Amogh
Last Activity: 10 Years ago
Sound waves are mechanical waves. They propagate because of the movement of the particles of the medium through which they travel. As a matter of fact, the transmitted part of thee sound waves travell faster in solid media than in other media. Thus, when sound waves “hit” an interface of two media reflection, transmission and absorption of some energy of the sound wave occours. How much energy is absorbed, how much is transmitted and how much is reflected is dependent of the nature of the medium. Thus, sound does not travell though sound-proof materials because, there, most energy is either absorbed or reflected and very little is transmitted. And, sound can easily travell through normal doors because their property is such that significant amount of energy can be transmitted through it.
But, light is not a mechanical wave. Light is just an electromagnetic wave and thus, they do not need a medium for propogation as they don’t travell due to the oscillation of particles. At the interface of two media , here too, some energy of the light rays are absorbed, some energy is transmitted and some energy is reflected. How much energy is absorbed, how much is transmitted and how much is reflected is dependent of the nature of the medium. In this case, based on how much of the energy carried by the light wave is transmitted through the medium, we classify the medium as “opaque”, “transparent”, or “translucent”. Thus, if you have a glass door, light will travel through it. If you have a wooden door, the light wave will not.
Finally, we can tell that light can’t travell through wooden doors because, the nature of the material does not allow it. But, sound waves can travell through it because the nature of the material allows it to. What is it about wood that causes it to have this specific property? That can be known only on studying the internal structure of wood.
