Unveiling ignis fatuus: Microlightning between microbubbles

作者：Yu Xia, Yifan Meng, Jianbo Shi, Richard N. Zare · 发表于：Proceedings of the National Academy of Sciences · 年份：2025 · DOI：10.1073/pnas.2521255122 · 被引用次数：7 · 研究领域：Nonlinear Dynamics and Pattern Formation、Mechanical and Optical Resonators、Electrohydrodynamics and Fluid Dynamics

Will-o'-the-wisps, ghostly blue flames seen at night in marshlands and long attributed to methane cool flames, have remained scientifically unexplained, a mystery caused by the lack of a known ignition mechanism. Here, we demonstrate that spontaneous electrical discharges, termed "microlightning", can occur between rising methane-containing microbubbles in water. High-speed optical imaging reveals brief flashes between charged bubbles, arising from strong electric fields at curved gas-liquid interfaces. These discharges initiate nonthermal oxidation of methane, producing luminescence and measurable heat under ambient conditions. Our findings offer a scientific basis for ignis fatuus and reveal a general mechanism by which electrified interfaces can drive redox reactions in natural environments without the need for external ignition sources.