Why is glass see-through?

Glass is an everyday part of our lives and we take its positive attributes for granted, but have you ever stopped to think about what it is which makes glass so different from other materials?

We have glass all over our homes, in our windows, shower cubicles, wine glasses and even the glasses we wear on our faces to improve our sight. Light passes through all these things to cast light into homes and allow us to view container contents.

So what is it that makes glass so special? Technically it is a solid, though it is sometimes referred to as a viscous liquid. In fact, it is an amorphous solid, but one with very different properties and composition than other building materials such as metal and wood. The cooling temperature of glass is such that the molecules within it move so slowly that at room temperature it would take forever to settle.

That’s why in the production of glass there are high temperatures as it’s shaped but the cooling process is extremely rapid – often referred to as quenching – this puts the liquid form glass into a solid once again but with the molecules so spread out that light can pass through it.

Light photons are what help us see the world around us; typically they react in three ways when they hit a physical object. They absorb, reflect or transmit. When photons reflect it’s because the molecules in the object are too close together (a solid), this then allows us to see this object as the light bounces into our eyes. When the particles hit an object and absorb it is effectively heating that object (explaining why some objects are warm to the touch in sunlight). Finally, if an object has too few molecules spread apart then the photons will transmit through the object. When light hits glass this is what happens, not 100% but more is transmitted than absorbed or reflected, and it is this which makes the glass see-through.

By adding texture or design to glass we make it more visible because the small fraction of photons which are reflected will be reflected in different directions. On the whole, an amorphous solid shares attributes of both liquids, where light passes through allowing us to see beyond it, as well as solids where we cannot pass an object through and can actually put our hands firmly on it.

There will no doubt be more scientific explanations of the process but for the purposes of a basic understanding these are the principles and key terms which you need to know about glass.

Here at Bridgewater Glass we provide the highest quality glass for all purposes including double glazing and for conservatories. To find out more about our products and to discuss how they can enhance your home or commercial premises then get in touch with us today.