New Insights Into Time in Quantum Systems
A study from the University of Birmingham, published in Physical Review Research, suggests that time might arise from internal processes within a quantum system rather than being an external dimension. Professor Giovanni Barontini demonstrated that the passage of time can be tracked without using any clocks at all. This finding challenges long-held assumptions about what time really is and how it operates.
Experiment and Key Results
For the experiment, Barontini created an isolated quantum system from a cloud of 24,000 rubidium atoms, cooled to just a few billionths of a degree above absolute zero. Laser traps held the atoms in place, while two beams of different frequencies split the cloud into a visible (bright) zone and a hidden (dark) zone. Over time, the bright region periodically contracted and expanded, driven by entropy—a measure of disorder within the system.
The quantum trap remained completely sealed off from the outside world, allowing atoms to migrate freely between the bright and dark areas. Once the atomic distribution became static, local time stopped. Barontini called this phenomenon "entropic time." He stated that
“our research provides the first controlled experimental evidence that time can be defined by changes within the system itself, rather than by an external ticking clock.”He also emphasized that in some theories, especially quantum gravity, time is not considered a fundamental parameter.
The professor further noted:
“Yet in everyday life, we clearly see time flowing from the past to the future.”He posed the question: “Why does this happen when most fundamental laws of physics work equally well forward and backward in time?”
The study reveals that time may not be strictly linear; it can speed up or slow down depending on how entropy redistributes inside the system. This offers a fresh perspective on the nature of time in quantum gravity, which, according to Barontini, “forms a clear arrow of time” that “consistently orders events even in a constantly pulsing system.”
These findings carry potential implications for understanding fundamental physics and the philosophy of time. If time can indeed be defined through internal changes in quantum systems, it could inspire new theories that bridge quantum mechanics and gravity. Studying entropy and its link to time may also open new avenues in thermodynamics and information technology.
This groundbreaking research opens up intriguing questions about the nature of time in quantum systems. For instance, another recent study has shown that photons can exhibit negative time, further challenging our conventional understanding of temporal flow. Exploring these phenomena may provide deeper insights into the fundamental principles governing time and reality.