Thomas Clausen (mathematician)
Thomas Clausen ( born January 16, 1801 in Snogbæk, community Sottrup, Duchy of Schleswig ( today Denmark ). . † 12 Maijul / May 24 1885greg in Dorpat ) was a Danish ( Schleswig shear ) astronomer and mathematician.
Clausen had, how many former scientist, played any regular university. He was born the son of a poor peasant farmers in the Danish North Schleswig, and came in 1813 still illiterate shepherd boy than to the pastor and lover of mathematics Georg Holst in the neighboring municipality Nybøl ( Nübel ), who hired astronomical observations among others. Holst enabled him to attend school and supported him in the acquisition of elementary math skills. In the final school exams Clausen fell to extraordinary achievement.
Around 1819 he came on the recommendation of Holst to Heinrich Christian Schumacher to Altona and already published in 1823 his calculation of occultations of stars by the moon to determine the longitude in the Astronomische Nachrichten. From 1824 to 1827 he worked at the line under Schumacher's observatory as an assistant and could mathematically much of Schumacher's assistant Peter Andreas Hansen learn there. During this time there were several inconsistencies with Schumacher, including because Clausen fell in love with a niece of Schumacher.
In January 1827 Joseph Utzschneider entered into an agreement with Clausen on an activity in the famous Institute of Optics Utzschneider to Munich. Clausen then renewed his courtship of Schumacher's niece, but received a renewed rejection and ban what he perceived as a very sensitive insult. It was not until the end of November 1828 broke Clausen on to Munich and was taken up by Utzschneider in his house. Again, there was some inconvenience. In 1833 he became seriously ill and out of time from 1834 to 1840 is nothing known about him. In June 1840, he arrived after a long journey on foot in a bad state of Munich again in Altona at Schumacher. Previously, Gauss wrote to Schumacher
"It would be very regrettable if its really excellent talent for abstract mathematics in the stunting so would not to reason. Liesse not do something for him? "
At the Altona Observatory, he took the place of a Observators and published in 1840 a treatise on the memorable comet of 1770, for which he was bestowed the Award of the Royal Society of Sciences in Copenhagen. In 1842 he was Mädler Observer and in 1865 professor at the observatory of Dorpat. In 1866 he followed Mädler the Directorate of the observatory of Dorpat, ( she had been postponed in 1867 to five years) until his retirement in 1872 he held the post.
His most important won Clausen expect Direction astronomer. In particular, he focused on cometary orbits. Even as a mathematician he possessed an extraordinary Rechenfreudigkeit. He writes on November 3, 1826 Utzschneider: " Theoretical study of mathematics has always had the most interest for me." He calculated the number π circuit of a test calculation on 250 decimal digits ( number of John Machin and Euler ). In this context, he also had interest in number theory questions; he found in 1840 independently by Karl Georg Christian von Staudt about the denominators of the Bernoulli's numbers today named after von Staudt and Clausen theorem. He further dismantled in 1853, the number to the prime factors 2071723 and 5363222357 and 1854, the Fermat number in 274 177 and 67 280 421 310 721, where he added that the last number is the largest known prime number. In the field of infinite series he has made significant individual results found. For example, he has already before 1830 Hjortnäs (1953 ) and Roger apery (1978) and Melzak (1973 ) indicated a rapidly converging series for:
In 1856 he obtains the Gaussian commemorative medal and in 1869 together with his colleague Ferdinand Minding honorary member of the St. Petersburg University. The otherwise very barren in praise Gauss had repeatedly valued the mathematical skills of Clausen.