Thorvald N. Thiele

Thorvald Nicolai Thiele ( born December 24, 1838 in Copenhagen, † September 26, 1910 ibid ) was a Danish mathematician and astronomer and is now considered one of the founders of modern actuarial science. He associated his life at the Danish royal court and founded both the Mathematical Society and the Actuarial Association of his country.

Life

Thiele was born on Christmas Eve 1838 as the son of Just Mathias Thiele, the royal librarian and director of the Queen's Printer. It was named after his godfather, the sculptor Bertel Thorvaldsen, a friend of the family.

After his education he began the study of astronomy at the University of Copenhagen, which he already graduated in 1860 at age 21. After six more years, he obtained his doctoral thesis on the motion of double stars doctoral degrees and married the following year, Marie Martine trolls, with whom he had six children. In 1878 he was appointed director of the Observatory of the University, which he directed until his retirement in 1907. In 1900 he served as Rector of the University.

In addition to his teaching and research activities Thiele has always worked as an actuary for an insurance company and was eventually co-founder of the Hafnia Insurance (now a part of the Danish Codan Insurance ) for which he worked as a senior actuary until his death. In addition, he was a founding member of the Danish Mathematical Society (1873 ) and the first Danish Chess Association (1865 ).

Work

The focus of his research activities were the three-body problem in astronomy, on whose research he was instrumental, as well as the statistics of time series. In his 1880 published work Om Anvendelse af mindste Kvadraters method i Nogle Tilfælde, hvor en complication af visse Slags uensartede tilfældige Fejlkilder giver Fejlene en ' systematisk ' Karakter ( On the application of least squares method in cases where certain types of random error sources the mistakes of a " systematic " character to ) he took many statistical phenomena ( moving average, correlated errors ) anticipates that have not been evaluated systematically again much later. This work is now regarded as the first mathematical work in which a Brownian motion occurs - 25 years before it was statistically analyzed by Albert Einstein.

One of Thiele's most famous contributions to actuarial science is now ascribed to differential equation, which describes the course of the premium reserve over time:

The reserve, the mortality rate and the level of contributions is. Thiele not even published this result, but by Jørgen Pedersen Gram his colleagues got the formula to the public and is still today one of the most important tools of life insurance mathematics.

Number Theory: Thiele parquet

Even with number theory, Thiele employed professional: He examined quadratic residues in the rings of the Gaussian integers and Eisenstein integers. In his 1894 published work Om Talmønstre ( about number patterns ), he discovered that the quadratic residues symmetrical patterns result in quotient rings of the above rings on the Gaussian plane. A witness reported that the stove was tiled in Thiele's private home for such a pattern, and also the entrance hall on the seat of the Hafnia Insurance received a tile pattern of square residues. However, it was not until in 2002 the mathematics professor Steffen Lauritzen from Aalborg with a group of students to decipher the Orchestra: There are quadratic residues modulo 71, the age Thiele in 1910 at the opening of the building.

Thiele's heritage

In honor of his former professor, the University of Copenhagen holds the TN Thiele Symposium from an international lecture series on actuarial topics, and the University of Aarhus has launched in 2004 under the name Thiele Centre for Applied Mathematics research center to life.