Space, the cosmos and famous people...help????

Question

I have a science assignment where I have to fill out this table, with the name, year of birth/death, Year of Cosmological Understanding Reached,Description of Discovery (in 1 sentence), Technological development that made discovery possible and Change in cosmological thinking (1 to 3 sentences)

The people are:Aristotle,Nokolaus Copernicus (only one variation of name),William Herschel,Henrietta Leavitt,Fred Hoyle. I've found their birth and death dates, but I'm really stuck with the others....

Help?

Answer 1

Wikipedia might be a good start.