This kind of circles back to something I said earlier... That if we take it at face value that the NIST simulation is accurate and done correctly, it shows that fires could cause a collapse. But it doesn't show that fires could cause the observed collapse. To accomplish that, the simulation would have to match the observations more closely in my opinion. But I'm not asking for perfection. If NIST produced a simulation that showed for example 1.8 seconds of FFA instead of 2.25 seconds, I think it would be pretty unreasonable for me to still whine about it. I would say that would be pretty damn good and convincing. But it's ultimately arbitrary when you think the simulation is "close enough" to be satisfactory.
It would be a tremendous waste of effort to try to achieve such accuracy in a simulation of the later stages of the collapse because no one even knows for sure exactly how the internal stages of the collapse progressed and that cannot be known.
NIST very painstakingly and carefully describes the limitations of its model given the limitations of its knowledge of the exact conditions of the building pre-collapse and the simplifying assumptions the software must make in simulating the structure and its failures. After millions and millions of calculations based on such simplifications and given imprecise starting conditions, of course the simulation will significantly diverge from the real event. It's amazing, frankly, that NIST and Weidlinger Assocs. were able to build the robust collapse models that they did that showed some significant aspects of the collapse that matched real world observations (even though they both started from differing initial assumptions). (ARUP didn't go that far (but didn't pretend to) and Hulsey couldn't go that far but flat-out faked that he did with misleading, hand-animated graphics.)
The fact that NIST's simulation ultimately did show a massive buckling event across the north face that corresponded with "Stage 1" of the north face collapse, and then a period of little resistance that corresponded with "Stage 2" of that collapse, is even more amazing, whether or not it perfectly synced up to the observations (which no reasonable person in their right mind should expect it to, given the limitations). Taken in the context of everything else we know about the collapse, NIST thus presented a reasonable enough explanation (which is consistent with first principles) of how it could likely have happened.
It feels like this type of conversation always just circles endlessly because, at the end of the day, truthers like you and @Thomas B
, are just grasping endlessly for reasons to not believe that fire caused the collapse, so you hold the NIST report up to some arbitrary and ridiculous standard that has nothing to do with what the NIST report even claims (if you actually read it after all these years), as if its failure to meet that standard is the thing
that's preventing you from looking at the preponderance of the evidence across all the available reports, public testimonies, photographs, videos, etc. and realizing that, at this point, it is beyond obvious that fire, and not some still-undefined controlled demolition methodology, brought the building down. In the chaotic noise of the collapse, truthers misinterpret the short period of near free fall acceleration of a portion of WTC7 as a signal of controlled demolition. Unsurprisingly, they are just "finding" the only signal they are looking for in the noise. But it's not a signal; it's just noise.
And, think about it, if NIST were trying to bamboozle the public on this point, wouldn't they just artificially build this period of acceleration perfectly into their model like Hulsey did? (And I know that's not fair to Hulsey--he didn't even have a model; he only had an animation.