Feb 27, 2010
The editors of the Journal of 9/11 Studies are pleased to announce publication of the following peer-reviewed article in the February 2010 volume of the Journal:
Destruction of the World Trade Center North Tower and Fundamental Physics
By David Chandler
Physicist David Chandler continues his insightful analysis of the destruction of three WTC skyscrapers on 9/11/2001 in this very readable paper. From the summary:
The fact that the roof line of the upper section of the North Tower continued to accelerate downward through the collision with the lower section of the building indicates that the upper section could not have been acting as a pile driver. As long as the roof line was accelerating downward, the upper block exerted a force less than its own static weight on the lower section of the building. Any accretion of material into the upper block would have acted as an inertial brake, reducing the force of interaction even further. The undamaged lower section of the building was built to support several times the weight of the material above it, but whether or not we take the safety factor into account, the reduced force exerted by the falling mass could not have been what caused the violent destruction of the building seen in numerous videos. The persistent acceleration of the top section of the building is strong confirmation that some other source of energy was used to remove the structure below it, allowing the upper block to fall with little resistance.
The editors highly recommend this article and the associated videos by David Chandler.