Researchers at the CUNY Graduate Center Initiative for the Theoretical Sciences conducted a study on the mystery of the arrow of time (also known as the flow of time). The arrow of time arises from the microscopic interactions among particles and cells, but little is known about the dynamics of this process. Time moving from past to future is a central feature of how humans experience the world. The study published in Physical Review Letters shows how they deconstructed the arrow of time to better understand it.
The arrow of time arises from the second law of thermodynamics. This is the principle that microscopic arrangements of physical systems tend to increase in randomness, moving from order to disorder. The more disordered things become, the more difficult it is to return to order and the arrow of time intensifies. Scientists explain that we experience time flowing in one direction due to the universe’s tendency toward disorder.
The research team illustrated decomposition on simple models of logical computations. They then applied it to the analysis of patterns of neural activity in the retina as it responds to complex dynamic visual scenes. Lead author Dr. Christopher Lynn explained the investigation: “The two questions our team had were, if we looked at a particular system, would we be able to quantify the strength of its arrow of time, and would we be able to sort out how it emerges from the micro scale, where cells and neurons interact, to the whole system?” Lynn believes the findings contribute to a better understanding of how the arrow of time influences daily life experiences impacted by microscopic activity.
The researchers showed that the arrow of time can be broken down into different pieces: those produced by parts working individually, in pairs, in triplets or in more complicated configurations. They analyzed existing experiments on the neural responses in a salamander retina to different movies. One movie portrayed a single object moved across the screen randomly. Another movie showed complex scenes found in nature. The arrow of time emerged from the simple interactions between pairs of neurons rather than large groups. The researchers also found that the retina showed a stronger arrow of time when watching random motion than a natural scene.
The study’s findings could have implications for research in the disciplines of physics, neuroscience, and biology.
Sources: CUNY Graduate Center Initiative for the Theoretical Sciences, Eureka News Alert, Physical Review Letters
