Use of Scale Model or Full Sized models for investigating 9/11 collapses

My take away on the study of these collapses would be to first recognize that their designs were very unique... As no other buildings share these design elements the studies are only to understand the failure modes in these designs. The twins suffered way out of spec mechanical damage, plus the infusion of thousands of gallons of jet fuel and a sprinkler system that instantly failed. 7wtc seemed to have no sprinklers almost from the beginning of the attack and burned for 7 hrs... way longer than the 2 hrs fire rating for steel in building codes.

I posed a question on another forum is a single column failure could result in total collapse in a typical latex/grid steel frame (or even concrete frame). I think there is enough redundancy and ability to transfer loads that a single column failure would no progress to a total building collapse. If it was col 79 in 7wtc (which I doubt)... it was above the load transfer structures which could fail from the dynamic loads of 40 stories falling on any one of them. As they were all interconnected... one down takes them all down and the guts of the building collapses and the facade comes down and folds in.

The lesson for me is don't put all your structural eggs in one basket (transfer structures in 7wtc) and OOS floor system in the twin towers. These become the Achilles heels and will take the whole structure down if they fail.

Engineers can see this if they bother to look. Lay people see these as just huge massive and strong skyscrapers like all the others around the world. Lay people won't get it. More robust fire protection strategies for steel frames are a good idea and are being implemented.
 
Welcome benthamitemetric - thanks for the list of links. https://www.metabunk.org/members/benthamitemetric.6172/

@J Orling.
Sander check out the witness testimonies referenced by benthaqmitemetric - follow the link and read this testimony:
Supplemental and Amended Second Declaration of Joseph P. Colaco

HINT:
...he is a man after your own heart. ;)
I skimmed through a few bits there and some of them below align wih my suspicions

Jose L. Torero pretty much states my suspicion of TTF.

"Based on my work to date, including computer modeling performed by me and my staff at the University of Edinburgh, it is my opinion that a diesel fuel fire occurred on September 11, 2001 on the fifth floor of WTC7 in the area of the transfer trusses. Such fires, fueled by between 7,350 and 9,300 gallons of diesel fuel from a leak in the Salomon Brothers’ Standby Generator System, would have been of such high temperatures and lasted for such duration that they would have compromised the strength of the transfer trusses, caused their failure, and ultimately caused the failures of Columns 79 and/or 80 leading to a global collapse of WTC7.

Specifically, a diesel fuel fire in the fifth floor mechanical room would heat: (1) the members of Truss 2 that are fully immersed in the mechanical room, including Columns 77, 80, and the eastern diagonal of Truss 2; and (2) the members of Truss 1 immersed in the north wall of the mechanical room, though to a somewhat lesser degree.

The diesel fuel fire would have generated sufficiently high structural temperatures in the members of Truss 2 to cause them to lose strength and fail.

This failure of the eastern side of Truss 2 would have caused load redistribution towards Truss 1 and Column 79, which would overload these members. The east diagonal of Truss I, which had the lowest factor of safety, would have likely failed first and resulted in the subsequent failure of Column 79. This was manifested visibly as the sinking of the East Penthouse.

The combined effect of the failure of the eastern side of Truss 2, Column 79 and the east diagonal of Truss 1, would have resulted in significant load transfer to Columns 73 and 74, as well as the core. This was manifested visibly as the “kink”. As Columns 73 and 74 were not immersed in the mechanical room, and therefore not significantly heated, a delay was observed between the sinking of the penthouse and the subsequent “kink”.

As described in the Second Declaration of Guy Nordenson, loss of the eastern region of the building’s interior created a large area of laterally unbraced perimeter frame and activated the fracturing of the floor slabs at the western trench headers leading to global collapse."

and Guy Nordensen (who I worked with on a project briefly) said:

"Disproportionate collapse of the building interior spread westward due to failure of the transfer trusses and then to the exterior because the cantilevered transfer girders on the north face were supported by one of the transfer trusses. The stacking of critical structural transfer elements created interdependence such that the loss of the transfer truss caused: (1) the cantilevered transfer girders to fail; (2) the perimeter frame to redistribute load and buckle in the unbraced lower northeast comer of the building, and (3) formation of the “kink” in the north facade visible in the video footage.

Whether the failure of Columns 79 and/or 80 was initiated by a diesel fuel fire on the fifth floor or an office contents fire between the ninth and thirteenth floors, the horizontal progression and global collapse ensued as a result of one or more of the following omissions: (1) girder to column connections that are weak in tension and did not brace the columns in accordance with the NYCBC requirement that the bracing be able to support 2% of the design vertical load carried by the column; (2) inadequate redundancy in the configuration of the transfer structures; or (3) lack of structural integrity (resistance to disproportionate collapse) in the design and construction of WTC7, including, without limitation, disregard for floor segmentation caused by the trench headers.1L"

and this from Frederick W. Mowrer:
"After 3:30 PM, photographic evidence shows fires and smoke consistent with a petroleum-based diesel fuel fire emanating from the vicinity of the fifth/sixth floor louvers on the east side of WTC7. One such photograph is attached hereto as Exhibit B. Four of the nine generators comprising the Salomon Brothers’ Standby Generator System were located in the northeast corner of the fifth floor.

The Standby Generator System installed by Solomon Brothers on the fifth floor of WTC7 constituted an electric power generating plant under Sections 27-250 and Reference Standard RS 3-3 of the NYC Building Code. As such, the area surrounding the generators and associated fuel piping required a higher fire resistance rating than the rest of the building. Sections 27-239 and 27-240 of NYC Building Code required that spaces having a higher fire index than the rest of the building be separated from adjoining spaces both vertically and horizontally by fire divisions having at least the fire resistance rating specified in Table 5-2 of NYC Building Code.

WTC7 was generally classified as a Group E occupancy. As an electric power generating plant, the Salomon Brothers’ Standby Generator System was classified as Group D-I occupancy under RS 3-3, thus mandating 3-hour fire resistive separation construction. Absence of such 3-hour fire resistive separation of the generator spaces on the fifth floor of WTC7 made it non-compliant with the NYC Building Code."


and this:

However, if you read chapter 4 of the report, you'll find that the buckling of the exterior columns at the lower floors was the first part of the global collapse, but that this was only the last stage of the failure. When column 79 failed (and redistributed forces causing columns 76-78, 80 and 81 to fail as well), large sections of the interior of the building failed and collapsed, but they pulled inward and away from the exterior facade of the building.

This is why in videos, you can see the penthouse collapse well before the building as a whole goes down - the penthouse shows what's going on inside the building.

"During the period of global collapse, there were 2.25 s of approximate free-fall because the structure of the building had already collapsed enough to allow that. What was falling was the facade, and what remained of the other floors. Stage (1) of the global collapse (buckling of exterior columns on lower floors) occurred because the interior columns had already failed; the facade and remains of the floors was essentially unsupported at this point, which was why they were able to collapse so quickly (for about 2.25 s, which was around a third of the total collapse time), which would be until they hit the debris and remaining structure in the lower floors."
 
...The culmination of that research was a post to /r/skeptics on reddit that drew a moderate amount of attention, but then faded into the ether of the internet. You can find that post here.
... There are plenty of more peer reviewed wtc 1 & 2-specific papers on other topics, as well.
Wow, I am impressed.
That's a slam-dunk.
I think your reddit-post deserves its own thread here - titled something like "Debunked: Claim that no engineering experts reviewed and support NIST's report on WTC7 (methods and conclusions)". And its own thread everywhere :D
 
Wow, I am impressed.
That's a slam-dunk.
I think your reddit-post deserves its own thread here - titled something like "Debunked: Claim that no engineering experts reviewed and support NIST's report on WTC7 (methods and conclusions)". And its own thread everywhere :D

Is "Claim that no engineering experts reviewed and support NIST's report on WTC7 (methods and conclusions)" an actual claim that is made though? Are there links to examples?
 
Mick, that's a valid question, but I think it is mostly a matter of time and effort to find such claims. Late at night here, and I feel a little sick (that's why I am still up), so I don't have a mind to diligent industriousness. But haven't seen it often how truthers claims the NIST reports aren't "peer-reviewed"? This may often refer to a formal process, construed as being the same as journal peer-review (and silly, for a work comprising thousands of pages).
Harder to find clear examples of the wider claim that the science community at large hasn't produced support for the NIST work.
 
Those affidavits were not formal peer review... but they were very qualified engineers who offered their statements in support of a lawsuit by the insurance company against the property owner/developer. The thrust of the case (which I don't believe was heard in court)... was that the design - development - construction involved decisions which would be justification for the insurance claim to be invalid... sort misrepresenting the soundness of the building. Of course the surety should have investigated the property for code compliance and suitability of the engineering etc. before giving the owner a policy. This lawsuit seems to be an escape clause after the fact having failed to do their due diligence.

Of course I find these statements very interesting because they basically suggest the location and the causes of initiation(s) which I have been suggesting for several years now and that the structures' designs themselves contributed to their own rapid collapses. The truthers like to suggest that these were massively over structured buildings which couldn't collapse and had to therefore be demo'ed. NIST seems to suggest that in the case of 7... normal office contents fires which are uncontrolled can do in a building. NB that the fire experts' statements indicated that these types of fires only last 30 minutes in one location and then move as the fuel is consumed.... and this seems to throw some doubt on a floor 13 scenario for building 7. According these statements... steel did not certainly melt, not loose sufficient strength but over stress connections to the point of failure some of which were poorly designed when head caused steel to expand. Of course these 2010 statements are post the NIST report 7WTC and basically for come pretty damn close to TTF.

If these ideas were to prevail in court, NIST's work would be "officially/"legally" shown to be flawed.
 
Those affidavits were not formal peer review... but they were very qualified engineers who offered their statements in support of a lawsuit by the insurance company against the property owner/developer. The thrust of the case (which I don't believe was heard in court)... was that the design - development - construction involved decisions which would be justification for the insurance claim to be invalid... sort misrepresenting the soundness of the building. Of course the surety should have investigated the property for code compliance and suitability of the engineering etc. before giving the owner a policy. This lawsuit seems to be an escape clause after the fact having failed to do their due diligence.

Of course I find these statements very interesting because they basically suggest the location and the causes of initiation(s) which I have been suggesting for several years now and that the structures' designs themselves contributed to their own rapid collapses. The truthers like to suggest that these were massively over structured buildings which couldn't collapse and had to therefore be demo'ed. NIST seems to suggest that in the case of 7... normal office contents fires which are uncontrolled can do in a building. NB that the fire experts' statements indicated that these types of fires only last 30 minutes in one location and then move as the fuel is consumed.... and this seems to throw some doubt on a floor 13 scenario for building 7. According these statements... steel did not certainly melt, not loose sufficient strength but over stress connections to the point of failure some of which were poorly designed when head caused steel to expand. Of course these 2010 statements are post the NIST report 7WTC and basically for come pretty damn close to TTF.

If these ideas were to prevail in court, NIST's work would be "officially/"legally" shown to be flawed.

You are correct that the affidavits are not peer reviewed. As you pointed out, they, along with accompanying expert reports (which I will one day get around to requesting from the counsel indicated on the case's docket report) were part of a litigation that was ultimately dismissed. Without going too far into the ruling, the court ultimately declined to try to parcel out fault for the 9/11 damage to anyone other than the terrorists. There is some sound legal reasoning as to why the court would not want to walk down that path, but, as you seem to infer, that legal basis for dismissal does not mean those quoted experts were wrong and WTC7 was without faults. Had the tower come down in a context other than the crazy chain of causation that was 9/11, I highly suspect the case would not have been dismissed in such a manner.

In any case, I believe the peer review Oystein is referring to is the actual peer reviewed version of NIST's WTC 7 report, which was published ASCE's Journal of Structural Engineer: http://cedb.asce.org/cgi/WWWdisplay.cgi?286345. I had found that many of the individuals who believe 9/11 was some sort of inside job held as a core belief the idea that the NIST reports were never independently peer reviewed (I would argue the actual public comment period and number of people involved in such a massive project were sufficient reviews, but I digress). I was thus surprised when I learned that the WTC7 report, seemingly the most controversial of NIST's works, was in fact independently peer review by one of the most prestigious engineering journals in the world. That truncated report is behind a paywall, but like the other research I cited in the reddit post, I have obtained a copy of it for myself and can answer questions about its contents, etc., when I have time.
 
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Is "Claim that no engineering experts reviewed and support NIST's report on WTC7 (methods and conclusions)" an actual claim that is made though? Are there links to examples?

I found it to be a rather common claim, at least on reddit where I attempted to interface with conspiracy theorists for a prolonged period. A quick google search also turns up several claims by relatively prominent conspiracy theorists that the NIST reports (including the wtc 7 report) were not peer reviewed. David Griffin's invocation of the claim, for example, is within the first 10 results.
 
After going a little off topic with the reddit stuff, I thought I should note for posterity the conclusions of the Ming Wang paper re the scale model that I previously linked. Here they are, excerpted verbatim:


The fire and structures on the 96th floor of World Trade Center Tower 1 were reconstructed in a 1 / 20 scale. The choice of floor and wall materials and insulating material on structural system were based on the scaling rules to produce similarity between the scaled model and prototype. The testing of the scaled model shows a vivid example of using a scaled model to simulate a real-world disaster, and the results obtained help us to understand the failure mechanism involved in the disaster.

The testing of the scaled model provides the hot gas tempera-ture profile and the heat flux measurements at different locations. The total burning time of the fuels in the scaled model is about 25 min, which corresponds to the 120 min burning of the WTC1. Based on the structural analysis of WTC structural system at el-evated temperature conducted by NIST, the experimental results in the scaled model provide a timeline of structural response of WCT1 during the disaster. The results are summarized as follow-ing:

1. Fire was spread from the north to the south. The hot gas temperature reached a peak at 65 minutes in the north area and 110 min in the south area.
2. The peak hot gas temperature in the model reached 1,000 ° C.
3. The peak temperature of trusses reached 900 ° C and the peak temperature of exterior columns is about 600 ° C.
4. The time to reach the maximum steel temperature in the truss with 25.4 mm thick insulation is delayed about 10 min com-paring to the truss with 12.7 mm insulation. However, the peak steel temperature in both trusses is similar.
5. The scale experiment result reproduced a timeline of the pro-totype. Along with the numerical simulation results con-ducted by NIST2005[1], the scale experiment results indicate that the long-span floor trusses at the southwest corner would begin sagging significantly at 80 – 90 minprototype time[1]. This corresponds to the visual record which shows that the inward bowing of the south exterior wall was first observed at 96 min from the airplane impact. The scale experiment result indicates that the long-span floor trusses at the south-west corner would begin falling off the truss seats at around 85 – 95 min and the instability of the exterior columns could therefore occur at around 95 min. This matches the fact that WTC1 collapsed at 102 min.
6. A better understanding of the fire spreading and fire tempera-ture profiles at different locations of the 96th floor has been built based on the scale experiment results.
7. The results show that the testing of the scale model can rep-licate the prototype behavior in a satisfactory manner.
Content from External Source
 
I found it to be a rather common claim, at least on reddit where I attempted to interface with conspiracy theorists for a prolonged period. A quick google search also turns up several claims by relatively prominent conspiracy theorists that the NIST reports (including the wtc 7 report) were not peer reviewed. David Griffin's invocation of the claim, for example, is within the first 10 results.
I suggest that we (AKA "debunkers" in the current terminology) have created an ogre - a rod for our own backs - out of "peer review".

"Peer Review" is the process used in the field of academic and professional publishing to decide if a paper meets minimum standards for putting into professional debate. Nothing more. It is an entry threshold test - no where near a guarantee of veracity.

"Debunkers" from long before that term became popular used lack of peer review as the easy way to dismiss "truther" claims. And it has gained a status much higher than it deserves. And for several years "truthers" have been using it against us. Our own short-sighted folly IMO for taking the easy way through argument.

The NIST reports were subject to a potentially far higher standard of review - the process often used for Government Papers. It was put "out for comment" in the draft stage.

Whilst "out for public comment" does not mandate responses the NIST reports certainly attracted top level scrutiny and some highly professional comments. IMO to a higher standard than "peer review" is intended to achieve.

So the actual process for NIST was de facto more rigorous than academic/professional "peer review" BEFORE publishing.

Then the reality that the engineer in me repeats often - the test of any claim - especially in the field of physics applied to engineering forensics - is:
"Is the claim true?" NOT "Is it peer reviewed?" NOR "How many and how big are the author's degrees?" - and - also I suppose NOT "Has it been put out for open comments in draft stage?"

The lawyer side of me recognises those are different criteria to "weight of evidence" and "standard of proof' in a courtroom. Especially when the veracity of the technical claim is not the focus of the case before the court.
 
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After going a little off topic with the reddit stuff, I thought I should note for posterity the conclusions of the Ming Wang paper re the scale model that I previously linked. Here they are, excerpted verbatim:
Thanks for that. As a suggested lead towards more discussion of the thread topic let me pose a question.

Given that:
My focus has been deliberately on the hard nosed engineering pragmatics question "What value is there in (whatever) use of models of the 9/11 collapses."
AND
I recognise that scientists legitimately engage in detailed research which may be of specific value if applied to some future projects.

So this is the question:
"What value does that quoted paper impute for further modelling of WTC collapses?"

I see the generic value of research modelling. I don't see any value in further modelling of WTC collapses for reasons I have posted quite a few times.
 
So this is the question:
"What value does that quoted paper impute for further modelling of WTC collapses?"

I see the generic value of research modelling. I don't see any value in further modelling of WTC collapses for reasons I have posted quite a few times.

I suspect little value aside from testing sub systems for things like fire performance. There will never be a replication of the design and construction technologies used in the twin towers. Perhaps some concepts are already in place... the express elevator concept and some will not be seen such as long (or any) span bar truss/joists... which means that lightweight pre assembled floor systems likely are gone as well. OOS concepts will prevail but with more robust joists, connections and of course fire protection strategies. Erection technology and connection engineering perhaps needs testing and development.

Though there was no official sanction of the boneheaded developer driven engineering and code/use "decisions"... the engineering community has taken note and lessons were learned.

Politically 9/11 was a show to pin the tail on a convenient enemy and make more war... the endless war on terrorism. That was an unfortunate outcome, to say the least ... but totally predictable.
 
5. The scale experiment result reproduced a timeline of the pro-totype. Along with the numerical simulation results con-ducted by NIST2005[1], the scale experiment results indicate that the long-span floor trusses at the southwest corner would begin sagging significantly at 80 – 90 minprototype time[1]. This corresponds to the visual record which shows that the inward bowing of the south exterior wall was first observed at 96 min from the airplane impact. The scale experiment result indicates that the long-span floor trusses at the south-west corner would begin falling off the truss seats at around 85 – 95 min and the instability of the exterior columns could therefore occur at around 95 min. This matches the fact that WTC1 collapsed at 102 min.


So now we have two models, one scale physical model and the other computerized full scale, both consistent with each other. To my non-engineer's mind that pretty much seals it as far as what temperatures could be expected to have been reached in the compartment and the steel. It also further confirms the veracity of using the computer sim which, I believe, was a commercially available program that has been used in forensic investigations in other fires.
 
Thanks for that. As a suggested lead towards more discussion of the thread topic let me pose a question.

Given that:
My focus has been deliberately on the hard nosed engineering pragmatics question "What value is there in (whatever) use of models of the 9/11 collapses."
AND
I recognise that scientists legitimately engage in detailed research which may be of specific value if applied to some future projects.

So this is the question:
"What value does that quoted paper impute for further modelling of WTC collapses?"

I see the generic value of research modelling. I don't see any value in further modelling of WTC collapses for reasons I have posted quite a few times.

Having read the paper, it seems it helped the authors better understand how the fires likely spread across the floors of the wtc, how they heated elements on those floors, and at what point those elements failed from said heating. Of course, at least according to the imperfect metrics that can be found in google scholar, the paper hasn't been cited very frequently, so it's unlikely that it made more than a small incremental impact in the practice of fire engineering. Perhaps, however, it was more valuable for what it confirmed than for what it revealed as new in regards to the models of the fires within the twin towers, as it showed NIST's models (also largely created by a co-author of the scale model paper) were highly accurate in predicting fires as they actually developed in the scale model, indicating that the theories underlying the NIST paper were, at least, not without bases in reality. In fact, I think it's pretty fair to say the paper presents strong corroborative evidence of the high degree of accuracy of NIST's simulations.
 
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BTW, isn't replication of results as good or better than peer review?
Anything which "proves" results is better than peer review. (Put "proves" into acceptable language - either scientific or para-legal.) (And my comment relates to all aspects of claims - better reasoning as well as purely technical - e.g. some papers which have been peer reviewed present faulty argument - valid argument is better even if it has not been peer reviewed. Hence my assertion - the test of a claim is "Is the claim true?" Specific examples would be the later Bazant papers - all of which were peer reviewed - to the extent that they apply Bazants 1D "approximations" and purport to represent the WTC Towers collapses. They are not simply inaccurate. They are wrong. In fact some of them have been used to produce "near enough" numeric predictions. Getting the "right' answers for the wrong reasons - which as a far more insidious error.)
 
Anything which "proves" results is better than peer review. (Put "proves" into acceptable language - either scientific or para-legal.) (And my comment relates to all aspects of claims - better reasoning as well as purely technical - e.g. some papers which have been peer reviewed present faulty argument - valid argument is better even if it has not been peer reviewed.

Thus my use of "replicated". Perhaps " confirmed by replication" or even "veracity confirmed by replication"
Hence my assertion - the test of a claim is "Is the claim true?" Specific examples would be the later Bazant papers - all of which were peer reviewed - to the extent that they apply Bazants 1D "approximations" and purport to represent the WTC Towers collapses. They are not simply inaccurate. They are wrong. In fact some of them have been used to produce "near enough" numeric predictions. Getting the "right' answers for the wrong reasons - which as a far more insidious error.)
Bazant is correct for the situation as described in the Bazant papers. The issue is with the congruency between the paper's scenario and the reality of the situation in the WTC.
 
Thus my use of "replicated". Perhaps " confirmed by replication" or even "veracity confirmed by replication"
Yes.
Bazant is correct for the situation as described in the Bazant papers.
Take care. He is not - and it isn't ONE situation. Specifically don't confuse the B&Z limit case scenario where Bazant was correct within the bounds of the limit case - with the later papers which refer to crush-down/crush-up and which apply "columns in line 1D simplifications" to the actual WTC collapses. Those papers are wrong on those aspects applied to WTC.**
The issue is with the congruency between the paper's scenario and the reality of the situation in the WTC.
"the paper's" SINGULAR - if you mean that - i.e. B&Z OK.


** And his papers were peer reviewed - my comments aren't. Does that mean he is right and I am wrong? :oops:

**** Or even more specifically "on-topic" - would my version be correct if I built a physical model?? So it is not true till I build the model BUT becomes true once the model is built? Shades of psikey physics there.

(I'll stop there before my manic sense of humour gets me into trouble.)
 
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Yes.
Take care. He is not - and it isn't ONE situation. Specifically don't confuse the B&Z limit case scenario where Bazant was correct within the bounds of the limit case - with the later papers which refer to crush-down/crush-up and which apply "columns in line 1D simplifications" to the actual WTC collapses. Those papers are wrong on those aspects aplied to WTC.**
"the paper's" SINGULAR - if you mean that - i.e. B&Z OK.
I should have written it as "papers' " ie. as a body of work.

By the scenario in the "papers" I mean the situation as described within the, any , paper.As you are well aware the calculations can all be correct and even the conclusions can be yet still have no applicability to reality.

BUT the issue is that what he describes does not apply to the real situation of the towers, for instance wrt upper and lower column section being in line.

Shades of psikey physics there.

(I'll stop there before my manic sense of humour gets me into trouble.)
That's ok , so far his in not yet the name that shall not be mentioned.:eek:
 
As you are well aware the calculations can all be correct and even the conclusions can be yet still have no applicability to reality.
Correct - that infamous Nov 2007 first internet post of mine made just that point: "The paper....is typical of many which look impressive in detail to the non-engineer. The complex calculations may even be correct but the base premises are faulty and the resulting conclusions can readily be demonstrated to be totally wrong."
BUT the issue is that what he describes does not apply to the real situation of the towers, for instance wrt upper and lower column section being in line.
That is the key point. Universally true EXCEPT when M_T claims it on another forum. :rolleyes:
 
The problem with these debates is that way too many people are so invested in their views that they respond on a visceral level and feel their ego and standing and self worth is under assault. Their response is, instead to show understanding, or appreciation, or humility... they show arrogance and dismissiveness and launch into ad hom, insults and feel even more justified in their false beliefs.

This is very true of the vocal web warriors especially on the truther/conspiracy side. Once you show some good arguments revealing flaws in their thinking... you are then cast as a operative, cognitive infiltrator, government shill or apologist. When you get called such things.... you probably hit on some good points and a very raw nerve.

The big truthers will not get into these debates and confront those who can skillfully demolish their absurd positions. TSz was the last one and there are a few who still post nonsense such as MM or the clowns like KoKo... refusing to learn a thing. Whether it's the details of the over arching frame of 9/11 the truth position really doesn't hold water. Just because media, institutions, and individuals engage in PR and lie and will always seek to advance their agenda and avoid accountability for their mistakes intended or not... does not mean that EVERY world event is planned by the elite as a "false flag".

I want to use the world naivete with respect to the political views of these truthers... but it's really more paranoia.

Don't expect and serious attempts by truthers to model CD.
 
The reason I post that in this thread is because that same search for research led me to many, many similar papers that were not WTC 7-specific, including one that actually documented *drum roll please* phsyical scale modeling of the fires of the floors of wtc 1 and 2: http://cedb.asce.org/cgi/WWWdisplay.cgi?161328
Please. You're not seriously attempting to pretend that modelling fire on the 96th floor is the same as demonstrating experimentally that the supposedly gravity-driven mechanic of the collapse of the towers actually exists on any day other than 9/11?

My point from the outset has been that there is no model in existence that demonstrates the phenomenon that is said to have destroyed those structures from top to bottom by experimentally reproducing it (in simplified terms).

The best we have -- to my knowledge -- are these Blender models by the YouTube user Kostack Studio, which represent only a small section of the towers and show what appears to be "crush up" of the falling upper section of the structure occurring far, far sooner than Bazant et al suppose.

Mick has said he could use Blender to model the complete collapse sequence in order to demonstrate to gullible young folk that conspiracy theories involving explosives are unnecessary to fully explain how they could be destroyed so totally, but I am not sure if he has made any progress in this regard.

And so there are still no models, either physical or virtual, that explain through the basic scientific principle of reproduction a phenomenon whose explanation you all seem to assume is self-evident.

 
The following SITREP based on my memory - I haven't checked details but the broad outline is as follows:


Szamboti had an FEA of the affected girder/beams. Enik did a more realistic FEA taking the context broader - allowing for heat effects on the columns and nearby other structure. I think enik's work cast doubt on Szamboti's version - and enik is committed truther. All from memory as I said so we should check before relying on my 73yo memory.

There were extensive fires in the building all day.... and no fire fighting. Surely the frame was warping... it was reporting as warping and why the FDNY pulled their personnel from the building. THIS WASN'T ISOLATED TO A SINGLE WARPING DISTORTION AT ONE LOCATION ON FLR 13.

YOU CANNOT DO AN FEA AND IGNORE THE ENTIRE DYNAMICS OF THE BUILDING... ESPECIALLY IF IT WAS WARPING AS REPORTED.
 
My point from the outset has been that there is no model in existence that demonstrates the phenomenon that is said to have destroyed those structures from top to bottom by experimentally reproducing it (in simplified terms).
You are correct on the lack of models. But you seem to be searching for an explanatory model and the options have been explained several times.
The best we have -- to my knowledge -- are these Blender models by the YouTube user Kostack Studio, which represent only a small section of the towers and show what appears to be "crush up" of the falling upper section of the structure occurring far, far sooner than Bazant et al suppose.
They seem to be good explanatory models. What more is needed for such a model? And remember that Bazant's "crush down/crush up" is not a valid explanation of the actual WTC Twin Towers collapses. It is an artefact of a 1D approximation - one which is not "approximate" If applied to WTC 9/11 collapses - it is wrong when applied to WTC. It assumes columns end for end crushed as the main feature of the mechanism. That isn't what happened.

Mick has said he could use Blender to model the complete collapse sequence in order to demonstrate to gullible young folk that conspiracy theories involving explosives are unnecessary to fully explain how they could be destroyed so totally, but I am not sure if he has made any progress in this regard.
I'll leave that for Mick.

And so there are still no models, either physical or virtual, that explain through the basic scientific principle of reproduction a phenomenon whose explanation you all seem to assume is self-evident.
Not quite true - there are adequate explanations of the Twin Towers collapses and it has been explained previously why the mechanisms are self-evident to those who comprehend the physics - and it doesn't take a lot of physics.
 
Mick has said he could use Blender to model the complete collapse sequence in order to demonstrate to gullible young folk that conspiracy theories involving explosives are unnecessary to fully explain how they could be destroyed so totally, but I am not sure if he has made any progress in this regard.

Please don't paraphrase. Quote what I said.

Now I'm thinking I'll look into using Blender to build a model. While it's not engineering grade physics, it should suffice to demonstrate the principle of collapse, and how it varies with scale. It has scriptable constraints. But most of the existing models seem to be solid block type things.
 
There were extensive fires in the building all day.... and no fire fighting. Surely the frame was warping... it was reporting as warping and why the FDNY pulled their personnel from the building. THIS WASN'T ISOLATED TO A SINGLE WARPING DISTORTION AT ONE LOCATION ON FLR 13.

YOU CANNOT DO AN FEA AND IGNORE THE ENTIRE DYNAMICS OF THE BUILDING... ESPECIALLY IF IT WAS WARPING AS REPORTED.
That is the point I made to Tony. Several times. I'm glad you agree. Assuming as Tony does that the rest of the building was in original as built locations was - as I said - a "courageous" assumption. :rolleyes:
 
Not quite true - there are adequate explanations of the Twin Towers collapses and it has been explained previously why the mechanisms are self-evident to those who comprehend the physics - and it doesn't take a lot of physics.
Then it shouldn't take a lot of modelling: how curious that all attempts have been failures.

Or can you point to one that succeeds?
 
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Succeed at reproducing the total destruction of a model of the towers by representing (or using) the effect of gravity.

All the models I've seen -- by which I mean, videos of physical models such as psikey's -- fail completely to reproduce this shocking "global destruction phenomenon".

There are no videos of physically-accurate computer models that reproduce the complete collapse, to my knowledge.

Econ41 says the mechanism of collapse is self-evident to those who comprehend the physics. Why then has nobody ever been able to demonstrate their comprehension of this dramatic phenomenon with any experimental representation of the Tower's structures, however simplified?

Apparently "it doesn't take much" -- but it still remains totally beyond all the world's structural engineering students, experts, and academic faculties more than 13 years after these immensely significant events occurred.
 
There were extensive fires in the building all day.... and no fire fighting. Surely the frame was warping... it was reporting as warping and why the FDNY pulled their personnel from the building. THIS WASN'T ISOLATED TO A SINGLE WARPING DISTORTION AT ONE LOCATION ON FLR 13.

YOU CANNOT DO AN FEA AND IGNORE THE ENTIRE DYNAMICS OF THE BUILDING... ESPECIALLY IF IT WAS WARPING AS REPORTED.
Is it possible that the damage to the south side, especially the SW corner was causing some distorting forces throughout the structure as well?
 
Succeed at reproducing the total destruction of a model of the towers by representing (or using) the effect of gravity.

All the models I've seen -- by which I mean, videos of physical models such as psikey's -- fail completely to reproduce this shocking "global destruction phenomenon".

There are no videos of physically-accurate computer models that reproduce the complete collapse, to my knowledge.

Econ41 says the mechanism of collapse is self-evident to those who comprehend the physics. Why then has nobody ever been able to demonstrate their comprehension of this dramatic phenomenon with any experimental representation of the Tower's structures, however simplified?

Apparently "it doesn't take much" -- but it still remains totally beyond all the world's structural engineering students, experts, and academic faculties more than 13 years after these immensely significant events occurred.
Well psikey's model does not represent anything that was occurring in the towers, most certainly not any mechanism that was identified as the probable driver of global collapse.
 
Succeed at reproducing the total destruction of a model of the towers by representing (or using) the effect of gravity.

But nobody said they were trying to do this, did they? econ41 was discussing explanatory models.
You are correct on the lack of models. But you seem to be searching for an explanatory model and the options have been explained several times.

What attempts were you referring to with:
Then it shouldn't take a lot of modelling: how curious that all attempts have been failures.

Or can you point to one that succeeds?

Can you give an example of an attempt at "reproducing the total destruction of a model of the towers by representing (or using) the effect of gravity."
 
econ41 was discussing explanatory models.
If a model doesn't explain how a "gravity-driven mechanic" totally destroyed the structures (as opposed to explaining/representing only the initiation, or only a part of the collapse) then it can't really be described as an explanatory model, in my opinion.
Can you give an example of an attempt at "reproducing the total destruction of a model of the towers by representing (or using) the effect of gravity."
In my opinion psikey's model was an attempt to investigate this mechanic, at an abstract but still meaningful level of simplification. You may disagree with this -- and I see from the above that jaydeehess does -- but I'm not prepared to waste time defending that view here because you banned psikey from this discussion in what I considered a gross and cowardly move, and as a result he does not have the chance to respond to criticism of his model himself.

The point I am making is this: Econ41 says "it doesn't take much" to demonstrate the physics of the collapses and how gravity brought about the Towers' total destruction -- but all the world's structural engineering students, experts, and academic faculties have had more than 13 years since these immensely significant events occurred to demonstrate their simple understanding of the totality of the collapses experimentally, and yet they cannot.
 
@Tony Szamboti has posted here in the past, maybe he'
If a model doesn't explain how a "gravity-driven mechanic" totally destroyed the structures (as opposed to explaining/representing only the initiation, or only a part of the collapse) then it can't really be described as an explanatory model, in my opinion.

I think you are conflating "explain" with "mathematically prove exactly". There are many people in the "truth" movement who don't seem to understand the various aspects of the NIST hypothesis. For example, slender column buckling, or thermal expansion, or seated connections, or core column failure at the splices. These can be "explained" by words, or by the walls of text that some posters above are fond of.

But they can also be explained by a model. A model that might not be 99.999% physically accurate (as that's quite hard to do), but one that will illustrate the general principles of the collapse initiation and progression.

A very simple model is my 2D Jenga models. These are there to explain a point of the collapse hypotheses - that the floors are stripped away, leaving the columns without lateral bracing.


They explain a concept, it does not prove that the towers collapsed from damage, fire, and gravity. But it (hopefully) removes some misconceptions that people use as evidence that the towers could not have thusly collapsed.
 
In my opinion psikey's model was an attempt to investigate this mechanic, at an abstract but still meaningful level of simplification. You may disagree with this -- and I see from the above that jaydeehess does -- but I'm not prepared to waste time defending that view here because you banned psikey from this discussion in what I considered a gross and cowardly move, and as a result he does not have the chance to respond to criticism of his model himself.

He's had plenty of opportunities over many years, and has been shown to be incorrigible. He is not banned, he was just removed from this thread for repeated off-topic posts, culminating with this post:
https://www.metabunk.org/threads/us...ating-9-11-collapses.3828/page-16#post-131562
 
In my opinion psikey's model was an attempt to investigate this mechanic, at an abstract but still meaningful level of simplification.
That much is true - if we overlook psikey's characteristic reluctance to state explicitly what he is attempting.

HOWEVER the problem with the paper loops model is that it does not model the WTC collapses. It reflects the wrong side of a major confusion that has held sway in 9/11 WTC collapse discussion.

That confusion between models which misapply the assumptions of the Bazant and Zhou papers of 2001-2 - they assume that collapse resulted from progressive buckling of columns - usually referred to as a "columns in line model" - and models of the actual mechanism which did not have columns in line.

The actual collapse progression stage bypassed the columns. Mass falling down the Open Office Space sheared off the office space floors leaving the perimeter columns standing free but unbraced and they fell away. They were not crushed or buckled. A similar process destroyed the core without crushing the columns being a major factor.

The actual collapse was described by me - 2008, Major_Tom 2009 and by him labelled "ROOSD" (Runaway Open Office Space Destruction) and probably described by others unknown to me or M_T et al.

Psikey's model is a "columns in line model" with the crushing of paper loops representing crushing of columns. Wrong concept. Not what actually happened at WTC1 & 2 on 9/11. And that is why psikey's model is technically inappropriate. All the other emotive issues aside.

The point I am making is this: Econ41 says "it doesn't take much" to demonstrate the physics of the collapses and how gravity brought about the Towers' total destruction -- but all the world's structural engineering students, experts, and academic faculties have had more than 13 years since these immensely significant events occurred to demonstrate their simple understanding of the totality of the collapses experimentally, and yet they cannot.
Please take care to not misrepresent me. I said "understand" physics AND "explain" physics. I did not say "demonstrate". I try and IMO usually succeed in being precise in my choice of words. I also try to avoid ambiguity and innuendo. What you see is what I almost certainly mean - nothing more - nothing less - nothing implied.

PLUS your "but all the worlds....etc" is a false equivalence. Ease of understanding and/or explaining the physics DOES NOT imply ease of modelling .....or "demonstrating". They are distinctly different challenges.
 
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I said "understand" physics AND "explain" physics. I did not say "demonstrate".
Ease of understanding and/or explaining the physics DOES NOT imply ease of modelling .....or "demonstrating". They are distinctly different challenges.
This is not false equivalence, but let's leave that to one side. You appear to be saying that you understand something that is simple in principle yet too complex to represent experimentally, even in simplified form. This is laughable. Are we supposed to take your understanding on trust? Of course not. Why would anyone be convinced by such a self-contradicting argument? This is precisely is why reproducibility is a cornerstone of the scientific method.

Can you think of any other physical phenomenon that fits into this "simple in principle yet too complex to model" category you have invented? Today we can model systems as chaotic as the weather, or asteroid strikes.

The circularity of these arguments is depressing. We've already seen this "it's too complex to do" assertion on this thread. It's just handwaving. I refer you to the very start and the highly complex physical model of the Tacoma Bridge that was made and tested long before computer simulation was available to engineers.
 
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