Hermann Walther Nernst | Biography

As the nineteenth century drew to a close, physicists were gaining a greater understanding of the principles of heat and chemistry. This was due chiefly to the relatively new science of thermodynamics, the proponents of which sought to explain the activities of heat as energy. Two laws of thermodynamics had already been advanced. The first law, known as the law of conservation of energy, proved that the energy at the end of any chemical reaction was equal to the energy at its beginning. The second law, now called the principle of entropy, claimed that a certain amount of energy in a reaction was "lost" --converted into unusable heat. The last piece of the thermodynamic puzzle was provided by the German chemist Hermann Nernst who proposed the third law of thermodynamics: the determination of chemical equilibria.

Nernst was born in what is now Wabrzezno, Poland, in 1864. Though as a boy he longed to be a poet, his interests were eventually turned toward science. He attended the universities of Zurich, Berlin, and Graz before graduating summa cum laude from the University of Wurzburg in 1887. In the two years after receiving his degree, Nernst experimented with electric coils, determining the reason for the potential they produced. His work earned him a modest reputation as a skilled physicist, and he was courted by several universities to work in their laboratories.

In the late 1880s Nernst was introduced to Friedrich Wilhelm Ostwald, one of the founders of the new science of physical chemistry. In 1890 Nernst became Ostwald's assistant at the University of Leipzig. The two of them, along with several other prominent scientists, became the nucleus of a group that would take the fields of physical chemistry and thermodynamics farther than any had predicted.

Nernst's first individual accomplishment was the explanation of the ionization of water-soluble compounds. He showed how water, a natural insulator, weakened the electromagnetic bonds between positively-and negatively-charged ions. Thus weakened, it is easy to separate the ions through electrolysis. This principle was explained independently by Joseph J. Thomson and has come to be called the Nernst-Thomson Rule.

In 1891 Nernst was given his own professorship, at the University of Gottingen. He used his position of influence to author a textbook that would include the amazing new advances in thermodynamics and physical chemistry. This text was updated regularly in order to reflect the rapidly changing fields of chemistry and physics, and it was considered the foremost authority on physical chemistry until the emergence of quantum physics in the 1920s.

It was at Gottingen that Nernst conducted the research for his most important discovery, the third law of thermodynamics. Beginning in 1891 he assembled in his laboratory an impressive group of scholars specializing in both theoretical and experimental physics. They were interested in chemical reactions--specifically, why some reactions " worked" while others did not, and why some reactions worked longer than others. It was known that the nature of a chemical reaction was chiefly dependent upon the heat content (or enthalpy) and the amount of free energy. What was not known was what governed these factors.

It was becoming clear to Nernst that chemical reactions behaved very differently near absolute zero. His team succeeded in approaching absolute zero to within one degree in the laboratory; what they found was that the free energy and the heat content within the system approached each other as the temperature dropped, so that (theoretically) they would meet at absolute zero. However, thermodynamic principles showed clearly that equal heat and free energy was an impossibility. Thus, Nernst held his research to be a proof that absolute zero could not be attained.

The results of Nernst's eleven years of research were published in 1905, the same year that he accepted a professorship at the University of Berlin. Though his idea was viewed by other scientists as having limited application, Nernst immediately hailed it as the third law of thermodynamics. During the next five years thousands of experiments were conducted to test Nernst's heat theory. It was found to be a powerful tool for predicting chemical equilibrium and thus, for determining the feasibility of many chemical reactions. It also became evident that Nernst's Law supported the emerging theories of quantum physics; this delighted the likes of Max Planck and Albert Einstein, whose work was almost entirely theoretical.

Over the years experiments by Planck, Franz Simon (a student of Nernst's), and Nernst himself showed that the third law of thermodynamics had a wide variety of applications. For its development Nernst was awarded the 1920 Nobel Prize for Chemistry.

Nernst was also something of an inventor. He constructed, among other things, a ceramic lamp that would glow at relatively low currents. Though it was in no ways as useful or as popular as Thomas Edison's light, Nernst was paid one million marks for the patent (a sum which shocked Edison, who viewed professors as impractical dreamers).

As a citizen of Germany, Nernst was fiercely patriotic. He served his country in World War I as an administrator, weapons engineer, and even as an automobile driver. This loyalty was not reciprocated, however: when his daughters married men of "non-Aryan" origin Nernst was ostracized by the Hitler regime. He died of a heart attack in 1941.