Why doesn’t 101 sway?

Now is probably a good moment to talk about an important design feature of 101. The higher up a building, the more it sways laterally in a quake. Again on the 18th floor, I felt a fair bit of movement, so another 80 floors up you’d expect even more.

To address this problem, the designers of 101 built a huge, and I mean huge, ball of metal.

IIRC it’s about 650 tons and connected to the building – when the building shakes, it transfers the energy to the ball or in physics terms, acts as a damper. Not only an attraction inside the building, it’s spawned a child’s toy - ‘Damper Baby’ that you can buy all over the place…