Walther Nernst

Major contributions

• Derived the Nernst equation (1889), E = E° − (RT/nF) ln Q, relating the voltage of an electrochemical cell to concentrations, a direct application of Gibbs free energy
• Proposed the heat theorem (1906), that entropy changes in reactions vanish as temperature approaches absolute zero, now the third law of thermodynamics, and later the unattainability of absolute zero
• With colleagues, measured heat capacities of solids at low temperatures (1910–1911), confirming Einstein's quantum theory of specific heats (see Specific Heat Capacity)
• Organised, with industrialist Ernest Solvay, the first Solvay Conference (1911) on radiation and quanta, a turning point in the acceptance of quantum theory
• Invented the Nernst lamp, an early electric light using a ceramic glower, and contributed to photochemistry (chain reactions) and electrochemistry

Named concepts

Career

Nernst was born in Briesen, West Prussia (now Wąbrzeźno, Poland). He studied at Zürich, Berlin, Graz (with Ludwig Boltzmann) and Würzburg, where he received his doctorate in 1887, and worked with Wilhelm Ostwald in Leipzig. He was professor at Göttingen from 1891 and at the University of Berlin from 1905, later serving as president of the Physikalisch-Technische Reichsanstalt (1922–1924) and director of the Berlin physics institute.

Both of his sons were killed in the First World War. He retired in 1933 and was openly critical of the Nazi regime's policies; he withdrew from public scientific life and died at his country estate in 1941.

Key publications

• Nernst, W. (1889). “Die elektromotorische Wirksamkeit der Jonen.” Zeitschrift für Physikalische Chemie, 4, 129–181.
• Nernst, W. (1906). Nachrichten von der Gesellschaft der Wissenschaften zu Göttingen, 1–40.
• Nernst, W. (1918). Die theoretischen und experimentellen Grundlagen des neuen Wärmesatzes. Halle: Knapp.

Nobel Prize

Nernst received the 1920 Nobel Prize in Chemistry “in recognition of his work in thermochemistry”. The 1920 prize was awarded in 1921.

Historical context

The status of Nernst's heat theorem was debated for years, including with Max Planck, who gave the stronger form that entropy itself tends to zero (see Max Planck), and with Einstein, who analysed whether it could be derived from the second law. Nernst's Berlin institute was a centre of physics alongside Planck and Einstein, and his low-temperature measurements helped convince physicists that quantum effects were real (see Albert Einstein). His personality was described by contemporaries as both brilliant and combative, and his priority claims were sometimes disputed.