This is one of those questions which four year old's ask all the time. Also i would like to point out that there are plenty of other videos which address this question. However many of those fail to explain it in detail. This video covers many of those small details. I have been reading a lot about it. And while i was at it, many more questions came into picture, like why is the sun yellow, why are clouds white, why are oceans blue, etc. I have tried to cover up as much as possible in this video. I'll include all useful links below. -------------------------------------------------------------------------------------------- Collaboration - Untamed Science -------------------------------------------------------------------------------------------- This video is in collaboration with Untamed Science. Check out their channel at http://www.youtube.com/user/UntamedScience Special thanks to Rob and Haley. I hope you like the video. Rate, Comment and Subscribe if you would like to see more