Yet some people do not understand that, an aircraft that will be severely damaged by 500mph air under 14.7lbs/sq.in. or by hitting a 25 lb duck, cannot slice through a steel and concrete building as if it were moving through air. Oh, and did I say that the videos of flight 175 don't agree? Yes I did and after reviewing some of these films again, I noticed that the clouds in the pictures are different! Wait just a minute, "clouds"? Where did clouds come from on that crystal clear Sept. day? But there they appear in all their glory on some of the vids. The more you watch the videos the more anomalies you see.