In an Early Autograph Letter to the Future Head of NASA’s Jet Propulsion Laboratory, Einstein Defines the Ideal Values of a Mathematical Physicist: “Sharpness of scientific conceptualization in a purely mathematical field with a rare and rich knowledge of applied mathematics”

Max Abraham was a mathematician and physicist who worked on electromagnetism and relativity. He was first Max Planck’s assistant at the University of Berlin, a prestigious position. Abraham’s main work was related to Maxwell’s Theories, and his own achievements in electrodynamics. (Maxwell was a theoretical physicist who formulated a complete electromagnetic theory). Abraham was opposed to Einstein’s Theory of Relativity all his life. At first he objected both to the postulates on which relativity was based. By 1912 Abraham was prepared to accept that the theory was logically sound. He and Einstein disagreed about gravitation in 1912. Nonetheless, Einstein respected him and twice sought to assist him in his career.

In 1909 Abraham accepted a post at the University of Illinois in the United States. Disliking the small town atmosphere in Illinois, he returned within a few months to Göttingen. The Einstein Papers state that in April 1912 Einstein warmly recommended him to the University of Zurich for the post of Professor of Physics. He was, however, invited to Italy by mathematician Tullio Levi-Civita, and found work as the professor of rational mechanics at the Politecnico di Milano university until 1914. After World War I he was professor of physics at Technische Hochschule in Stuttgart. When his work there ended in 1921, Abraham sought a position in Aachen, and again Einstein intervened to aid him. However, before he started his work there he was diagnosed with a brain tumor. He died on November 16, 1922.

Known as the father of supersonic flight, Theodore von Kármán made major contributions to aviation and space technology, aerodynamics, and improved aircraft performance during an illustrious career. From 1913 through the 1920s he was Professor of Aerodynamics and Mechanics and then director at the Aachen Aerodynamics Institute. He oversaw the scientific development of the Institute and established interaction and cooperation in the field. From 1926 on Kármán commuted between Aachen and the California Institute of Technology in Pasadena, where he was the director of the Graduate Aeronautical Laboratories. After the Nazis came to power, he moved to California. Kármán made his first notable contribution to the study of supersonics in 1932 when he developed a new mathematical approach to studying airflow and supersonics that is now known as the Kármán-Moore theory. His laboratory became the most prominent in the world of aeronautical sciences. It later became the present NASA Jet Propulsion Laboratory, and he directed America’s first governmental long-range missile and space-exploration research program. By the end of his distinguished career, he had published more than 200 papers, advanced scientific collaboration from world leading scientists, developed many unique theories of aeronautical and space science, and played an important role in the creation of supersonic aircraft and ballistic missiles. In 1963, he was awarded the first National Medal of Science by President John F. Kennedy. Karman, like Einstein, was a German Jew who had fled Germany for life in the United States, and the two men had a warm friendship, as the photographs of Einstein with Karman’s wife and daughter attest.

On December 12, 1921, still back in Germany, Karman wrote Einstein. “I do not know whether you received my letter regarding the affair of the Aachen Gymnasium [secondary school], in which we wanted to appeal to you, among others as well. As a very good friend of mine from Aachen, Mr. Willy Renner, wants to see you about this matter, I am writing you quickly again. Please be kind enough to receive Mr. Renner; you would oblige me very much if you would amiably discuss this business with him. Mr. Renner is one of the most charming people I know, full of idealism and also of true democracy. Many former members of our Göttingen circle, such as Courant and I, have much to thank him for. A person of the noblest goodwill. The affair is briefly this, that the Belgian military authorities have confiscated for a few officers’ children Aachen’s only non-Catholic Gymnasium along with its equipment. Quite apart from the fact that this school educates an important segment of our polytechnic’s next generation, the illegality is clear and dangerous as a precedent. So we wanted to collect a few world-famous names, i.e., in the first place also from non-German scholars, for a submission to the Belgian government. I am convinced that the step would be successful, because the civilian authority was not for the confiscation, and it only happened as an arbitrary military act. May we hope that you will cosign it?”

On February 22, 1922, Karman again wrote Einstein, this time asking for a reference for Max Abraham to get a position at Aachen. And he also again raised the issue of the Aachen Gymnasium. “At the university a chair for mathematics has become vacant and we intend to nominate Max Abraham as first choice. We are of the opinion that someone who knows how to apply mathematical methods in a variety of creative ways is best suited as an instructor of mathematics at a technical university. Because this appointment does constitute somewhat of an exceptional case, I would be very grateful if you would communicate to me your view of Abraham’s personality as a scientist and of the matter of his appointment in a letter that I may present to my colleagues here. As this matter is very urgent, I request that you please reply as soon as possible.

“Sometime ago I wrote you on behalf of Mr. Renner. Thank you very much for receiving Mr. Renner so nicely and for your kind help in that affair. Mr. Renner asked me to excuse him, first, for having altered the wording of the letter somewhat, but that this had been definitely necessary as the factual circumstances had changed during the 6 weeks since the first letter had been drafted. Second, Mr. Renner asked me to apologize for having, at the instigation of an employee of the Manchester Guardian, demanded that you comment on some issues in the paper. He said that on the spur of the moment, and considering his multifaceted duties in Berlin, he had overlooked the inappropriateness of this request and asks you please not to hold it against him. I beg your pardon for having to bother you and assure you that I am very grateful for your help in all these matters. With deep respect, yours very sincerely, Kármán. P.S. Mr. Renner also instructed me to ask you whether you would mind if the news of interest to you and G[erhart] H[auptmann] regarding the school situation.”

Einstein responded. Autograph letter signed, February 24, 1922, to Karman. “Dear Mr Karman! I am sincerely pleased that you have given me the opportunity to put in a word for Abraham. Abraham is undoubtedly one of the most talented and accomplished researchers living in the field of mathematical physics. The focus of his talent is not in the area of generating new ideas, but in mathematical design. I consider the idea of promoting him to professor of mathematics at a technical university a good choice.

“He combines the sharpness of scientific conceptualization in a purely mathematical field with a rare and rich knowledge of applied mathematics. I am convinced that among the best-known men within this country, there is nobody as well suited for such a teaching position.

“I must confess that I did not particularly like the second version of Renner’s letter. I signed it right away in order to prevent further delay. In principle, I have nothing against Mr. Renner seeking to publish the fact, that I supported the petition regarding the school. However, I believe this will not help our cause, but would only endanger our success.

“This action will then be perceived as an attack by the other side and provoke the defiance of a petty Belgian, who is delighted in ‘having something to say’. Maybe for the first and only time in his life.”

All three of the scientists in this exchange, Einstein, Karman, and Abraham, were German Jews. It shows just how rich was the Jewish contribution to science in this era in Germany. Soon all the Jewish scientists in Germany would be dead or have found refuge elsewhere.