https://en.m.wikipedia.org/wiki/Pierre-Simon_Laplace https://en.m.wikipedia.org/wiki/Pierre-Simon_Laplace According to his great-great-grandson,[4] d'Alembert

https://en.m.wikipedia.org/wiki/Pierre-Simon_Laplace https://en.m.wikipedia.org/wiki/Pierre-Simon_Laplace According to his great-great-grandson,[4] d'Alembert received him rather poorly, and to get rid of him gave him a thick mathematics book, saying to come back when he had read it. When Laplace came back a few days later, d'Alembert was even less friendly and did not hide his opinion that it was impossible that Laplace could have read and understood the book. But upon questioning him, he realised that it was true, and from that time he took Laplace under his care. Another account is that Laplace solved overnight a problem that d'Alembert set him for submission the following week, then solved a harder problem the following night. D'Alembert was impressed and recommended him for a teaching place in the École Militaire.[8] With a secure income and undemanding teaching, Laplace now threw himself into original research and for the next seventeen years, 1771–1787, he produced much of his original work in astronomy.[9]