Challenge of ball lightning

Ball lightning and fireballs

As elusive natural phenomenon, ball lightning has puzzled physicists for two centuries. Usually  these luminous spheres suddenly appear during thunderstorms after lightning impact. The ball in the left photo above is a case in point. Over the years numerous eyewitness reports collected in data banks have fostered global consensus on ball lightning statistics. Man-made fireballs resembling ball lightning occurred on board of submarines upon interruption of accidental short-circuit currents from their propulsion battery.

A plasma sphere floating in air

A ball lightning is an independent plasma sphere of about 15 cm diameter with density similar to surrounding air. It floats in the air and can bounce on the ground. Most striking is the average  lifetime of several seconds at constant size and brightness. Some well-documented events lived longer than one minute, ionised ambient air and released energy at calorimetric levels.

Close encounters with scientists

Close encounters of ball lightning with two scientists add unique and puzzling details. The airliner event observed by English radio astronomer R. Jennison combined perfect spherical shape with absence of heat radiation. The outdoor event observed by Russian plasma chemist M. Dimitriev combined exceptional duration with coloured double halos and ionising radiation output. Clearly, self-confinement, long lifetime and energetic output of ball lightning violate basic laws of classical physics. So far, no test facility could reproduce these observed properties of ball lightning.