Ball lightning is so strange it might just come from another dimension

Mysterious floating orbs of light have puzzled scientists for centuries, inspiring no end of creative explanations. A new idea suggests they aren’t entirely of this world

By Eric Canan

ON A summer’s day in the early 1980s, a teenager sat in his bedroom watching an afternoon thunderstorm roll over the seaside landscape near Rome. Without warning, a glowing sphere the size of a football suddenly appeared in the corner of the room. Emitting no heat or smell, it hovered about a metre in front of him and slightly over his head. The boy was dumbfounded. The ball was dark yellow, completely opaque, with a wispy surface made from layered sheets of slowly rippling light. It floated there for about 10 seconds before vanishing as silently as it had come. He didn’t even have time to be scared.

Andrea Aiello remains fascinated by what he saw as a boy – and now, as a theoretical physicist at the Max Planck Institute for the Science of Light in Germany, he is developing his own ideas about it. The most likely explanation is that he witnessed ball lightning, a rare form of atmospheric electricity that can hover gently above the ground inside or outside buildings and even pass through closed windows. Scientists around the world take the phenomenon seriously, while remaining unable to explain, reproduce or authoritatively document it.

There are plenty of hypotheses, but little certainty. Some believe the phenomenon’s origins lie in the electrical power play of vast thunderstorms. Others think it might be caused by lightning strikes themselves. A few believe it is a messy tangle of electromagnetic field lines wandering Earth alone. So far, at least, none of these ideas can explain everything ball lightning seems to do. Is it time to consider some more exotic alternatives? …