Hermann Oberth, the German father of rocketry, has a mixed legacy. On the one hand, he developed the V-2 rocket for Nazi Germany during World II. On the other hand, his ideas, rejected as implausible when he submitted them as part of his doctoral thesis, paved the way for the development of rocketry, and he later helped launch the United States into space.
Source:
https://www.space.com/20063-hermann-oberth.html
James Naismith was a Canadian physical education instructor who invented basketball in 1891. The first formal rules were devised in 1892. Initially, players dribbled a football ball up and down a court of unspecified
dimensions. Points were earned by landing the ball in a peach
basket. Iron hoops and a hammock-style basket were introduced in 1893. However,
another decade passed before the innovation of open-ended nets put an end to
the practice of manually retrieving the ball from the basket each time a goal
was scored. US Patent #1,718,305 was granted to G L Pierce on June 25, 1929 for
the "basketball" used in the game.
Sources:
https://www.smithsonianmag.com/sponsored/patents-behind-basketball-180971830/
https://www.robinage.com/sports/know-more-basketball.htm
