Otto Stern

Otto Stern did not marry. As a young man, he was fond of good life and liked to dance. He was also a good tennis player and had many friends.

On March 8, 1939, he became a naturalized citizen of the United States of America. He spent the last part of his life at Berkeley, California. There he led a secluded life, but remained interested in the new discoveries in particle physics and astrophysics. He also went to movies regularly.

He died on August 17, 1969 at the age of 81 at Berkeley. He was stricken with heart attack while watching a movie and died soon after. He was buried in Sunset View Cemetery, El Cerrito, CA.

Otto Stern was born on February 17, 1888 in a prosperous Jewish family in Sohrau, now known as Zory. The town is located in the Upper Silesia region of Poland. However, at the time of his birth, it was part of the Kingdom of Prussia under German Empire.

His father, Oskar Stern, was a rich grain merchant and also owned flour mills. His mother’s name was Eugenia née Rosenthal. The couple had five children, among which Otto was the eldest. In 1892, the family moved to Breslau (now Wroclaw, Poland), where Otto was admitted to Johannes Gymnasium.

As Gymnasium emphasized more on the classics than on mathematics and sciences Stern supplemented his education by reading extensively in private. After passing out from school, he visited several universities as was the norm those days and finally in 1906, entered the University of Breslau with physical chemistry as his major.

Otto Stern completed his studies in 1912 earning his doctorate degree from the University of Breslau. In the same year, he joined Charles University at Prague to study under Albert Einstein.

When in 1913, Einstein returned to his alma mater, ETH Zürich, Otto Stern followed him. For one year he functioned as the Privatdozent of Physical Chemistry at ETH.

Once the war ended in 1918, Otto Stern returned to the University of Frankfurt am Main and remained there till 1921. Initially, he kept working on the theoretical problems and published a paper on the surface energy of solids. Very soon, he began to feel that he should provide experimental proof.

However, before he could complete his experiment, he received his first official academic post. In 1921, he joined the University of Rostock as the Associate Professor of Theoretical Physics.

In 1922, while teaching at Rostock, Stern along with Walther Gerlach performed their historic molecular-beam experiment. Known as Stern–Gerlach experiment, it confirmed the spin quantization theory, which stated that in a magnetic field, atoms can align themselves only in a few directions only.

Next in 1923, Stern joined the University of Hamburg as Professor of Physical Chemistry and Laboratory Director. Here he established an outstanding research group which undertook many pioneering experiments. Because of him University of Hamburg became a well-known center for atomic, molecular and nuclear research.

During this period Stern led further experiments into the quantum nature of matter. These experiments confirmed many other key manifestations such as wave nature of helium and hydrogen atoms by diffracting beams of these atoms, and irregular magnetic moments of proton and deuteron.

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.