Study explains the mystery of ball lightning

Sightings of ball lightning have been made for centuries around the world – usually the size of a grapefruit and lasting up to twenty seconds – but no explanation of how it occurs has been universally accepted by science.

In a paper published in the Journal of Geophysical Research Atmospheres entitled 'The Birth of Ball Lightning' CSIRO and Australia National University scientists present a new mathematical theory which explains how and why it occurs.

Previous competing theories have cited microwave radiation from thunderclouds, oxidising aerosols, nuclear energy, dark matter, antimatter, and even black holes as possible causes.

Led by CSIRO scientist John Lowke, the new theory focuses on how ball lightning occurs in houses and aeroplanes – and how it can pass through glass. His theory also proposes that ball lightning is caused when leftover ions (electric energy), which are very dense, are swept to the ground following a lightning strike.

"A crucial proof of any theory of ball lightning would be if the theory could be used to make ball lightning. This is the first paper which gives a mathematical solution explaining the birth or initiation of ball lighting," says Lowke.

Lowke proposes that ball lightning occurs in houses and aeroplanes when a stream of ions accumulates on the outside of a glass window and the resulting electric field on the other side excites air molecules to form a ball discharge. The discharge requires a driving electric field of about a million volts.