Template:Selected anniversaries/September 17
1743: Philosopher, mathematician, and early political scientist Marie Jean Antoine Nicolas de Caritat, Marquis of Condorcet born. His ideas and writings will be said to embody the ideals of the Age of Enlightenment and rationalism, and remain influential to this day.
1826: Mathematician and academic Bernhard Riemann born. He will make contributions to analysis, number theory, and differential geometry.
1857: Scientist and engineer Konstantin Tsiolkovsky born. He will be one of the founding fathers of modern rocketry and astronautics.
1877: Scientist, inventor, and photography pioneer William Henry Fox Talbot dies. Talbot invented the salted paper and calotype processes, precursors to photographic processes of the later 19th and 20th centuries. His work, in the 1840s on photomechanical reproduction, led to the creation of the photoglyphic engraving process, the precursor to photogravure.
1994: Philosopher and academic Karl Popper dies. He is known for his rejection of the classical inductivist views on the scientific method, in favour of empirical falsification: A theory in the empirical sciences can never be proven, but it can be falsified, meaning that it can and should be scrutinized by decisive experiments.
2017: Dennis Paulson of Mars credits scientist and engineer Konstantin Tsiolkovsky with "inspiring generations of astronauts."