The NIST video is interesting, largely for what it does NOT say.
It points out the computer-model simulation that they relied on for their explanation of the fall of WTC 7; and re-iterates their claim that there was "no evidence for explosives". What they did not say:
1. When one does a velocity-time analysis on their simulation (done by physicist David Chandler), one finds that the acceleration of the falling roof is NOT g= 32.2ft/s**2 as observed, but rather much less than g. So their simulation does NOT agree with the observed fall, the data.
2. The video states that the interior of the building first collapsed due to fire, then "the outside shell of the building fell". I have screen-captured the point in the video where this statement is made; attachment. Problems with this model include the fact that the falling "outside shell" mass still must hit lower shell mass, which will impede the motion so that acceleration at g= 32.2ft/s**2 would not be possible. (But that is what is observed in the videos, as admitted to by NIST.)
IOW, just because the mass of the floors is (NIST says) out of the way, one must still remove the mass of the lower shell to permit acceleration at g= 32.2ft/s**2 as observed. Math example: 39 floors-worth of "outside shell" hitting just one floor of "outside shell", then by conservation of momentum at time of collision the speed drops by 2.5% (1/40), and the next floor the speed drops by another nearly 2.5% (1/41) -- and already we find this "model" is OUTSIDE the allowed error for the fit to the observed g= 32.2ft/s**2 which I posted earlier. So material must be moved out of the way, according to the data.
Further, the observed fall during this 105 feet (over eight floors!) is symmetrical -- the roof does not appreciably tilt to one side during this stage. This means that the otherwise-impeding lower-outside-shell must be removed SYMMETRICALLY and essentially simultaneously. How is this done (without explosives)? NIST just does not mention all this.
3. NIST states that there was "no evidence" for explosives. They said the same thing with regard to the Towers. But did they look for explosive residues? I will quote from my co-authored paper published in the Open Journal of Civil Engineering, which I hope you will read!
NIST has been asked about this important issue recently, by investigative reporter Jennifer Abel:
Abel: "..what about that letter where NIST said it didn't look for evidence of explosives?” Neuman [spokesperson at NIST, listed on the WTC report]: "Right, because there was no evidence of that." Abel: But how can you know there's no evidence if you don't look for it first? Neuman: "If you're looking for something that isn't there, you're wast- ing your time... and the taxpayers’ money.” .
The evident evasiveness of this answer might be humorous if not for the fact that NIST’s approach here affects the lives of so many innocent people. We do not think that looking for thermite or other residues specified in the NFPA 921 code is “wasting your time.” We may be able to help out here as well, for we have looked for such residues in the WTC remains using state-of-the-art analytical methods, especially in the voluminous toxic dust that was produced as the buildings fell and killed thousands of people...
4. NIST failed to mention here that they have adamantly refused to allow me or other scientists to have access to their computer model. Thus, there is no opportunity for peer-review by other scientists, no professional courtesy extended. A result which cannot be challenged does not represent good science.
5. NIST in their final report admitted that they had set the thermal conductivity of steel to ZERO
, and that they had the fires burning near the critical column 79 for several HOURS. In reality, the thermal conductivity of steel is not zero, so that heat is transported away from the point where the fire is heating the steel -- wicked away to connected structural beams. NIST turned this heat conductivity to ZERO -- and they're getting away with it! You see, I would like to put reasonable PHYSICAL parameters into the computer simulation -- and see if the building actually will fail and fall at g=32.2ft/s**2 when this is done...
There is more, but I'd really like to get at the LC circuit I'm analyzing.