But the report has stood the test of time. Been studied worldwide, and no credible invalidation of it has be put forward by any academic body anywhere in the world. And the less credible attempts at refutation, like Gage and Griffith, fall apart when you start looking into them.
As you say we must leave the computer simulation to one side in this, as independently unverified models are unacceptable. That's quite a lot of work to leave to one side, though. The "classic" CT objection to the suggestion that the CD hypothesis was adequately explored by NIST is that the report does no more than calculate the likely effect of a hypothetical blast event caused by RDX, while the specific thermate hypothesis is only considered in terms of its unlikelihood. Can you debunk this, perhaps by pointing to where NIST has considered multiple charges as a possible cause of the collapse symmetry seen in the video evidence?
Multiple charges would be covered by the single charge blast event. As they considered the smallest possible charge. More charges would be a lot louder.
But the idea here is to demonstrate that NIST's own hypothesis is invalid, not that they failed to consider every possible other hypothesis. I'm simply claiming their hypothesis is plausible, and fits the observed facts, not that it is true.
Do you think NIST made reasonable efforts to invalidate its own hypothesis? Does Occam's Razor cut out a serious consideration of the CD hypothesis for you?
Not necessarily. I was just curious to know if Mick would consider CD in the same category as, say, space beams, which I would cut out. The razor as I'm sure you know allows for a less simple explanation if it has greater explanatory power, and is not logically irrefutable as a heuristic.
Multiple charges would be covered by the single charge blast event. As they considered the smallest possible charge. More charges would be a lot louder.
I see: so you are saying that the supposed lack of recorded explosions -- at a distance of six years -- does indeed represent sufficient scientific effort to eliminate the possibility of accelerants. Is this really the sum total of the NIST case in this respect?
I see: so you are saying that the supposed lack of recorded explosions -- at a distance of six years -- does indeed represent sufficient scientific effort to eliminate the possibility of accelerants. Is this really the sum total of the NIST case in this respect?
So did nothing buckle, for no reason? Did the words "far too slender" bounce right off? How might a tower five hundred times larger, with hundreds of very thin cross-connecting floors and very slender columns, buckle differently, do you think?
That's irrelevant, unless there's something to indicate the alternative hypothesis. Considering the audio is sufficient. But also the lack of evidence of cut beams.
So did nothing buckle, for no reason? Did the words "far too slender" bounce right off? How might a tower five hundred times larger, with hundreds of very thin cross-connecting floors and very slender columns, buckle differently, do you think?
It might -- but it didn't in the model shown in the video you posted, so that didn't help your argument What was that model supposed to prove again? That buckling happens?
That's irrelevant, unless there's something to indicate the alternative hypothesis. Considering the audio is sufficient. But also the lack of evidence of cut beams.
How does explosives have greater explanatory power? Since there is nothing unexplained by the NIST hypothesis, then there's no need to add to it.
My question was whether or not alternative hypotheses had been adequately considered. In the case of the CD hypothesis, I understand your position as being that it is scientifically acceptable to rule out this question principally because there was some videotape of the collapse that didn't record the audio.
Hypothesis 1: Debris damage, Fire, Collapse completely with precise observable symmetry, at a speed at or close to free-fall
Hypothesis 2: Debris damage, Fire, Carefully planned explosive demolition that works around the fire, Collapse completely with precise observable symmetry, at a speed at or close to free-fall.
Really? Could you point out the flaws in the NIST WTC7 report NCSTAR 1-9 (ignoring the simulation, just the other stuff). And be specific. Quote the most significant flaw.
Oh and why would be ignore the simulation ? Isn't it the culmination of the NIST hypothesis ? Shouldn't it be able to recreate the failure to a significant degree ? Why would you single out any portion of the NIST report.
If the shoe fits, but then again, what if it doesn't ?
Oh and why would be ignore the simulation ? Isn't it the culmination of the NIST hypothesis ? Shouldn't it be able to recreate the failure to a significant degree ? Why would you single out any portion of the NIST report.
If the shoe fits, but then again, what if it doesn't ?
Hypothesis 1: Debris damage, Fire, Collapse completely with precise observable symmetry, at a speed at or close to free-fall
Hypothesis 2: Debris damage, Fire, Carefully planned explosive demolition that works around the fire, Collapse completely with precise observable symmetry, at a speed at or close to free-fall.
It buckled closer to the bottom. The bottom part supported the upper part, so once the upper part had basically no support then it would descend. Essentially the same as if the buckled portion was removed.
Problem with this theory is found in how caissons work. The bottom of a caisson only actually holds about 10% of the load, the surface tension of the rest of the tube holds the rest. So how much of the load was held by the remaining intact floor structures ? I'd guess quite a bit but again, architects and engineers for truth just received the blueprints of the building so a little time will be needed to analyze the new data
None of it. Watch this video. You've seen it before, but, hell, let's watch it again:
1:09 "The important thing to understand is that this (intermediate) floor doesn't carry any of the load; the only function of this floor is to tie the columns together".
29. The simulation of the collapse modeling of WTC 7 does not match the video footage of the collapse. In particular, the large inward deformations of the upper exterior walls after the beginning of global collapse are not visible in the video footage. Can NIST explain the difference between the results of its computer model of the collapse and the available video evidence?
NIST conducted two global collapse analyses, one that included damage due to debris-impact from the collapse of WTC 1, and one that did not include any debris-impact damage. These two analyses were conducted to determine the influence of the debris-impact damage on the response of WTC 7 when subjected to the effects of the fires that burned on floors 7 to 9 and 11 to 13. In its comparison of the two analyses (see NIST NCSTAR 1A Section 3.5), NIST showed that the analysis with the debris-impact damage better simulated the sequence of observed events, and it is this simulation that is considered here.
NIST believes that the simulation of the collapse, based on the analysis with debris-impact damage, does capture the critical observations derived from the digital video recording. The critical observations and corresponding failures identified in the structural analysis include: 1) east-west motion of the building beginning at approximately the same time as failure of floors 6 through 14 around Column 79, 2) the formation of the “kink” in the roofline of the east penthouse approximately one second after Column 79 was found to buckle, 3) window breakage on the east side of the north face as the buckling of Column 79 precipitated the failure of upper floors, and 4) the beginning of global collapse (vertical drop of the building exterior) within approximately one-half second of the time predicted by analysis. Both measured time and analytically predicted time, from the start of failures of floors surrounding Column 79 to the initial downward motion of the north face roofline, was 12.9 seconds (see NIST NCSTAR Report 1A, Table 3-1). The collapse observations, from video analysis of the CBS News Archive video, are covered in detail in NIST NCSTAR Report 1A Section 3.5 and NIST NCSTAR Report 1-9, Section 8.3. Only in the later stages of the animation, after the initiation of global collapse, do the upper exterior wall deformations from the NIST analysis differ from the video images.
Uncertainties associated with the approach taken by NIST are addressed in NIST NCSTAR Report 1A, Section 3.5, where it is noted, “Once simulation of the global collapse of WTC 7 was underway, there was a great increase in the uncertainty in the progression of the collapse sequence, due to the random nature of the interaction, break up, disintegration, and falling debris.” The contribution to stiffness and strength of nonstructural materials and components, such as exterior cladding, interior walls and partitions, was not considered in the analyses conducted by NIST. It is well known that such non-structural components can increase the stiffness and strength of a structural system, but their contribution is difficult to quantify. Given these factors, disparities between the video and the animation in the later stages of collapse would be expected.
Problem with this theory is found in how caissons work. The bottom of a caisson only actually holds about 10% of the load, the surface tension of the rest of the tube holds the rest. So how much of the load was held by the remaining intact floor structures ? I'd guess quite a bit but again, architects and engineers for truth just received the blueprints of the building so a little time will be needed to analyze the new data
None at the point the penthouse collapsed. The connections were seated. The beams sat on little shelves that were welded to the column. They were incapable of holding it up. They were not designed to hold it up. They were not moment resisting. And have you seen the length of the spans around column 79?
Seated vs. moment-resisting is the key to understanding the collapse.
And with reference to that diagram, here's what seems like a plausible sequence to me:
Heat from the uncontrolled fires caused thermal expansion of the steel beams on the lower floors of the east side of WTC 7, damaging the floor framing on multiple floors.
Eventually, a girder on Floor 13 lost its connection to a critical column, Column 79, that provided support for the long floor spans on the east side of the building (see Diagram 1). The displaced girder and other local fire-induced damage caused Floor 13 to collapse, beginning a cascade of floor failures down to the 5th floor. Many of these floors had already been at least partially weakened by the fires in the vicinity of Column 79. This collapse of floors left Column 79 insufficiently supported in the east-west direction over nine stories.
The unsupported Column 79 then buckled and triggered an upward progression of floor system failures that reached the building's east penthouse. What followed in rapid succession was a series of structural failures. Failure first occurred all the way to the roof line—involving all three interior columns on the easternmost side of the building (79, 80, and 81). Then, progressing from east to west across WTC 7, all of the columns failed in the core of the building (58 through 78). Finally, the entire façade collapsed.
What the simulation shows is everything up to the last sentence.
None of it. Watch this video. You've seen it before, but, hell, let's watch it again:
1:09 "The important thing to understand is that this (intermediate) floor doesn't carry any of the load; the only function of this floor is to tie the columns together".
What that video demonstrates is that a weight placed on top of inadequate support will invariably twist off in an asymetrical manor and not, fall directly into the footprint of the structure bringing virtually every single bit of the structure along with it.
What that video demonstrates is that a weight placed on top of inadequate support will invariably twist off in an asymetrical manor and not, fall directly into the footprint of the structure bringing virtually every single bit of the structure along with it.
No it depends on whether or not your wiling to admit the NIST simulation is miles off from the film evidence of the actual event. So the invisible part, your claiming matches NIST predictions perfectly and your unwilling to admit that there are significant differences in the way the NIST model varies from the actual collapse.
Seems black is not black and white is not white at this point.
Nope, physics is physics, any amount of supporting structure will influence the fall of the mass placed above, scale has nothing to do with that simple fact. An asymmetrical influence will result in an asymmetrical result.
So the invisible part your claiming matches NIST predictions perfectly and your unwilling to admit that there are significant differences in the way the NIST model varies from the actual collapse
All the significant parts are there. The simulation is to determine how it starts to collapse. Not what happens after. That would be a pointless extra million dollars of computer time. Pointless because there are too many unknowns in the initial conditions to extrapolate that far into a complex situation.
Nope, physics is physics, any amount of supporting structure will influence the fall of the mass placed above, scale has nothing to do with that simple fact. An asymmetrical influence will result in an asymmetrical result.
Physics is physics but 100 feet is not an inch. Things react differently at different scales. That little tower is supporting 100x its own weight. WTC7 cannot support 1x its own weight. Because of scale.
Even if you ignore scale (which you should not), then the dimensions and construction of this structure are entirely different to WTC7. It illustrates a principle.
I remember being taught scale effects in year 2 of a BE - so that you could test scale models and get realistic results. I've never had to use the math since and only vaguely recall it, but I do recall that the the square and cube laws make things vastly different to simple linear scaling.
I remember being taught scale effects in year 2 of a BE - so that you could test scale models and get realistic results. I've never had to use the math since and only vaguely recall it, but I do recall that the the square and cube laws make things vastly different to simple linear scaling.
Ah but in that demolition we see a comparison to the top down demolition of WTC 1 & 2 vs the bottom up demolition of WTC 7. In the 7 collapse there was no possible excuse for a top down demolition which they were going to explain away as gravity based. In 7 we have a classic demolition, where the total mass of the building above is used to demolish basically nothing below it, just trying to land it on the pile all nice and neat, and let the building decelerate from there as it contacts the rubble pile, which is far more sponge like than an intact lower half a building . So there would be no jolt per se until the rubble pile itself came into play.
Nice try tho was at least some scientific analysis of at least some remotely similar structure, rather than a slinky or some tooth picks.
Ah but in that demolition we see a comparison to the top down demolition of WTC 1 & 2 vs the bottom up demolition of WTC 7. In the 7 collapse there was no possible excuse for a top down demolition which they were going to explain away as gravity based. In 7 we have a classic demolition, where the total mass of the building above is used to demolish basically nothing below it, just trying to land it on the pile all nice and neat, and let the building decelerate from there as it contacts the rubble pile, which is far more sponge like than an intact lower half a building . So there would be no jolt per se until the rubble pile itself came into play.
Nice try tho was at least some scientific analysis of at least some remotely similar structure, rather than a slinky or some tooth picks.
Heres some pics for your scientific analysis. I guess if a taller building falls, it leaves a hole. If a smaller building falls, it leaves a big pile. Pretty good for some slinky toothpicks.
All the significant parts are there. The simulation is to determine how it starts to collapse. Not what happens after. That would be a pointless extra million dollars of computer time. Pointless because there are too many unknowns in the initial conditions to extrapolate that far into a complex situation.
None of the significant parts are there. The interior depiction is pure speculation, which by the way does not in any way lead to the failure of the exterior in a manor consistent with that of the photographic evidence
I think its pretty apparent your not going to be able to admit the photographic evidence and the NIST models do not even remotely match. The question becomes why are you not able to admit it. Instead you've dreamed up this concept of it being irrelevant, When in fact its exactly relevant. There's a reason the rubble pile was whisked away ASAP with zero consideration for its fall pattern or "complete" evidence of connection failures. I believe its called plausible deniability.
The reason your unable to admit what is right in front of everyone's eyes is that it would require you to admit the NIST hypothesis is entirely inadequate to even remotely describe the photographic evidence accurately. For instance in the NIST models portions of the pent house are still intact long after the outer wall begins to fail, yet this is in direct opposition to what the photographic evidence shows. Clearly their computer models, based off their ridiculous theory is wildly flawed.
In the first NIST simulation there is clear distortion of the left hand side of the structure prior to the complete collapse of the penthouse, followed by a radical distortion in the right hand side corner closest to the viewer. Not even remotely what is seen in the photographic evidence. In the second NIST simulation there is a completely different fall pattern to the exterior walls than in the photographic evidence.
Neither simulation runs more than a second or two into the actual collapse sequence and neither run through to completion, very suspicious as we can clearly see a major deviations from the photographic evidence even only one second in, let alone at completion.
The NIST simulations not just completely, but embarrassingly fail to represent the photographic evidence. Period.
Any failure to acknowledge that is tantamount to denial
You keep saying this, but it's pure nonsense. The simulations were only ever intended to be somewhat accurate up until collapse initiation. Because their purpose was to find out WHY the building collapsed.
Given the vast number of uncertainties as to the initial state (with impact damage), and the actual spread of the fires, the results of the simulation are remarkably accurate. All the significant features up until the collapse of the exteriors are represented very well.
If you disagree, then point out exactly where it differers, and we can compare in more detail.
Of the four significant features that can actually be seen in the video evidence, are any of them counterindicative of CD? Or are they all also consistent with the CD hypothesis, like the collapse of the penthouse?
it is still a wholly acceptable forensic application of the scientific method, you feel, to completely eliminate the question of CD from the investigation on the basis that there was some videotape of the event that didn't seem to record the audio.
What was that model supposed to prove again? That buckling happens?
