The title pretty much says everything; I just want to know how the speed of light was discovered.
- This question does not appear to be about physics within the scope defined in the help center.
In 1672 a Danish astronomer was the first who reportedly measured the speed of light by noticing that one of Jupiter's moons would emerge from its eclipse 11 minutes early or late depending on the time of year when the earth was closer or further away from Jupiter. His name was Olaf Romer.
Read about him here