Ball lightning

Still open in the literature as of 2026.

Reports of glowing, floating balls of light associated with thunderstorms date back centuries, but ball lightning has always been rare, unpredictable, and hard to study under controlled conditions. Numerous theoretical models have been proposed over the past century - vaporized-silicon combustion, trapped microwave radiation, plasma or soliton constructs - and laboratory experiments have produced short-lived glowing balls resembling some reports, but none has been confirmed as the actual natural mechanism. A rare 2014 event in which Chinese researchers on the Tibetan Plateau incidentally recorded the optical spectrum of a natural ball lightning occurrence during a lightning survey provided the first direct spectroscopic data, consistent with vaporized soil elements, but this remains a single data point, and ball lightning is still considered a genuinely open problem in atmospheric physics.

Centuries of eyewitnesses, from farmers to airline pilots, describe the same eerie glowing sphere drifting through storms, yet physics still cannot say with confidence what it actually is.

Explanations that circulated

• Ball lightning is sometimes dismissed as pure optical illusion or misperception of ordinary lightning afterimages; some instrumented observations, including a 2014 spectroscopic recording during a natural thunderstorm, show real luminous phenomena consistent with eyewitness descriptions, so a blanket 'it's not real' explanation is not well supported.
• Various single-mechanism theories (vaporized silicon nanoparticles burning in air, trapped microwave-cavity plasma, electromagnetic solitons, 'Rydberg matter' clusters) have each been proposed as the explanation, but none has been experimentally confirmed to reproduce the full range of reported properties, so treating any one as settled is premature.

References

• Field observations support ball lightning theory, Physics Today staff, summarizing Chinese Tibetan-Plateau spectroscopic observation, Physics Today, 2014