As sunlight passes through the atmosphere, particles in the air scatter blue light more efficiently than any other color in the light spectrum, creating a blue sky. Learn more about the sky and light in this episode of BrainStuff. Whether the topic is popcorn or particle physics, you can count on the HowStuffWorks team to explore - and explain - the everyday science in the world around us on BrainStuff. Watch More BrainStuff on TestTube http://testtube.com/brainstuff Subscribe Now! http://www.youtube.com/subscription_center?add_user=brainstuffshow Watch More http://www.youtube.com/BrainStuffShow Twitter http://twitter.com/BrainStuffHSW Facebook http://facebook.com/BrainStuff Google+ http://gplus.to/BrainStuff