>The nearest star to Earth besides the Sun (Proxima CentauriAlpha Cen C) is 4.3 light-years away. So, traveling at the speed of light, it would take about 4 years and 2 months to get there.

I just had to butt in here... Technically, if we were traveling at the speed of light, it would take absolutely no time to get there, thanks to relativity. At least, I *think* that's what would happen... Length contracts with velocity according to Lo*sqrt(1-v^2/c^2), so at the speed of light, the distance between any two places would reach zero. And, it takes no time to travel zero distance. But, from the point of view of a person on earth, it'd take 4.3 years.