How a steel ball protected Taiwan’s tallest skyscraper in an earthquake

When a 7.4-magnitude earthquake rocked Taiwan on Wednesday, people inside the island’s tallest skyscraper, Taipei 101, were protected by a large yellow pendulum at the building’s center that helped absorb the shock.

Known as a “tuned mass damper,” the 730-ton steel sphere is suspended between several floors at the top of the building, where it can be viewed by the public. The observatory is a popular tourist attraction in the capital city.