Add Yahoo as a preferred source to see more of our stories on Google. Hovering blue flames that flicker over bogs and marshes have inspired ghostly folktales for centuries. Known as “will-o’-the-wisp, ...

Bubbles merging in water can spontaneously generate electric sparks powerful enough to ignite methane, which could explain mysterious flashes of light known as will-o’-the-wisps. In bogs, swamps and ...

Hovering blue flames that flicker over bogs and marshes have inspired ghostly folktales for centuries. Known as “will-o’-the-wisp,” “jack-o’-lantern,” “corpse candle” and “ignis fatuus” (“foolish fire ...