Glass windows are as solid as the materials that surround them, yet they let light through. Learn the physics of why glass can be so transparent -- and why it took humans thousands of years to create totally clear glass -- in this episode of BrainStuff, based on this article: https://science.howstuffworks.com/question404.htm

How Did Weasels Get a Bad Rap?
15:37

How Did Napoleon I, the Emperor of the French, Rise and Fall?
15:08

BrainStuff Classics: How Did Alchemy Create Chemistry?
07:11