Somebody once told me that when you look into the night sky to view stars, you are actually looking at something that happened a long, long time ago (millions?, billions?, trillions of years ago?). I understand this has something to do with the speed of light and the distance of the stars from earth. I am familiar with c = 3*10^8m/s, and I'm sure with a bit of research I could find how far a star is from earth and do the basic math to find the time taken. I'm just wondering if the principles behind what I have been told are correct. Cheers!