Walther Hermann Nernst (25 June 1864–18 November 1941) was a German physical chemist and physicist who is known for his theories behind the calculation of chemical affinity as embodied in the third law of thermodynamics, for which he won the 1920 Nobel Prize in chemistry.
Nernst invented, in 1897 an electric lamp, using an incandescent ceramic rod.

In 1905, he established what he referred to as his "New Heat Theorem", later known as the Third law of thermodynamics.
In 1911, with Max Planck, he is the main organizer of the first Solvay Conference in Brussels.
In 1920, he received the Nobel Prize in chemistry in recognition of his work in thermochemistry.
In 1924, he became director of the Institute of Physical Chemistry at Berlin, a position from which he retired in 1933.
Nernst developed an electric piano, the "Neo-Bechstein-Flügel" in 1930 in association with the Bechstein and Siemens companies, replacing the sounding board with radio amplifiers.
Nernst died in 1941 and is buried near Max Planck in Göttingen, Germany.