Talk:Collapse of the World Trade Center/Archive 6

At the risk of stirring things up again,
I'd like to suggest rewriting the "conspiracy theory" section. First, the title is a bit misleading since no conspiracy is described. Surely, "individuals who disagree with the findings of U.S. Government engineers" are not by definition conspiracy theorists. Second, it's a pretty clunky piece of a prose; the language seems to have suffered greatly under the strain of the discussion here, and the grasping for a covering term for "the group of individuals" (?) and a source to attribute it to is virtually contortionist. Third, the "main article" that is linked to describes a specific hypothesis that is not even touched on here. Lastly, I find the controlled demolition hypothesis to be of interest in understanding the WTC collapses independent of the conspiracy theories with which it is apparently invariably associated with. After all, part of learning how the buildings collapsed includes understanding the possible alternative mechanisms. CD could obviously have done the job. What is interesting about the WTC collapses is that it may not have been necessary. Thinking that issue through should be possible without wondering whether you're a rebel or crazy or both. So I suggest the following edit to replace the conspiracy theory section, which proceeds from the "alternative hypothesis" legitimized by NIST itself. I've provided non-conspiriatorial sources, and I can of course put in external links in the actual article.


 * Controlled Demolition Hypothesis


 * Main article: 9/11 conspiracy theories#World Trade Center towers


 * The NIST study "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) However, NIST did not analyze the actual pattern of the WTC's collapse; the scope of the investigations was limited to the events leading up to the collapse: "The focus of the Investigation was on the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower. [The NIST report] includes little analysis of the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable." (NIST) Also, the NIST report did not provide computer visualizations of the complete collapse their global models of the towers, which would normally provide engineers with a way of testing the hypothesized collapse mechanism against the video evidence (NCE). Finally, the study did not include the collapse of Building 7. Defenders of the controlled demolition hypothesis argue that it better explains the actual progress of the collapse (which, again, was not described by the NIST report) even if NIST provides a plausible mechanism for its initiation.

Any thoughts? I'll let it stand here for a week and then make the edit if there are no objections or suggestions.

--Thomas Basboll 19:38, 19 July 2006 (UTC)


 * Object: The draft you presented may carry a notion of POV in favor of the conspiracy theorists. The paragraph lists "shortcomings" of the NIST report and nothing else, leaving the reader with the idea that there was a sinister plot behind the tragedy. Also, the present paragraph serves to introduce the reader to a new topic. The main article you list can elaborate on the topic without assistance from this article. In other words, the status quo is good enough. --physicq210 20:21, 19 July 2006 (UTC)


 * Objection noted. Here are some thoughts: I think "limitations of scope" would be more accurate than "shortcomings". I suppose this limitation of the NIST report could be included somewhere else in the article, but it seems to be most relevant here. If we did move that information elsewhere, however, we would be left with:


 * The NIST study "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) Defenders of the controlled demolition hypothesis nonetheless argue that it better explains the actual progress of the collapse, which was not described by the NIST report (see above at [wherever we put it]), even if NIST provides a plausible mechanism for its initiation.


 * Moving along ... since the NIST report is central to this topic, I don't see how introducing its own "alternative hypothesis" is a "new topic" - it is an alternative hypothesis to explain the title event of this article, i.e., the collapse of the WTC towers. The main article link is not mine, it is status quo. My draft simply summarises that article on the ground that has been established in this one, i.e., the NIST report. The CD hypothesis is not a sinister theory in and of itself, it as an alternative hypothesis that has been officially rejected; it is part of the official report. What must be understood (and what many readers, like me, will be trying to understand when they look this article up) is how the airplane impact + damage was able to accomplish what controlled demolition, according to the (status quo's) "government engineers", did not. I don't see the harm in quoting NIST's mention of the alternative for someone who is perhaps specifically wondering about CD. --Thomas Basboll 21:13, 19 July 2006 (UTC)


 * I'm not objecting to you introducing the summary. The problem is how you put out the summary to conform to WP:NPOV guidelines. Good start though. I congratulate you for at discussing your potential edits (unlike some in the past). --physicq210 21:28, 19 July 2006 (UTC)


 * Thanks Physicq, here's my new suggestion then.

New Draft to Replace "Conspiracy Theories" section with two other sections.


 * Limitations of the NIST study


 * While the NIST report is the most comprehensive study of the collapse of the World Trade Center to date, it is limited in a number of ways. First, it did not analyze the actual progress of the WTC's collapses, limiting the scope of the investigations to "the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower. [The NIST report] includes little analysis of the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable." (NIST) Accordingly, the NIST report did not provide computer visualizations of the complete collapse of their global models of the towers, which would normally provide engineers with a way of testing the hypothesized collapse mechanism against the video evidence of the actual progressive collapse (NCE). Finally, the study did not include the collapse of Building 7.


 * Controlled Demolition Hypothesis


 * Main article: 9/11 conspiracy theories#World Trade Center towers


 * The NIST study "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) Defenders of the controlled demolition hypothesis nonetheless argue that it better explains the actual progress of the collapse, which was not described by the NIST report (see "Limitations"), even if NIST provides a plausible mechanism for its initiation. Supporters of this hypothesis constitute a minority in the relevant fields (primarily physics and engineering).

I'm aware of the meaning of NPOV, and I think that these are in full compliance. But feel free to point out potential oversights.--Thomas Basboll 22:08, 19 July 2006 (UTC)


 * I'm wondering where you got the impression that "computer visualizations of the complete collapse of their global models of the towers would normally provide engineers with a way of testing the hypothesized collapse mechanism against the video evidence of the actual progressive collapse". Do you have a source that says that such "computer visualizations" (presumably an animation?) are normally (or ever) used for testing hypotheses in the context of structural collapse?  Toiyabe 22:26, 19 July 2006 (UTC)


 * The idea originally came to me from the simulation of the collapse of a bucket wheel reclaimer by a company called Sydac using something called ADAMS, which you can read about it here (PDF: ):


 * Like the NIST report, it does a finite element analysis that tries out various loading until collapse begins.


 * Unlike the NIST report, "The [simulated] mechanism was then allowed to collapse under gravitational forces."


 * The Sydac ADAMS report explains why: "Comparing independent results from a finite element analysis of the structure with the results of the initial static analysis [of the final state of the actual equipment] validated the model. Comparisons of the simulated and final collapsed states provided evidence that the correct failure mode had been identified." It also says: "By matching simulated collapse results for various initial fault conditions, with the final state of the actual equipment, the most likely initial fault was identified. Investigation effort was then focused in this area to confirm the failure initiator."


 * But this idea of simulating collapses and comparing with "the actual equipment", was applied to the WTC case in an by Dave Parker in the New Civil Engineer (NCE).


 * NIST showed detailed computer generated visualisations of both the plane impacts and the development of fires within WTC1 and WTC2 at a recent conference at its Gaithersburg HQ. But the actual collapse mechanisms of the towers were not shown as visualisations.


 * University of Manchester (UK) professor of structural engineering Colin Bailey said there was a lot to be gained from visualising the structural response. "NIST should really show the visualisations, otherwise the opportunity to correlate them back to the video evidence and identify any errors in the modelling will be lost," he said.


 * And they then asked NIST about it, who even said they'd consider it. I'll find the exact reference if you like.--Thomas Basboll 22:50, 19 July 2006 (UTC)


 * PS, I found the NCE story: Dave Parker "WTC investigators resist call for collapse visualisation", New Civil Engineer, 6 October 2005" (I think this link will work: )


 * PPS, the Sydac simulation has an html version here: .--Thomas Basboll 23:10, 19 July 2006 (UTC)


 * That's an interesting case, but certainly not normal. The WTC towers include many more elements than the mining equipment in the report you linked to, about the same number as a single floor truss out of ~80 in each of the 110 floors of each tower, not to mention columns and other structural elements. Add in the greater uncertainties in loading (file cabinets, office furniture, people etc) and the limited knowledge of the specifics of the fire and it becomes a more difficult problem by several orders of magnitude.  And the uncertainties would be also be greater by several orders of magnitude.


 * So I guess it's OK to say that Colin Baily, a Professor of Structural Engineering at the University of Manchester recommended that NIST perform such an analysis, but it is wrong to say that such an analysis is normal or imply that it is easy. Toiyabe 23:52, 19 July 2006 (UTC)


 * Fair enough, thanks for your input. I propose rewriting that sentence to read: "Accordingly, the NIST report did not provide visualizations of the complete collapse of the computer models of the two towers, even though this might have provided engineers with a way of testing the hypothesized collapse mechanism against the video evidence of the actual progressive collapse (NCE)."


 * As an aside, it would satisfy a good deal of my curiosity to see the models they did have (in the NIST report) elaborated to go all the way down to the ground (I understand they didn't even make their models that "global") and then subjected to "collapse initiation". This even if the model had to simplify some things. All models are simplifications - that goes for the Sydac bucket retainer as well. As long as the video evidence is analysed in like terms at various stages (to be compared with the progress of the simulation at the same stages), and the distribution of wreckage in the final state is mapped and simplified accordingly, there should be no (insurmountable) problem.--Thomas Basboll 00:09, 20 July 2006 (UTC)


 * NIST did not publish a global static model, and it doesn't appear that they developed one. So they couldn't make that model dynamic and "take it all the way to the ground".  What they did develop is quasistatic models (no inertial effects, only load-related and thermal deformation) for specific sub-systems of interest.


 * The article from the New Civil Engineer is pretty misleading IMHO. Throughout the article it implys (at least the way I read it) that NIST does have a "visualization" but is refusing to share it, although NIST says they never developed one.  Your proposed addition also seems (to me at least) to imply that.  I would prefer something like the following:


 * "NIST did not develop a global dynamic model of the collapse of the WTC towers, only static models of specific subsystems. Some engineers belive that a comparison of an animated sequence of the collapse derived from  a global dynamic model to the video evidence of the collapse would greatly increase our understanding of the failure mechanisisms(NCE)."


 * Personally, I think in your aside you are vastly underestimating the difficulties of a dynamic simulation of such a complex mechanisism. I'd be interested to see how Professors Colin Bailey and Roger Plank proposed doing that. Toiyabe 16:45, 20 July 2006 (UTC)


 * Just came back here and read Toiyabe's suggested text, which I really like. I thought at least part of the NIST model was dynamic and was subjected to simulated loading. I still think that's (at least partly) right. In any case, with that info properly sourced to the part of the NIST report that describes the models, I think this would be a nice addition to the proposed "limitations" section.--Thomas Basboll 07:37, 21 July 2006 (UTC)


 * I'm not certain you understand what dynamic means in the structural modeling context. A static model is one where the sum of forces (and moments) on a structure is zero.  F=m*a, a = 0 therefore the sum of F = 0.  So, the applied loads are equal to the support reactions. A dynamic model is one where the sum of the forces is not zero and therefore a is not zero and the structure is accelerating (e.g. falling towards the ground).  As long as the structure is in free-fall, the dynamic model is pretty simple.  If you have collisions, the dynamic model is very complex.


 * A static model is valid up to the point of failure. Betweeen failure and catastrophic failure, a quasi-static model that includes deformation may be valid.  After catastrophic failure only a dynamic model can be valid.  So to model what happens when floor 71 falls onto floor 70 you need a dynamic model.  To model what happens up to the point where floor 71 begins to fall you can use a static model, which is what I understand that NIST did.  Toiyabe 15:29, 21 July 2006 (UTC)


 * You're right, I didn't understand (still don't really) that difference. I've tried to put your suggstion into the article. Please make sure I got it right.--Thomas Basboll 23:36, 22 July 2006 (UTC)

Delete "Conspiracy Theories", add two new sections (Draft)
Here's my suggestion at this stage. We remove the section on conspiracy theories, and replace it with these two:


 * Limitations of the NIST study


 * While the NIST report is the most comprehensive study of the collapse of the World Trade Center to date, it is limited in a number of ways. First, it did not analyze the actual progress of the WTC's collapses, limiting the scope of the investigations to "the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower. [The NIST report] includes little analysis of the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable." (NIST) Accordingly, the NIST report did not provide visualizations of the complete collapse of the computer models of the two towers, even though this might have provided engineers with a way of testing the hypothesized collapse mechanism against the video evidence of the actual progressive collapse . Finally, the study of Building 7 is not yet complete.


 * Controlled Demolition Hypothesis


 * Main article: 9/11 conspiracy theories#World Trade Center towers


 * The NIST study "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) This alternative hypothesis, however, was primarily intended to explain the structural response of the lower floors, especially the completeness and rapid progression of the collapse. Its defenders therefore maintain that NIST found no evidence to support the controlled demolition hypothesis only because they were not looking at aspects of the collapse that would yield such evidence (see "Limitations").

Looking forward to hearing your comments.--Thomas Basboll 00:48, 20 July 2006 (UTC)

No...too POV.--MONGO 04:21, 20 July 2006 (UTC)

No. Misleading selection of facts. --Mmx1 04:27, 20 July 2006 (UTC)


 * Mongo and Mmx1, with all due respect: since the edits I'm proposing have taken some real effort to produce, I'd appreciate an argument for these dismissals. Which of the two proposed sections are too POV, in what sense are they POV, and is there something that could be done to make them less so? Perhaps you could specify the POV from which they seem to be written.


 * How are the facts I've selected misleading? I.e., what falsehoods do they lead one to believe?


 * In both cases, surely there are ways of improving the passages rather than just dismissing them. Given the really odd looking "Conspiracy Theories" section as it stands, surely this is at least something of an improvement? My point of departure has been that the "main article" link is poorly related to the text in this section. That's what I've tried to fix by situating the part of the CTs that pertains to the WTC collapse (not 9/11 in general) in the space left open by the NIST report and for which it has been criticized in the mainstream engineering community (NCE). (For more of my take on this, see my arguments above at "At the risk...")--Thomas Basboll 06:57, 20 July 2006 (UTC)
 * Firstly, stating that there are limitations about the NIST and FEMA reports is POV. This is because they didn't examine the possibility of alternative theories since there was no evidence that supported it. Their job, primarily was to explain how the collapse happened, not how it might have happened, and in this I believe they are correct. Secondly, controlled demolition is not a hypothesis, and it's not even a theory...it is nothing more than an opinion. It is not supported by the scientific community and not a single reputable engineer anywhere has published a single paper regarding proof of controlled demolition.--MONGO 07:13, 20 July 2006 (UTC)


 * Mongo, I'm puzzled, are you saying that identifying the limitations of a report by quoting it's own statement of them is POV? The limitations with respect to visualization were criticized by NIST's own scientific community at a conference it hosted, and it publicly acknowledged that criticism (that's from Parker's NCE piece).
 * Moreover, NIST calls CD an "alternative hypothesis" in their official report (a part I've also quoted). But what do you mean by "hypothesis"? Most people would say "it's not a theory, it's not even a hypothesis", since a hypothesis is a much less corroborated element of science than a theory. I will grant that it is also an opinion that some people hold. But I have not presented it here as a fact or even a claim. I have presented it as a hypothesis to be tested. Thus "defenders of the hypothesis" are not necessarily defending the claim that CD brought down the WTC but rather the need to investigate that possibility. Part of their argument is that NIST, as you also say, did not really look into that possibility.
 * Finally, let me say that I see CD as a kind of baseline mechanism that certainly could bring down the WTC in a manner consistent with how it looked, at least on video, and in its final state as evidenced by photos, satelite imagery, arial photos, i.e., the material that NIST looked at. NIST identified a potentially equally destructive mechanism (impact damage, weakening by fire, collapse initiation), but they did not explore the sufficiency of that mechanism to cause a complete progressive collapse of the whole structure. That's what Prof. Bailey (who is not a conspiracy theorist) pointed out: he would have liked to see what their proposed mechanism would do to the WTC in theory (and in greater detail) and then compare it with what actually happened (i.e., the actual "structural response" of the building).
 * Best,--Thomas Basboll 08:16, 20 July 2006 (UTC)
 * So in a nutshell, you believe that the U.S. Government is culpable?--MONGO 08:24, 20 July 2006 (UTC)
 * Huh?--Thomas Basboll 08:31, 20 July 2006 (UTC)
 * Thomas please let's avoid expressing our personal belief on the facts: what metter here are not our belief or opinions, what matter are just sources of informations, criteria to accept them and way to express these informations.--Pokipsy76 08:41, 20 July 2006 (UTC)
 * The rules here on the talk pages are a bit looser, right Pokipsy? Mongo just asked me for a personal opinion that didn't seem relevant. And I didn't answer. Mongo "believes" NIST was correct in limiting their study, but that my effort to get these limits into the article are wrongheaded, because POV. My views on CD (as, say, a baseline mechanism, not to be proved but to be matched in destructive force by the final explanation) actually state my curiosity rather than my belief. The article, as it stands, does not satisfy my curiosity. Reading the NIST report went a long way to rectify that because it at least mentions explosives but it then, like I say, stops short of settling the matter of the actual collapse sequence (the roughly 16 seconds after initiation).
 * Anyway, I take it the discussion pages are the place to try out ideas and beliefs, and the article are the place to put the factual information we discover. Right now, I've contributed as series of well-documented official facts that we need to get somehow into the article in order to make it more informative.--Thomas Basboll 08:54, 20 July 2006 (UTC)


 * It occurs to me that it may be misleading to offer both the FEMA (and NOVA/Eagar) and NIST accounts of the progressive collapse. NIST's mechanism would not start a floor-pancaking but rather a column failure. So the NOVA animation, for example, does not fill in the account after NIST's "collapse initiation", though I imagine many people still think so. There are perfectly good scientific accounts that are consistent with NIST report out there (I'll get the reference shortly), but they also stop short of actually modelling the progressing collapse. They are very much a "how could it have happened" rather than "how did it happen".--Thomas Basboll 08:31, 20 July 2006 (UTC)
 * Okay, but what is the hypothesis, and do you or do you not think that the U.S. Government was involved. There was also the situation with airplanes hitting them of course.--MONGO 08:47, 20 July 2006 (UTC)
 * Of course. The CD hypothesis does not deny the airplane impacts. Sometimes, for the sake of argument, it even grants them to be sufficient (along with fire) to initiate collapse. It's the behaviour of the 70+ stories of cold steel underneath the impacts that are at issue, as I understand it, and as am trying to represent it here.
 * The CD hypothesis, in so far as it pertains to the structural collapse of the WTC and not 9/11 in general, proposes only that there were explosives in the building. There are a number of different ideas about what kind and how they were distributed. Depending on which phenomena you want to account for, and the level of abstraction (i.e., are you trying to explain particular puffs of smoke or just the speed and thoroughness of the collapse), various suggestions have been made. Like the "who dunnit" question, it's a out of my league at this point. And this article certainly doesn't need details of that kind to muddle the issue. It would be a bit like going into great detail about al-Qaida training and financing, I'd think.--Thomas Basboll 09:06, 20 July 2006 (UTC)
 * Controlled demolition is a bunch of rubbish...not one person of reputable merit has published a single paper in any respected journal that controlled demolition occured. You're in the wrong article and I suggest you take that nonsense over to the 9/11 conspiracy theories article.--MONGO 10:11, 20 July 2006 (UTC)


 * Well, in a sense, I'm trying to get the refutation of CD into this article without pitching it from a POV, a clear example of which seems to be yours. The way to do that is to quote the cool assessment of the NIST report and then make a reference to the minority view it rejects (for balance). As the article stands, the reader will not find NIST's explicit rejection of CD anywhere in the article. On this point, there is nothing wrong with 9/11 conspiracy theories article. So I don't see why I should try to make changes over there.
 * I think my proposal (and certainly the section on limitations) works even if CD is untrue. I don't think the idea that it is "rubbish" would pass either the stylistic or NPOV guidelines at WP.--Thomas Basboll 10:46, 20 July 2006 (UTC)
 * The CD stuff cannot be reliably sourced since it has never been published in any reputable journal related to examining the issue from a peer reviewed and scientific position. We do not publish original research here.--MONGO 10:52, 20 July 2006 (UTC)
 * Thomas, You will never win with mongo - his unfailing belief in NIST is faith based. If you so much as point out a misspelling or incorrect grammar he pulls out an objectection from his lucky-bag of abuse. He'll call you a conspiracy theorist, declare you NPOV or his favourite, NPA. This article is his personal kitty-litter and he won't stand to see it defiled with fact or information. Seabhcán 10:59, 20 July 2006 (UTC)
 * Everything you have commented on about me, a.) has nothing to do with making the article better, b.) is a personal attack. It amazes me that you can't see that.--MONGO 11:02, 20 July 2006 (UTC)
 * I was just informing the newby of the special rules that apply to this talk page.Seabhcán 11:04, 20 July 2006 (UTC)
 * Thomas - you should also note the unusual meaning of Original Research used here: It means anything Mongo disagrees with. Seabhcán 11:08, 20 July 2006 (UTC)
 * So what's next? Tell him I'm some top secret federal operative on some special mission to spread lies?--MONGO 11:09, 20 July 2006 (UTC)
 * Ha ha. Mongo - I don't doubt that you 'spread lies', as you put it, in your spare time. Seabhcán 11:13, 20 July 2006 (UTC)
 * Now you state that you don't doubt I spread lies...nice...--MONGO 11:26, 20 July 2006 (UTC)
 * Mongo, the evidence for CD at present has no reliable source, certainly not one that is comparable to the sources behind NIST's column failure theory, which provides the substance of this article.
 * But the dismissal of CD does have a reliable source: NIST, which I have provided.--Thomas Basboll 11:17, 20 July 2006 (UTC)
 * I.e.: I am not suggesting anything like the publication of original research, but rather the simple reporting of the official conclusions of the NIST study, its own statement of scope, and some criticism levied at it at a conference it hosted, by a perfectly reputable peer, reported in a perfectly reputable engineering trade magazine.--Thomas Basboll 11:23, 20 July 2006 (UTC)

Back to the left...you lost me...you want to show how CD wasn't looked at by NIST? Why would we do that?--MONGO 11:24, 20 July 2006 (UTC)

I'm with ya on the left, but nope: I simply want NIST's conclusion that there is no evidence for CD to be cited in the article. I also want it to be noted that NIST did not model the 16 seconds of each collapse after they were initiated.

Here's a different suggestion:

"Conspiracy Theories" (New Draft)

 * The World Trade Center was one of the major technical systems that failed as a result of the terrorist attacks of September 11, 2001. Although no major studies of the collapses had ever proposed such hypotheses, the NIST report states that it "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) This conclusion may have been a response to the widespread use of the term "controlled demolition" in the popular media to describe the disaster. In one case, a demolitions expert was misquoted as proposing explosives planted in the building as the initiator of the collapse. In his correction, he clarified that it only "looked like" controlled demolition. (Alb. Journal on Van Romero.)


 * Despite the NIST report's conclusions, the collapse of the World Trade Center has become a central issue in the 9/11 truth movement and is a staple of 9/11 conspiracy theories, along with the failure of other social and technical systems, including those of the air defenses and the intelligence community.

I'm no Bertrand Russell, but you can't tell me that isn't better prose, and more informative, than what we've got there now.--Thomas Basboll 11:58, 20 July 2006 (UTC)

"Limitations of the NIST study" (draft of proposed new section)
Independent of what we do with the conspiracy theories/CD hypothesis, here are my best thoughts on the text of a new section as of today:
 * While the NIST report is the most comprehensive study of the collapse of the World Trade Center to date, it is limited in a number of ways. First, it did not analyze the progress of the WTC's collapses through to the conclusion, limiting the scope of the investigations to "the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower. [The NIST report] includes little analysis of the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable." (NIST) That is, the total progressive collapse of the building in an estimated 16 seconds has to date not been simulated. Accordingly, the NIST report did not provide visualizations of the complete collapse of the computer models of the two towers, even though this might have provided engineers with a way of testing the hypothesized collapse mechanism against the video evidence of the actual progressive collapse, as critics noted . Finally, the study of Building 7 is not yet complete.

Comments on above proposals
This is the sort of information I had been looking for when I looked this article up.--Thomas Basboll 12:11, 20 July 2006 (UTC)
 * I think that these sections would be a major improvement to the article. No fair and reasonable person could label this as anything but NPOV and informative. Seabhcán 13:33, 20 July 2006 (UTC)
 * I agree and Back Thomas up completely. EyesAllMine 13:47, 20 July 2006 (UTC)


 * I do not see anything new in this discussin. Leaving aside the problems with sourcing, and original research by synthesis, the proposal gives undue weight to a fringe theory. We have a link to the conspiracy theories in the template, and we have a section with a paragraph and links pointing the reader to the main article, and to references. To my mind that is already excessive coverage. We should certainly not expand it further. Tom Harrison Talk 13:52, 20 July 2006 (UTC)
 * If there is "undue weight" maybe we can solve the problem expanding the informations about the "majoruty view" so much to make the weights are adequate.--Pokipsy76 14:10, 20 July 2006 (UTC)


 * I would note that there is nothing new in the accusation of "original research by synthesis" and this illdefined term has been used to knock down every reasonable suggestion. Taken to this Wahhabist extreme there is very little on this page, or infact on the whole of wikipedia, that would survive. By definition, any quotation from NIST give it "undue weight" and "synthesis", because any given quote or fact is mentioned only once in the 10,000 pages. But of course, Tom, you have no intention of applying this fanaticism uniformly. You wish only to remove statement from NIST that you feal they should not have made. I think this style of protest against an agency of your government would be more fruitful if you addressed it directly to NIST and ont on Wikipedia. Write them a letter. Seabhcán 14:05, 20 July 2006 (UTC)
 * If these sections were added they would represent only about 5-10% of the article. How small would they have to be before they didn't have "undue weight"? Seabhcán 14:14, 20 July 2006 (UTC)

Frankly, I don't see a necessity in changing the status quo. Even the 9/11 article doesn't have this "Limitations of the NIST study" thing or the summary of conspiracy theories. If we start now, will we soon have to do it on every article related to terrorist attacks? --physicq210 17:01, 20 July 2006 (UTC)

It seems odd to me to have a "Limitations of the NIST Study" section without a section on the NIST study itself. Toiyabe 17:06, 20 July 2006 (UTC)


 * I thought the rest of the article was on the NIST study. Seabhcán 17:25, 20 July 2006 (UTC)


 * Maybe put a "NIST Analysis" (including last five paragraphs of current "Collapse of the two towers" section) and a new "Limitations of NIST Analysis" sub-sections in the "Collapse of the two towers" section? Toiyabe 17:47, 20 July 2006 (UTC)


 * I like this idea.--Thomas Basboll 19:51, 20 July 2006 (UTC)

Physicq, I think the status quo on the CT section is awful. Here's what it says:
 * Some people doubt the mainstream account of September 11th and say there has been a cover-up. This group of individuals, called "A New Generation of Conspiracy Theorists" by New York Metro, disagree with the findings of U.S. Government engineers and accounts published in mainstream media sources, and raise questions they say are not adequately answered in the official 9/11 Commission Report.

Here's what it could say (at a comparable level of brevity):
 * The NIST report states that it "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) Nonetheless, the collapse of the World Trade Center has become a central issue in the 9/11 truth movement and the controlled demolition hypothesis is a staple of 9/11 conspiracy theories.

Keeping the heading and the link to the main article the same, this is surely better than status quo. It doesn't have to be new, just a better, more informative, way of establishing the link to the CT article.--Thomas Basboll 19:51, 20 July 2006 (UTC)

Tom H., the limitations section is not primarily about fringe theories at all. The most important reason to include it is probably that non-fringe engineers (like Bailey) would have liked to see the model collapse completely. But it is also important to note that the NIST report marks a transission from the "pancake collapse" image (and animation) of the buildings' "structural response" to, in effect, no image of that response, except "catastrophic failure" or something like that. We need the limitations section to avoid a natural misunderstanding, namely, that the NIST-collapse initation mechanism progresses by transforming itself into essentially the NOVA/Eagar proposal. NIST, as far as I can tell, actually refuted that proposal and put nothing in its place.--Thomas Basboll 20:05, 20 July 2006 (UTC)


 * I'm sorry, you mention that the status quo is "awful," but didn't say how it is awful. Please elaborate on how it is "awful." --physicq210 21:58, 20 July 2006 (UTC)
 * No problem, my reasons for not liking the status quo are right at the top of this archive now, immediately under "At the risk...".--Thomas Basboll 07:10, 21 July 2006 (UTC)

As the article is now, the conspiracy theories section has a breif mention and a link to the subpage and that is plenty. This is not the place to go around trying to POV push unproven and unreferencable things. If the simple fact that not one engineer of merit has ever published a single article in a respected journal about controlled demolition or these "alternative theories" isn't enough for the POV pushers of nonsense to understand, then I don't know what else to say. Unless you have some way to properly reference this information, then it simply has no reason to be here.--MONGO 22:45, 20 July 2006 (UTC)
 * It is not unproven that NIST found no evidence for controlled demolition. It can be easily referenced to the NIST report. Nor is it POV to include, in the section linking to the conspiracy theories about the WTC collapse, the hypothesis that pertains specifically to the collapses, namely, controlled demolition, which is not mentioned that section now. (In fact, the title should by "controlled demolition hypothesis".) The remainder of my proposal just rephrases and better sources the opposition of the NIST reports conclusion with the CTers, i.e., as the status quo puts it, "disagree with the findings of U.S. Government engineers and accounts published in mainstream media sources" (the second half of which - the media - is a red herring). Finally, the links I propose in the text is much more informative way of referencing "the group of individuals" that the section gestures at. This group, and those individuals, is easily identifiable in the WP articles I link to. Your admirable aim of not "pushing" controlled demolition seems to be overwhelming the more basic mission of providing informative content. Please note that I'm not introducing the conspiracy theories into this article (they are already there), I am improving the two sentences that deal with them.--Thomas Basboll 07:10, 21 July 2006 (UTC)

Conspiracy Theories, another draft
I don't think the following text to replace the body of the "conspiracy theory" section can be considered a "POV push of unproven and unreferencable things":
 * The NIST report states that it "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) Nonetheless, the collapse of the World Trade Center has become a central issue in the 9/11 truth movement and the controlled demolition hypothesis is a staple of 9/11 conspiracy theories.

I think that MONGO's point that "not one engineer of merit has ever published a single article in a respected journal about controlled demolition or these alternative theories" could also reasonably be added. Again, anyone who has been faced with the task of evaluating the CD hypothesis will want this sort of information: (a) NIST explicitly rejects it (with page references), (b) no one in mainstream engineering defends it, (c) an identifiable group of people, represented in WP, still pursues the hypothesis (with links to WP articles).--Thomas Basboll 07:10, 21 July 2006 (UTC)
 * If Mongo's point ("not one engineer of merit has ever published a single article in a respected journal about controlled demolition or these alternative theories") were to be added it would need a source. If there is a source for this, I'd be happy to see it added. Seabhcán 10:17, 21 July 2006 (UTC)
 * Instead, demostrate one paper that has been properly peer reviewed and published in a scientific journal.--MONGO 10:19, 21 July 2006 (UTC)
 * I'm willing to believe that this is not "a respected journal", if you can provide a source for this statement:
 * Research in Political Economy, Vol 23, The Hidden History of 9-11-2001, published by Elsevier Science publications (Science Direct link).
 * Also, many engineers have come out in support of CT, however it is your contention that these people are not 'of merit'. You will need to source that claim. That can't be hard, now can it? Seabhcán 10:29, 21 July 2006 (UTC)
 * The first linking abstract discusses that the hijackers were not on the planes essentially, so right off the bat, this looks simply to be unreliable. What engineers have come out in support, compared to the tens of thousands who haven't or have never bothered to because they have no proof of controlled demolition.--MONGO 10:35, 21 July 2006 (UTC)
 * How about Jeff King of MIT. Can you source a claim that he is not of Merit? Seabhcán 10:40, 21 July 2006 (UTC)
 * I don't think the statement, "The controlled demolition hypothesis has not been proposed in mainstream engineering scholarship," needs a source. It can stand til it falls since it is easily refuted with the reference. The above is obviously not such scholarship.--Thomas Basboll 10:30, 21 July 2006 (UTC)
 * Ok. Agreed. Seabhcán 10:32, 21 July 2006 (UTC)
 * I didn't say that, I said nothing has ever been published by a reputable source...see WP:RS.--MONGO 10:35, 21 July 2006 (UTC)
 * Sorry, MONGO, I'm a bit stupid today - perhaps you can explain which part of Reliable sources applies to Research in Political Economy? Is Elsevier not a good publisher? Seabhcán 10:39, 21 July 2006 (UTC)
 * Nothing wrong with the publisher...it appears to be a collection of chapters in a book titled "Research in Political Economy"...correct me if I am mistaken. Does that mean, since we are discussing simply chapters in a book, that this somehow equates with appearing at the very least in an issue of the magazine Discover, but wouldn't it be more of a reliable reference if it was from a real journal related to the situation, as in an engineering journal?--MONGO 10:49, 21 July 2006 (UTC)
 * My question isn't whether you think its bad or not, its (first), seeing that you linked it above which part of Reliable sources says its unreputable? (Second) Can you provide a source for your claim that "no reputable Engineer..." and third, What is wrong with Jeff King from MIT, and can you show a reputable source saying he is without merit? Seabhcán 10:57, 21 July 2006 (UTC)
 * I missed Jeff King...where is that listed...is it in another discussion further up? Can you demostrate a reputable enginner that has published anything anywhere that would fit the criteria for inclusion under WP policy? You ask me to prove a negative, when your chore of demostrating that there has indeed been a reputable engineer who has indeed published evidence of controlled demolition in a reliable source, should be much easier, since we both know that even if this has happened, it has only happened in one or two instances...show me the published information that has been properly vetted.--MONGO 11:07, 21 July 2006 (UTC)
 * Mongo, if your statement is to be included it will need a source. Or do you suggest that all negative statements can be included unsourced? If so I propose including the statement "No reputable journal has ever supported the belief that the World trade center was not made of cheese" Seabhcán 11:16, 21 July 2006 (UTC)
 * No, if your statements are to included they will need a source...demostrate a single reputable engineer who has published evidence of controlled demolition in a reputable scientific journal...let's see you demodstrate that. You can't demostrate that...let's see you provide refutation of this simple point. The reason? Because controlled demolition didn't happen, outside some people opinions. I looked up Jeff King...nothing of his has been published regarding contolled demolition on 9/11...all I see is him talking with 9/11 conspiracy theorists on google videos, which, interestingly enough, can most easily be linked through conspiracy theory websites, which are not peer reviewed. I'm sick of your snide commentary, very sick of it.--MONGO 11:22, 21 July 2006 (UTC)
 * Mongo, quit trying to change the subject. I DONT propose including anything about 'reputable engineers'. YOU DO propose including unsourced negative statements. I object to that. Seabhcán 11:25, 21 July 2006 (UTC)
 * I made a comment above that CD needs to be reputably referenced, I didn't once say that I want the comment: "there has never been a reputable engineer who has published that controlled demolition happened on 9/11 in any reputable source." I was only discussing what can and cannot qualify based on policy.--MONGO 11:38, 21 July 2006 (UTC)
 * Isn't this point a bit moot given the material I'm trying to introduce? I was under the impression that a consensus had been reached that "reputable source" in this article ultimately means "respected by the mainstream engineering community" or something on that order. Hence my use of mainly NIST and NCE as source.--Thomas Basboll 11:27, 21 July 2006 (UTC)
 * My recollection is that you want to say that NIST didn't find any evidence of controlled demolition becuase they didn't look for any...correct me if I am mistaken.--MONGO 11:38, 21 July 2006 (UTC)
 * Well, I'm a dynamic and open minded guy, so I've given in on that (actually, I wanted to say that those who pursue the CD hypothesis have suggested that, but the source probably wouldn't pass here). Here's exactly what I "want to say", i.e., change the CT section to say:

Conspiracy Theories, current draft proposal

 * The NIST report states that it "found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." (NIST) Indeed, the controlled demolition hypothesis had not been proposed in mainstream engineering scholarship prior to the publication of the report, and has not been suggested since. Nonetheless, the collapse of the World Trade Center has become a central issue in the 9/11 truth movement and the controlled demolition hypothesis is an important element in many 9/11 conspiracy theories.

That's my suggestion for the text. My opinions about CD, of course, aren't at issue.--Thomas Basboll 12:12, 21 July 2006 (UTC)

I just found a source that allows the following improvement:
 * "NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." This clarification was added to Part III and the executive summary of the final report in "consideration of public comments" that had been made to an earlier draft . Indeed, the controlled demolition hypothesis had not been proposed in mainstream engineering scholarship prior to the publication of the report, and has not been suggested in such scholarship since. Nonetheless, it remains a concern for some members of the public. The collapse of the World Trade Center has become a central issue in the 9/11 truth movement and the controlled demolition hypothesis is an important element in many 9/11 conspiracy theories.

Let's concentrate on this for now. I'll make the edits early next week and then move on to the limitations question.--Thomas Basboll 12:43, 21 July 2006 (UTC)
 * They will probably be reverted.--MONGO 12:48, 21 July 2006 (UTC)
 * Reverted by whom? If the person is you what's the need to speak impersonally? If it is not you why don't you let those people say themself what they think rather than speaking for them.--Pokipsy76 14:03, 21 July 2006 (UTC)


 * On what basis? Seabhcán 12:49, 21 July 2006 (UTC)
 * Well, the linking in of the 9/11 "Truth movement" which by title alone is complete POV and because he still is using the terminology of hypothesis in his summary, when it isn't that, it's simply unreliably referenced opinions that have yet to be published by a single reputable source that would properly review the material before presenting it in their journal. Seabhcan, you do understand that I have seen no evidence yet of a single reliable source regarding controlled demolition. As fas as I am concerned, if the only way Jeff King can get his opinion heard is via the consipracy theory channels, then he obviously doesn't have anything credible to say, aside from his opinion.--MONGO 12:58, 21 July 2006 (UTC)
 * Yeah, may as well air those reason now, and propose an alternative formulation. For example, there seems to me to be no reason to prefer reverting over erasing everything but the last sentence--mostly on stylistic grounds. (The New York Magazine could even kept as the source of that sentence.) I think reverting, now that that option is on the table, could only be done in bad faith.--Thomas Basboll 12:53, 21 July 2006 (UTC)
 * Why? If I find your edit to be POV and not reliably sourced, then it has no reason to stand.--MONGO 12:58, 21 July 2006 (UTC)
 * Do you refuse to explain your reasoning? Please see WP:OWN Seabhcán 13:26, 21 July 2006 (UTC)


 * Mongo, Can you explain, as a completely separate point, why you object to using NIST's own word, "hypothesis", to talk about controlled demolition in this context.--Thomas Basboll 13:02, 21 July 2006 (UTC)
 * I cannot explain why the "term" was used...I suppose they're simply trying to find a non-insulting term perhaps. You're seemingly wishing to think they called it a hypothesis as the CD had some basis in fact, when it doesn't. Other government reports about the plane that hit the Pentagon "vaporizing" (as was stated in federal reports, has also been taken out of context. Let's not do word play in some attempt to bring substance to something that has no substance.--MONGO 13:37, 21 July 2006 (UTC)
 * Ah, I see. We aren't using "hypothesis" in the same way. As I understand the word, hypotheses are not based in fact but derived from appearances and subsequently tested against facts and accomodated (or not) by theory. But you get me thinking. Maybe applying the "mainstream engineering" standard, CD is not a hypothesis, since it does not follow from appearances as perceived by mainstream/NIST engineers. Still, if we leave in your qualification that mainstream engineers do not hold it in high regard, I don't think there would be a misunderstanding. I think we're entitled to use the word "hypothesis" as loosely as NIST, don't you? Anything else would be word games, right?--Thomas Basboll 13:59, 21 July 2006 (UTC)
 * 1) Maybe NIST used the term "Hypotesis" because NIST wanted to use a neutral point of view wording like wikipedia should do?
 * 2) What's the relevance in giving your personal interpretation about what people are "wishing to think"?
 * 3) How citing NIST can be viewed as "word game"?
 * --Pokipsy76 14:04, 21 July 2006 (UTC)


 * Based on past experience, I am concerned that this change will be used to legitimize fringe theories, or will result in false information being added to the article. There's already a link in the template to 9/11 conspiracy theories, and that is enough. Tom Harrison Talk 13:48, 21 July 2006 (UTC)
 * Can you say a bit about what you imagine might happen? I simply don't see how an even stronger dismissal of controlled demolition than is in the article now, could have the effects you are concerned about.--Thomas Basboll 13:59, 21 July 2006 (UTC)
 * Recently a user calling himself 'Truthseeker' added material he cited to a New York Times article. The material he added claimed a different, tendentious headline and included a "quote" and other words that appeared nowhere in the article. The same ironically-named truthseeker created another account that he used to deliberately add false information to the article. Lies, I suppose, to help us better understand Truth. Of course you, Thomas Basboll, would never do a thing like that, so maybe my concerns are misplaced. Tom Harrison Talk 14:33, 21 July 2006 (UTC)
 * So far IMHO I haven't done anything to call my good faith into question, or even to associate myself with the sort of editor you are describing. But they exist, so my assurances aren't going to make a lot of difference. Pokipsy (below) is probably right that we just have to keep our heads up. In any case, the status quo is not a better guard against it. In fact, since it could obviously use some work (it sticks out like a sore thumb in terms of style, sense and sources) its more open for gratuitous editing than my suggestion. IMHO, the passage I'm suggesting sets a higher standard.--Thomas Basboll 15:35, 21 July 2006 (UTC)


 * It's up to you and other editors to avoid that a change could be used in that way, it's not a reason to reject a valid change.--Pokipsy76 14:04, 21 July 2006 (UTC)
 * We don't allow violations of reliable sources to stand...there are no reliable sources for controlled demolition.--MONGO 14:14, 21 July 2006 (UTC)
 * I just see people asking to cite NIST, are you suggesting NIST is not reliable?--Pokipsy76 14:55, 21 July 2006 (UTC)


 * Nor are any claims for controlled demolition being made. Nothing in the proposed text says that WTC were brought down by controlled demolition. In fact, it is not even presented as a viable hypothesis. The passage claims, truthfully, that NIST found no evidence (and provides NIST as a source); it goes on to claim, truthfully, that mainstream engineering scholarship has not proposed CD even as a hypothesis; it claims, truthfully, that NIST was confronted with inquiries from the public about CD (citing NIST as source); finally, it claims, truthfully, that, despite this, the 9/11 truth movement and 9/11 conspiracy theories continue to pursue controlled demolition as a hypothesis.--Thomas Basboll 15:52, 21 July 2006 (UTC)

---

I think we've reached the same old impass again. Mongo doesn't want anything changed, Tom is afraid of changing anything and MMX1 (which stands for "Mini-Me of Mongo X1") will chime in any moment now with a WP:NPA warning. Seabhcán 14:30, 21 July 2006 (UTC)
 * WP:NPA--MONGO 14:31, 21 July 2006 (UTC)


 * Wow, you beat him to it! Good work. Seabhcán 14:38, 21 July 2006 (UTC)

9/11 Truth Movement
Mongo says that "the linking in of the 9/11 'Truth movement' ... by title alone is complete POV". What does this mean? I.e. how does something become POV "by title alone"? I'm new here and still learning. This is by far the most difficult edit I've made yet.--Thomas Basboll 17:04, 21 July 2006 (UTC)


 * Meaning that the "9/11 Truth Movement" is neither truth nor a movement. Perhaps you could modify by saying something like "self-described '9/11 Truth Movement'", or something that idicates that "9/11 Truth Movement" is not a description but a name.  Toiyabe 17:17, 21 July 2006 (UTC)


 * (Just a thought... How can a movement, that isn't a movement, be a self-described movement. If it isn't a movement (ie, doesn't exist) then how can it describe itself? Seabhcán 17:38, 21 July 2006 (UTC))


 * Semantics ... If I legally changed my name to "Tall Man" then an article that mentions me should take care that the reader knows that's my actual name, not a description of me, regardless of whether the description is accurate.


 * This isn't a point I'm particularly concerned about, I'm just articulating what I think are other people's concerns. Toiyabe 17:54, 21 July 2006 (UTC)


 * If we go down that road, we'd have to put the prefix "self descibed" before everything. I think I'll start with myself. Self-Described Seabhcán 17:57, 21 July 2006 (UTC)


 * You said it is not a movement and in fact a "self described movement", the problem is what is this thing that is describing itself as a movement if not a movement? A person? A group? What?--Pokipsy76 18:05, 21 July 2006 (UTC)


 * OK, how bout this "Nonetheless, the collapse of the World Trade Center has become a central issue for a number of groups and individuals collectively known as the 9/11 Truth Movement and the controlled demolition hypothesis is an important element in many 9/11 conspiracy theories." Toiyabe 18:27, 21 July 2006 (UTC)


 * I think the "groups and individuals" phrase begins to get us back to the clunkiness of the status quo, but I think I see what you're driving at. You don't want to suggest that "the movement" has any agency of its own, i.e., is no more than the sum of its parts (which must then be named in order for there to be "someone" to have the "issue"). There's something to be said for that. But the article on the movement actually lists controlled demolition as a "characteristic". So perhaps we could say: "Nonetheless, the controlled demolition hypothesis has become characteristic of the 9/11 Truth Movement and many 9/11 conspiracy theories." It has the virtue of brevity. The "known as" is not a big issue for me, but it should applied equally, so we'd have: "Nonetheless, the controlled demolition hypothesis has become characteristic of what is known as the 9/11 Truth Movement and many so-called 9/11 conspiracy theories." Again, it approaches the clunkiness I was trying to avoid. But I don't think I'd revert an edit that made those qualifications. (I might try to talk the editor out of them, though.)--Thomas Basboll 18:54, 21 July 2006 (UTC)
 * Why do we need to mention the 9/11 Truth Movement...is that the biggest or most trusted of the movements out there? I can see no reason to mention them in this article since the only thing they have to sell is not properly vetted.--MONGO 18:57, 21 July 2006 (UTC)
 * My aim was to be a bit more specific than "group of individuals that New York magazine called conspiracy theorists". It ("9/11 Truth Movement") is an accurate way of identifying a milieu where the discussion is going on (after having made it clear that mainstream engineers do not discuss it.) It's the most economical way of doing that. The alternative would be list specific names (Jones, Hoffman, King, etc.) and organizations (like Scholars and MUJCA, etc.) People who are being informed about the hypothesis should be informed about where it is being pursued. I'd want to know that sort of thing.--Thomas Basboll 19:15, 21 July 2006 (UTC)
 * I can live with either of the bolded phrases. I prefer the first one. Toiyabe 19:12, 21 July 2006 (UTC)
 * Me to. Thanks.--Thomas Basboll 19:15, 21 July 2006 (UTC)
 * I suppose it could be capitalized as you have done, indicating that it is a name. Clicking on the link would straighten out any remaining confusion about what it means (though there is something odd about that link ... anyone know how to fix it?). I definitely mean it as a name. But I think "self-described" might be pejorative (like so-called). As I understand the name, it means only (implicitly) that the whole truth is not known (which is really not very controversial) and that more ought to be done to move towards it (which is the controversial part and the goal of the "movement"). The question of whether or not it really is a movement is probably exactly as moot as the status of the discussion about deleting the WP article about it. So long as that article exists, mentioning it can't "by title alone" be wrong. Or what?
 * Anyway, thanks for the suggestion, Toiyabe. I'll make sure to mark it clearly as a name not a description.--Thomas Basboll 17:30, 21 July 2006 (UTC)


 * It's tough to find the wording that makes everyone happy. 9/11 Truth Movement (note caps) is the correct link. Toiyabe 17:40, 21 July 2006 (UTC)

The opening of the article
I've cleaned up quite a bit in the opening few paragraphs in order to provide a clear summary of the basic collapse mechanism, and the structural response/performance issues that have been central to the FEMA and NIST investigations. I hope I haven't killed anybody's darlings too cruelly. Note that I moved the "row erupts" part into the "design criticisms" section. I didn't know where else to put it and I didn't think it should be lost altogether; it just didn't seem to fit the now more confident tone of the intro. If anyone wants it back, I suggest adding a single sentence like, "Though the FEMA and NIST investigations have settled most questions among engineers, some engineers still fault the design of the towers to varying degrees."--Thomas Basboll 00:36, 22 July 2006 (UTC)

Old and new info?
I've been looking at the article's sources and it strikes me that instead of presenting the best explanation (NIST's), the sections sort of cobble together bits and pieces of all the explanations that were provided (including some that date back to late 2001.) I've therefore added a section for "earlier theories and investigations", where these ideas, which may be of historical interest, can be presented. I suggest always checking whether your source was published before or after September 2005, which was when the NIST report (in its final form) came out. Not that earlier sources will be wrong, just that they may conflict (like NOVA, Eagar, and much of FEMA's reports) with what NIST finally determined to have happened. In most cases, no expert opinions other than NIST's conclusion really need to be cited. I'm open to disagreement on this, of course.--Thomas Basboll 08:09, 22 July 2006 (UTC)

Removed Tom Wilkinson's theory (outdated)
I've taken out some of the early speculation about the collapsed, which has been superceded by the NIST report and now doesn't fit into the collapse mechanism section. It could perhaps be worked into the section on earlier theories. Here's what I took out:


 * In the south tower, intense fires led to a sudden bursting of bolts in one section, while the failures in the north tower core involved slower creep and softening effects.
 * The two towers collapsed in markedly different ways, which may indicate that there were two modes of failure. The north tower collapsed directly downwards, "pancaking" in on itself, while the south tower fell at an angle during which the top 20 or so stories of the building remained intact for the first few seconds of the collapse, then pulverized into dust in mid-air, and the tower continued straight down. In spite of these differences, an Australian structural engineer believes that the "same mechanism of failure, the combination of impact and subsequent fire damage, is the likely cause of failure of both towers"

The coverage of the NIST report is actually pretty thin (as you can now see). I'll try to add some detail. Anyone who wants to help should look at page 179 and forward of the NIST report.--Thomas Basboll 14:32, 22 July 2006 (UTC)

Removed Eagar's theory (outdated)
Here's the text:


 * The two towers collapsed in markedly different ways, which may indicate that there were two modes of failure. The north tower collapsed directly downwards, "pancaking" in on itself, while the south tower fell at an angle during which the top 20 or so stories of the building remained intact for the first few seconds of the collapse, then pulverized into dust in mid-air, and the tower continued straight down. In spite of these differences, an Australian structural engineer believes that the "same mechanism of failure, the combination of impact and subsequent fire damage, is the likely cause of failure of both towers"


 * Subsequent modeling suggests that in the north tower the internal trusses supporting the concrete floors failed as a result of heat-induced warping. This would have placed additional stress on the bunched core columns, which were losing integrity from both impact damage and heat. When the core columns gave out on one of the impact floors, this floor collapsed into the floor below. Once the collapse started, it was unstoppable; the huge mass of the falling structure had sufficient momentum to act as a battering ram, smashing through all the floors below. Witnesses from within the tower stated they heard "something like a heavy freight train approaching".

This stuff (and especially the "pancaking") is misleading after the publication of the NIST report, but it should definetly be worked into the "earlier theories" section. Again, the "collpase mechanism" as actually described by NIST turns out to be very under-represented in the article. Working on it....--Thomas Basboll 14:40, 22 July 2006 (UTC)

On second thought...
I see Mongo's point of reverting. I just wanted to get the early speculations (even though they have references - old ones) out of the known collapse mechanism. There will be a little work to do to rewrite the "earlier" section as a narrative in the past tense.--Thomas Basboll 15:07, 22 July 2006 (UTC)

New section: "Cleanup"
It would be interesting to have some information on the extensive and difficult clean up process. It would also be an approapiate place for this excellent photo which keeps getting removed because some editor mistake it for evidence of demolition (its actually just a picture of the clean-up opperation) Self-Described Seabhcán 21:51, 22 July 2006 (UTC)


 * Good idea. There are a lot of rumours about the cleanup. It would be good to have some basic, uncontroversial facts about (1) when it began, (2) who was in charge, (3) when the site was finally cleared, (4) where the materials went (and how they entered the investigation process.)--Thomas Basboll 22:17, 22 July 2006 (UTC)

New section: Dust
Theres a lot of interesting material out there on the dust. There's some in the article already, but I think it would be useful if we collected it under one heading. It also effected a lot of people in New York, not least the rescue workers, some of whom have died from exposure. It also has no connection to any conspiracy theories that I am aware of (I think we can all accept that there was dust and it was a result of the collapse) - so we (hopefully) can discuss it's inclusion with civility. Self-Described Seabhcán 14:37, 23 July 2006 (UTC)


 * Maybe a section about the aftermath, with sub-sections for the clean-up/rescue operations and one about the effects on the city. There's a mainstream scandal (not CT) in which the Whitehouse revised the EPA's statements about air quality in order to re-open Wall Street as quickly as possible. The current "other buildings" could also be moved in there, maybe.--Thomas Basboll 16:08, 23 July 2006 (UTC)


 * You are aware there is an article on the Aftermath_of_the_September_11,_2001_attacks, right? The after-effects of the dust belong there, not here. Unless you have a point to make about squibs such ideas. --Mmx1 16:52, 23 July 2006 (UTC)


 * No, I wasn't. Thanks. It looks like it would suffice to add a section called "Aftermath" and link to directly to the sections that are relevant in the article you point out.--Thomas Basboll 17:20, 23 July 2006 (UTC)
 * On the other hand, the dust cloud itself is a physical feature of the collapses that does belong here, including its composition of various toxic particles (from the computer, fire-detectors, etc.). Some of that information is very briefly touched on in the "Aftermath" article. The details belong here.--Thomas Basboll 17:24, 23 July 2006 (UTC)
 * Sure, I can see a sentence mentioning that the collapse generated dust from office equipment; for unity, why not put that as part of the synopsis paragraph of "Aftermath" here, and link to the "Aftermath" Article. There, I think, it would be appropriate to expand and go fully into an analysis of the composition of the dust. --Mmx1 17:36, 23 July 2006 (UTC)
 * Let's be bold and try to work it out in practice. I think the section on the practical aftermath (like rescue and cleanup) could be very short and link to the main article; but the physical properties of the collapses (which includes the duration of the fires at ground zero and the dimensions and composition of the dust cloud) belong in the article on the collapses itself. I'm going to look at some of the official accounts and try to come up with a description of them that includes the dustcloud right at the beginning of the "Collapse of the two towers section". Then I'll add a "see also" link.--Thomas Basboll 17:43, 23 July 2006 (UTC)
 * Great. I wish I could help but I'm engaged in another research effort ATM. I'm just offering suggestions on how to properly organize and segregate the information you're coming up with. Great work so far.--Mmx1 18:03, 23 July 2006 (UTC)

Suggested merger of construction, impact and design criticism sections
The section on design criticism needs some work anyway, so I though maybe we could merge the relevant parts of it into the section on the construction and aircraft impacts sections (where the kinetic energy comparisons would be very useful). The design has been officially exonerated (twice) and this is noted at the top of the article. The specific criticism of the lightweight design could be worked into the "search" narrative in the collapse section. Any thoughts?--Thomas Basboll 19:11, 23 July 2006 (UTC)


 * I think that the design criticisims section should be merged into the construction section, with a sub-section for the enumerated points. There's some information at the bottom of the criticisims section that is redundant and can probably be removed without adding it back in elsewhere.


 * The crux of the criticisims is not that the design did not meet its requirements - it's that a more traditional design would be better able to survive unforeseen events (i.e. events not part of the requirements). It's a larger philosphical issue in modern engineering - in my field the issue is expressed in method specifications vs. performance specifications.  Up until recently we had predominantly method specifications, which dictate how the structure should be built, largely based on previous experiance.  The newer performance specifications dictate performance parameters (e.g. shall have a maximum roughness of X after Y years of service), but give the engineer a lot of leeway in figuring out how to meet those parameters.  This can lead to much more efficient designs, but (arguably) exposes you to more risk in errors in modeling and unexpected events (i.e. events that you didn't consider at design-time).


 * For example, an older method spec for fireproofing might require X inches of concrete around the steel members. A newer performance spec might require fireproofing such that the steel's strength not be reduced more than Y% after Z hours of exposure to a fire at W temperature.  So under the performance spec you could design fireproofing that has better fire resistance than the old method spec and is lighter, but it may have less impact resistance - the condition that was not considered in the performance spec.  Note that this is just an example, I'm not that familiar with fireproofing specifications.  Toiyabe 17:22, 24 July 2006 (UTC)

Another merger proposal
A merger proposal is gaining steam at Articles for deletion/Survivors of the September 11, 2001 attacks. Comments from regular editors of this article would be most appreciated. Thanks!--Kchase T 07:21, 24 July 2006 (UTC)

Opprobrium for Robertson?
I took this out:
 * Some see the WTC as an irresponsible experiment in lightweight, rent-space-maximized construction and place particular opprobrium on Leslie E. Robertson, its Chief Structural Engineer. Others see it as a landmark in structural engineering simply in need of refinement due to unforeseen, and probably unforeseeable, variables.

If someone has a source for this and the idea remains current after the NIST report, you can put it back in in the construction section.--Thomas Basboll 19:23, 24 July 2006 (UTC)

Single bolt theory out
I removed Eagar's single bolt theory from the construction notes. This is the text:
 * Single-bolt connections binding the longspan floorplates with the load-bearing external columns were extremely light in weight for their assigned task. A study group from the Massachusetts Institute of Technology concluded the proximal cause of the south tower collapse was failure of these bolts in the southeast corner of the building. Double-bolts should have been used.

If there's anythin you want to keep, please put it into the past investigations section (where Eagar now has his own subheading.--Thomas Basboll 19:41, 24 July 2006 (UTC)

Controlled demolition, anyone?
Well, yes, and here we go again ... as Hunter S. Thompson might say. As you can all see, I've been moving things around quite a bit in the article, bringing the current best explanation into the foreground while marking early speculations, like "fires melting the the steel", as just that: speculations, hypotheses, etc. They were each more or less right, but all ultimately wrong. According to NIST, everything from steel-melting fires, to truss failures (Eagar's single bolts) and floor pancaking (NOVA), have been given a sympathetic ear but lovingly rejected. My question is: why not put controlled demolition in this category and give it a place in the history of the investigations? It was accidentally suggested by the controlled demo expert, Van Romero, and even Shyam Sunder has said he's "sympathetic" to the hypothesis but "the facts are the facts". I don't see the argument for silencing the idea as one among many early hypotheses. If you think about it, it is only as wrong as the fires-melting-the-steel idea. When it was originally proposed, i.e., in the mass media as a "secondary device" theory, it was naturally assumed to be bin Ladin's idea. Anyway ... have at me.--Thomas Basboll 20:18, 24 July 2006 (UTC)
 * You've been doing some great work on the article, Thomas. About the controlled demolition move, I think its a good idea so long as it doesn't mean removing the short section and link to the conspiracy theory article. That should stand so as to direct editors and readers to the correct article. Self-Described Seabhcán 20:43, 24 July 2006 (UTC)
 * Couldn't it simply go under a "controlled demolition" subsection in the investigations section?--Thomas Basboll 20:50, 24 July 2006 (UTC)
 * To clarify: at bottom I don't see controlled demolition as a conspiracy theory but as a hypothesized collapse mechanism. I understand that the two have historically come to be inseparable, but from an engineering perspective, CD is (apparently) just an unecessary assumption that was not needed to explain the collapses. It has nothing in particular to with "folks gettin together to commit a crime".--Thomas Basboll 21:00, 24 July 2006 (UTC)
 * In the main stream, yes CD has been dismissed and is seen as unnecessary to explain the collapse. However, in the CT world they continue to debate CD. We should separate the officially dismissed early CD suggestions from the CTs, both because these strands of thought are completely seperate and also because a seperate, short, CT section and link will serve to channel users to an article where, rightly or wrongly, these views are tolerated. Self-Described Seabhcán 21:11, 24 July 2006 (UTC)


 * Hello Thomas. I created this article (unfortunately the history got garbled due to somebody doing a messy title change) and kept it current for about a year before deciding to let it stew for awhile on its own. Many of the changes are really good, a few are awful and will collapse in 10 or perhaps 12 seconds after they appear in my edit box... I like most of the very recent changes you are making and am thinking that with a little more sourcing, a little tuning in the "thematic progression" department, a few more direct quotes from leading experts, and a good grammar/spelling scrub, it may well merit a FA nomination... BUT, I can't go with you on the idea of including controlled demolition among the primary hypotheses. Perhaps it "has a place in the history of the investigations", but, for folks who spend most of their time outside asylums, that place would mostly be one of psychological interest rather than structural engineering interest. But we can discuss this too... Well I went and got all revved up to make the last push on this article, but I'm not sure how much I can deliver. Cancer, unfortunately. If Lady Luck hops into the sidecar and I have good energy for a few stretches among the next 7 days, and you're up for it, I think we can dress this baby up into the single best synopsis of the subject to be found on the `net. JDG 21:17, 24 July 2006 (UTC)

I've stepped back from editing but have watched Thomas's work and it mostly looks fine. As far as this being on a level par with featured status, well, we can shoot it through the peer review process and get some more outside feedback. Maybe folks there will demand we address the issue of controlled demo...maybe they won't. With the pletoria of imagery available, we could add sme more pictures. Care must be taken in this matter however since about 1 billion people lost someone they know or were greatly impacted by the event watching it unfold in front of their very eyes, or on the tele. I, for one am opposed to the controlled demolition for a couple of reasons. I'll try to be polite about it. Not a single engineer, CD expert, or even forensic study of structural evaluation has been performed which has been published in a reliable journal dedicated to close examination of such processes. The NIST, FEMA reports have been screened by outside bodies and they concur with the evidence presented. Secondly, if the controlled demolition stuff is entered into the article, the cross examination of this will result in the article becoming longer substantially, and it will become unmanageable. I have seen that almost no scientists even bother to argue with the CD proponents. So, unless we do in house cross examination, we only can say, well, no that couldn't have happened because the NIST report says this....anyway, no to controlled demolition.--MONGO 21:40, 24 July 2006 (UTC)


 * Hi, JDG, thanks for the encouraging words. Sorry to hear about the cancer ... my very best thoughts, for what they're worth. And I look forward to polishing this article off with its originator. An honour. The topic is certainly worthy of an FA, but, as Mongo points out, there are still issues.
 * Anyway, yes, I think we should talk about the "psychological" interest of the CD theory. I've never spent any time in an asylum, and have no engineering training. I'm just an ordinary mind trying to make sense of an extraordinary event. I think many people who have really tried to understand how those buildings went down have been puzzled by it at least for a while. The CD hypthesis, if it were true, would make sense of appearances (as Van Romero pointed out ... see below). The NIST mechanism, even now that I've sketched it in some detail, still doesn't make sense to me. There are those 80ish floors of cold steel, a "rigid box", that are completely obliterated by a process engineers seem to think "inevitable" but ordinary mortals like me would like to see simulated (or at least given a new NOVA animation.)--Thomas Basboll 21:53, 24 July 2006 (UTC)

To be concrete, here's what I propose to insert in the "Investigating the collapses" section, near the top:

The controlled demolition hypothesis

 * On the day of the attack, Van Romero, an explosives expert in New Mexico, told the Albuquerque Journal that the collapses of the towers looked "too methodical" to be triggered by the aircraft impacts and fires. He said they looked like they had been triggered by "explosive devices inside the buildings" . He later clarified his position, saying that he did not believe that any such explosives had in fact been involved; he was merely noting that that is what it looked like Indeed, NIST would find "no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001." This clarification was added to Part III and the executive summary of the final report in "consideration of public comments" that had been made to an earlier draft. Indeed, the controlled demolition hypothesis had not been proposed in mainstream engineering scholarship prior to the publication of the report, and has not been suggested in such scholarship since. Nonetheless, the controlled demolition hypothesis has become characteristic of the 9/11 Truth Movement and many 9/11 conspiracy theories.

Please accept or reject this idea in the new context of the article as is. I am suggesting we delete the "conspiracy section", for the reasons stated above.--Thomas Basboll 21:53, 24 July 2006 (UTC)


 * Accept : That looks excellent. you've changed my mind. Self-Described Seabhcán 22:01, 24 July 2006 (UTC)
 * Change last sentence from "Nonetheless, the controlled demolition hypothesis has become characteristic of the 9/11 Truth Movement and many 9/11 conspiracy theories." to "The controlled demolition hypothesis is a fundamental concept embraced by most 9/11 conspiracy theories." I see no reason to have the 9/11 Truth Movement mentioned at all. They are just one group and not particularly more notable than any other group, aside from being perhaps the loudest...their arguments are no more convincing, however.--MONGO 22:12, 24 July 2006 (UTC)
 * Conditional Accept : accept after applying MONGO's above proposed change. --physicq210 22:16, 24 July 2006 (UTC)
 * I think the phrase "a fundamental concept embraced by most" is a bit presumptuous. Making that claim would demand, if you'll pardon it, some original research. The word "characteristic" comes from the WP article on the truth movement, which is not to be confused with Scholars for 9/11 Truth (who may be the small, loud group you're thinking of.) 9/11 TM is just a covering term for a bunch of activities being carried out by a bunch of people interested in the same thing very broadly speaking. When I began to look into this stuff it very quickly made ordinary sense ... as people have pointed out, a bit like Gay Pride and the Peace Movement. I think you're making too big a deal of it.--Thomas Basboll 22:19, 24 July 2006 (UTC)

OK, being bold...
I've accepted Mongo and Physicq's corrections. And drawn a bit on the status quo. See if you like it. I'd still like to add "...and it is a characteristic issue of the 9/11 Truth Movement." But I'll take this one step at a time.--Thomas Basboll 22:41, 24 July 2006 (UTC)
 * I see zero reason to mention them...this will make for a serious issue as I see no reaosn to use this article for a platform for their misinformation...sorry.--MONGO 06:15, 25 July 2006 (UTC)
 * I think you and I have a different sense of who "they" are, Mongo. When we return to this issue (after the remaining cleanup work has been done), I think we should compare notes about what we think the movement is.--Thomas Basboll 06:29, 25 July 2006 (UTC)

Smoothness of Article
I'm starting to think that the article is getting way too choppy. We have information, but at the expense of smoothness, clarity, and conciseness. Or maybe the article is just one big construction site for the time being. Any thoughts? --physicq210 22:42, 24 July 2006 (UTC)
 * I'll grant that. I think the new headings serve to emphasize a choppiness that was already there, but less visible on the surface before. The article jumped around from theory to theory, fact to fact, a bit too much for my taste. I've basically just been putting all the odds in ends in neat(er) piles. Give us a week or so and see if it gets better. It's certainly easy to navigate now (and, as an now frequent editor, I've come to appreciate the ability to take one section at a time into the text-editor.)--Thomas Basboll 22:52, 24 July 2006 (UTC)


 * I would recommend moving the "The collapse mechanism" sub-section into the "National Institute for Standards and Technology (The NIST Report)" section, and moving that to the top of the "Investigating the collapses" section and putting the rest in an "Other Investigations" sub-section (confused yet?).


 * After the outline is decent, maybe we should cool off on big changes for a while to re-group and polish what we've got. Toiyabe 23:02, 24 July 2006 (UTC)


 * Agreed. --physicq210 23:08, 24 July 2006 (UTC)


 * Another option: group construction, impact, fire, collapse characteristics, and collapse mechanism under one first main section called "The NIST Report", which would also explain how it was written and what its scope was. That would make the presentation of the NIST report and the presentation of the best explanation one and the same thing. Then have another main heading that goes through the previous attempts to explain the collapses.--Thomas Basboll 23:27, 24 July 2006 (UTC)


 * I think it would be best to try and keep observations and analyses separate, realizing that the line can be a bit fuzzy. In my mind, construction, impact fire and collapse characteristics are on one side of the line and NIST Report and other investigations are on the other, although NIST report also includes useful information on the construction etc.  Toiyabe 23:55, 24 July 2006 (UTC)


 * Yes, I was actually thinking that the NIST report could be taken as the definitive statement on the construction and, especially, the impacts and fires (which is where they really did their modeling.) For example, we need to add something about the hat truss in the construction section, since it turned out to be so important.--Thomas Basboll 06:45, 25 July 2006 (UTC)

FYI: Interesting story in UK
Glasgow tower block to shed light on 9/11 fire - A PROFESSOR of engineering is to destroy a Glasgow tower block in an effort to understand why the Twin Towers collapsed in the 9/11 attacks. Jose Torero, Professor of Fire Safety Engineering at Edinburgh University, will set the disused building in the east end of Glasgow alight and study the effects... Self-Described Seabhcán 23:31, 24 July 2006 (UTC)

A.S. Usmani, Y.C. Chung, J.L. Torero; "How did the World Trade Center Collapse: A New Theory", Fire Safety Journal, 38, 6, 501-591, 2003 (PDF) (Torero is the above mentioned professor Self-Described Seabhcán 23:50, 24 July 2006 (UTC))
 * Okay, and? Are these strutures at all similar to the WTC...is he also going to impact them with wide body jets? No and no. It looks like he is mainly focused on how to make buildings safer in fire. I think, that computer modeling does the best in terms of analizing the events of 9/11...so unless someone does the same thing to the Sears Tower or a similar tall building of similar construction and getting hit by similar size jets with about the same amount of fuel and flying at the same speed, it is pretty hard to actually "recreate" the situation as they happened in real life.--MONGO 06:21, 25 July 2006 (UTC)
 * Alos, as the abstract plainly points out..."This investigation does not take into account the structural damage caused by the terrorist attack."...so it is just a fire analysis.--MONGO 06:47, 25 July 2006 (UTC)
 * I don't understand your complaint, Mongo. With the Fire Safety Journal reference and the Scotsman story, this looks like a perfectly legit (though perhaps flawed) scientific inquiry into the performance of steel frame buildings under (what it claims are) WTC conditions. Ideally, we would wait til Torero publishes his results, but if he interprets it as WTC-relevant experiment and his peers agree with him in their review, then what's the problem?--Thomas Basboll 06:39, 25 July 2006 (UTC)


 * This part of the story may be worth pursuing: "[Torero] is one of a number of experts across the world who believes that the Twin Towers should have stayed up after they were hit by hijacked airliners on September 11 2001."--Thomas Basboll 06:42, 25 July 2006 (UTC)
 * If he isn't going to fly wide body jets into the buildings, then what good is it as a cross examination?--MONGO 06:45, 25 July 2006 (UTC)
 * He could go in an cut a comparable percentage of the columns. He could remove one column section on one floor and trace the load redistribution. He could observe the weakening of the steel. I'm not exactly sure, but isn't he, and not you and I, the reputable expert?--Thomas Basboll 06:59, 25 July 2006 (UTC)
 * Well, of course, but the point is, what columns does one cut, is he going to study load distribution...are the buiildings steel framed or instead built in a very closely parallel manner to those at the WTC? What we seem to have is someone doing a fire investigation, rather than a collapse study. Is the building going to have similar materials, similar venting, aviation fuel used as an the primary combustible. Is the building even remotely similar in mass, of a similar height and is the fire going to be at a zone of similarity, such as a similar mass percentage above the fire point. The study looks like it will be a fire study, and we already have plenty of those from real life...albeit, they are mostly of steel framed buildings and none of them were hit by a wide body jets laden with aviation fuel at flying at 500mph or greater.--MONGO 07:10, 25 July 2006 (UTC)
 * My point wasn't so much that he would do anything in particular, but mainly that he and his peers are better qualified than you and I to determine whether it is a WTC-relevant experiment. We don't (I certainly don't) know enough about engineering in general, or his study specifically, to make this judgment call. But we've got reputable source that makes the call for us. Keep in mind that the NIST study was largely, and in its decisive aspects, a fire study. To simulate the hypothesized collapse mechanism you might just have to take out some percentage of columns and see if fire can cause the buckling of the remainder. (Naturally, the most interesting thing from my point of view is what happens after "collapse ensues".)--Thomas Basboll 07:26, 25 July 2006 (UTC)
 * Prof Torero's theory is that the fires were primarially/totally the cause of the collapse - which is why he isn't simulating the plane impacts. A note on his theory and experiments can added to the section "The Fires" or, as he disagrees with the NIST and his research continues today, to the "The Last Word?" section. Self-Described Seabhcán 09:31, 25 July 2006 (UTC)
 * Yes, with the NCE piece it does look there is an open question there in the mainstream eng. community: would fire alone have done it? (That's an argument for putting it in the "last word" section.)--Thomas Basboll 14:24, 25 July 2006 (UTC)

This is why the popular press is not so helpfull on these sort of issues. If you read carefully it appears that the experiment is about how a fire spreads through a building. - "Experts now want to understand why the fires spread so quickly and how to stop it happening in future." and "The concept is that if we can get an accurate idea of what is happening inside the building, I can lead people to safety and minimise the growth of the fire." I don't see anything about structural considerations.

Of course if the building does not collapse, which is pretty likely, some folks will think that is a vindication of the CD theory. If it does collapse, the opposite. In reality, that's not what the experiment is about. Toiyabe 15:09, 25 July 2006 (UTC)


 * It isn't entirely the fault of the press - I imagine that Prof Torero suggested the connection with the WTC, as I doubt it would have occured to the reporters themselves. My experience with the press is that if you want to get a scientific press release published you have to make it sexy, I'd imagine thats what Prof. Torero did. Self-Described Seabhcán 08:56, 26 July 2006 (UTC)

I've put this theory (that fires were a sufficient cause of the collapse) into the article under "early attempts". The Usmani et al. paper is a very interesting read, with lots of structural modeling (albeit admittedly simplified). Some readers may find it useful.--Thomas Basboll 09:19, 26 July 2006 (UTC)


 * I've noticed that virtually all papers on the subject refer to Bazant and Zhou (2002) to explain the global collapse, and thus every paper now simply tries to explain what brought the structure to the point of failure. Bazant and Zhou (2002) makes the claim that the forces exerted on the lower structure by the upper structure falling on it were an order of magnitude above what the building could withstand. They also try to explain the speed of the collapse using a sort of shock wave idea which weakended the structure in advance of the battering ram effect of the falling upper floors. Self-Described Seabhcán 09:30, 26 July 2006 (UTC)


 * That seems reasonable. Why not just put it in near the top of the "early attempts" section and include your observation about that they seem to be the first to offer an explanation of the global collapse?--Thomas Basboll 09:42, 26 July 2006 (UTC)


 * Ok, I'll do it later today. Self-Described Seabhcán 10:17, 26 July 2006 (UTC)
 * Just added section on Bazant paper. It got me thinking that we could combine some of these sections: 5.1 5.3 and 5.4 could be combined under "Global Collapse", 5.2 and 5.11 could be combined under "The Fires". Self-Described Seabhcán 11:14, 26 July 2006 (UTC)


 * Prof. Torero's experiment has taken place. I'm looking forward to his publications on this. Self-Described Seabhcán 11:31, 27 July 2006 (UTC)

Footnote numbering is off
Can somebody please fix -- I'm not familiar with the citation style. Morton devonshire 05:55, 25 July 2006 (UTC)

New Outline
I've reorganized the article to reduce choppiness and improve flow, while continuing the process of foregrounded the best (NIST) explanation we have. If you like this, I want to go through section 1 and make sure it is really based as much as possible on the approach and conclusions of the NIST report. And of course to clean up the prose and order of ideas.--Thomas Basboll 10:41, 25 July 2006 (UTC)
 * I'd like to let the recent changes settle for a few days. Tom Harrison Talk 14:24, 25 July 2006 (UTC)
 * I second that. Let's look over what we have, as honestly, I watched the article go through changes working from beginning to ending and now the shifts seem to be to incorporate more conversation about psudeoscientific CD elements.--MONGO 15:22, 25 July 2006 (UTC)
 * Fair enough, Tom. But I really liked Toiyabe's suggestion about moving the NIST analysis up to the top of the article. Since NIST is the most authoritative source for the individual components (construction, impacts, fires, collapse initiation) it seemed tidier to do it that way; and it avoided the current sub-sub-heading level. Anyway, let's see how the current sections settle.--Thomas Basboll 18:41, 25 July 2006 (UTC)
 * Mongo, I think you'll find that only one of the changes has anything to do with CD, and nothing to do with the general overhaul. The article has simply achieved enough balance to be as sympathetic as, say, Shyam Sunder is to those who would consider CD for a while (as part of the activity of working through the collapses and arriving at an understanding of them) and then reject it. Just like the steel-melting fires nonsense. We might say the article no longer needs to feel threatened by CD.--Thomas Basboll 18:41, 25 July 2006 (UTC)
 * I disagree..the article is not the place to take psuedosicence and then debunk it...I say stick to the known facts and leave the psuedoscience at the curb. I don't even see a reason to link to the conspiracy theory junk science article(s)...what for?--MONGO 12:30, 26 July 2006 (UTC)
 * I know you disagree with that, but when I got here, that link seemed to be the standing consensus. If we remove the link we will have to provide a couple of sentences detailing the hypothesis. I take it the link is there to avoid that unhappy prospect?
 * There is no debunking in this article. There is mention of a series of early hypotheses that did not stand the test of time and, where applicable (in at least two cases), mention of those who have not let the NIST report end their pursuit of their original hypotheses.--Thomas Basboll 12:39, 26 July 2006 (UTC)

Construction section
I've re-written the construction section. It's a little short on references - I'm not sure how to handle that without putting a reference after every fact. The information all came out of the FEMA report, chapter 2 and NIST-NCSTAR1-1A. Any thoughts? Toiyabe 18:27, 25 July 2006 (UTC)
 * Good work. That's the sort of thing we need to do with every section.--Thomas Basboll 18:59, 25 July 2006 (UTC)
 * PS. I wonder if it could stand shortening. It may be more detailed than is necessary for understanding the collapses. Maybe we could move some of it over to the WTC article?--Thomas Basboll 07:30, 26 July 2006 (UTC)


 * If we are going to be talking about floor trusses, hat trusses, core columns, perimeter columns, spandrels etc. in the Investigations section, it makes sense to introduce those terms in the Construction section. Maybe there is too much information.  I would suggest that once we get the Investigations section into better shape (there's a lot of work left to be done) we go back and re-evaluate the construction section.  Toiyabe 15:10, 26 July 2006 (UTC)
 * Agree.--Thomas Basboll 15:31, 26 July 2006 (UTC)

Bazant's latest: controlled demolition
(Okay that's a somewhat sensationalist headline but) here's a reputable source that acknowledges the usefulness of considering the structural response of buildings under demolition in understanding the WTC collapse.
 * "The mode and duration of collapse of WTC towers are consistent with the derived model, but nothing more can be learned because the motion was obstructed from view by a cloud of dust and smoke ... It is proposed to monitor the precise time history of displacements in building demolitions ..."

Here's the PDF: .--Thomas Basboll 12:18, 26 July 2006 (UTC)


 * Booked marked it - but don;t have time to read it in full now. From the abstract, to be clear, he suggests modelling the collapse as if it were a demolition. He does not suggest it is a demolition. He also says "Regardless of the load capacity of the columns, there is no way to deny the inevitability of progressive collapse driven by gravity alone if this criterion is satis¯ed (for the World Trade Center it is, with an order- of-magnitude margin)." Self-Described Seabhcán 12:26, 26 July 2006 (UTC)
 * True, true. But it is interesting that he confirms, not only that the collapses were surprising to all engineers who were at all serious, but also that until the WTC collapses the main source of examples of progressive collapse was CD.--Thomas Basboll 12:43, 26 July 2006 (UTC)

OK here's what's going on in the paper - The authors are presenting a model for what goes on in a progressive collapse. Unfortunately, they don't have the data to feed that model for the WTC collapse (or any other collapse). The authors propose instrumenting buildings scheduled for demolition in the future to determine some of the parameters of their model and validate the model.

I don't see what has you so excited about this. Toiyabe 22:58, 26 July 2006 (UTC)
 * Well, if my aim were to prove CD then there'd be nothing to get excited about, I agree. (In fact, this paper is the most convincing dismissal of CD I've read to date.) But it also validates the relevance of the CD hypothesis for understanding WTC. In sense, it makes me feel I haven't been as nuts as has been suggested for even entertaining the idea.--Thomas Basboll 07:17, 27 July 2006 (UTC)
 * Well, no one thinks you're nuts...but whenever someone says controlled demolition I equate that with coverup and the only response I feel like yelling is "you're nuts". But I try to not do that. Couple of people asked me why I bothered to even converse with those that propose controlled demolition...they looked at me and said, "you do realize those people are nuts, don't you"...in other words, I must be crazy to waste my time.--MONGO 07:45, 27 July 2006 (UTC)
 * I hope I've made an at least partly convincing case these last few says that the controlled demolition hypothesis is sometimes an indication of real curiosity and a desire to understand very difficult material (the difficulty being both social and technical), rather than a symptom of a diseased mind: that finding a place for CD in this article has actually been a substantial improvement.
 * Much of your early response to my efforts here did seem like a barely repressed yell of "you're nuts", i.e., it was pretty clear that that's how you felt (also when interpreted in the light of a quick read through of past discussions). The most telling part was probably when you went fishing for my take on a conspiracy theory ("U.S. government complicity") I had not given any indication of endorsing. That was basically an ad hominem move. I guess I hope I have given you reason to stop equating curiosity and doubt with paranoia.
 * In any case, if you see your time commitment with me in the light of the changes that have been made to the article in the same period, I think we can agree that you weren't wasting your time by a long shot.--Thomas Basboll 09:11, 27 July 2006 (UTC)

The new Bazant paper is very interesting. He relies on his earlier paper to claim that global collapse is inevitable following local collapse, so nothing new there. But now he proposes to use data from controlled demolitions to support his theory of progressive collpse. Think about this people. In the future engineers will be able to blame any demolition on fires, and will use data from demolitions to "prove" it. Bazant is Orwellian in the extreme. —The preceding unsigned comment was added by 213.202.87.66 (talk • contribs) 11:54, 27 July 2006 (UTC).

I'll try once more. Brazant and Verdure have a model of what happens during a progressive collapse. That model requires several parameters specific to the structure. One of the most sensitive of those parameters is the energy dissipation per unit height. They don't know how to go about accurately calculating that parameter based on structural details. The best they can do is an order of magnitude estimation.

So, they need some experimental data both to point the way on how to estimate those parameters and to validate the model - even if they knew the exact value of those parameters they would still need to compare their model to the real world to see if the model is reasonably correct. It's possible that they made a math error in developing their models, or that they neglected or assumed that some factor was negligible whereas in fact it is important. Only a fool trusts a model that has not been experimentally validated, regardless of the reputation of the people who created it.

One way to get that experimental data is to instrument every building on earth and wait for one of them to collapse. Another way to get that data is to instrument a few buildings that they know will collapse, i.e. ones that are scheduled for demolition. Sort of like if you want to measure the value of g. You could set up some speed traps and wait for a random object to fall through them, or you could get up on a step ladder and drop an object yourself. Toiyabe 15:22, 27 July 2006 (UTC)


 * I really appreciate your efforts here, Toiyabe. Do you think you could put a brief explanation of the "order of magnitude estimation" into the Bazant and Zhou section? I was going to add that figure of 8.4 times what would be necessary, but I'm not sure I understand how they arrive at it. As I understand it, they're more than certain that 0.5 meters of free fall (a couple of feet) would release enough kinetic energy to render the structural resistance beneath it negligible. That's really the part I'm trying to get my mind around these days. In your remarks above, I take it you're not suggesting that experiments would be able to show that their estimate is so wrong that the building really shouldn't have collapsed. But doesn't their approach to this proposed experiment suggest that, after initiation, the building collapsed exactly as it would under controlled demolition? The reason I ask is that the thought occured to me that, contrary to those who argue for controlled demolition, a real demolition may actually have been much less "explosive", much neater. I'd like to add some pictures of the towers in mid collapse, but only if we have some prose around them that explain their very dramatic appearance.--Thomas Basboll 18:04, 27 July 2006 (UTC)


 * I can understand the analysis Bazant and Zhou paper that leads to the 8.4 ratio that you're talking about, although I don't know the exact numbers they used.


 * The ratio is the ratio of the gravitational potential energy of the structure (Wg) above the failure point to the energy absorption of the structure below the failure point (Wp). Wg/Wp ~ 8.4.


 * Wg = m*g*h. g = 9.8 m/s^2.  I'm not sure exactly what m he used, but in the Elastic Dynamic Analysis section he uses 58x10^6 kg for the mass of the portion of the north tower above the failure point.  h is two stories, one story of free-fall and one at least one story under arrest of the structure below (conservative because if more then this number will be higher).  I'm not sure what h he used - I estimate it as the total height divided by the number of storeys times two. So:
 * Wg = 9.8 * 58x10^6 * 417/110 *2 = 4.3 GNm (giga newton-meters)
 * The paper puts Wg at 4.2GNm.


 * Wp is very conservatively (i.e. upper bound) estimated as the energy to plastically bend all of the perimeter columns through an angle of 2pi (probably not a single plastic hinge of 2pi, but the sum of up to 4 hinges of lesser rotation). They would certainly fracture before that point, and the energy to fracture the truss seats would also be much lower.  Thus Wp = Mp * 2pi * 280, where Mp is the plastic hinge moment of a single column.  Without knowing the grade of steel or the cross-section of the columns at the critical floor (they varied over the height of the tower) I can't come up with a very good estimate for Mp.  Assuming 36 ksi steel and 14" square cross-section and 0.5 inch thick plate I get:


 * Mp = (14 in * 0.5 in * 36 kip/in^2 * 6.75 in) + (7 in * 0.5 in * 36 kip/in^2 * 3.5 in) * 2 = 2583 kip-in = 291827 newton-meter
 * Wp = Mp * 2pi * 280 = 291827 N m * 6.28 * 280 = 0.51 GN m


 * The authors don't provide this intermediate calculation. Their result is 0.5 GN m. I adjusted the plate thickness to get an answer that was close to theirs, and assumed ASTM A36 steel.


 * Thus by their Wg/Wp ~ 4.2 GN m / 0.5 GN m ~ 8.4. By mine Wg/Wp ~ 4.3 GN m / 0.51 GNm ~ 8.4.  Close enough for a talk page.


 * This analysis bears no relation to what acutally happened. Rather, the authors state that this is an upper-bound, best case scenario.  Seems reasonable to me.  Wow, where did my lunch break go?  This is probably not going to help anyone, and I'm still hungry.  Toiyabe 19:59, 27 July 2006 (UTC)
 * Note, I corrected a minor math error in the Wg calculation above. As corrected my number is essentially equivalent to the author's.  Toiyabe 21:31, 27 July 2006 (UTC)


 * Go eat. I think that is a very excellent cross examination, only unless you publish it, we can't reference it. But definitely close enough for a talk page. Good work...it is even understandable to us laymen.--MONGO 20:21, 27 July 2006 (UTC)
 * Yes, thanks for that. Quick point of clarification. Why do only the perimeter columns need to be bent or fractured? Or did I miss the role of the core in this calculation?--Thomas Basboll 20:30, 27 July 2006 (UTC)
 * My calculations do not include any energy dissipation by the core columns. I'm pretty sure that Bazant and Zhou didn't either - their "framed tube" appears to be the perimeter columns only.  I don't know why they didn't, but please keep in mind that this is back-of-the-envelope type stuff (not the sort of thing that I would dare publish).  There were only 48 core columns, but they were beefier sections.  Including them would change Wp by less than a factor of 2.   Toiyabe 21:48, 27 July 2006 (UTC)

Peer review
The article is decent, but will need many more facts, many of them easy to find, to get it through peer review. I'll work later or tomorrow on cleaning up the references as I just got through doing at Steven E. Jones--MONGO 21:12, 27 July 2006 (UTC)

References in introduction?
Mongo has added a bunch of tags calling for references up in the introduction to facts that are in all but one case mentioned again in the body of the article and referenced there. In the one case where we don't mention it again (the death toll) the facts are public knowledge, easily verifiable, etc. Finally, all of the facts in the introduction (including the death toll) are accounted for in a single source (NIST), which is referenced in the introduction. There are limits to the marginal utility of providing sources, some of which are stylistic. But in this case, it gives also gives the reader the wrong impression: that each fact has a separate source or a separate substantiating argument, when all we're doing in the introduction is presenting a completely uncontroversial summary of the most superficial aspects of the received view. We risk sending the reader into a thicket of primary sources when we should be standing in a clearing. We risk giving the impression that everything is in question. Not referencing every sentence simply can't violate WP:RS or whatever. For an example of more judicious use of sources (especially in the intro), see Earth.--Thomas Basboll 22:23, 27 July 2006 (UTC)
 * No, it is standard to reference information as many times as is needed if this is to be going to peer review and possibly to the FAC process. The second paragraph in the intro may only need one reference for the section. The first section after the intro only has one reference! The intro needs cleaning up anyway, as I find it a bit of a jumble.--MONGO 04:37, 28 July 2006 (UTC)

Van Romero statement
In the section "controlled demolition I read":
 * On the day of the attack, Van Romero, an explosives expert in New Mexico, told the Albuquerque Journal that the collapses of the towers looked "too methodical" to be triggered by the aircraft impacts and fires. He said they looked like they had been triggered by "explosive devices inside the buildings" He later clarified his position, saying that he did not believe that any such explosives had in fact been involved; he was merely noting that that is what it looked like.

This account is misleading: he did not just say that, he said "My opinion is, based on the videotapes, that after the airplanes hit the World Trade Center there were some explosive devices inside the buildings that caused the towers to collapse". Moreover it is misleading to say that he "clarified his position": he actually changed his position, as it is evident from this quoting.--Pokipsy76 07:33, 28 July 2006 (UTC)
 * I know what you mean. But Romero was also later asked about this episode by Popular Mechanics, which framed the later statements as a "retraction" by the Alb. Journal, i.e., claimed that he had been misquoted. Here's the PM version:
 * Demolition expert Romero regrets that his comments to the Albuquerque Journal became fodder for conspiracy theorists. "I was misquoted in saying that I thought it was explosives that brought down the building," he tells PM. "I only said that that's what it looked like."
 * Romero, who agrees with the scientific conclusion that fire triggered the collapses, demanded a retraction from the Journal. It was printed Sept. 22, 2001.
 * "It" = "a retraction", i.e., PM is saying "[a retraction] was printed on Sept. 22". Rereading the two articles, I can see that this is probably a post hoc rationalization and that the Journal certainly doesn't offer a retraction of the original quote. PM seems to be spinning this one a bit in Romero's favour. But I'm not sure it's our call. Romero is on record in PM about "what he meant" the first time around. I think we should give him the benefit of the doubt.--Thomas Basboll 08:16, 28 July 2006 (UTC)
 * I think that if we want to speak about Van Romero in an eciclopedic and neutral way we should tell all the story with Romero asserting to have been misquoted: the account of the article would be correct if we assume that Romero was actually misquoted, but we are not allowed to make such assumptions.--Pokipsy76 08:36, 28 July 2006 (UTC)

Dan Rather and Peter Jennings said it looked like controlled demolition too...but how it looked and what really happened are certainly two different things.--MONGO 08:23, 28 July 2006 (UTC)
 * Of course but the problem is wheter we can say the same about Van Romero.--Pokipsy76 08:38, 28 July 2006 (UTC)
 * Again, I understand your concerns, but I think too much (but never enough) detail here risks insinuating that Romero is lying. I don't think there's any reason to do that in this article. It's conspiracy theory stuff, not demolition hypothesis stuff, if you ask me. Romero's opinion as a demolitions expert about how the collapses looked is relevant, and he confirmed it twice (first to the Alb. J., then to PM). PM also confirms that it plays an important role in keeping the CD hypothesis alive. So it's a good, solidly referenced judgment by an expert that has played an important role in one of the offered explanations for the collapses. All the other details are IMHO elements of spin. PM may like to do that kind of thing, but I think WP should be above it.--Thomas Basboll 09:09, 28 July 2006 (UTC)
 * On the other hand too few detail here risks insinuating that Albuquerque Journal is lying. What's the problem if we say what the journal reported and what Romero said about that?--Pokipsy76 12:16, 28 July 2006 (UTC)
 * No, I think we're playing it very safe. We are allowing the reader to think that AJ conveyed VR's expert opinion that the collapses looked like controlled demolitions. Neither AJ nor VR could reasonably object to that way of putting it. The problem is that the details that are next in line here address the claim that there were demolitions explosives in the building. Romero is on record (at PM) for never having said that. That doesn't mean he didn't say it, it just means there's no simple way of reporting it in the article. It's claim against claim, and that's where it starts to look like someone is lying. That kind of controversy will needlessly muddy this article.--Thomas Basboll 12:30, 28 July 2006 (UTC)


 * Would this be better
 * On the day of the attack, Van Romero, an explosives expert in New Mexico, told the Albuquerque Journal that the collapses of the towers, in his opinion, appeared "too methodical" to be triggered by the aircraft impacts and fires, suggesting "explosive devices inside the buildings" instead. He later clarified his position by saying that the collapses only looked like demolitions and that he had not meant to suggest that any explosives had in fact been involved.
 * ?--Thomas Basboll 09:34, 28 July 2006 (UTC)
 * The problem is the word "clarified", it is not appropriate o the situation, he is not "clarifying" a statement, he is correcting it. It would be better to say that he said to be misquoted.--Pokipsy76 12:35, 28 July 2006 (UTC)
 * See my remarks above. But I suggest you work out a couple of sentences that you think would be better; that might either be enough, or it might make it easier for me to show you what I mean.--Thomas Basboll 12:44, 28 July 2006 (UTC)
 * My suggestion is to replace "he later clarified his position by saying that ..." with "he later claimed to have been misquoted and to have just said that..." (or something like that, english is not my mother language, maybe you can find a more elegant form)--Pokipsy76 13:07, 28 July 2006 (UTC)

Okay. Here is what you might be suggesting:
 * On the day of the attack, Van Romero, an explosives expert in New Mexico, was quoted in the Albuquerque Journal as saying that the collapses appeared "too methodical" to have been triggered by the aircraft impacts and fires alone and that, in his opinion, "there were some explosive devices inside the buildings that caused the towers to collapse." He later claimed that he had been misquoted (source: PM); as he informed the AJ ten days after his original statement, his opinion was only that the collapses "looked liked" demolitions (source: Sept 21 AJ story).

But the word "claim" suggests that he may not be telling the truth. Moreover, we would have to add that AJ showed no indication of admitting to misquoting. AJ, after all, uses the the phrase "now says", meaning they stand by their original quotation. So we would be introducing an unresolved controversy about what was said when. All three stories agree on one thing: Van Romero said and believed that the collapses looked like demolitions. That's something we can safely say. (I'm not at my most imaginative right now; maybe someone else has a better turn of phrase?)--Thomas Basboll 13:57, 28 July 2006 (UTC)
 * If you want to avoid any reference to the controversy then just say that Van Romero "said and believed that the collapses looked like demolitions" also avoinding to say that Romero "clarified" anything: the word "clarify" suggest a particular point of view about the controversy.--Pokipsy76 16:39, 28 July 2006 (UTC)
 * You could just say "Van Romero believes.." and leave it at that. Anyone who is interested in the precics wording and sequence of his statements can quickly find it on the web. Self-Described Seabhcán 16:46, 28 July 2006 (UTC)