/sci/ - Science & Math

So, if motion must be restarted at every floor, the total collapse time must be more than 10 seconds. Given that the building disintegrated from the top down, it is difficult to believe there could be much momentum to transfer, if any. Also, consider the energy required to pulverize the floor between each "pancake." After being pulverized, the surface-area/mass is greatly increased and the air resistance becomes significant. I don't believe this pulverized material can contribute any momentum as it "hangs" in the air and floats down at a much-much slower rate than the "collapsing" floors.

This is a view from West Street, looking east across the remains of WTC1. FEMA entered this photo on 9/13/01, which is the earliest date for any posts for the 9/11 event. Other photos they have for 9/13/01 show much more people and equipment present. So, it is believed that this photo was taken on 9/11/01, but entered into their files on 9/13. Where did the building go?