Escape Velocity
Awkward on land, emperor penguins soar through the sea. Now scientists have discovered the secret of their speed.
Roger Hughes has never seen emperor penguins in the wild. But when he saw them in a BBC documentary, rocketing through the sea with trails of bubbles in their wakes, he had an insight that would lead to a surprising discovery. A marine biologist at Bangor University in north Wales, Hughes had recently been talking with his wife about the lubricating properties of new competitive swimsuits. He wondered: Maybe those bubbles help penguins swim faster.
Over beer in a pub, Hughes bounced his hypothesis off his friend John Davenport, a marine biologist at University College Cork in Ireland. “Roger thought I’d have the answer straightaway,” says Davenport, who studies the relationship between animals’ body structures and their movements. But he didn’t know what the bubbles did for the penguins. It turns out no one else knew either. The two men combed the scientific literature and found that the phenomenon had never even been studied. So they decided to do it themselves.
With the help of Poul Larsen, a mechanical engineer at the Technical University of Denmark, they analyzed hours of underwater footage and discovered that the penguins were doing something that engineers had long tried to do with boats and torpedoes: They were using air as a lubricant to cut drag and increase speed.
