Why is glass see through?

Answer 1

http://www.straightdope.com/classics/a1_120.html

Answer 2

I just want to add some extra details along the line of the main points.

Every time light travels from one medium to another with a different refractive index, some will be reflected and some will be bent. I think this explains why crushed glass is not transparent (compared to a single block). I think this refraction is wavelength-dependent too, but I'm not sure.

The transparency of a substance depends on the wavelength of the radiation passing through the substance. Light will be absorbed if there is some molecular/electronic state transition with an energy change on the same order as the energy of the radiation. For example, an electron could rise to a higher level and fall (this is how fluorescent lighting works...and why the light produced has discrete frequencies). Another example with less energy is the state of molecular vibration, which has energy states on the order of infrared (much less energetic).

This means that in glass (which is amorphous silicon dioxide--it doesn't have a regular lattice) doesn't have an effective electronic transition to absorb light. On the other hand, it does not pass infrared radiation because it has many vibrational states to switch among.

This is why the interior of your car gets so hot when it is left in the sun. Solar radiation (strongest in the visible light region) passes through the glass (which doesn't absorb light) and heats up the interior of the car. The warmed interior radiates IR radiation back but it is blocked by the glass, making the interior warmer. This is the greenhouse effect (for actual greenhouses, the atmospheric greenhouse effect is different).

Answer 3

As a general rule, transparent substances are electrical insulators and reflective substances are conductors. So glass, an insulator, is transparent and metals are shiny. This is because when an electromagnetic wave like light or a radio wave strikes a conductor it makes the free electrons oscillate and they re-radiate the electromagnetic field back. In glass, the electrons aren't free to move so this doesn't happen. If the glass is crushed it reflects light in all directions so you can't see through it.Tinted transparent substances like brown glass? Their electrons oscillate at some frequencies but not others, so they block some colours but not others.

Answer 4

Transparency and opaqueness depend on the order of the molecular arrangements which determines if the light rays can get through. The transparency is due to the high order of silicon dioxide molecules in glass. If you will fill in your ice trays with hot water and place in freezer the ice cubes will be clear, if not totally transparent for same reason: H2O molecules are arranged in higher order when at temperature drops drastically. The order allows light to pass through the substance. Opaque substances are those in which molecule are in random disorder and the light cannot get through.

Answer 5

Glass is not totally transparent. It has reflective properties as well but mostly light waves actually slow down through the medium of glass. It slow down even in air. Glass is made of silicon molecules and is less dense than other media. Sand or silica is melted and you get glass. Then you get less densely packed molecules and it allows light waves to travel through. Water and liquids are less dense than solids and those liquids allow light waves to pass through.

Answer 6

because when the mixture for glass is heated the matter changes state and becomes se through

Answer 7

Glass is mostly silicon dioxide. It is made by melting the crystalline solid and what results is an almost colorless. transparent material.

Answer 8

It only absorbs 11% of light, and passes the rest. It is actually a very viscous liquid.

Answer 9

Why u can see an object ??.......... becoz light incident on object and some part of it get absorbed. and some gets reflected............ and reflected light banged on our eye.......... thats why we can see an object.

But in case of glass the most of the light is get refracted .... and almost none part of light banged on eyes.......... thats why it is almost impossible to see an glass.....