Have you ever wondered how light waves work? No, I mean really. How do they travel? Well, here's some food for thought. It's imperative to our survival that light travels where there is nothing, not even air. Why? What's the biggest vacuum you can think of? The one in the closet? The one called your siblings room, where things enter and never leave? Wrong! Here's a hint: the largest vacuum is a big space! That's right, it's space! And guess what? If light didn't travel there, we'd all be dead! And if you don't believe me, think of how many things need light to survive and grow.
How does light move, you ask? Well, do you want the short or long answer? I'll give you the short. Light waves always move in straight lines. Have you ever been to Saskatchewan? I've been a couple times. If you have you'll have noticed that the place is so flat you can see the curvature of the earth. If you don't believe me then find out if you know anyone in Saskatchewan and get your parents to take you. Preferably driving. That way you'll see the highway, and that's one of the best places to veiw the curvature of the earth. Anyway, you can see things for miles because the light travels in a straight line.
Light always travels in a straight line. Imagine if it didn't! You wouldn't be able to see anything in front of you! That could get a little painful! :)