building that that is false? you think that that is false? >> yes, do i. and for a couple of reasons. one is that building seven came down, it went into a sudden collapse across the full width and length of the building. 2.25 seconds which amounted to 105 feet or eight 13-foot tall storeries. it was in full free flow acceleration. that is impossible because in a natural collapse columns would have to buckle. when columns buck there will is a minimum resistance. it means it never goes to zero. it is impossible. you can't reach -- >> here is in lay men's terms. what he is saying is that the top floor collapses and hits the next floor and the next floor and bang, bang, bang, bang, the weight of the upper floors. >> it would slow down. it was in full free flow acceleration. all of the potential energy. >> instead of what i just zee described it just collapsed