What is Light Year?
1.
1. The distance light travels in one year, or approximately 5.88 trillion miles.
2. A figure of speech meaning very advanced.
1. The nearest star is about 4 light years away, and our galaxy is about 100,000 light years across.
2. If alien's exist, chances are they're light years ahead of us in technology.
See
2.
1 Light Year = 9324744613632km
One light year is defined by travelling for 365 days at the constant speed of light, which is 299 792 458 m/s
where:
m = distance in metres
s = time in seconds
Proxima Centauri is 4.3 light-years from the Sun.