Add Yahoo as a preferred source to see more of our stories on Google. A group of hikers look at one of the smoke rings A group of hikers look at one of the smoke rings Europe's most active volcano, ...

Air rings blown by dolphins swimming underwater and rings of smoke emitted by jet engines are just two examples of vortex rings. These doughnut-shaped structures and their mesmerizing movement have ...

Better understanding the formation of swirling, ring-shaped disturbances -- known as vortex rings -- could help nuclear fusion researchers compress fuel more efficiently, bringing it closer to ...

Mount Etna in Sicily, the largest active volcano in Europe, has been blowing spectacular “smoke rings” into the sky. The "volcanic vortex rings," a rare phenomenon that is generated by the combination ...

Some scientists think we can better understand volcanoes by learning how the gaseous vortexes emerge. By Carolyn Wilke Some volcanoes perform a rather subtle trick: blowing rings of vapor that waft ...

Mount Etna, Europe’s largest active volcano, puffed out a string of near-perfect rings over the weekend — prompting comparisons to smoke rings, or a fleet of giant flying saucers floating gently into ...

Three-ring circus. The sky over Italy’s Mount Etna fills with ‘smoke rings’ as a newly formed crater puffs out perfect circles of vapour. The circles — called volcanic vortex rings — form when cold ...