Hermann Von Research Articles

Relevance of noise control for the development of acoustics in 20th century

Driven by progress and requirements of the advancing machine age, Acoustics of the 20th century has run through a tremendous development. Starting from a profound understanding and formulation of its theoretical physical framework by Hermann von Helmholtz and Lord Rayleigh at the end of the 19th century, Acoustics and its many sub-disciplines developed to an important technical and engineering discipline which, at the beginning of the 21st century, had become a basic design tool for environmental compatibility and comfort features of most technical products and utilities. In Europe, this development has strongly been driven by urgent requirements of fast after-war reconstruction and growing needs of noise control which enforced particular interactive efforts of research institutes and companies to cope with the challenges of the time. Based on recent widespread contributions to the history of European Acoustics presented at Forum Acusticum 2023 in Torino, the relevance of noise control for the development of Acoustics in the last century will be highlighted and appreciated. With reference to some typical examples, it will be shown how the disciplines of engineering acoustics and noise control essentially contributed to renew and strengthen acoustics as an indispensable interdisciplinary field of science and technology.

Helmholtz and the Conservation of Energy: Contexts of Creation and Reception

Helmholtz and the Conservation of Energy: Contexts of Creation and Reception

Helmholtz and the Conservation of Energy: Contexts of Creation and Reception

Helmholtz and the Conservation of Energy: Contexts of Creation and Reception

Helmholtz, Schrödinger, and the First Non‐Euclidean Model of Perceptual Color Space

AbstractThis paper explores the groundbreaking contributions of Hermann von Helmholtz and Erwin Schrödinger to the geometry of color space ‐a 3D space that correlates color distances with perceptual differences. Drawing upon his expertise in non‐Euclidean geometry, physics, and psychophysics, Helmholtz introduced the first Riemannian line element in color space between 1891 and 1892, inaugurating a new line of research known as higher color metric, a term coined by Schrödinger in 1920. During his tenure at the University of Vienna, Schrödinger extensively worked on color theory and rediscovered Helmholtz's forgotten line element. In his 1920 papers titled “Grundlinien einer Theorie der Farbmetrik im Tagessehen,” published in the Annalen der Physik, Schrödinger elucidated certain shortcomings in Helmholtz's model and proposed his refined version of the Riemannian line element. This study delves into this captivating chapter in the history of color science, emphasizing the profound impact of Helmholtz's and Schrödinger's work on subsequent research in color metrics up to the present day.

Emissaries of Pope Innocent IV to Alexander Nevsky: Riddles of Biographical Histor

One of the most mysterious reports from the Life of Alexander Nevsky about the visit to the Rus’ prince of the Pope Innocent IV’s envoys, Cardinals Gald and Gemont, most likely has a real basis. Several characteristic details testify to this. In particular, the total number of Cardinals noted in the Life, who were with the Pope (twelve), corresponds to the actual number of Cardinals appointed by Innocent IV. The visit of the pope’s representatives to Alexander was to take place in the second half of 1252 or at the beginning of 1253, when the powers of Archbishop Albert Suerbeer as papal legate in Rus’ were temporarily terminated. During their trip, the papal envoys visited two of the strongest Rus’ Princes at once – Alexander Nevsky and Daniil Galitsky. Papal emissaries at this time could be the Bishop of Verona, Jacopo da Breganze, and the Bishop of Kammin, Hermann von Gleichen. In the Galician-Volhynian Chronicle they were attributed according to their belonging to episcopal sees (Bishops Beren’sky and Kamenets’ky), and in the Life of Alexander Nevsky – according to their relationship with the Cardinals who led their mission. These could be Guglielmo Fieschi, who was then in charge of allied negotiations with the Byzantine Church, as well as Hugo de Saint-Cher, who acted as legatus a latere in Central-Eastern Europe.

The Helmholtz legacy in color metrics: Schrödinger’s color theory

This study is a continuation of the authors’ previous work entitled “Helmholtz and the geometry of color space: gestation and development of Helmholtz’s line element” (Peruzzi and Roberti in Arch Hist Exact Sci. https://doi.org/10.1007/s00407-023-00304-2, 2023), which provides an account of the first metrically significant model of color space proposed by the German polymath Hermann von Helmholtz in 1891–1892. Helmholtz’s Riemannian line element for three-dimensional color space laid the foundation for all subsequent studies in the field of color metrics, although it was largely forgotten for almost three decades from the time of its first publication. The rediscovery of Helmholtz’s masterful work was due to one of the founders of quantum mechanics, Erwin Schrödinger. He established his color metric in three extended papers submitted in 1920 to the Annalen der Physik. Two memoirs were devoted to the so-called lower color metric, which laid the basis for the development of his higher color metric, exposed in the last paper. Schrödinger’s approach to the geometry of color space has been taken as a starting point for future elaborations of color metrics and allows a close examination of the current assumptions about the analysis of color-matching data. This paper presents an overall picture of Schrödinger’s works on color. His color theory developed a tradition first inaugurated by Newton and Young, and which acquired strong scientific ground with Grassmann’s, Maxwell’s, and Helmholtz’s contributions in the 1850s. Special focus will be given to Schrödinger’s account of color metric, which responded directly to Helmholtz’s hypothesis of a Riemannian line element for color space.

Hermann von Boyen the Elder and his Impact on the Prussian Army After 1815

Author of Hermann von Boyen's biography, Friedrich Meinecke stated that the contributions of Prussian twice (1815–1819 and 1841–1847) Minister of War to the military theory were almost completely forgotten. Despite the existence of many thousands of manuscript pages, this opinion is still considered valid to this day. The chief architect of the Landwehr system was also the founder of the concept of the ‘defence system’, crucial to understanding Prussian military thought in the first half of the nineteenth century. This idea influenced, in my opinion, the way of thinking about warfare within the Prussian Army far more than the Carl von Clausewitz's Vom Kriege.

Fundoscopy in the smartphone age: current ophthalmoscopy methods in neurology.

The observation of the human retina in vivo began in 1851 after the invention of the first ophthalmoscope by the German physicist Hermann von Helmholtz. In the following decades, direct and indirect ophthalmoscopy, with the use of ophthalmoscopes and condensing lenses, respectively, became part of the clinical examination, especially in ophthalmology and neurology. Today, over 170 years later, many ophthalmoscopes and condensing lenses exist on the market. Nevertheless, ophthalmoscopy is still not widely adopted as part of the physical exam of general practitioners, and the teaching of ophthalmoscopy in medical school remains challenging. Studies have shown that students prefer using newer ophthalmoscope models or condensing lenses during training, but most do not feel confident in performing ophthalmoscopy afterwards, regardless of the models used. Also, few students acquire ophthalmoscopes for their future practice, and clinical trials have not clearly demonstrated superiority of newer ophthalmoscope models over the conventional ones in diagnostic accuracy. The technological improvement of smartphone cameras in recent years has made it feasible to photograph the fundus of the eye using ophthalmoscopes or condensing lenses, reducing the need for retinographs and similar equipment. Smartphone assisted indirect fundoscopy is becoming increasingly popular. This approach allows adequate identification of the structures of the fundus, is cost-efficient, easy to implement, and permits easy recording and sharing of the images obtained, which is useful for case discussions and medical teaching. However, controlled clinical trials validating this method in the evaluation of optic nerve pathologies are needed.

Johannes Müller (1801-1858) and his school: pioneer and giant of German physiology

Johannes Müller was indisputably the most versatile and brilliant physiologist in the mid-nineteenth century. Müller was born in Koblenz in 1801 as the eldest of five children. He received an excellent education in mathematics and the ancient languages and was thus able to read with ease the writings of Aristotle in the original.He served a year with the Pioneers after graduating from high school in 1818. In 1819 he enrolled at the University of Bonn. In 1821, while still a student, he was awarded the scientific university prize for his work on foetal respiration. Müller received his doctorate at the university of Bonn in 1822. He moved to Berlin, where he continued to attend lectures by the anatomist Karl Asmund Rudolphi.He obtained his habilitation in physiology and comparative anatomy in 1824. After his years in Bonn, he accepted a chair at the University of Berlin in 1833 as Rudolphi's successor. His famous "Handbuch der Physiologie" (1833-1840) was published in Berlin. Müller's main areas of interest were physiology, human anatomy, comparative anatomy and anatomical pathology.Müller has numerous publications in addition to his famous book on physiology. He and his distinguished students (Emil du Bois-Reymond, Ernst Haeckel, Hermann von Helmholtz, Friedrich Gustav Jakob Henle, Carl Ludwig, Theodor Schwann and Rudolf Virchow amongst others) made the Berlin Physiological Institute world famous. The natural-philosophical approach to medicine that was still dominant at the beginning of the 19th century was increasingly replaced by a scientifically oriented methodology by Müller.

The political ecology of the entropy principle: 19th century physics and the electrification of Germany

The formalisation of the entropy law by Rudolf Clausius in 1865 marks a shift in 19th century physics. By defining energy as a process, German physicists were able to shape the necessary epistemological instruments for the second industrial revolution. The Berlin School of Thermodynamics applied physics for industrialising the recently unified Prussian state, making energy an important site of state governance. The entropy principle, an economic abstraction of the entropy law, called for a stronger interconnection of science and economics. Facilitated by a pessimistic anthropocentrism of Hermann von Helmholtz, German physics pushed for the application of statistical thermodynamics to the real world. Thus, nature's chaotic energy flows were rationalised for them to be legible to the state. Based on archival research in Berlin and Munich, this paper tells the story of such development, by highlighting how the entropy principle became institutionalised for industrialisation. Next to Clausius paradigm shift in 1865, it focusses on the foundation of the Physical Technical Reich Institute in 1887 and the International Electricity Exhibition in Frankfurt in 1891. The latter introduced the centralised production and grid-like distribution of electricity, revolutionising modes of production in urban as well as rural spaces. The analysis of such socio-technical development of the energy system in the fin de siècle enables the necessary thrust to make wider claims about how environmentalism, changing modes of production and the craft of the state are intertwined. This has great relevance for the historicization of current modes of transition towards a low-carbon economy in Germany and beyond. Physical knowledges and institutional arrangements of the energy system were shaped in conjunction, establishing a certain path dependency to such developments.

Materialism, Lebenskraft and the limits of science: metaphysical vitalism in post-Kantian scenarios

Kant's legacy in the history of life sciences has notoriously included a critique of the use of soul and ‘vital force’ ( Lebenskraft ). In this paper I focus on a less-known side of this legacy, i.e. Kant's late critique of vital materialism and its impact on nineteenth-century German science and philosophy. I show that Kant considered materialism as a kind of metaphysical hypothesis since the 1760s and pointed out that it was empirically impossible to distinguish it from different kinds of hypotheses (such as monadology). I focus on Kant's late essay on Samuel Sömmering (1796), arguing that the critical rejection of materialism and the notion of Lebenskraft belonged to an anti-reductive program for life sciences. I maintain that Kant's views influenced Alexander von Humboldt's turn concerning vitalism in the late 1790s and the anti-metaphysical and physicalist epistemology of Hermann von Helmholtz. I follow this Kantian legacy in the works of Friedrich Lange, Emil du Bois-Reymond and Erich Adickes. Finally, I argue that this tradition provides a vantage point to reconsider contemporary debates over materialism and panpsychism.

Photodynamic therapy: Innovative approaches for antibacterial and anticancer treatments.

Photodynamic therapy is an alternative treatment mainly for cancer but also for bacterial infections. This treatment dates back to 1900 when a German medical school graduate Oscar Raab found a photodynamic effect while doing research for his doctoral dissertation with Professor Hermann von Tappeiner. Unexpectedly, Raab revealed that the toxicity of acridine on paramecium depends on the intensity of light in his laboratory.Photodynamic therapy is therefore based on the administration of a photosensitizer with subsequent light irradiation within the absorption maxima of this substance followed by reactive oxygen species formation and finally cell death. Although this treatment is not a novelty, there is an endeavor for various modifications to the therapy. For example, selectivity and efficiency of the photosensitizer, as well as irradiation with various types of light sources are still being modified to improve final results of the photodynamic therapy. The main aim of this review is to summarize anticancer and antibacterial modifications, namely various compounds, approaches, and techniques, to enhance the effectiveness of photodynamic therapy.

Helmholtz and the geometry of color space: gestation and development of Helmholtz’s line element

Modern color science finds its birth in the middle of the nineteenth century. Among the chief architects of the new color theory, the name of the polymath Hermann von Helmholtz stands out. A keen experimenter and profound expert of the latest developments of the fields of physiological optics, psychophysics, and geometry, he exploited his transdisciplinary knowledge to define the first non-Euclidean line element in color space, i.e., a three-dimensional mathematical model used to describe color differences in terms of color distances. Considered as the first step toward a metrically significant model of color space, his work inaugurated researches on higher color metrics, which describes how distance in the color space translates into perceptual difference. This paper focuses on the development of Helmholtz’s mathematical derivation of the line element. Starting from the first experimental evidence which opened the door to his reflections about the geometry of color space, it will be highlighted the pivotal role played by the studies conducted by his assistants in Berlin, which provided precious material for the elaboration of the final model proposed by Helmholtz in three papers published between 1891 and 1892. Although fallen into oblivion for about three decades, Helmholtz’s masterful work was rediscovered by Schrödinger and, since the 1920s, it has provided the basis for all subsequent studies on the geometry of color spaces up to the present time.

An Unnatural Attitude: Phenomenology in Weimar Musical Thought. By Benjamin Steege

Many American monographs in the history of theory have chronicled the grand projects of individuals now central to the discipline’s canon, such as Jean-Philippe Rameau, François-Joseph Fétis, Hugo Riemann, and Hermann von Helmholtz. In Benjamin Steege’s An Unnatural Attitude: Phenomenology in Weimar Musical Thought, by contrast, no hero emerges. Instead, Steege’s characters comprise a diffuse ensemble cast, united by their proximity to the Weimar Republic and their shared task of bringing music theory to bear on the philosophical domain of phenomenology. To use the language of one of Steege’s characters, Hans Mersmann, An Unnatural Attitude contributes less to a “history of heroes” than to a “history of problems” (194). Steege’s history of problems sits squarely within the aims of its parent book series, New Material Histories of Music, which “sets out to embrace the many accounts of materiality that are invigorating music studies today.” In music theory, specifically, many new accounts of materiality have gone hand in hand with phenomenology, especially in areas like transformational theory, performance studies, and embodied cognition. As a participant in music theory’s phenomenological turn, An Unnatural Attitude embarks on a tantalizing historical project, querying music theory’s first encounters with phenomenology in the early- to mid-twentieth century. Piecing together a wide variety of primary texts, the book presents an intellectual history peopled not only by musicologists but also by philosophers like Edmund Husserl and Martin Heidegger, whose ideas exert direct influences on the fascinating musical thought of their disciples.

Military and Patriotic Mobilisation in Prussia During the Liberations Wars of 1813–1815

The author focuses on the first mass mobilisation in Prussia carried out by the Prussian government during the Liberation Wars of 1813–1815. He aims to answer the question of how successful this mobilisation was and whether the Prussian political elite managed to obtain the popular support for the war against Napoleonic France. Methodologically, the study is based on the theory of modernisation, according to which, during the Napoleonic Wars, universal conscription was introduced in the countries of Europe and modern mass warfare emerged. The introduction deals with the general causes prompting the government of the Prussian King Frederick William III to introduce the universal conscription in Prussia in the spring of 1813. The author pays attention is paid to the military reforms conducted by Gerhard von Scharnhorst, Hermann von Boyen and other reformers. He focuses on legislative acts of March and April 1813 which laid the foundation for the mass mobilisation in Prussia, namely. royal decrees abolishing all exemptions from the military service and establishing voluntary detachments or the Prussian National Militia (Landwehr and Landsturm). The author also analyses the social and provincial origin of those who were mobilised in the Prussian army. In the second part of the article, he considers the organisation of the patriotic propaganda which was indispensable for the mass mobilisation. To this end, he examines official governmental proclamations, newspaper articles, pamphlets, leaflets, brochures, political lyrics, and sermons. He emphasises that not only men were supposed to be mobilised for the needs of war but women as well. He concludes that the first mass mobilisation in Prussia in 1813–1815 turned out to be highly successful and effective. The Prussian government managed to mobilise large groups of people within a very short period of time. The universal conscription became law in 1814, and the pantheon of national heroes who died for the freedom of the Fatherland was created. The massive public support for the war against Napoleon significantly contributed to Prussia's rapid rise to the leading power among all German states.

Метафорическое соотнесение как механизм мышления

This article proposes an interpretation of the metaphorical correlation (MC) as a mechanism of thinking aimed at the search for, and development of, a thinking strategy, set down and conveyed by language, that will be most ef­fective in the given cultural and historical context. The MC mechanism is de­fined as a process by which some characteristics of an object (those selected by thinking) interact and some others are suppressed, with a chance at later actualisation. As a result, awareness of the self as an existentially non-static system bearing with it ‘the world as an accepted sense’ makes it possible to re­think the connection between language, thinking and perception. Here, a prob­lem assuming a special prominence is attaining the obviousness and veracity (a primary cohesion of experience) by possessing which cognising agents con­struct a reality for themselves. The article considers Gustav Gerber’s ideas and Hermann von Helmholtz’s definition of perception as ‘unconscious inference’, as well as Immanuel Kant’s assertion about the ‘logical tact’ lying ‘in the ob­scurity of the mind’. Metaphorical correlation is shown to be able to act as a mechanism of a sui generis intuitive logic, which marks the starting point of cognitive reflection and paves the way for linguistic reality. Metaphorical correlation is a mechanism of abstraction and conceptualisation that deter­mines the angles of cognitive reflection. The author concludes that if thinking is to be viewed as a calculus of the best possible strategy for interpreting expe­rience (this vision is reflected in language, ever illuminating the substantive aspects of an object that are existentially important for a native speaker), the MC mechanism, which is immanently intrinsic to thinking processes, makes it possible to ‘calculate’ a thinking strategy whose adaptive value lies in the pos­sibility of explicating the elements of experience for which there is a com­pelling existential need and inhibition of those whose explication is not requi­site at the moment.

Livonian Werewolves: Assessing Their Historical Significance Through the Case of Old Thiess

This paper seeks to investigate the phenomenon of Livonian werewolves from the early modern era (1500-1700s). Noting their uniqueness in comparison to contemporaneous werewolves hailing from other geographic areas, the paper suggests that the Livonian werewolf is a metaphor for Livonian society at that time, one which was characterized by social turmoil and strict class hierarchy. This metaphor was utilized by different classes to establish their own interests in society, and thus the paper concludes that the werewolf is a mutable artifact whose value is contingent on its social context. This is demonstrated with the particular case of Old Thiess—a poor, elderly Livonian peasant who gave an unorthodox and anomalous testimony when accused of being a werewolf. In his court statement, it is shown how Thiess was in fact alluding to social tensions by lambasting the rich German elite and establishing the righteousness of the peasantry, of which he was a member of. A close reading method was utilized on the trial transcript of Old Thiess, translated from Hermann von Bruningk’s Der Werwolf in Livland. Through a contextual reading of Livonia’s social atmosphere, the paper draws connections between the content of the trial to wider societal disturbances happening at the time.

Colour vision: From sensation to science (in Norwegian)

Throughout history there have been different approaches to pursuing a better understanding of colour and colour vision, depending on the phenomena one wanted to explain. For instance, although seemingly irreconcilable, the opponent-colour theory of Hering (with its yellow-blue and red-green chromatic pairs) and the three-colour theory of Young-Helmholtz (with red, green, and violet as mixture primaries) did in fact illuminate different aspects of colour vision. Thomas Young and Hermann von Helmholtz set out to explain the qualities of colours, but with the help of James C. Maxwell this theory eventually became a three-receptor theory describing additive colour mixtures and colour matches. The three-receptor theory is the foundation of trichromatic colour measurements and a thriving colour technology. Ewald Hering, who also had colour perception as his main concern, appears to have recognized the distinction between receptor excitations and perception. He postulated opponent physiological processes as basis for the two pairs of chromatic colours. Today these theories are combined in an attempt to understand how colour is processed in the higher brain centres.

Baroque “Spin-Doctoring”: The Manipulative Use of Caprara’s Reports from Constantinople in 1682

Before the Second Siege of Vienna in 1683, there was a famous tug-of-war between “Easterners” and “Westerners” at Leopold I’s court. At that time, the Habsburg monarchy did not yet boast a “Foreign Office”. The institution in charge of relations with the Ottoman Empire was the Aulic War Council. Its president, Margrave Hermann von Baden, was the leading “Westerner”, and clearly thought that Louis XIV posed a greater menace to the monarchy than the Ottomans did. That is why, when the ambassador extraordinary to Constantinople, Conte Alberto Caprara, started sending alarmist reports in the summer of 1682, Baden manipulated them in a rather breathtaking fashion, almost turning their meaning on its head. The episode poses a fascinating question about the nature of “absolutism”: Was Baden’s “spin doctoring” designed to delude the Emperor himself – or was it part of a complex game enacted with Leopold’s approval?

Helmholtz equation and non-singular boundary elements applied to multi-disciplinary physical problems

The famous scientist Hermann von Helmholtz was born 200 years ago. Many complex physical wave phenomena in engineering can effectively be described using one or a set of equations named after him: the Helmholtz equation. Although this has been known for a long time, from a theoretical point of view, the actual numerical implementation has often been hindered by divergence-free and/or curl-free constraints. There is further a need for a numerical method that is accurate, reliable and takes into account radiation conditions at infinity. The classical boundary element method satisfies the last condition, yet one has to deal with singularities in the implementation. We review here how a recently developed singularity-free three-dimensional boundary element framework with superior accuracy can be used to tackle such problems only using one or a few Helmholtz equations with higher order (quadratic) elements which can tackle complex curved shapes. Examples are given for acoustics (a Helmholtz resonator among others) and electromagnetic scattering.