A video recorded by accident of ball lightning in China is now shedding light on the phenomenon's mysterious origins, researchers say. Ball lightning occurs as glowing spheres ranging in size from a golf ball to a very large beach ball (1 to 100 centimeters, or 0.4 inches to 39 inches, in diameter). These fiery orbs can be white, yellow, red, orange, purple or green, and can persist for seconds or even minutes. Ball lightning typically appears during thunderstorms and usually hovers near the ground, drifting over the Earth at a few miles per hour, but it has also been seen on ships and even within airplanes. Over the centuries, people have reported thousands of sightings of ball lightning. However, these occurrences are rare and unpredictable in nature; as a result, "our knowledge of ball lightning so far is based mostly on accidental, eyewitness reports," said Eli Jerby, a microwave researcher at Tel Aviv University in Israel, who did not take part in this study. [ Countdown: … [Read more...] about Strange Ball Lightning Caught on High-Speed Video