HERE’S THE BACKGROUND — Polystyrene is an especially ubiquitous polymer that’s best known as the key ingredient in styrofoam. Aside from its light, airy incarnation in fast food containers ...

Polystyrene has a glass transition temperature ... "We hypothesized that it's due to a density effect," Curro said. "In an unconfined bulk liquid, the density is constant throughout the sample.

The sheets of plastic you get in a Shrinky Dinks kit is polystyrene—the same stuff ... being used in the manufacture of solar cells, high-density displays and chemical sensors.