Glasses of yesterday, today and tomorrow

Discovered seemingly by chance some 5,000 years ago, glass has continued to evolve, giving rise to increasingly sophisticated products. While some glass compositions seem to have evolved relatively little, the purity of the raw materials used and the care taken in glass manufacture have led to constant improvements, such as spectacular advances in transparency and in the mastery of glass coloring. Curiously, since ancient times, some tints have been due to nanometric aggregates formed within the glass during an annealing operation. We'll see where this coloring comes from and how it has been used over the centuries. However, the amorphous structure of glass, far more complex than that of a crystallized material, remains insufficiently understood by physicists. Only recently have the nano-cracks that cause glass to break been observed. The hope is to find new ways of making this hard but fragile material unbreakable. Today's glass products, increasingly used in the building and automotive industries, possess sophisticated properties that enable them to adapt to the challenges of energy savings, environmental protection and comfort. These properties are often due to complex multi-layers deposited on the glass surface. Although highly elaborate, these structures should not add prohibitively to the cost of finished products. Finally, a few examples of the most recent glass products or those under development were given.