Tom/TFK, I found Ryan Mackey's old email in a different location. This is the one that talks about the eight floors hanging on inside Building 7:
"Really focus on the full video starting with east penthouse at the top left. Notice how one second before the global collapse, there is little kink in the building.
after east penthouse falls, no movement. I say structural resistance to the collapse IS happening during that 8 seconds.
The strong exterior framing failed only during the final stages. The bracing failed on multiple floors, and this buckling resulted in an almost invisible collapse over many floors. This collapse loaded the next column, and it fails next. Then the next columns. And so on until the entire core is destabilized and falls in on itself. When the east penthouse fell downward into the building, you could see sunlight through the windows because there was nothing back there. Other windows broke out on the north face at the ends of the building core as the perimeter wall was being damaged.
When the perimeter goes, it is literally pulled down by an eight-story section of the interior that didn't detach during the core collapse.
in the second before the big collapse, the roofline moves down a bit, and then it starts descending at free fall. The previous second is consistent with large-scale buckling. Think of pushing down on a long stick -- you can push it down just a little as it bends, and then it snaps, and you fall on the ground.
The approach taken by NIST is summarized in Section 3.6 of the final summary report, NCSTAR 1A (released Nov. 20, 2008; available at http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR%201A.pdf
) and detailed in Section 12.5.3 of NIST NCSTAR 1-9 (available at http://wtc.nist.gov/NCSTAR1/PDF/NCST...%20Vol%202.pdf
In WTC 7 our best guess is that a major internal column buckled after its
The part of WTC 7 that the conspiracy peddlers focus on starts AFTER the core has already gone -- they focus on the part they can see in YouTube videos, namely the perimeter. The perimeter was carrying little weight other than its own. The core collapse sheared off the floor connections and the majority of the structure's weight. So the perimeter collapsed last.
When the columns buckle, they don't "shrink" very much but they lose practically all of their structural strength. Thus, after buckling, the entire perimeter comes down, and there's really nothing to slow it down. There's no momentum transfer like there was in WTC 1 and 2 (because there's nothing to hit), and there's no strength left to oppose the weight.
We know the core failed before perimeter collapse for several reasons. The penthouse collapses are one of them -- as the conspiracy folks already know, there wasn't much fire on the upper floors of WTC 7, so for them to sink into the structure means there is nothing at all left underneath them. Another way we know this is from the windows in the perimeter -- as detailed in NIST's report, you can actually see into the structure and tell there's nothing left inside, if you examine the video carefully.
We also know the perimeter buckled because of it's behavior. The conspiracists focus on the "free fall" portion. They ignore what happens Same thing. Just much larger."