Why does this skyscraper stabilizing ball work?

[HappyEngineer]

I just saw this article about a skyscraper stabilizing ball:
http://deputy-dog.com/2008/06/22/in-action-a-skyscrapers-amazing-728-ton-stabilising-ball/

Why does that work? It's a swinging ball which also has some sort of supports underneath it. Are the supports just there to keep the ball from swinging too far?

I tried to imagine that this was similar to holding a mace over my head and swaying the mace handle back and forth. But I can't picture it. Why would the mace ball stabilize my hand when held straight up?

I just can't picture why this works. I saw the animation on that page, but I just don't see why that swinging motion helps to stabilize the skyscraper. Even if it somehow pulls it back, once it starts swinging wouldn't it reinforce the tilt of the skyscraper?

 

[Borek]

http://en.wikipedia.org/wiki/Tuned_mass_damper

 

[astrokreng]

The skyscraper stabilizing ball works by utilizing the principle of a pendulum. A pendulum is a weight suspended from a pivot point that, when set in motion, swings back and forth due to the force of gravity. In the case of the stabilizing ball, the weight is the 728-ton ball and the pivot point is the structure of the skyscraper itself.

The swinging motion of the ball creates a counterforce that helps to stabilize the building. When the building sways due to external forces such as wind or earthquakes, the ball swings in the opposite direction, creating a force that counteracts the sway. This helps to reduce the overall movement of the building and keeps it stable.

The supports underneath the ball are there to prevent it from swinging too far and potentially damaging the building. They also help to distribute the weight of the ball evenly and ensure that it stays in place.

To understand why this works, imagine the mace example mentioned in the question. If you were to hold a mace straight up and sway it back and forth, the weight of the mace head would create a force that stabilizes your hand. Similarly, the weight of the ball in the skyscraper stabilizing system creates a force that stabilizes the building.

Additionally, the swinging motion of the ball helps to dissipate the energy of the building's movement. This is similar to how a pendulum clock works, where the swinging motion of the pendulum helps to regulate the timekeeping mechanism.

Overall, the skyscraper stabilizing ball is an innovative and effective way to counteract the forces that can cause buildings to sway. It is a testament to the ingenuity and creativity of engineers and architects in finding solutions to complex problems.