Kaluza began his mathematical studies at the age of eighteen at the University of Konigsberg, where he prepared a doctoral dissertation on Tschirnhaus transformation under Professor F. W. F. Meyer and qualified to lecture there in 1909.

Kaluza began his mathematical studies at the age of eighteen at the University of Konigsberg, where he prepared a doctoral dissertation on Tschirnhaus transformation under Professor F. W. F. Meyer and qualified to lecture there in 1909.

Theodor Kaluza was a German mathematician, physicist, and a professor of mathematics at Konigsberg and Kiel. He is known for the Kaluza-Klein theory, which involves field equations in five-dimensional space-time.

Background

Theodor Kaluza was born on November 9, 1885, in the German Empire's Prussian Province of Silesia. His father was Max Kaluza. He belonged to a family which had lived in Ratibor (now Raciborz, Poland) for around 300 years. Max Kaluza was a fine scholar and, although German, he was a leading expert on the English language and English literature, with his special field being the study of Chaucer.

Education

Kaluza was a bright student at school. Beginning his mathematical studies at the age of eighteen at the University of Konigsberg, he prepared a doctoral dissertation on Tschirnhaus transformation under Professor F. W. F. Meyer and qualified to lecture there in 1909.

In 1909 Kaluza became privatdozent at Königsberg, and remained there for two decades. By the time Kaluza was past forty, Einstein, recognizing his worth and finding him in a position far below his merits, recommended him warmly for something better. At last, in 1929, Kaluza obtained a professorship at the University of Kiel. In 1935 he moved to the University of Gottingen, where he became a full professor. Two months before he was to be named professor emeritus, Kaluza died after a very brief illness.

Kaluza was born and raised in a Roman Catholic family.

Politics

Kaluza refused the Nazi ideology, and his appointment to the Göttingen chair was possible only with difficulties and by protection of his colleague Helmut Hasse.

Views

By the close of the nineteenth century, the concept of ether had become an integral part of physics. It was generally expected that the ether, and perhaps even the electromagnetic equations themselves, would explain all of physics, including gravitation. But when Einstein developed his general relativity theory (1910-1920), in which gravitational effects are traced to changes in the structure of a four-dimensional Riemannian manifold, the question arose as to whether the electromagnetic field could be incorporated into such a manifold. The aim was to give a unified picture of the gravitational and electromagnetic phenomena. This was referred to as the unitary problem.

Kaluza’s essentially mathematical mind was attracted to the problem. He initiated a line of attack by introducing into the structure of the universe a fifth dimension which would account for the electromagnetic effects. When he communicated his ideas to Einstein, the latter encouraged him to pursue such an approach, submitting that this was an entirely original point of view. Kaluza’s major paper on this question appeared in 1921. Here he combined the ten gravitational potentials, which arise in Einstein’s general relativity theory as the components of the metric tensor of a four-dimensional space-time continuum, with the four components of the electromagnetic potential. He did this by means of his fifth dimension, which had the characteristic restriction that in it the trajectory of a particle is always a closed curve. This makes the universe essentially filiform with respect to the fifth dimension.

Kaluza’s theory was criticized on the ground that the fifth dimension is a purely mathematical artifice, with only a formalistic significance and no physical meaning whatever. Nevertheless, the five-dimensional idea was explored by several mathematical physicists.

Kaluza also worked on models of the atomic nucleus, applying the general principles of energetics. He wrote on the epistemological aspects of relativity and was sole author of or collaborator on several mathematical papers. In 1938 a text on higher applied mathematics written by Kaluza and G. Joos was published; in this work he showed himself as a mathematician rather than as a mathematical physicist.

Personality

Kaluza was a man of wide-ranging interests. Although mathematical abstraction delighted him tremendously, he was also deeply interested in languages, literature, and philosophy. He studied more than fifteen languages, including Hebrew, Hungarian, Arabic, and Lithuanian. He had a keen sense of humor. A nonswimmer, he once demonstrated the power of theoretical knowledge by reading a book on swimming, then swimming successfully on his first attempt (he was over thirty when he performed this feat). Kaluza loved nature as much as science and was also fond of children.

He was liked and respected by his students and had extremely good relations with his colleagues. He never used notes while lecturing, except on one occasion, when he had to copy down a fifty-digit number which showed up in number theory.

Interests

languages, literature, philosophy

Connections

Kaluza married in 1909. In 1910 his son Theodor Kaluza was born; he also became a notable mathematician.