Recreated the work of Aristarchos of Samos (310–230 BCE), and touched public awareness this time. Died on publishing his work in 1543, so never met his critics. The publishing was simultaneous with Andreas Vesalius (1514–1564)'s massive update to anatomy.
Created calculus & we use his notation, not Newton's. Created distinction between fact-truth and logical truth.
"Everything we know about plants and animals shall be a science. I shall name it biology."
Military service. Accident? Quit. French Revolution -> King died. …
All living things share some attributes. Metal doesn't share anything with us. Living things change over time, grow and die.
Got a partial idea of evolution, said that if giraffes stretch their necks to reach leaves, they might lengthen their necks and pass that characteristic on to their children.
Of course, giraffes are also spotted in appearance, and the idea that giraffes actively tried to be spotty was a difficult one to swallow. Darwin would solve that.
Wrote The Art of Computer Programming (TAOCP), of which Bill Gates said "If you think you're a really good programmer… read Art of Computer Programming… You should definitely send me a resume if you can read the whole thing."