Tricking the Wind

A shape that works on paper can still rattle in a real storm. So before building, engineers tested scale models in a wind tunnel and reshaped the tower until the air gave up.

The trick is to never let wind find a steady rhythm. As the tower rises, its wings step inward in a spiraling pattern, so each set of floors meets the wind at a slightly different angle. Wind that lines up to shove one level hits the next at the wrong spot. Instead of one big, organized push, the building scatters the force into smaller, harmless gusts.