The explanation from Brian Greene's "The Fabric of Cosmos" is by far the easiest to understand.
It's all about relativity. The faster you move, the slower time goes by in relation to everything else. If you were to move at almost the speed of light, seconds would pass by for you while millions, even billions of years pass by on earth. At exactly the speed of light, time simply stops. That's why light doesn't age.
Also, Light always moves at 300,000km/second in relation to any object. If you were to move at exactly the speed of light, light would still appear to move 300,000km/second in relation to you.
I hope I got this all correct. It's been more than 2 years since I read that explanation from Greene's book, but I've thought about it a lot.
It's all about relativity. The faster you move, the slower time goes by in relation to everything else. If you were to move at almost the speed of light, seconds would pass by for you while millions, even billions of years pass by on earth. At exactly the speed of light, time simply stops. That's why light doesn't age.
Also, Light always moves at 300,000km/second in relation to any object. If you were to move at exactly the speed of light, light would still appear to move 300,000km/second in relation to you.
I hope I got this all correct. It's been more than 2 years since I read that explanation from Greene's book, but I've thought about it a lot.