List of Famous people born on November 21st

Rudolf Paul Joachim Kochendörffer was a German mathematician who was a Professor of mathematics in the University of Rostock specialising in algebra, Group theory and theory of finite groups and their representation. During World War II, Kochendörffer worked as a mathematical cryptanalyst in the mathematical referat of Inspectorate 7/IV, that would later become part of Referat I of Group IV of the General der Nachrichtenaufklärung, the signals intelligence agency of the Wehrmacht and was known as a cryptographic tester of the Enigma cipher machine. Kochendörffer was a Member of the Scientific Advisory Council for Mathematics at the State Secretariat for the Higher and Specialist Schools of the GDR, a staff member of Mathematical Reviews and collaborated with the Zentralblatt MATH

Olena Ivanivna Kazymyrchak-Polonska was a Ukrainian astronomer and member of the International Astronomical Union, who studied the motion of comets and their orbital evolution. Asteroid 2006 Polonskaya was named in her honor.

Elizabeth George Speare was an American writer of children's books, best known for historical novels including two Newbery Medal winners. She has been called one of America's 100 most popular writers for children and some of her work has become mandatory reading in many schools throughout the nation. Indeed, because her books have sold so well she is also cited as one of the Educational Paperback Association's top 100 authors.