petgoat
(1000+ posts)
Send PM |
Profile |
Ignore
|
Fri Oct-14-05 02:59 AM
Response to Reply #15 |
16. If the zipper theory is correct, a plane crash could initiate |
|
the unzipping and the collapse just as well as explosives could. But NIST (the latest official theory) doesn't subscribe to the zipper theory. NIST insists that the truss "clips" were so strong that sagging floors buckled the perimeter columns.
Whether MIT will bother to defend their theory in the face of official opposition will be interesting to see.
Why do pro demolishers use so many charges? Conventionally-framed buildings are arrays of columns and beams; if they are not brought down all at the same time, chaotic collapse could result. This is one reason the absolutely symmetrical center-first collapse of WTC7 is so unbelievable. How could random fires or random structural damage result in a textbook controlled collapse?
|