Hermann von Helmholtz: biography of this German physician and physicist

Hermann von Helmholtz is one of the most important researchers in the history of modern science. Renowned in his native Germany and famous throughout the world, this scientist contributed enormously in all kinds of fields of knowledge.

Physiology, mechanics, chemistry, physics, and even psychology were disciplines in which von Helmholtz contributed in one way or another. In fact, it is thanks to being Wilhelm Wundt's tutor and inspiration that the first empirical psychology laboratory was developed.

Next we will discover the life of this researcher through a biography of Hermann von Helmholtz, what people he influenced, his contributions and major works, and the honors he received.

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Brief biography of Hermann von Helmholtz

Hermann von Helmholtz was a historical figure of the 19th century, and like the vast majority of thinkers of his time, he did not dedicate himself to just one profession, but to several. He was a German physician and physicist, but with his contributions he can also be considered a physicist, chemist, neurologist, experimenter in psychology of perception, and philosopher.

, all of them professions that at first may seem that they do not hit much, but that of course had an important scientific base thanks to the genius and work of this German.

In physiology and psychology he is known for his work on the functioning and perception of the human eye and ear. He contributed in physics with his theory on the conservation of energy, his works on electrodynamics, chemical thermodynamics and the mechanical foundation of thermodynamics. As for his contribution to philosophy, his way of defending a more empirical and materialistic thought is known. He was also the inventor of devices such as the ophthalmoscope, the ophthalmometer, and various devices with which he analyzed sounds.

Early years

Hermann Ludwig Ferdinand von Helmholtz was born in Potsdam, Prussia (now Germany) on August 31, 1821. He was the eldest of four siblings but, due to his poor health, he remained confined in his home until he was seven years old. His father, Ferdinand Helmholtz, was a professor of philosophy at the Gymnasium in Potsdam and a close friend of Johann Gottlieb Fichte, while his mother was a descendant of William Penn, the founder of the state of Pennsylvania.

It is said that from his mother she inherited calm and perseverance, qualities that accompanied her throughout her life as a scientist, while from his father she received a important cultural heritage, being this man who trained him in classical languages, French, English and Italian, in addition to introducing him to the philosophy of Immanuel Kant and Fichte.

Training as a doctor

His father would motivate him to study medicine, which he started right after finishing high school.. He would do it at the Berlin medical school (Instituto Federico Guillermo Medico-Surgical), popularly known as the Pépinière in Berlin. The reason he ended up there was that there was no tuition to pay, which was important since his family was not very wealthy. In order to study there, the young Helmholtz agreed to serve eight years in the army. There he would choose to train in physiology, being a pupil of Johannes Peter Müller.

Four years later the young Helmholtz would leave the Pépinière as a doctor of anatomy to do an internship at the Charité in Berlin. In 1841 he began his doctoral thesis under Müller's direction, which was a study of the structure of the nervous system in invertebrates.. During the development of this thesis he discovered that nerve fibers arise from cells that had already been previously identified by Christian Gottfried Ehrenberg.

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Military medicine and physiological research

In 1843 he was posted to the hospital in his native Potsdam where he would work until 1848, working as a military physician. Besides working as a doctor, he was able to do research on his own account since he had plenty of free time. In fact, he could be in charge of equipping a barracks to transform it into his laboratory. This modest place would be the scene of several investigations, among them those that he carried out on the production of heat during muscular contraction.

His research showed that heat was not carried by blood or nerves, but was produced by the muscles themselves.. Thus he deduced a mechanical equivalent of heat, finding the exact formulation of the principle of the conservation of energy, incorporating it in his 1847 dissertation "Über die Erhaltung der Kraft" (On the Conservation of Energy).

With this work he suggested that there were no "vital forces" that moved the muscles and rejected the speculative tradition of natural philosophy, mainstream in German physiology of the moment. Thanks to this work Helmholtz is considered one of the great founders of the principle of conservation of energy, being among the most prominent physicists of the nineteenth century, including Julius von Mayer, James Prescott Joule and William Thomsom, Lord Kelvin.

Years of teaching and end of his life

After all this he was able to leave the army and begin teaching anatomy at the Prussian Academy of Arts, thanks in part to the help provided by Alexander von Humboldt. Later he would obtain a place in the chair of physiology in Königsberg (1849) and then in Bonn (1955) and Heidelberg.

In 1871 he was appointed holder of the chair of physics and director of the Institute of the University of Berlin and, in 1888, he assumed the position of president of the Physical-Technical Institute of Charlottenburg. At this time he would study wave phenomena, the laws of the vertiginous motion of fluids and investigations about the wave motion of fluids.. A few years later he died, specifically on September 8, 1894, at the age of 73.

During the last years of his life, great scientists and minds of the intellectual panorama of the 19th century passed through his classes, including Max Planck, Heinrich Kayser, Wilhelm Wien, Eugen Goldstein, Arthut König, Wilheml Wundt, Henry Augustus Rowland, Albert A. Michelson, Fernando Sanford and Michael I. Pupin.

Works and theoretical-practical contributions

His first great investigative work was his doctoral thesis "Über die Erhaltung der Kraft" (1847) in which he exposed the exact formulation of the principle of conservation of energy, which had already been discovered by Julius von Mayer but presented with little scientific rigor. This document, which was read before the Berlin Physical Society, was what made Helmholtz one of the great physicists of the moment. In addition, he himself had the merit of extending this principle also to electrical and magnetic phenomena.

It would be later when he would dedicate himself to physiology. He studied some physical-physiological points and established a theory of sensations. He achieved notable fame especially his "Manual of Physiological Optics", his "Investigations on Sensations sound "and" Physiological theory of music ", all of them investigations and treatises appeared during the period of 1863 and 1867.

His studies on sensory physiology would be the basis of Wilhelm Wundt's work., being a student of Helmholtz himself and who would end up founding the first experimental psychology laboratory. In fact, Wundt describes Helmholtz's method as a kind of empirical philosophy in which the mind was studied as an independent element. Helmholtz had rejected natural philosophy and stressed the importance of materialism.

In 1849, while at Königsberg, Helmholtz he measured the speed of nerve impulse transmission. At that time it was already suspected that nerve signals traveled along the nerves at enormous speed, but it was not known by how much. In order to verify this, he used a sciatic nerve from a frog and a muscle from one of its haunches. By means of a galvanometer and a method in which he incorporated the use of a mirror to reflect light into the room so that the device could detect it, he could check what the speed of the impulse was: 24.6-38.4 meters per second.

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Physiological studies

The "Manual of Physiological Optics" was published in three parts in 1856, 1860, and 1866. It includes many investigations carried out by the author that were important contributions to contemporary knowledge about the eye, psychological optics, dioptrics ocular and visual sensations and perceptions, belonging to the field of psychology and which is why Helmholtz is highly esteemed within the behavioral and behavioral sciences. perception. It is also in his manual that he describes the ophthalmometer and ophthalmoscope, two instruments that he himself had made.

The treatise "Investigations on sound sensations" of 1863 was the founding document of the history of acoustics as a science. In it the author wondered about the essence of the sound sensation and discovered that it was due to periodic movements of the air. He also investigated what it was that differentiated musical tones from each other and established the existence of three characteristics: intensity, height and timbre.

In relation to timbre, Herlmholtz admits that this is due to the existence of "partial tones higher ”, a phenomenon that today we know as harmonics and that are superimposed on the tones fundamental. The number and intensity of harmonics is what characterizes the timbre of a sound. To investigate the timbre of vowels he built resonators that consisted of hollow spheres of different diameter, each one of them entered into a different vibration by resonance when a sound with a period equal to theirs was produced near them own.

In this work also spoke about the beatings, which he studied experimentally using a polyphonic siren made by himself and he established that when the number of beats for two simple tones was less than a certain number, dissonance was generally obtained. By means of these investigations Herlmholtz arrived at an explanation of the harmony by which in music the most pleasant effects were provided by the simplest relationships between vibrations, an explanation that answered one of the most debated questions since ancient times. of Pythagoras.

In his "Physiological Theory of Music" (1863) he exposed a whole homogeneous and well-ordered body on the notions and facts discovered by illustrious musicians, physicists and physiologists about the art of the muses, modifying and explaining them in mathematical and mechanical. The main theme of this work is that of resonance in physical and physiological terms.

Studies in mechanics and other works

In the more purely physical field he dealt with wave phenomena and, in 1858, he had already come to formulate de mathematical way the laws on the vertiginous motion of fluids, thus initiating a new chapter in the mechanics.

In analytical mechanics he applied to electrodynamics the principle of least action which would lead him later to the formulation of a new theory of electromagnetism, more complete than the one he had proposed James Maxwell. In 1881, studying the electrolytic effects of current, he intuited a concept as modern as the quanta. He would apply the principle of conservation of energy to chemical processes, advancing physical chemistry and thermodynamics.

In addition to the works we have discussed, it is worth mentioning the "Popular Science Conferences" (1865-1870), "Counting and Measuring" (1887) and the "Collections of Scientific Dissertations" (1882-1895). His university physics lectures appeared posthumously written in five volumes between 1897 and 1898 under the title "Lectures on theoretical physics."

Helmholtz honors and legacy

Helmholtz's work and contributions were so important that both in life and posthumously he was awarded numerous international honors. In 1881 he was elected an honorary member of the Royal College of Surgeons of Ireland and that same year he would be awarded the French Legion of Honor. In 1884 he was granted honorary membership of the Scottish Institution of Engineers and Shipbuilders.

In 1883 he was honored by the Emperor of Prussia by giving him a noble title, stylizing his surname with the "von" in front of him which, although not it meant gaining land, it meant receiving a title of respect within German society and it was hereditary in nature, giving it a certain cachet Social. However, the greatest honor to his scientific work is undoubtedly being baptized with his name the largest association of scientific institutions in Germany: the Helmholtz Association.

Bibliographic references:

• Cahan, D. (1993). Hermann Von Helmholtz and the Foundations of Nineteenth-Century Science. University of California Press. p. 198. ISBN 978-0-520-08334-9.
• Patton, L., (2009), Signs, Toy Models, and the A Priori: from Helmholtz to Wittgenstein, Studies in the History and Philosophy of Science, 40 (3): 281–289.
• Turner, R. S. (2014) In the Eye's Mind: Vision and the Helmholtz-Hering Controversy, Princeton University Press, p. 36.