Luxury skyscraper hotel completely engulfed by fire in Grozny, Chechnya (VIDEO, PHOTOS)

[cpwm17]

178. "basics of it does not change with scale"

That is where you are completely wrong. This fact frequently trips up 9-11 conspiracy supporters. You can't compare the behavior of those smaller and more solid objects in the video to what happened on 9-11.

As you scale up objects, all else being equal, the mass 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 approximately proportional to its cross section area only. If you double it dimensions its strength to mass ratio is approximately cut in half.

Engineers can't overbuild large buildings without adding a tremendous amount of mass. The large buildings were designed to withstand normal loads, but not what happened on 9-11.

Also, with all else being equal, as you scale up an object its mass increases much faster than its height. The amount of force required to accelerate the object laterally increases greatly relative to its height, but the force of gravity is always the same for every bit of matter in the object. Gravity always wants the object to accelerate straight down.

Try balancing a toothpick on your finger and then try balancing a baseball bat on your finger. For various reasons, the behaviors of the two objects are very different.