# Kostantinos Karatheodoris

Kostantinos Karatheodoris was one of the leading mathematicians of the world, as well as the most outstanding Greek mathematician of our century.

He was born on 13^{th} September,1873 in Berlin and passed away on 2^{nd} February,1950 in March.

Konstantinos spend his childhood in Brussels. He spoke both Greek and French as mother tongues .At an early age he showed talent for mathematics and he was twice awarded tha first prize in competitions against all Belgium students.

From 1891 to 1895 he completed his studies in engineering at the military school of Brussels gaining technical knowledge.

His academic career includes professorships on Mathematics at the GERMAN universities of Bonn,Hannover, Breslan, Gottingen, Berlin and Munich.This way he is distinguished as a prominent mathematician at a global level. In 1920,Karatheodoris,hired by Eletterios Venizelos ,takes on responsibility for organizing the newly-founded Ionian university of Smyrna ,as well as the universities of Athens and Thessaloniki. He was the one who achieved to save the university Library After the Destruction of Smyrna in 1922,transferring everything with him to the university of Athens .Between the years 1922 and 1924 he becomes a professor of Mathematics and Engineering at the National Metsovion Polytechnic. I n 1924 he permanently settles down to Munich but he returns to Greece in 1930 to contribute to the reorganization of the universities of Athens and Thessaloniki .He made importants contributions to the theory of real functions, conformal representations, calculus of variations and to the theory of point set measure ,as well as to Thermodynamics, Geometry ,Astronomy and Einstein’s relativity theory.

It should be noted that there was a close scientific cooperation and mutual appreciation between Konstantinos Karatheodoris and Albert Einstein. The former is considered a teacher by the latter .It is insignifant that Karatheodoris is not as well-known in the public as Einstein. It is a fact that the supreme Greek mathematician was proved of considerable help for Einstein concerning the mathematical knowledge background of the relativity theory Einstein was a leading physicist, but not a mathematician. That was why he relied to a certain extent upon the maths gift of Karatheodoris .Physics needs to be expressed through the Mathematical language.

The actual cooperation of the two men is clearly shown by a letter sent by Einstein to the Greek professor most probably in 1916 in which he states :”

Dear colleague,

I find your derivation wonderful. You should publish the theory in this new form in the Annals of Physics, since the Physicists do not normally know anything about this subject as was also the case with me.

With my letter I must have come across to you like a Berliner who had just discovered Crunewald and wondered whether people were already living there .If you wouldn’t mind also making the effort to present to me the canonical transformations,you will,find in me a grateful and attentive audience .If you ,however ,answer the question about the closed time trajectories, I will appear before you with my hands folded. The underlying truth,though,is well worth some perspiration”

Albert Einstein ,in his last interview ,given in 1955 he had stated referring to his teacher that he was asked about thousands of things, but not about who his teacher was, or who showed him the way to higher mathematics both in terms of thought and research. He said characteristically that his great teacher was the incomparable Greek Konstantinos Karatheodoris to whom himself personally and the mathscience, the physics and the wisdom of our century owe everything.

Reading Einstein’s letter to K. .Karatheodoris in which he states that he appears before him with his hands folded thanks to the questions Kratheodoris answered concerning Einstein’s math calculations about the relativity theory ,we cannot help acknowledging the magnificence of the mathematician Konstantinos Karatheodoris.