My contention that there were 100s or 1000s of scenarios and innumerable variables was/is based on the fact the events during the collapse (after the collapse of the column) would have had variables that grew exponentially. I wasn't clear I guess when I said there were so many possible scenarios. There may be other possible scenarios for the initiating event (i.e. something other than the collapse of 79), but I'm not aware of what they would be. The NIST mentions clearly that they knew how great an extent the variables during the collapse event would grow, and there was a lot of information they couldn't account for (like interior walls and other support structures) because it A) either wasn't available and/or B) it would have been most likely been impossible to model. In any case, Jeffrey wants to know why they contend that it was the failure of column 79, and while I need to get to work now, I will say that the relevant information is in Chapter 8 of NIST NCSTAR 1-9. Specifically, the beginning of the initiating event details start on page 328. The entire chapter deals with the reasons why they concluded that the failure was column 79. I'm not a structural engineer, so I can't make any claims about what other events could have led to the collapse, but I can imagine that other events were possible but at the same time can reason that the people who conducted the investigation were experienced and knowledgeable enough to not just screw it all up.
One of the critiques, really the only one, that I've seen of the NIST video model is that the end of the video shows buckling of the top edge of the building and the inward movement of the outer shell of the building. These events shown in the model are not reflected in the video. There is explanation of the reason for this in chapter 3.5 of NIST NCSTAR 1A on and around page 42. Specifically, they note something similar to what I said earlier: that the variables during the collapse event become nearly impossible to model as the time advances.
Thanks for clarifying the statement.
My position is as follows.
The single column failure (79) leading to a global collapse as we saw as not be demonstrated. God only knows what inputs they plugged into their FEA to make that silly GIF animation which does not resemble the real world by a long shot. Why? I would guess because their girder walk off column 79 theory is a load of bunk. On that point I agree with the truthers.
Of course trying to model what happened is well nigh to impossible because of the 10s of thousands of nodes and energy inputs vary in location and intensity... key data that NIST doesn't have. So they have to make it up... and they did.
So rather than do a forensic investigation examining the steel and trying to reconstuct the event as the NSTB would do... they simply make an FEA model with inputs and expect the public and the professions to accept that as an explanation.
It's rubbish. And it doesn't even come close to matching the real world event.
Sure if the EPH collapsed through the building column line 79 would have to cease to function... as in get out of the way. Tony deludes himself and his buds by saying the EPH only collapse a single floor and so the perps placed explosives on floor 46 to take out that nasty EPH. But that's rubbish too.
The EPH went all the way down when it did. All the way? Well we don't know how far because no one was inside or could see the tell tale sign of it going down lower than perhaps floor 20 (don't know the precise floor) because the view was blocked by the building between the north facade and the camera position. NIST decided to celebrate 13 for some reason... but it's more like that something even lower pooped out and so the entire line above that dropped. And for the EPH to drop there were 9 columns below it as far down as floor 3... so they probably pooped too. And this is why TTF makes a helluva lot more sense than girder walk does.
Why doesn't NIST go there to party? That's the $64,000 question. We can only guess at the answer. But of course they expected the question so they answered it in advance with their usual evidence challenged made up out of who cloth assertion that there were no fires down there.
Admittedly we are evidence challenged... certainly more so that NIST. But as they make up evidence for their column 79 fantasy they can just as easily disappear it when it represents some inconvenient (truth). How easy to pass that off because.. we all know that there were no transducers or video cameras inside and so forth. All you have is a few fire fighter who were looking for people to rescue for a few hrs... who were no equipped to or probably tasked to figure out where the building was going to initiate the collapse. All the FDNY says is that they believed the tower would collapse because... it was warping????
Cool... they were proven correct. But then again... steel and fire doesn't mix very well for long.
And then there's all that pesky diesel fuel and flammable leaked coolant oil from Con Ed gear... tens of thousands of gallons potentially. So we have massive fires throughout this building and no oil or diesel decides to burn. How clever. Blame it on poet it nots, envelopes, files and carpet and pressboard table tops. Why not? Whose gonna defend them being there?
When one poses the question about the diesel.. the truthers get their knickers in a twist because the bow down to the CD god of bombs, nano thermite and secret eutectic devices (maybe). See no hear no smoke no fire no way Jose! They recovered it all except the 12,000 they can't account for which didn't do anything. Don't forget no one saw any smoke. And of course smoke stays right were the fire is... doesn't rise or enter ducts and so forth. Reading WTC smoke it like reading tea leaves a bit. Ya know white stuff is themite... black stuff is oxygen starved low temp...
The inconvenient truth about a problem down below 7 is that there wasn't much in the way of office contents to burn... especially on floors 5 - 7 where those magnificent transfer trusses were holding up close to maybe a hundred thousands of tons of building. You don't want that falling on your toes! Where was the diesel stored? Where were the oil cooled electrical transformers and switch gear? Where were those trusses? Oh no you don't say... Down on floors 5-7 under the EPH and right next to our friend 79. What a coincidence. Nothing interesting down there NIST said.
Makes you wonder a bit don't it? Who are they thinking about and for here?