Helmholtz made several contributions, including [[Helmholtz's theorems]] for vortex dynamics in inviscid fluids.<gallery>
File:Helmholtz-1.jpg|1889 copy of Helmholtz's "Über die Erhaltung der Kraft", no. 1
File:Helmholtz-2.jpg|Title page of "Über die Erhaltung der Kraft", no. 1
File:Helmholtz-3.jpg|First page of "Über die Erhaltung der Kraft", no. 1
</gallery>

===Sensory physiology===

Helmholtz was a pioneer in the scientific study of human vision and audition. Inspired by [[psychophysics]], 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 of [[Wilhelm Wundt]], Helmholtz's student, who is considered one of the founders of experimental [[psychology]]. 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 of [[Naturphilosophie]], stressed the importance of [[materialism]], and was focusing more on the unity of "mind" and body.<ref>{{Cite book| title = Making Modern Science: A Historical Survey | author = Peter J. Bowler and Iwan Rhys Morus | publisher = University of Chicago Press | year = 2005 | page = 177 | isbn = 978-0-226-06861-9 | url = https://books.google.com/books?id=LEl3s-wYg10C&q=Helmholtz+materialism++sensory+nineteenth-century+Naturphilosophie&pg=PA177 }}</ref>

===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, titled ''Handbuch der Physiologischen Optik'' (''Handbook of Physiological Optics'' or ''Treatise on Physiological Optics''; English translation of the 3rd volume [https://web.archive.org/web/20180320133752/http://poseidon.sunyopt.edu/BackusLab/Helmholtz/ here]), provided empirical theories on [[depth perception]], [[colour vision]], and [[motion 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 of [[unconscious inference]]s for perception. The ''Handbuch'' 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 reflex|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 colour vision. This dispute divided the discipline of physiology during the second half of the 1800s.

===Nerve physiology===

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.<ref name="glynn">{{cite book |last1=Glynn |first1=Ian |title=Elegance in Science|year=2010 |publisher= Oxford University Press|location=Oxford|isbn= 978-0-19-957862-7|pages=147–150 }}</ref> He used a recently dissected sciatic nerve of a frog and the calf muscle to which it attached. He used a [[galvanometer]] 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.<ref name="glynn"/> Helmholtz reported<ref>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. [http://vlp.mpiwg-berlin.mpg.de/library/data/lit29168 MPIWG Berlin]</ref><ref>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. [http://vlp.mpiwg-berlin.mpg.de/library/data/lit1862 MPIWG Berlin]</ref> transmission speeds in the range of 24.6 – 38.4 meters per second.<ref name="glynn"/>

===Acoustics and aesthetics===
[[File:Hermann von Helmholtz-2.jpg|thumb|Last photograph of von Helmholtz, taken three days before his final illness]] [[File:Helmholtz resonator 2.jpg|right|thumb|The Helmholtz resonator (''i'') and instrumentation]]

In 1863, Helmholtz published ''[[Sensations of Tone]]'', once again demonstrating his interest in the physics of perception. This book influenced musicologists into the twentieth century. Helmholtz invented the [[Helmholtz resonance|Helmholtz resonator]] to identify the various [[audio frequency|frequencies]] or [[Pitch (music)|pitches]] of the pure [[sine wave]] components of [[Fourier analysis#Applications in signal processing|complex sounds containing multiple tones]].<ref name="Helmholtz1885">{{cite book |url=https://archive.org/details/onsensationston00unkngoog |last=von Helmholtz |first=Hermann |year=1885 |title=On the sensations of tone as a physiological basis for the theory of music |edition=Second English |translator-first1=Alexander J. |translator-last1= Ellis |location=London |publisher=Longmans, Green, and Co. |page=[https://archive.org/details/onsensationston00unkngoog/page/n69 44] |access-date=12 October 2010 }}</ref>

Helmholtz showed that different combinations of resonators could mimic [[vowel]] 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 the [[harmonic telegraph]] principle.<ref>{{cite web | title = PBS, American Experience: The Telephone – More About Bell | website = [[PBS]]| url = https://www.pbs.org/wgbh/amex/telephone/peopleevents/mabell.html| archive-url = https://web.archive.org/web/20000511203124/http://www.pbs.org/wgbh/amex/telephone/peopleevents/mabell.html| url-status = dead| archive-date = 11 May 2000}}</ref><ref name="MacKenzie2008">MacKenzie 2003, p. 41.</ref><ref>Groundwater 2005, p. 31.</ref><ref>Shulman 2008, pp. 46–48.</ref>

[[File:Ludwig Knaus - Der Physiker Hermann von Helmholtz (1881).jpg|thumb|left|upright|Helmholtz in 1881, portrait by [[Ludwig Knaus]]]]

The translation by [[Alexander 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).<ref>{{cite book |title=On the Sensations of Tone as a Physiological Basis for the Theory of Music |author=Hermann L. F. Helmholtz, M.D. |year=1912 |edition=Fourth |publisher=Longmans, Green, and Co |isbn=9781419178931 |url=https://archive.org/details/onsensationston01helmgoog}}</ref>

===Electromagnetism===

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, titled ''On Electrical Oscillations'', he indicated that the perceptible damped electrical oscillations in a coil connected to a [[Leyden jar]] were about {{frac|1|50}} second in duration.<ref>{{cite book|url=https://books.google.com/books?id=JCNWAAAAMAAJ&q=electrical+oscillation+helmholtz&pg=PA268|title=Hermann von Helmholtz|first=Leo|last=Koenigsberger|date=28 March 2018|publisher=Clarendon press|isbn=978-0-486-21517-4|access-date=28 March 2018|via=Google Books}}</ref>

In 1871, Helmholtz moved from Heidelberg to Berlin to become a professor of physics. He became interested in [[electromagnetism]], and the [[Helmholtz equation]] is named for him. Although he made no 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 wave]]s. 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.<ref>John D. Jackson, Classical Electrodynamics, {{ISBN|0-471-30932-X}}.</ref>

==Philosophy==

Helmholtz's scientific work in physiology and mechanics occasioned much that he is known for in [[philosophy of science]], including ideas on the relation between the laws of perception and the [[physical law|laws of nature]] and his rejection of the exclusive use of [[Euclidean geometry]].<ref>{{cite book |last1=Helmholtz |first1=Hermann von |chapter=On the Origin and Significance of the Axioms of Geometry |series=Boston Studies in the Philosophy of Science |date=1977 |title=Epistemological Writings |chapter-url=https://link.springer.com/content/pdf/10.1007/978-94-010-1115-0_1?pdf=chapter%20toc |volume=37 |pages=1–38 |doi= 10.1007/978-94-010-1115-0_1|isbn=978-90-277-0582-2 |access-date=13 October 2024}}</ref>

His philosophy of science wavered between some version of [[empiricism]] and [[transcendentalism]].<ref>{{cite journal 
   |last1=De Kock  
   |first1=Liesbet
   |date=2018 
   |title=Historicizing Hermann von Helmholtz's Psychology of Differentiation 
   |url=https://jhaponline.org/jhap/article/view/3432 
   |access-date=1 January 2022
|journal= Journal for the History of Analytical Philosophy
   |volume= 6
   |issue= 3
   |pages= 
   |doi=10.15173/jhap.v6i3.3432 
   |s2cid=187618324
 |quote=Hermann von Helmholtz's peculiar wavering between empiricism and transcendentalism in his philosophy of science in general, and in his theory of perception in particular, is a much debated and well-documented topic in the history and philosophy of science.
|doi-access=free|hdl=1854/LU-8552480|hdl-access=free}}</ref> 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.<ref name="Patton"/>

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 exclusive ''a priori'' science of [[physical space]]. Helmholtz introduced a new conception of the ''a priori'' in space: that of the determination of the manifold of possible orientations in perceptual space. These developments inspired new readings of Kant<ref name="Patton"/> and contributed to the rise of late modern [[neo-Kantianism]] movement in philosophy.

== 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]], [[Albert A. Michelson]], [[Wilhelm Wundt]], [[Fernando Sanford]], [[Arthur Gordon Webster]] and [[Michael I. Pupin]]. [[Leo Koenigsberger]], who was his colleague from 1869 to 1871 in Heidelberg, wrote the definitive biography of him in 1902.

== Honours and legacy ==
[[Image:Hermann von Helmholtz-Statue vor der Humboldt-Universität zu Berlin.jpg|thumb|upright|Helmholtz's statue in front of Humboldt University in Berlin]]

* In 1873, Helmholtz was elected as a member of the [[American Philosophical Society]].<ref>{{Cite web|title=APS Member History|url=https://search.amphilsoc.org/memhist/search?creator=&title=&subject=&subdiv=&mem=&year=1873&year-max=1873&dead=&keyword=&smode=advanced|access-date=3 May 2021|website=search.amphilsoc.org}}</ref>
*In 1881, Helmholtz was elected [[Fellowship of the Royal College of Surgeons|Honorary Fellow]] of the [[Royal College of Surgeons in Ireland]].<ref>{{cite web|url=http://www.igp-web.com/IGPArchives/ire/countrywide/xmisc/rcsi-hon-fellows.txt|title=Honorary Fellows of the Royal College of Surgeons (RCSI) since 1784|publisher=Ireland Genealogy Project|year=2013|access-date=4 August 2016|archive-url=https://web.archive.org/web/20180203005705/http://www.igp-web.com/IGPArchives/ire/countrywide/xmisc/rcsi-hon-fellows.txt|archive-date=3 February 2018|url-status=dead}}</ref>
* On 10 November 1881, he was awarded the [[Legion of Honour|Légion 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, or ''Adel''. The ''Adelung'' 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.
* Helmholtz was conferred the Honorary Membership of the [[Institution of Engineers and Shipbuilders in Scotland]] in 1884.<ref>{{cite web|url=http://www.iesis.org/honorary-fellows.html|title=Honorary Members and Fellows|publisher=The Institution of Engineers and Shipbuilders in Scotland}}</ref>
* The largest German association of [[research institution]]s, the [[Helmholtz Association of German Research Centres|Helmholtz Association]], is named after him.<ref name="Gemeinschaft"/><ref name=History>{{cite web|title=History of the name in the About section of Helmholtz Association website |url=http://www.helmholtz.de/en/about_us/history |access-date=30 April 2012 |url-status=dead |archive-url=https://web.archive.org/web/20120414190640/http://www.helmholtz.de/en/about_us/history/ |archive-date=14 April 2012 }}</ref>
* The asteroid [[11573 Helmholtz]] and the lunar crater ''[[Helmholtz (lunar crater)|Helmholtz]]'' as well as the crater ''[[Helmholtz (Martian crater)|Helmholtz]]'' on Mars were named in his honour.<ref name="Asteroid" /><ref>{{GPN|2438|name=Lunar crater Helmholtz}}</ref><ref>{{GPN|2439|name=Martian crater Helmholtz}}</ref>
* In [[Charlottenburg]], [[Berlin]], the street ''Helmholtzstraße'' is named after von Helmholtz.<ref>{{cite web |url=https://www.berlin.de/ba-charlottenburg-wilmersdorf/ueber-den-bezirk/freiflaechen/strassen/artikel.177427.php |title=Helmholtzstraße |access-date=18 July 2018 |website=berlin.de |date=21 September 2014 }}</ref>

{{multiple image
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|footer=Decree awarding Helmholtz (listed in first page) the [[French Legion of Honour]]
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|image2=French Presidential Decree -Award of Legion of Honour to Helholtz, Bell and Edison -10 November 1881 Pg. 3.jpg
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{{clear}}

== Works ==
* {{Cite book|title=Über die Erhaltung der Kraft|volume=|publisher=Wilhelm Engelmann|location=Leipzig|year=1889|language=de|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=6555455}}
* {{Cite book|title=Vorlesungen über die elektromagnetische Theorie des Lichts|volume=|publisher=Johann Ambrosius Barth|location=Leipzig|year=1897|language=de|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=6723936}}
* {{Cite book|title=Vorlesungen über die mathematischen Principien der Akustik|volume=|publisher=Johann Ambrosius Barth|location=Leipzig|year=1898|language=de|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=6725127}}
* {{Cite book|title=Vorlesungen über die Dynamik discreter Massenpunkte|volume=|publisher=Johann Ambrosius Barth|location=Leipzig|year=1898|language=de|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=6725946}}
* {{Cite book|title=Dynamik continuirlich verbreiteter Massen|volume=|publisher=Johann Ambrosius Barth|location=Leipzig|year=1902|language=de|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=6727137}}
* {{Cite book|title=Vorlesungen über die Theorie der Wärme|volume=|publisher=Johann Ambrosius Barth|location=Leipzig|year=1903|language=de|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=7174058}}
* {{Cite book|title=Vorlesungen über Theoretische Physik|volume=|publisher=Johann Ambrosius Barth|location=Leipzig|year=1903|language=de|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=7174058}}

===Translated works===
* ''[https://books.google.com/books?id=C1i4AAAAIAAJ&pg=PA114 On the Conservation of Force]'' (1847) [http://hdl.handle.net/2027/uc1.b4252190?urlappend=%3Bseq=124 HathiTrust]
* {{Cite book|title=Lehre von den Tonempfindungen als physiologische Grundlage für die Theorie der Musik|volume=|publisher=Masson|location=Paris|year=1874|language=fr|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=6723591}}
* {{cite journal |volume=16 |pages=15–39 |last=Helmholtz |first=Herman |title=On the Limits of the Optical Capacity of the Microscope |journal=Monthly Microscopical Journal |year=1876 |url=https://books.google.com/books?id=-DE4AAAAMAAJ&q=optics%20limit%20abbe%20fripp&pg=PA15 |doi=10.1111/j.1365-2818.1876.tb05606.x}}
* {{Cite book|title=Populäre wissenschaftliche Vorträge|volume=|publisher=Appleton|location=New York|year=1885|language=en|url=https://gutenberg.beic.it/webclient/DeliveryManager?pid=10984881}}
*''[http://www.bartleby.com/30/125.html On the Conservation of Force]'' (1895) Introduction to a Series of Lectures Delivered at [[Karlsruhe|Carlsruhe]] in the Winter of 1862–1863, English translation
*''[https://archive.org/details/onsensationsofto00helmrich On the Sensations of Tone as a Physiological Basis for the Theory of Music]'' (downloadable from California Digital Library) Third Edition of English Translation, based on Fourth German Edition of 1877, By Hermann von Helmholtz, Alexander John Ellis, Published by Longmans, Green, 1895, 576 pages
*''[https://archive.org/details/onsensationston01helmgoog <!-- quote=helmholtz. --> 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
*''[https://web.archive.org/web/20180927064524/http://poseidon.sunyopt.edu/BackusLab/Helmholtz/ Treatise on Physiological Optics]'' (1910) three volumes. English translation by Optical Society of America (1924–25).
*''[https://archive.org/details/popularlectureso00helmuoft Popular lectures on scientific subjects]'' (1885)
*''[https://archive.org/details/popularlectureso00helmrich Popular lectures on scientific subjects]'' second series (1908)

== See also ==
* [[Helmholtz coil]]
* [[List of people from Berlin]]
* [[List of things named after Hermann von Helmholtz]]
* [[Neo-Kantianism]]
* [[Theory of Colours]]

== References ==
=== Citations ===
<references>
<ref name="Asteroid">{{cite web
  |title      = 11573 Helmholtz (1993 SK3)
  |website       = [[Minor Planet Center]]
  |url        = https://www.minorplanetcenter.net/db_search/show_object?object_id=11573
  |access-date = 2 February 2018}}</ref>
</references> <!-- end of reflist -->

=== Sources ===
* Cahan, David ''Helmholtz: A Life in Science.''    University of Chicago Press, 2018.  {{ISBN|978-0-226-48114-2}}.
* Cohen, Robert, and [[Marx W. Wartofsky|Wartofsky, Marx]], eds. and trans. Reidel. ''Helmholtz: Epistemological Writings'', 1977.
* Ewald, William B., ed. ''From Kant to Hilbert: A Source Book in the Foundations of Mathematics'', 2 vols. Oxford Uni. Press, 1996.
** 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.
* Groundwater, Jennifer. ''Alexander Graham Bell: The Spirit of Invention''. Calgary: Altitude Publishing, 2005. {{ISBN|1-55439-006-0}}.
* Jackson, Myles W. ''Harmonious Triads: Physicists, Musicians, and Instrument Makers in Nineteenth-Century Germany'' (MIT Press, 2006).
* Kahl, Russell, ed. Wesleyan. ''Selected Writings of Hermann von Helmholtz'', Uni. Press., 1971.
* Koenigsberger, Leo. ''Hermann von Helmholtz'', translated by Frances A. Welby (Dover, 1965)
* MacKenzie, Catherine. [https://books.google.com/books?id=iFOcw4lN_ZYC ''Alexander Graham Bell''.] Whitefish, Montana: Kessinger Publishing, 2003. {{ISBN|978-0-7661-4385-2}}. Retrieved 29 July 2009.
* Shulman, Seth. ''[[The Telephone Gambit]]: Chasing Alexander Bell's Secret''. New York: Norton & Company, 2008. {{ISBN|978-0-393-06206-9}}.

== Further reading ==
* {{cite book|last=McKendrick|first=John Gray|title=Hermann Ludwig Ferdinand von Helmholtz|year=1899|publisher=T. Fisher Unwin|url=https://archive.org/details/hermannludwig00mckeiala/}}
* {{cite book|last=Koenigsberger|first=Leo|title=Hermann von Helmholtz|year=1906|publisher=Oxford Clarendon Press|url=https://archive.org/details/hermannvonhelmho00koenrich/hermannvonhelmho00koenrich/}}
* David Cahan: ''Helmholtz: A Life in Science'' (University of Chicago, 2018). {{ISBN|978-0-226-48114-2}}
**[[Steven Shapin]], "A Theorist of (Not Quite) Everything" (review of David Cahan, ''Helmholtz: A Life in Science'', University of Chicago Press, 2018, {{ISBN|978-0-226-48114-2}}, 937 pp.), ''[[The New York Review of Books]]'', vol. 66, no. 15 (10 October 2019), pp.&nbsp;29–31.
* David Cahan (Ed.): ''Hermann von Helmholtz and the Foundations of Nineteenth-Century Science.'' Univ. California, Berkeley 1994, {{ISBN|978-0-520-08334-9}}.
* 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, {{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.
* Kenneth L. Caneva: ''[https://mitpress.mit.edu/9780262045735/helmholtz-and-the-conservation-of-energy/ Helmholtz and the Conservation of Energy: Contexts of Creation and Reception]''. The MIT Press, Cambridge, MA, 2021, ISBN 978-0-262-04573-5

== External links ==
{{Wikiquote}}
{{wikisource|works=or}}
{{Commons category|Hermann von Helmholtz}}
* "[https://books.google.com.hk/books?id=5aUOAAAAIAAJ&pg=PR17 Hermann von Helmholtz]" (Obituary). Royal Society (Great Britain). (1894). ''Proceedings of the Royal Society of London''. London: Printed by Taylor and Francis. p. xvii.
* "[http://plato.stanford.edu/entries/hermann-helmholtz Hermann von Helmholtz]" in [[Stanford Encyclopedia of Philosophy]], written by Lydia Patton
* {{FamilySearch|id=MG9M-XWN|title=Prof. Dr. Hermann Ludwig Ferdinand von Helmholtz}}
* {{MacTutor|id=Helmholtz}}
* [http://vlp.mpiwg-berlin.mpg.de/people/data?id=per87 Biography, bibliography and access to digital sources] in the [[Virtual Laboratory]] of the [[Max Planck Institute for the History of Science]]
* {{IMSLP|id=Helmholtz, Hermann von}} (''Die Lehre von den Tonempfindungen'')
* Helmholtz's (1867) [http://lhldigital.lindahall.org/cdm/ref/collection/color/id/10550 ''Handbuch der physiologischen Optik''] {{Webarchive|url=https://web.archive.org/web/20190412080803/http://lhldigital.lindahall.org/cdm/ref/collection/color/id/10550 |date=12 April 2019 }} – digital facsimile from the [[Linda Hall Library]]
* {{MathGenealogy|id=49057}}
* {{Librivox author |id=16353}}

{{Copley Medallists 1851-1900}}
{{Authority control}}

{{DEFAULTSORT:Helmholtz, Hermann Von}}
[[Category:Hermann von Helmholtz| ]]
[[Category:1821 births]]
[[Category:1894 deaths]]
[[Category:Acousticians]]
[[Category:Color scientists]]
[[Category:German fluid dynamicists]]
[[Category:Foreign members of the Royal Society]]
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[[Category:German biophysicists]]
[[Category:19th-century German physicists]]
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[[Category:Members of the Royal Society of Sciences in Uppsala]]
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