Von Helmholtz 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.

From the Cosserats mechanics backgrounds to modern field theory

In the paper, yet weekly known, Cosserats’ original four concepts as follow: the four-time unification of rigid body dynamics, statics of flexible rods, statics of elastic surfaces and 3D deformable body dynamics; the intrinsic formulation based on the local, von Helmholtz symmetry group of monodromy; the invariance under the Euclidean group. The concept of a set of low-dimensional branes immersed into Euclidean space are revalorized and explained in terms of the modern gauge field theory and the extended strings theory. Additionally, some useful mathematical tools that connect the continuum mechanics and the classical field theory (for instance, the convective coordinates, von Mises’ “Motorrechnung”, the Grassmann extensions, Euclidean invariance, etc.) are involved in the historical explanation that how the ideas were developing themself.

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.

Перцептивное пространство в рассказе И. С. Тургенева «История лейтенанта Ергунова»

The paper is the first to examine the system of perceptual imagery in I. S. Turgenev’s short story “Lieutenant Yergunov’s Story”. The scientific novelty of the research is accounted for by its subject – the analysis of the structure of perceptual space, which includes all types of “physiological” (P. A. Florensky) spaces: visual, acoustic, olfactory, tactile, gustatory. The aim of the research is to show the dependence of the perceptual image on the point of view of the character (subject of perception) and the narrator (subject of expression). In accordance with the stated aim, special attention was paid to liminal space, the description of the state of the protagonist’s transition from wakefulness to sleep and delirium. As a result of the research, it has been found that I. S. Turgenev purposefully creates an artistic narrative about the transformation of perception under the influence of the external environment: he shows how the deprivation of visual and acoustic sensations actualizes other forms of sensory perception – smell and touch. Thus, the short story, to which researchers tend to refer as “mystical”, is presented as an artistic version of the description of human psychophysiology, as a response to the works of H. von Helmholtz and I. M. Sechenov, with which the writer became acquainted in the 1860s.

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.

The objectivist critique of Hermann Helmholtz's theory of perception: The case of Ramón Turró (1854-1926).

In this article, we look into the development of the Helmholtz theory of perception in the light of Spanish biologist Ramón Turró's objectivist critique of the theory. In the first part, we explain the decisive role that Helmholtz's theory of perception played in the evolution of his own general philosophical stance. Through the work of Helmholtz, we show how the dialectic between philosophical surmises and models of perception was an ongoing, fundamental part of the period that saw the formation of scientific psychology. In the second part of the article, we examine Turró's original, unique contribution to the discourse. Early on in his theoretical work, Turró defended a model of perception closely resembling Helmholtz's, but, because of his objectivist philosophical convictions, Turró eventually elaborated an original theory of perception based largely on the trophic experience. His proposal rested on his own research as a physiologist and featured the elimination of all mentalistic components, in contrast to the voluntaristic leanings he detected in Helmholtz's work. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Prestrain in the eardrum investigated using laser-ablation perforation: A proof of principle study on the New Zealand white rabbit

While the presence of residual stress (also called prestress) in the tympanic membrane (TM) was hypothesized more than 150 years ago by von Helmholtz (1869), little experimental data exists to date. In this paper, a novel approach to study residual stress is presented. Using a pulsed laser, the New Zealand white rabbit TM is perforated at seven predefined locations. The subsequent retraction of the membrane around the holes is computed using digital image correlation (DIC). The amount of retraction is the so-called prestrain, which is caused by the release of prestress due to the perforation. By measuring the prestrain using DIC, we show that residual stress is clearly present over the entire rabbit TM surface. In total, fourteen TMs have been measured in this work. An automated approach allows tracking the holes’ deformation during the measurement process and enables a more robust analysis than was previously possible. We find similar strains (around 5%) as reported in previous work, in which slits were created manually using flattened surgical needles. However, the new approach greatly reduces measurement time, which minimizes dehydration artifacts. To investigate the effect of perforation location on the TM, the spatial decrease of the prestrain (α) around the perforation was quantified. Perforations inferior to the umbo showed the least negative α values, i.e., the most gradual decrease around the hole, and were the most consistent. Perforations on other locations showed more negative α values, i.e., steeper decrease in strain, but were less consistent across samples. We also investigated the effect of the holes’ creation sequence but did not observe a significant change in the results. Overall, the presented method allows for consistent residual stress measurements over the TM surface. The findings contribute to our fundamental knowledge of the mechanics of the rabbit TM and provide a basis for future work on human TMs.

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.

Hermann von Helmholtz and the Quantification Problem of Psychophysics

Hermann von Helmholtz has been widely acknowledged as one of the forerunners of contemporary theories of measurement. However, his conception of measurement differs from later, representational conceptions in two main respects. Firstly, Helmholtz advocated an empiricist philosophy of arithmetic as grounded in some psychological facts concerning quantification. Secondly, his theory implies that mathematical structures are common to both subjective experiences and objective ones. My suggestion is that both of these differences depend on a classical approach to measurement, according to which the arithmetic laws of addition define what is measurable as a particular domain for their application, and, at the same time, the extensibility of these laws to all known physical processes works as a heuristic principle for empirical research. Such an approach is worth reconsidering, not only because it lends plausibility to some of the controversial aspects of Helmholtz’s theory, but also because it offers a philosophical perspective on quantification problems that originated in the nineteenth-century.This paper draws insights on Helmholtz’s philosophical views from his engagement with the measurability of sensations via Fechner’s psychophysical law. This seems to be in contrast with the fact that the reception of Helmholtz’s theory culminated with the formulation of the theory of extensive measurement. I will contend that Helmholtz reached a no less important standpoint in the nineteenth-century debate on whether sensations are different (i.e., intensive) kinds of magnitudes and on how, if at all, they can be measured.

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.

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.

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.

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.

Unconscious inferences in perception in early experimental psychology: From Wundt to Peirce.

What are unconscious inferences in psychology? This article investigates their journey from the early philosophical psychology of Wilhelm Wundt (1832-1920) to the experimental psychology of the American pragmatist Charles S. Peirce (1839-1914). Peirce's reception of Wundt's early works situates him in an international web of 19th-century experimental psychologists and its reconstruction opens new perspectives on the relation between philosophy, psychology, and epistemology. Moreover, this reception testifies to a heretofore overlooked strand of influence of Wundt on North American experimental psychology. The notion of unconscious inferences, of which Hermann von Helmholtz is usually considered the chief exponent, becomes the backbone of Peirce's theory of perception mostly because of the affinity between Wundt's early philosophy of mind and Peirce's logic-mediated approach to psychology.