Ball lightning has remained one of the most elusive and enigmatic natural phenomena to ever perplex physicists.
Until very recently, physicists have tended to be very skeptical about whether or not ball lightning even occurs despite thousands of eyewitness accounts. The problem lies with the wide variety of behaviors associated with the phenomena which makes pinning down a specific cause difficult.
According to reports, ball lightning usually occurs during thunderstorms, but can also occur when the weather is completely clear and calm. It can range in size from a few centimeters to many meters. It can be spherical or misshapen. It can hover, roll along surfaces, bounce against surfaces, or pass through them. It doesn't radiate heat, but generally burns whatever it passes through. Natural ball lightning usually lasts more than a few seconds, far longer than more common forms of lightning. It can disappear with a bang, dissipate, or be absorbed into an object. It has been known to interact benignly with people, but has also caused burn injuries, and possibly even death. It is best to stay far from it! The smell of ozone is usually associated with ball lightning.
The relative rarity of the phenomena makes it nearly impossible to reproduce in the lab. However a handful of scientist have been able to make what could be ball lightning under controlled conditions. Generally though these instance last for a few milliseconds and are much smaller than naturally occurring ball lightning. Hobbyists have also attempted to recreate it but the evidence is anecdotal and poorly documented. The most common method for replicating ball lightning involves the use of a common microwave magnetron, and a fuel material such as carbon fiber, steel wool, or ceramic embedded with metals. These experiments do not replicate the full range of behavior associated with ball lightning, especially their sometimes minutes-long persistence, and may not be the same phenomena as naturally occurring ball lightning.
The current leading theory is that the ball is a cloud of plasma burning from silica dust or other naturally occurring particulate matter. However, plasma is very hot and tends to rise in the air like a hot air balloon, while natural ball lightning is cool and doesn't automatically rise. This phenomena will likely remain unexplained in the near future.
