Creative Speculation
In reply to the discussion: What doesn't add-up for me [View all]cpwm17
(3,829 posts)Last edited Thu Dec 29, 2011, 08:21 PM - Edit history (1)
As you scale up objects, all else being equal, the larger object has a lower strength to weight ratio.
As you scale up objects, the weight increases in three dimensions but the strength only increases in two dimensions. For a cylinder the weight is proportional to its cross section area times its height, and its strength is proportional to its cross section area only. If you double it dimensions, its strength to weight ratio is cut in half.
This is a big reason why ants can carry many times their own weight.
The strength to weight ratio is far less for the towers than for any experiment in this video.
Plus the towers weren't solid, nor did they give a continuous resistance to the collapsing top sections. The towers weren't over built. They were design to withstand normal loads, not the tremendous loads of large collapsing sections of buildings from above.