Hermann Walther Nernst
Walther Hermann Nernst was German physicist and chemist mainly known for the Nernst Equation and the Third Law of Thermodynamics. He also developed methods for measuring dielectric constants and was the first to show that solvents of high dielectric constants promote the ionization of substances. Nernst proposed the theory of solubility product, generalized the distribution law, and offered a theory of heterogeneous reactions.
Walther Hermann Nernst was born in Briesen, West Prussia (now Wabrzezno near Torun, Poland), on June 25, 1864. His father, Gustav Nernst, was a district judge. Walter spent his early school years (Gymnasium) at Graudentz (now Grudziadz, Poland) where his studies focused on classical literature, humanities, and natural science. As a young man in Prussia, Hermann expressed his ambition to become a poet. In 1883, he had graduated first in his class (Abitur) at the Gymnasium of Graudenz, and subsequently went to the Universities of Zurich, Berlin and Graz, studying physics and mathematics.
Walther Hermann Nernst visited lectures by Ludwig Boltzmann and performed experimental studies together with Albert von Ettingshausen. At Graz Nernst published work with von Ettinghausen in 1886 which formed part of the experimental foundation of the modern electronic theory of metals (Nernst-Ettingshausen Effect: When a conductor or semiconductor is subjected to a temperature gradient and to a magnetic field perpendicular to the temperature gradient, an electric field arises perpendicular to both the temperature gradient and the magnetic field.). Nernst took his Ph.D. at Wurzburg under supervision of Friedrich Kohlrausch, beginning his career as a physicist. He graduated in 1887 with a thesis on electromotive forces produced by magnetism in heated metal plates.
Nernst et al., Graz University, 1887
(Standing, from the left) Walther Nernst, Franz Streintz, Svante Arrhenius, Hiecke, (sitting, from the left) Aulinger, Albert von Ettingshausen, Ludwig Boltzmann, Ignaz Klemencic, V. Hausmanninger.
In 1887 Nernst joined Wilhelm Ostwald at Leipzig University, where van’t Hoff and Arrhenius were already established, and it was in this distinguished company of physical chemists that Nernst began his important researches. Nernst’s early studies in electrochemistry were inspired by Arrhenius’ dissociation theory which first recognized the importance of ions in solution.
In 1889 he elucidated the theory of galvanic cells by assuming an “electrolytic pressure of dissolution” which forces ions from electrodes into solution and which was opposed to the osmotic pressure of the dissolved ions. In the same year he derived equations which defined the conditions by which solids precipitate from saturated solutions. Nernst applied the principles of thermodynamics to the chemical reactions proceeding in a battery.
In 1889, he showed how the characteristics of the current produced could be used to calculate the free energy change in the chemical reaction producing the current. Nernst first explained the ionization of certain substances when dissolved in water. He constructed an equation, known as the Nernst Equation, which related the voltage of a cell to its properties. Independently of Thomson, he explained why compounds ionize easily in water. The explanation, called the Nernst-Thomson rule, holds that it is difficult for charged ions to attract each other through insulating water molecules, so they dissociate.
In Easter 1890, Nernst moved to the Gottingen University where he was appointed as assistant and private lecturer with Eduard Riecke. In 1891 Nernst was promouted to Extraordinary professor in the Gottingen University. He lived at Buhlgasse 36, Gottingen. In 1890/1891 Nernst developed the Distribution Law. “If two liquids (or solids) a and b are partially immiscible and if there is a third component i present in both phases which behaves individually as an ideal solute (if it is sufficiently dilute), the ratio of its concentrations x is independent of the individual values of x”:
xia / xib = const
Walther Nernst and his Opel cars
In 1892 Walther Hermann Nernst married Emma Lohmeyer, daughter of a Gottingen medical professor. They had 5 children, two sons (Rudolf and Gustav, both died in World War I) and three daughters (Hildegard, Edith and Angela).
In 1894 Nernst received invitations to the Physics Chairs in Munich and in Berlin, as well as to the Physical Chemistry Chair in Gottingen. He accepted this latter invitation, and in Gottingen founded “Physikalisch-Technisches Reichsanstalt” (now the Institute for Physical Chemistry and Electrochemistry) and became its Director in 1922, a position he retained until his retirement in 1933. His transition to chemistry actually began in Leipzig, but developed fully in his subsequent position as an associate professor of physics at Gottingen.
Photograph taken in front of the Gottingen physicochemical institute, summer semester 1903, shows Nernst with his colleagues: Sauer, Levin, Grafenberg, Gerassimoff, Pickel, Stern, Conrad, Senter, Byk, Klopstock, Gardner, Bornemann, Siemens, Jahn, Clement, Wassiljewa, Nernst, Coehn, Kruger, Wulf, v. Lerch
Nernst was mechanically minded and he was always to the forefront in considering ways of applying the results of scientific research to industry. His improved electric light, the Nernst Lamp (patent D.R.P. No. 104872 in 1897), used a ceramic body and it might have assumed importance had not tantalum and tungsten filaments been developed.
The Nernst glower is a continous source of (near) infrared radiation used in spectroscopy. Typically it is in the form of a cylindrical rod composed of a mixture of certain oxides (e.g., zirconium oxide ZrO2, yttrium oxide Y2O3 and erbium oxide Er2O3 at a ratio of 90:7:3 by weight) and it is electrically heated to about 2000 Â°C. Initially it requires external heating because it is an insulator at room temperature. The Nernst glower exhibits also a bright emission in the visible spectrum (white light), and it was initially used for ordinary electric illumination. The Nernst lamp could be operated in ambient air, whereas the carbon filament lamp of Thomas Edison (1879) required a vacuum environment which was quite a disadvantage.
Hanging Nernst lamp
Emil Rathenau who had already (1882) acquired the patent of Edison for the AEG (Allgemeine Elektricitats-Gesellschaft, the German General Electric Company, which soon became the largest German electrical enterprise) also bought the patent of Nernst (1898). At the World’s Fair (World Exhibition) 1900 in Paris where the AEG pavilion was illuminated by 800 Nernst lamps, W. Nernst received the Grand Prix. Following the commercial success of his lamp, Nernst donated 40000 Mark for additions to the Gottingen institute building.
Nernst Lamp Company, Pittsburg
In the United States, George Westinghouse undertook the commercial development and introduction of the Nernst lamp. In 1901 the Nernst Lamp Company was organized and took up its quarters in Pittsburg in a five-story factory building with a total floor area of 101,000 square feet. Yttria (Y2O3) was obtained from the mineral gadolinite which the company extracted from its own mine at the legendary Barringer Hill, Texas (since 1937 buried beneath the waters of Lake Buchanan, Colorado River).
By 1904 a total of over 130,000 Nernst glowers had been placed in service throughout the country. However, the Nernst lamp lost competition when the more convenient incandescent light bulbs containing a metal (e.g., tungsten) filament and filled with an inert gas (e.g., argon) became available soon after (Irving Langmuir, a student of Nernst, General Electric Company, 1913). The Barringer Hill mine was closed for good in 1906.
Closely related to the Nernst lamp are the Lambda Sensor and solid oxide fuel cells (SOFC) which utilize quite the same solid state electrolyte.
In 1905, Nernst was appointed Professor of physical chemistry in the University of Berlin. Nernst and his students in Berlin proceeded to make many important physico-chemical measurements, particularly determinations of specific heats of solids at very low temperatures and of vapour densities at high temperatures. All these were considered from the point of view of quantum theory.
Nernst Heat Theorem (Third Law of Thermodynamics) was presented by Walther Nernst on December 23, 1905 at a meeting of the Konigliche Gesellschaft der Wissenschaften zu Gottingen. The Theorem says: “The entropy change in a reaction between pure substances approaches zero at T = 0 K.” Max Planck subsequently (1912) made the stronger statement: “As the temperature diminishes indefinitely, the entropy of a chemically homogeneous body of finite density approaches indefinitely near to the value zero” (M. Planck, Treatise on Thermodynamics).
As a consequence, it follows from the Third Law that the absolute zero of the (absolute) temperature scale, i.e., a temperature of zero kelvin (T = 0 K) cannot be attained by any means. This principle of the unattainability of the absolute zero has been formulated by Fowler and Guggenheim as follows: “It is impossible by any procedure no matter how idealized to reduce the temperature of any system to the absolute zero in a finite number of operations” (R. H. Fowler and E. A. Guggenheim, Statistical Thermodynamics, Cambridge University Press, 1940, p. 224).
Modern science has attained temperatures only one-millionth of a degree above absolute zero, but absolute zero itself cannot be reached. Simply stated, the law postulates that, at a temperature above absolute zero, all matter tends toward random motion and all energy tends to dissipate. In addition to its theoretical implications, the theorem was soon applied to industrial problems, induding calculations in ammonia synthesis.
Although Fritz Haber is more usually credited with responsibility for driving forward Germany’s chemical weapons research initiative, it was Nernst who initially argued the military benefits of using chemical agents as a weapon. Nernst was an early pioneer of Germany’s chemical weapons research programme. He developed an irritant powder, dianisidine chlorosulphate, fired with bullets in shrapnel shells to obtain an additional lachrymatory effect (i.e. tear gas).
To evade the 1899 international ban, the Germans put shrapnel in the shell so the “sole” purpose was not gas dissemination. On 27 October 1914, the Germans fired 3,000 of these projectiles at the British near Neuve-Chapelle, but with no visible effects. The explosive aspect of the shells destroyed the chemical aspect. In fact, the British were apparently unaware that they were the victims of the first large-scale chemical projectile attack.
It is said that German Army Chief of Staff Erich von Falkenhayn’s son won a case of champagne for remaining in a cloud of Nernst’s “irritant” substance for a full five minutes without exhibiting any signs of discomfort. Was Nernst possibly a saboteur? As a consequence of the experiment’s failure Nernst returned to his laboratory in Berlin and played no further role in German wartime chemical weapons production, although his ideas were utilised and expanded upon by others, including Haber.
In 1918 Nernst’s studies of photochemistry led him to his atom chain reaction theory. This assumed that once the energy of a quantum has initiated a reaction in which free atoms are formed, these formed atoms can themselves decompose other molecules with the liberation of more free atoms and so on. The reaction can thus continue for long periods without further outside initiations.
In order to explain the large value of the quantum yield, Nernst considered the H2-Cl2 explosion on exposure to light as an atom chain reaction. He proposed and provided evidence that the reaction, once stared, proceeds purely chemically. Hydrogen and chlorine gases are normally made up of 2-atom molecules. These molecules are quite stable and non-reactive.
Light can “dissociate” the chlorine molecules into two atoms, and the separated atoms are highly reactive. Each wanders around until it meets a hydrogen molecule, at which point it proceeds to “steal” one of the hydrogen atoms from its companion to make a stable hydrogen chloride molecule. The remaining hydrogen atom is also highly reactive and “steals” a chlorine atom from its companion… and so on. Since the reactions are rapid and “exothermic”, or heat-releasing, an explosion occurs.
Cl-Cl + hv = 2 Cl
Cl + H-H = H-Cl + H
H + Cl-Cl = H-Cl + Cl
Cl + Cl + M = Cl-Cl + M
Photograph of Nernst, 1924
Walter Hermann Nernst received the Nobel Prize in Chemistry 1920 in recognition of his pre-war work on heat theory and photochemistry. Many other distinctions and awards were bestowed upon him for his contributions to science. In later years, he occupied himself with astrophysical theories, a field in which the heat theorem had important applications.
Surprisingly, Nernst invented an electrical piano, which replaced the sounding board with radio amplifiers, however this piano did not gain acceptance among musicians. The Neo-Bechstein piano was a modified acoustic piano using pick-ups to capture naturally produced sound and subject it to electronic modification and amplification. It was invented and designed by Nernst in 1930, together with the companies Bechstein (mechanical parts) and Siemens (electrical parts).
The sound of the instrument resembles that of an electric guitar rather than an acoustic piano. About 15-20 instruments were built of which about 5 are still in existence. However, only one is still functioning. Recently, it was played in a performance as part of the Kryptonale 8 festival in Berlin in October 2002.
Walther Nernst had scientific contacts with many famous scientists including Einstein, Plank, Sommerfeld, Curie, etc. In 1914 Walther Hermann Nernst and Max Planck succeeded in bringing Albert Einstein to Berlin, and after the war, in 1919, arrangements were made for Max von Laue, Planck’s favourite student, to come to Berlin as well. Nernst has organized scientific conferences (e.g. Solvay Congress) providing exchange of scientific information and collaborations between scientists from different European countries.
Nernst with a group of famous scientists at Solvay Congress, Hotel Metropole, Brussels, 1911
Sitting (left to right): Nernst, Srillouin, Solvay, Lorentz, Warburg, Wien, Perrin, Madame Curie, Poencare.
Staying (left to right): Goldschmidt, Plank, Rubens, Sommerfeld, Lindemann, De Broglie, Knudsen, Hasendhrl, Hostelet, Herzen, Jeans, Rutherford, Kamerungli Onnes, Einstein, Langevin.
William Henry Bragg, Marcel Louis Brillouin, Louis de Broglie, Marie Curie, Albert Einstein, James Hopwood Jeans, Heike Kamerlingh Onnes, Martin Hans Christian Knudsen, Paul Langevin, Max von Laue, Hendrik Antoon Lorentz, Walther Nernst, Heinrich Rubens, Ernest Rutherford, Arnold Johannes Wilhelm Sommerfeld, Joseph John Thomson, Emil Gabriel Warburg, Wilhelm Wien, Robert Williams Wood (October 1913, Second Solvay Congress, Brussels)
Two photos made on the occasion of Millikan’s visit to Berlin, 1928, left to right: Nernst, Einstein, Planck, Millikan, Laue
Nernst devoted his time not only to science, but also to teaching, considering teaching duties as a very important part of his work.
Walther Nernst’s fundamental contributions to electrochemistry, the theory of solutions, thermodynamics, solid state chemistry and photochemistry are recorded in a series of monographs, and in his many papers to learned societies, etc. His book “Theoretische Chemie vom Standpunkte der Avogadro’schen Regel und der Thermodynamik” (“Theoretical chemistry from the standpoint of Avogadro’s rule and thermodynamics”) was first published in 1893 and the tenth edition appeared in 1921 (the fifth English edition in 1923).
Together with A. Schonflies he wrote a textbook “Einfuhrung in die mathematische Behandlung der Naturwissenschaften” (“Introduction to the mathematical study of the natural sciences”), which reached its tenth edition in 1923. Of his other books, his monograph “Die theoretischen und experimentellen Grundlagen des neuen Warmesatzes” (1918, second edition 1923) was also published in English (“The New Heat Theorem”, 1926).
Having lost his two sons in The First World War, Nernst was something of a national hero. But his pacifist views were not welcomed by the Nazis, and when they came to power in 1933, he retired to his estate and took no further part in academic or civil life. His favourite pastimes were hunting and fishing (breeding carp, shooting at Zibelle).
Walther Nernst died on November 18, 1941, at his house Rittergut Zibelle (Oberlausitz, near Muskau; now Niwica, Poland). He is buried with his wife Emma Nernst (nee Lohmeyer) and two daughters: Hilde and Edith. In Berlin, district Treptow / Johannisthal / Adlershof (new science campus) a little road is now named Walther-Nernst-StraÃŸe.