Researched
Discovery of Neptune
Le Verrier calculates from Uranus's orbit where an unseen planet must be, and Galle finds Neptune there on 23 September 1846.
Open in the interactive tree →It was a triumph for Newtonian mechanics: a planet found with pen and paper first. It showed that unseen mass can be inferred from its gravity.
Prerequisites
- The telescope1608
- Newtonian Mechanics1687
Unlocks
- Evidence for Dark Matter1970Same logic as Neptune: unseen mass inferred from its pull on visible bodies