Editing Walther Nernst (section)

=== Professional career ===
[[Wilhelm Ostwald]] recruited him to the first department of physical chemistry at [[Leipzig University]]. Nernst moved there as an assistant, working on the thermodynamics of electrical currents in solutions. Promoted to lecturer, he taught briefly at the [[Heidelberg University]] and then moved to the [[University of Göttingen]]. Three years later, he was offered a professorship in [[University of Munich|Munich]]. To keep him in Prussia the government created a chair for him at Göttingen. There, he wrote a celebrated textbook ''Theoretical Chemistry'', which was translated into English, French, and Russian. He also derived the [[Nernst equation]] for the electrical potential generated by unequal concentrations of an ion separated by a membrane that is permeable to the ion. His equation is widely used in cell physiology and neurobiology.

The [[Incandescent light bulb|carbon electric filament lamp]] then in use was dim and expensive because it required a vacuum in its bulb. Nernst invented a solid-body radiator with a filament of rare-earth oxides, known as the [[Nernst lamp|Nernst glower]], it is still important in the field of [[infrared spectroscopy]]. Continuous [[Joule heating|ohmic heating]] of the filament results in conduction. The glower operates best in wavelengths from 2 to 14 micrometers. It gives a bright light but only after a warm-up period. Nernst sold the patent for one million marks, wisely not opting for royalties because soon the tungsten filament lamp filled with inert gas was introduced. With his riches, Nernst in 1898 bought the first of the eighteen automobiles he owned during his lifetime and a country estate of more than five hundred hectares for hunting. He increased the power of his early automobiles by carrying a cylinder of [[nitrous oxide]] that he could inject into the carburetor.<ref>{{cite journal|last1=Cherwell|first1=F. Simon|title=Walther Nernst, 1864–1941|journal=Obit. Not. Fell. R. Soc. Lond.|date=1942|volume=4|issue=11|page=1022}}</ref> After eighteen productive years at Göttingen, investigating [[osmotic pressure]] and [[electrochemistry]] and presenting a theory of how nerves conduct, he moved to Berlin, and was awarded the title of ''[[Geheimrat]]''.

[[File:Nernst, Walther 1912.jpg|left|thumb|Nernst 1912, portrait by [[Max Liebermann]]]]

In 1905, he proposed his "New Heat Theorem", later known as the [[Third law of thermodynamics]]. He showed that as the temperature approached absolute zero, the [[entropy]] approaches zero {{mdash}} while the [[Gibbs free energy|free energy]] remains above zero. This is the work for which he is best remembered, as it enabled chemists to determine free energies (and therefore equilibrium points) of [[chemical reaction]]s from heat measurements. [[Theodore William Richards|Theodore Richards]] claimed that Nernst had stolen his idea, but Nernst is almost universally credited with the discovery.<ref>{{cite book | last=Coffey | first=Patrick| pages=[https://archive.org/details/cathedralsscienc00coff/page/n98 78]–81 | title=Cathedrals of Science: The Personalities and Rivalries That Made Modern Chemistry | url=https://archive.org/details/cathedralsscienc00coff | url-access=registration | location=Oxford | publisher=[[Oxford University Press]] | year=2008 | isbn=978-0-19-532134-0}}</ref> Nernst became friendly with [[Wilhelm I|Kaiser Wilhelm]], whom he persuaded to found the [[Kaiser Wilhelm Society|''Kaiser Wilhelm Gesellschaft'']] for the Advancement of the Sciences with an initial capital of eleven million marks. Nernst's laboratory discovered that at low temperatures [[specific Heat|specific heats]] fell markedly and would probably disappear at absolute zero. This fall was predicted for liquids and solids in a 1909 paper of [[Albert Einstein]]'s on the [[quantum mechanics]] of specific heats at cryogenic temperatures. Nernst was so impressed that he traveled all the way to [[Zürich]] to visit Einstein, who was relatively unknown in Zürich in 1909, so people said: "Einstein must be a clever fellow if the great Nernst comes all the way from Berlin to Zürich to talk to him."<ref>{{cite book|last1=Stone|first1=A. Douglas|title=Einstein and the quantum : the quest of the valiant Swabian|url=https://archive.org/details/einsteinquantumq0000ston|url-access=registration|date=2013|publisher=Princeton University Press|page=[https://archive.org/details/einsteinquantumq0000ston/page/146 146]|isbn=9780691139685 }}</ref> Nernst and Planck lobbied to establish a special professorship in Berlin and Nernst donated to its endowment. In 1913 they traveled to Switzerland to persuade Einstein to accept it; a dream job: a named professorship at the top university in Germany, without teaching duties, leaving him free for research.<ref>Stone 2013, p. 165.</ref>

In 1911, Nernst and [[Max Planck]] organized the first [[Solvay Conference]] in Brussels. In the following year, the [[impressionist]] painter [[Max Liebermann]] painted his portrait.