Scientist of the day Otto Stern

Otto Stern 

Famous As: Physicist

Nationality: German

Birth Date: February 17, 1888

Died On: August 17, 1969

Otto Stern was a German born American physicist who won the Nobel Prize in Physics in 1943. He was born in a prosperous Jewish family towards the end of the nineteenth century in the Kingdom of Prussia. Because of the financial affluence of his family, he did not have to look for jobs immediately after he finished his education. Instead, he worked as Privatdozent in chosen universities for a long time before landing at his first official academic post in the early 1920s. Initially he concentrated more on theoretical problems. It was only after he met great experimentalists like James Franck and Max Volmer that he began to take interest into experimental physics. Within a short period he developed molecular-beam method and discovered spin quantization with Walther Gerlach. It not only brought him fame, but also opportunity for further research work. Measurement of atomic magnetic moments, demonstration of the wave nature of atoms and molecules, and discovery of the proton's magnetic moment are few of his important works. He migrated to the USA and took up American citizenship when Hitler’s Nazi Party came to power. After working at Carnegie Mellon University for more than twelve years he finally retired and settled in California.

Major Works

The Stern–Gerlach experiment of 1922 is one of the most important works carried on by Otto Stern. He and Walther Gerlach sent a beam of silver atoms through inhomogeneous magnetic field onto a glass plate and observed their diffraction.

According to classical physics, the beam should have spread out as a continuous band; instead only two beams were observed. It not only confirmed the spin quantization theory, but also paved the way for further development of modern physics.

Measuring the magnetic momentum of proton by using molecular beam is another of his important work. Undertaken in 1933, the experiment proved that the actual measurement is two and half times of its theoretical value.

He also published many papers. Among them, a series of thirty outstanding papers titled ‘Untersuchung zur Molekularstrahl-Methode, UzM’ (Investigations by the molecular-beam method) is most noteworthy.

Awards & Achievements

Otto Stern received the 1943 Nobel Prize in Physics for his discovery of spin quantization theory. Although the work was done in collaboration with Walther Gerlach, he alone received the prize because Gerlach had stayed back in Germany and was active during Nazi period.

In addition, he was also elected as a member of American Association for the Advancement of Science, American Philosophical Society, National Academy of Sciences and Royal Danish Academy of Sciences.

Trivia

Otto Stern was the second most nominated person for the Nobel Prize. He received 82 nominations between 1925 and 1945. He ultimately won it in 1943.