This is how the speed of light was calculated.

Actually it has nothing to do with the distance the Earth is from Jupiter, it is an effect of whether the earth is getting closer or farther away from Jupiter during the occlusion of Io.

This explanation can’t possibly be correct because the light from Io as it went behind Jupiter would also be delayed a varying amount of time because of the varying distance. The fellow who said it’s down to the earth moving closer or further during the occlusion seems better

Interesting, didn’t thought that it was first calculated this way

Space folk will eat anything

That's really cool

It’s fukin’ chewsday innit?

Go into a dark room. Flick the light switch on. Time how long it takes the light to hit your eyes after flicking the switch. Divide distance between you and bulb by the time taken and you have the speed of light.