Does glass move over time? That’s the question tackled by a team of researchers at Texas Tech University, Lubbock, who say that glass remains in solid form, unless shattered, of course. The idea for this research came from a doctoral student's qualifying exam, said Gregory McKenna, a professor of chemical engineering. He gave Jing Zhao a problem relating to diverging time-scales using polyvinyl acetate, a substance often found in adhesives. Her results were consistent with a lack of divergence, which is contrary to popular thought.

So, to prove the point further, they decided to perform similar experiments on a much older, ultra-stable glass—20-million-year-old Dominican amber, performing calorimetric and stress relaxation experiments on the samples.

"Glass transition is related to the performance of materials, whether it is inorganic glass or organic polymers," said McKenna. "What we found is that the amber relaxation times did not diverge," McKenna said. "This result challenges all the classic theories of glass transition behavior."

This research is supported by the National Science Foundation under a grant from the Division of Materials Research, Polymers Program. The process and results were recently published in Nature Communications.

The team has recently acquired additional samples from around the world, including 220-million-year-old Triassic amber from Eugenio Ragazzi, a pharmacology professor at the University of Padova in Italy and plans to perform similar experiments on the new samples.

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