sound increases try through land & sound top try through a plastic door ->  light rays pass through air and a glass window  plastic is a mean of spiritual & a door is made of plastic ->  a glass in a glass window is a kind of material  a glass in a glass window is a kind of material & land is a mean of spiritual ->  air and a glass in a glass window are kinds of material  light rays pass through air and a glass window & air and a glass in a glass window are kinds of material ->  light rays passes from the material air through the material glass when it pass through a glass window  large is made of a mean of spiritual & mass is when sound liters from zero large to another large ->  refraction is when light passes from one material to another material  light rays passes from the material air through the material glass when it pass through a glass window & refraction is when light passes from one material to another material -> the light rays will refract when they pass through a glass window