A recent study on glass has found something astonishing – the movement of molecules within glass appears to be time-reversible, challenging our understanding of the second law of thermodynamics. This phenomenon suggests that the arrow of time, which always points forward in our experience, may not apply to certain materials.
In contrast to other physical laws, the second law of thermodynamics is unique in its directionality. It states that everything tends towards disorder, and entropy can only increase in an isolated system. However, researchers have discovered that glass and a few similar materials exhibit time-reversible fluctuations, making it difficult to determine whether they are moving forward or backward in time.
The study used the concept of “material time” to explore the physical aging of glass. This concept involves measuring time within materials based on how long it takes their molecules to rearrange themselves. The researchers employed a state-of-the-art camera and laser to monitor the movement of molecules in a sample of glass, finding that the fluctuations appear to be time-reversible.
While this discovery may raise questions about the reversibility of aging processes in these materials, the study’s authors emphasize that it does not mean the aging process can be reversed. Glass will still age, but the rate at which it ages is measured by its internal clock, or material time.
The findings of this study open up new avenues for research, including exploring whether other materials exhibit similar time-reversible fluctuations and how their internal clocks differ. The study has been published in the journal Nature Physics, and further investigation into these questions may lead to exciting and weird results.
Source: https://www.iflscience.com/times-arrow-within-glass-appears-to-go-in-both-directions-raising-huge-questions-75551