Overview

• A Jianghan University team led by Yu Xia recreated the phenomenon with a bubble generator and high-speed imaging in a peer-reviewed PNAS study.
• Charge builds on the curved gas–liquid surfaces of rising methane microbubbles, and interactions create opposite charges that discharge as brief microblitzes.
• These micro-sparks ignite methane without external heat, producing cool blue‑violet flames associated with lights over wetlands and graveyards.
• Ignition occurred only when many bubbles rose simultaneously and drew close, indicating the mechanism depends on high bubble density and proximity.
• Similar microdischarges appeared with air and air–hydrogen bubbles, pointing to a broader role for electrified interfaces in driving natural redox reactions.