Aug 312016


Today is the birthday (1821) of Hermann Ludwig Ferdinand von Helmholtz a Prussian physician and physicist who made significant contributions to several widely varied areas of modern science. In physiology and psychology, he is known for his mathematics of the eye, theories of vision, ideas on the visual perception of space, color vision research, and on the sensation of tone, perception of sound, and empiricism. In physics, he is known for his theories on the conservation of energy, work in electrodynamics, chemical thermodynamics, and on a mechanical foundation of thermodynamics. As a philosopher, he is known for his philosophy of science, ideas on the relation between the laws of perception and the laws of nature, the science of aesthetics, and ideas on the civilizing power of science. Some of his ideas are a bit spaced out and are not widely supported, or even known, any more. But there’s no question that Helmholtz had a fertile mind.

Helmholtz’ father, Ferdinand, had been in the Prussian army fighting against Napoleon, but, despite an excellent university education he preferred to teach in a secondary school in Potsdam, which left the family struggling financially.  Ferdinand was an artistic man and under his influence Hermann grew up to have a strong love of music and painting, which he then put to use in his contemplation of the unity of a number of investigations, especially physics and aesthetics. It’s in this area that I most know his work.

Hermann attended Potsdam Gymnasium where his father taught philology and classical literature. His interests at school were mainly in physics and he would have liked to have studied that subject at university. But the financial position of the family, however, meant that he could not go to university unless he received a scholarship. Financial support of this kind was not available for physics so his father persuaded him to study medicine which was supported by the government.


In 1837 Helmholtz was awarded a government grant to enable him to study medicine at the Royal Friedrich-Wilhelm Institute of Medicine and Surgery in Berlin. He did not receive the money without strings attached, however, and he had to sign a document promising to work for ten years as a doctor in the Prussian army after graduating. In 1838 he began his studies in Berlin. Although he was officially studying at the Institute of Medicine and Surgery, being in Berlin he had the opportunity of attending courses at the University. He took this chance, attending lectures in chemistry and physiology.

Given Helmholtz’s contributions to mathematics later in his career it would be reasonable to have expected him to have taken mathematics courses at the University of Berlin at this time. However he did not, rather he studied mathematics on his own, reading works by Laplace, Biot and Daniel Bernoulli. He also read philosophy works at this time, particularly the works of Kant. His research career began in 1841 when he began work on his dissertation. He rejected the direction which physiology had been taking which had been based on “vital forces” which were not physical in nature. Helmholtz strongly argued for founding physiology completely on the principles of physics and chemistry, and ultimately this approach led to his contemporary fame.

Helmholtz graduated from the Medical Institute in Berlin in 1843 and was assigned to a military regiment at Potsdam, but spent all his spare time doing research. His work concentrated on showing that muscle force was derived from chemical and physical principles. If some “vital force” were present, he argued, then perpetual motion would become possible. In 1847 he published his ideas in his paper “Über die Erhaltung der Kraft” which laid down the mathematical principles behind the conservation of energy.


Helmholtz argued in favor of the conservation of energy using both philosophical and physical arguments. He based many ideas on earlier works by Sadi Carnot, Clapeyron, Joule and others. That philosophical arguments came right up front in this work was typical of all of Helmholtz’s contributions. He argued that physical scientists had to conduct experiments to find general law. In that way science

 … endeavours to ascertain the unknown causes of processes from their visible effects; it seeks to comprehend them according to the laws of causality. … Theoretical natural science must, therefore, if it is not to rest content with a partial view of the nature of things, take a position in harmony with the present conception of the nature of simple forces and the consequences of this conception. Its task will be completed when the reduction of phenomena to simple forces is completed, and when it can at the same time be proved that the reduction given is the only one possible which the phenomena will permit.

He then showed that the hypothesis that work could not be continually produced out of nothing inevitably led to the principle of the conservation of kinetic energy. This principle he then applied to a variety of different situations. He demonstrated that in various situations where energy appears to be lost, it is, in fact, converted into heat energy. This happens in collisions, expanding gases, muscle contraction, electrostatics, galvanic phenomena and electrodynamics. The paper was quickly viewed as an important contribution and played a major role in Helmholtz’ career. The following year he was released from his obligation to serve as an army doctor so that he could accept the vacant chair of physiology at Königsberg.


His career progressed rapidly in Königsberg. He published important work on physiological optics and physiological acoustics. He received great acclaim for his invention of the ophthalmoscope in 1851 and rapidly gained a strong international reputation.  In 1855 he was appointed to the vacant chair of anatomy and physiology in Bonn, but because his approach to physiology as a matter of physics and chemistry and not “magic,” he got a lot of complaints from traditionalist students, and wound up at Heidelberg University in 1858 where they promised to set up a new physiology institute for him.

Some of his most important work was carried out while he held this post in Heidelberg. He studied mathematical physics and acoustics producing a major study in 1862 which looked at musical theory and the perception of sound. In mathematical appendices he advocated the use of Fourier series. In 1843 Ohm had stated the fundamental principle of physiological acoustics, concerned with the way in which one hears combination tones. Helmholtz explained the origin of music on the basis of his fundamental physiological hypotheses. He formulated a resonance theory of hearing which provided a physiological explanation of Ohm’s principle. He also explained why you get a note when you blow across the neck of a bottle, and why the note changes depending on how much liquid is in the bottle. Technically this is called a Helmholtz resonator.


From around 1866 Helmholtz began to move away from physiology and move more towards physics. When the chair of physics in Berlin became vacant in 1870 he indicated his interest in the position and in 1871 he took up this post. He had begun to investigate the properties of non-Euclidean space around the time his interests were turning towards physics in 1867. This led Helmholtz to question the adequacy of Euclidean geometry to describe the physical world, and, in general, broadened his thinking into the realms of philosophy.

There’s more but I’ll stop. I’ve probably already caused a few glassy eyes. On the one hand, Helmholtz revolutionized many scientific fields because he was a true polymath at a time when scientific fields were becoming narrower and narrower in their focus. Many would do well to follow his lead, but this is virtually impossible in today’s highly professionalized and specialized world. Occasionally these days physicists stumble on ancient Chinese philosophy and the like, and you get a bit of playful synthesis. But it does not to amount to anything of any importance. A person of Helmholtz’ stature might do better nowadays, but with so much technical matter to cover this may be impossible. Pity. Helmholtz was driving down a path to show that the natural science of the physical would eventually explain EVERYTHING from the motion of objects to the aesthetic appreciation of color and sound. Good luck with that. The science of the 19th century is simply not up to the task; nor that of the 21st century in my oh so humble opinion. I believe we need a new paradigm, which I doubt will be forthcoming in my lifetime. I will give Helmholtz A++ for effort though (generous of me, I know).

Potsdam, Helmholtz’ birthplace, was the capital of Prussia, but ceded its central place to neighboring Berlin when Germany was unified in Helmholtz’ lifetime, although Potsdam remained the residence of the Kaisers until 1918. As with other manufactured nations, we can speak of German cuisine as a whole, which notion has some merit, but also blurs over regional distinctions. The fact is, though, that certain dishes are universal, and the potato, which was popularized by Frederick the Great of Prussia dominates to this day. So, I suggest German potato pancakes, Kartoffelpuffer, which are widespread in German cuisine. I’ve never used a recipe, but I’ll give you one for completeness. The main issue is that the potatoes are grated raw, so you need the right quantity of egg and flour to bind the potatoes together, otherwise they will fall apart when cooked. Trust me – I know this. In Prussia they are served as a side dish with meat or with applesauce as a sweet dish.




1 kg/2 lb potatoes, peeled and coarsely grated
1 onion, peeled and grated
2 large eggs, beaten
salt and pepper
2 tbsp flour
vegetable oil


Drain all excess moisture from the potatoes but do not squeeze them dry. This will ruin the taste.

Mix the potatoes, onion, and egg together in a bowl, and add salt and pepper to taste.  Add enough flour, a little at a time, to absorb any excess moisture in the potatoes.

Divide the mixture into 8 and shape each portion into flat, round patties. Place the patties individually on trays, and  let them rest in the refrigerator for at least 30-45 minutes.

Heat the oil in a frying pan over medium heat and cook the kartoffelpuffer in small batches, flipping once so that they are golden brown on both sides and cooked through. This part takes some practice. Don’t be tempted to cook them too quickly, or they will not cook all the way through.

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