Well, probably the most obvious point is that it’s easier to read and write “light years” continuously, than writing a number with at least twelve zeros all the time. An example of this is the following: the nearest galaxy to the Milky Way is called the Andromeda Galaxy. It is just over two and a half million light years away, which means that the light we see from there is just over two and a half million years old because this is the distance between us and the Andromeda Galaxy. Now imagine those numbers written out. Wait, don’t even attempt it, I’ll write them for you. The nearest galaxy to our Milky Way is the Andromeda Galaxy. It is just over 14,500,000,000,000,000,000 miles or 233,354,880,000,000,000,000,000,000 kilometers away. I’m not even going to continue writing because my fingers are so tired from writing those amazing twenty digits (a digit is a single number from one to nine). Now you know why we use light years, but you don’t exactly know what they are. For starters, let’s take a lamp. When you flick that lamp on, you could think that it the light it gives off just appears, right? In reality, light travels, all the time, and everywhere at the same speed. This
Well, probably the most obvious point is that it’s easier to read and write “light years” continuously, than writing a number with at least twelve zeros all the time. An example of this is the following: the nearest galaxy to the Milky Way is called the Andromeda Galaxy. It is just over two and a half million light years away, which means that the light we see from there is just over two and a half million years old because this is the distance between us and the Andromeda Galaxy. Now imagine those numbers written out. Wait, don’t even attempt it, I’ll write them for you. The nearest galaxy to our Milky Way is the Andromeda Galaxy. It is just over 14,500,000,000,000,000,000 miles or 233,354,880,000,000,000,000,000,000 kilometers away. I’m not even going to continue writing because my fingers are so tired from writing those amazing twenty digits (a digit is a single number from one to nine). Now you know why we use light years, but you don’t exactly know what they are. For starters, let’s take a lamp. When you flick that lamp on, you could think that it the light it gives off just appears, right? In reality, light travels, all the time, and everywhere at the same speed. This