A
phenomemon which occurs near the ground during
thunderstorms, manifesting itself as a small, flying, luminous
sphere several inches in diameter. Ball lightning is usually red, orange, or yellow, and is frequently accompanied by a
hissing noise and distinct
odor. It occurs most frequently
outdoors, although it can also occur in enclosed spaces such as a house or
airplane cabin. Ball lightning usually lasts about five seconds, after which it either suddenly
explodes or silently disappears.
In about one quarter of observed cases, ball lightning has caused minor damage, including injury to people. In other cases, the sphere passes through objects (such as doors) without causing damage. The cause of ball lightning and its relation to common lightning are unknown. Some scientists feel that synthetic ball lightning could be harnessed as a source of power.
Possible causes? Air or gas behaving abnormally; high-density plasma; an air vortex containing luminous gases; and microwave radiation within a plasma shell.
Also known as globe lightning.