Not everyone found the theory satisfying. Dr. Wolynes and his collaborators so insisted they were right that “you had the impression they were trying to sell you an old car,” said Jean-Philippe Bouchaud of the Atomic Energy Commission in France. “I think Peter is not the best advocate of his own ideas. He tends to oversell his own theory.”

Around that time, the first hints of the dichotomy of fast-moving and slow-moving regions in a solidifying glass were seen in experiments, and computer simulations predicted that this pattern, called dynamical heterogeneity, should exist.

Dr. Weitz of Harvard had been working for a couple of decades with colloids, or suspensions of plastic spheres in liquids, and he thought he could use them to study the glass transition. As the liquid is squeezed out, the colloid particles undergo the same change as a cooling glass. With the colloids, Dr. Weitz could photograph the movements of each particle in a colloidal glass and show that some chunks of particles moved quickly while most hardly moved.

“You can see them,” Dr. Weitz said. “You can see them so clearly.”

The new findings did not faze Dr. Wolynes. Around 2000, he returned to the glass problem, convinced that with techniques he had used in solving protein folding problems, he could fill in some of the computational gaps in his glass theory. Among the calculations, he found that dynamical heterogeneity was a natural consequence of the theory.

Dr. Bouchaud and a colleague, Giulio Biroli, revisited Dr. Wolynes’s theory, translating it into terms they could more easily understand and coming up with predictions that could be compared with experiments. “For a long time, I didn’t really believe in the whole story, but with time I became more and more convinced there is something very deep in the theory,” Dr. Bouchaud said. “I think these people had fantastic intuition about how the whole problem should be attacked.”

For Dr. Garrahan, the University of Nottingham scientist, and Dr. Chandler, the Berkeley scientist, the contrast between fast- and slow-moving regions was so striking compared with the other changes near the transition, they focused on these dynamics. They said that the fundamental process in the glass transition was a phase transition in the trajectories, from flowing to jammed, rather than a change in structure seen in most phase transitions. “You don’t see anything interesting in the structure of these glass formers, unless you look at space and time,” Dr. Garrahan said.

They ignore the more subtle effects related to the impossible-to-reach ideal glass state. “If I can never get there, these are metaphysical temperatures,” Dr. Chandler said.