"We're trying to give some guidance on why this works and how it can be improved — that's the long term goal," said Voigtmann. "What we're trying to do is give a theoretical physics explanation for empirical laws."
To formulate this explanation, the scientists used both theoretical physics and experimentation. Molecular interactions are particularly difficult to observe because they occur on such a small scale. Instead of zooming in to the molecular level, the researchers took advantage of a glass substitute: colloids. A colloid is a type of substance with particles suspended in a solution. The common colloid paint, for example, consists of solid pigments floating in liquid.
"These colloids act like atoms," explained Voigtmann. "It's a model system that in many respects behaves like window glass, but it's on a blown-up scale: colloids are big enough to watch under a microscope."
The researchers put colloids under stress and then observed their behavior through a microscope. This led them to develop a physical theory that describes why forces in molten glass remain locked in the material.
Although this theory accurately models the behaviors that the researchers observed during experiments, the understanding of glass remains a "hotly debated" topic, said Voigtmann.