so telescopes "see" planets and stars light years away, wouldnt take us the same time to see them? i mean because we need light to get the image of it
Answers (1)
Yes, and that is how the speed of light was first measured. A philosopher was using his newfangled telescope to look at the moons of Jupiter. He carefully recorded the time when a moon passed behind the planet and the time when it appeared on the other side. The times were not one half the orbit: the appearance was late. He realized that it was because of the speed of light, so he calculated the speed and he got it fairly close considering what crummy clocks they had in those days.