Anders Lindstedt meetings of the Swedish Actuarial Society until shortly before his death in 1939. Anders Lindstedt Anders Lindstedt (27 June 1854 – 16 May 1939) was a Swedish mathematician, astronomer, and actuarial scientist, known for the Lindstedt-Poincaré method. Lindstedt was born in a small village in the district of Sundborns, Dalecarlia a province in central Sweden. He obtained a PhD from the University of Lund aged 32 and was subsequently appointed as a lecturer in astronomy. He later went on to a position at the University of Dorpat (then belonging to Russia, now University of Tartu in Estonia) where he worked
Stephen Alexander (astronomer) Stephen Alexander (astronomer) Stephen Alexander (September 1, 1806 – June 25, 1883) was a noted astronomer and educator. He was born in Schenectady, New York. He was the brother-in-law of Joseph Henry, the first secretary of the Smithsonian, and worked closely with him. He graduated from Union College in 1824. He became a tutor in mathematics at Princeton University in 1832; he would later become professor of astronomy and mathematics and advocate for the construction of Princeton's first observatory. Alexander relied on the assistance of a free African American man named Alfred Scudder, who worked for him at Princeton during