Time is one of the most fundamental concepts in physics, but also one of the most mysterious. We experience time as a one-way flow, from past to future, but is this always the case? A new study by German physicists suggests that some materials, such as glass and plastic, have an internal clock that can reverse time under certain circumstances.
The Experiment
The study, published in Nature Physics, was conducted by Till Böhmer and Thomas Blochowicz at the Institute for Condensed Matter Physics at the Technical University of Darmstadt. They used a novel technique to measure the molecular movements in glass and plastic, which are composed of tangled molecules that constantly rearrange themselves in search of a lower energy state. This process, known as aging, changes the material’s properties over time.
The researchers shone a laser beam on a glass sample and recorded the scattered light with an ultra-sensitive video camera. The scattered light created a chaotic pattern of light and dark spots on the camera’s sensor, which reflected the molecular fluctuations in the material. By using statistical methods, the researchers calculated how these fluctuations varied over time, effectively measuring the pace at which the material’s internal clock ticked.
The Discovery
The surprising finding was that, within the scope of material time, the molecular fluctuations were time-reversible. This means that if the material time was allowed to run backwards, the fluctuations would look exactly the same as if they ran forwards. This is analogous to a pendulum that swings back and forth in a video played in either direction.
This discovery challenges the common perception of time as an irreversible arrow, dictated by the second law of thermodynamics, which states that disorder in a system tends to increase over time. For example, a broken cup does not spontaneously reassemble itself. However, the researchers found that this law does not apply uniformly to all systems, especially those that are disordered, such as glass and plastic.
The Implications
The study has profound implications for our understanding of time and its relation to matter. It suggests that time is not a universal property of nature, but rather a relative and emergent phenomenon that depends on the perspective and scale of observation. It also opens up new possibilities for materials that could heal themselves or store information in a fundamentally new way.
The researchers stress that their findings are just the beginning of a new field of inquiry. They plan to investigate further how the internal clock differs for different materials and under what conditions it can be reversed or manipulated. They also hope to explore the connection between material time and quantum mechanics, which could reveal deeper insights into the nature of reality.
Conclusion
Time travel may not be possible for humans, but it seems to be possible for some materials. A new study by German physicists reveals that glass and plastic have an internal clock that can reverse time under certain conditions. This discovery challenges our understanding of time as a one-way street and opens up new avenues for research and innovation.