Despite being known for millennia, glass continues to be a cutting-edge material and has yet to reveal all its secrets. If we are to understand every aspect of the unusual material we call glass, we need to take a much closer look and examine its atomic structure. All types of glass show a disordered arrangement of atoms, similar to what you would expect from a liquid. This ‘disordered’ or more properly ‘amorphous’ state (as opposed to a ‘crystalline’ state) becomes fixed when the material cools rapidly, and bestows upon glass its numerous properties.