Carl H. Hermann

Carl Heinrich Hermann, also spelled Karl Hermann, was a German physicist, crystallographer, and resistance fighter in Nazi Germany. He is known for his research in crystallographic symmetry, nomenclature, and mathematical crystallography in N-dimensional spaces.
Hermann was a pioneer in crystallographic databases and, along with Paul Peter Ewald, published the first volume of the influential Strukturbericht in 1931.
In 1943, he and his wife were imprisoned by the Gestapo for harboring a Jewish family. They were honored with medals of the Righteous Among the Nations by Yad Vashem in 1976.

Biography

Early life and education

Hermann was born in the north German port town of Lehe to Gerhard Heinrich Hermann, a merchant sailor officer for Norddeutscher Lloyd who also co-owned a stonework factory, and Clara Auguste née Leipoldt, was dedicated to religious studies. His grandfathers were both pastors of Protestantism. He had six siblings, including mathematician Grete Hermann, and they grew up middle class.
He studied mathematics and physics at the University of Göttingen, where he received his doctorate in 1923, as a pupil of Max Born and a fellow student with Werner Heisenberg. Upon graduation, he moved to Berlin-Dahlem to work under Herman Francis Mark at the Kaiser Wilhelm Institute for Fiber Chemistry. Later in 1925, he joined Paul P. Ewald at the University of Stuttgart, where he achieved his habilitation in 1931.

Early career

Along with Ewald in Stuttgart, he nurtured the growing field of crystallography, especially the study of space groups, and began what was later to become Structure Reports, a reference series giving every known crystal structure determination. During his Stuttgart years, Hermann also developed the first description of anisotropic properties of materials from a crystallographic perspective.
When the Nazi Party rose to power, he objected to its political restrictions on academic positions, leaving to take a position as a physicist with the industrial dye firm I.G. Farben at Ludwigshafen, where he continued his crystallographic research and studied symmetry in higher-dimensional spaces.

World War II

During World War II, he and his wife Eva Hermann, who were both Quakers and pacifists, helped provide deported Jews with food, clothing and other resources. After the city of Mannheim was declared Judenfrei, they hid Jews in their home from Nazi authorities. In 1943 he and his wife were arrested and brought before a special tribunal. As his scientific work was deemed too essential to the war effort, Hermann was given a "mild" sentence of eight years of imprisonment, while Eva was sentenced to three years. He was allowed to continue his research while imprisoned, being brought to his laboratory in the mornings and taken back to his cell at night. After two years of imprisonment, he and Eva were both released at the end of the war.

Post-World War II

After the war, he lectured briefly at Darmstadt Polytechnic between 1946 and 1947. Then, in 1947, he accepted a newly formed chair in crystallography at the University of Marburg, where he became director of the Crystallographic Institute and remained until his death. During his Marburg years, Hermann's research laid the foundation for N-dimensional crystallography. He died unexpectedly of a heart attack in his sleep in September 1961.

Legacy

The symmetry notation introduced by Hermann and Charles-Victor Mauguin, which later became an international standard notation for crystallographic groups known as the Hermann–Mauguin notation or International notation.
In 1976, for their work in saving Jews from the Holocaust, Hermann and his wife Eva were honored as Righteous Among the Nations by Yad Vashem. Eva Hermann wrote about the honor: "I am fully conscious of the fact that my late husband and I did nothing special; we simply tried to remain human in the midst of inhumanity."
In August 1994, the German Crystallographic Society established the Carl Hermann Medal, its highest distinction, for outstanding contributions to the science of crystallography.

Books

Selected articles