Tiny Engine Heats Particle to Solar Temperatures, Challenging Thermodynamics limits
Scientists have created a microscopic engine capable of heating a single particle to 13 million Kelvin – hotter than the surface of the sun – while maintaining a drastically cooler surrounding environment. The experiment, detailed in Physical Review Letters, allows researchers to probe the fundamental limits of thermodynamics at a scale previously unattainable, revealing how the laws of physics behave when pushed to extremes.
The engine, built using an electrically controlled trap and applied “noise” to simulate heat, operates on principles similar to a Stirling engine, but with vastly different temperature gradients. While a conventional Stirling engine relies on a temperature difference to generate work, this microscopic setup achieves a contrast impossible to replicate at larger scales: the particle itself reached 13 million K, while the surrounding environment remained roughly 100 times cooler.
This extreme disparity doesn’t violate the laws of physics, researchers explain, because the second law of thermodynamics – which dictates that entropy always increases – applies to averages at the microscopic level. Brief, localized fluctuations can appear to defy the law, such as instances where the particle briefly exhibited an efficiency rate exceeding 100 percent, but thes are temporary and resolve when averaged over time.
The team cycled the system through expansion and contraction phases, observing significant fluctuations in heat exchange over 700 to 1,400 cycles.Crucially, the particle’s movement wasn’t random; it exhibited ”position-dependent diffusion,” meaning its motion varied based on its location within the trap, influenced by the changing temperature and consistency of the surrounding medium.
This phenomenon has implications for understanding complex biological systems, where particles interact with cellular structures like membranes and tissues. Researchers suggest the setup could be used to investigate processes like drug transport within the body.
The team plans to further explore the system’s behavior by pushing it even further from equilibrium, aiming to unravel the unusual physics governing motion and energy at the smallest scales.
