Happy birthday to American #astronomer Henrietta Swan Leavitt (1868-1921) who set the scale of our Universe. 🐡🧪🔭👩🏻🔬#histsci In her day, women scientists were regularly hired to do menial chores. She was hired to count images on photographic plates as a "computer". In studying these plates, in 1908 🧵1/
