Ball lightning is an extremely rare and poorly understood atmospheric phenomenon that accompanies electrical storms. It manifests as a glowing ball about the size of a basketball, but sometimes as small as a golf ball or as large as a small car. It hovers in the air somewhere between a few seconds and a couple minutes, with an average of 25 seconds, then disappears either silently or with a loud bang. Some scientists have studied ball lightning for upwards of 20 years and are still uncertain that it actually exists.

The phenomenon of ball lightning is so infrequent that not a single scientifically confirmed video of it even exists, though most scientists accept its existence because reports of it extend all the way back to Ancient Greece. Also supportive is that a majority of the reports that we do have tell a rather consistent tale, instead of being all over the place as we would expect if ball lightning were merely a misidentification of more common atmospheric phenomena. When details vary too widely from the most common reports, it is likely a misidentification, wishful thinking, or fraud. It is plausible that so-called ball lightning is merely an positive afterimage left on the eye in the wake of a lightning flash.

A newspaper in 1960 conducted an informal poll and found that 5% of respondents claimed to have witnessed ball lightning, though the true figure is probably much lower. If 5% of people truly witnessed ball lightning, there would be video footage of it. Nevertheless, reports continue to come in, and ball lightning is sometimes regarded as a UFO - an unidentified flying object - meaning something in the sky which cannot be readily identified.

The current prevailing physical theory for ball lightning is the atmospheric maser theory. Large clouds of charged water molecules are put into an excited state by electrical activity, briefly causing light amplification by stimulated emission of radiation, or the laser effect. However, before this can be confirmed as the true cause of ball lightning, it must be replicated in a laboratory first, which has not yet occurred. There may come a day where we can be sure that ball lightning is a real phenomenon, but unfortunately for the enthusiasts, that day is not here yet.