Anders Johan Lexell Johan Stén (2015): A Comet of the Enlightenment. Anders Johan Lexell's Life and Discoveries. Basel: Birkhäuser. Anders Johan Lexell Anders Johan Lexell (24 December 1740 – ) was a Finnish-Swedish astronomer, mathematician, and physicist who spent most of his life in Imperial Russia, where he was known as Andrei Ivanovich Leksel (Андрей Иванович Лексель). Lexell made important discoveries in polygonometry and celestial mechanics; the latter led to a comet named in his honour. La Grande Encyclopédie states that he was the prominent mathematician of his time who contributed to spherical trigonometry with new and interesting solutions, which he took as
Nationality Nationality Nationality is a legal relationship between an individual person and a state. Nationality affords the state jurisdiction over the person and affords the person the protection of the state. What these rights and duties are varies from state to state. By custom and international conventions, it is the right of each state to determine who its nationals are. Such determinations are part of nationality law. In some cases, determinations of nationality are also governed by public international law—for example, by treaties on statelessness and the European Convention on Nationality. Nationality differs technically and legally from citizenship, which is a