## shashawna 3 years ago A light-year is the time it takes light to reach Earth from any given star right?

1. Kainui

No, a light year is the distance that light travels in a year. So if you know the speed of something, could be light, but could also be a car; then you can multiply the speed by an amount of time and find the distance. Similar to the formula, d=rt. If your car goes 60 miles an hour, then if it travelled a year we could multiply that with the amount of hours in a year to find out how far the car would travel in a year if it only travelled in a straight line at 60 miles an hour. Similarly, we do the same with light, except that it goes nearly 300 million meters per second and we multiply that times the number of seconds in a year to find out how far light travels in a year. Then we use these to measure distances of us from everything else in the universe. That's how large the universe is! An interesting thing to know is that it takes 8 minutes for the light of the sun to reach us before we see it. So where ever you see the sun in the sky, that's really where it was 8 minutes ago! Similarly, stars far off could have died off long ago and the light we see could be from stars that don't exist anymore. That's why when you look at the night sky it's like looking into the distant past. Interesting huh?

2. shashawna

THATS AWESOME! lol sorry i feel like a geek for saying that lol thank you for your help i apprctiate it! :)