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Title: 9/11 demolition theory challenged
Source:
BBC
URL Source: http://news.bbc.co.uk/2/hi/science/nature/6987965.stm
Published: Sep 11, 2007
Author: staff
Post Date: 2010-07-17 17:31:29 by buckeroo
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Keywords: None
Views: 37929
Comments: 1209
An analysis of the World Trade Center collapse has challenged a conspiracy theory surrounding the 9/11 attacks. The study by a Cambridge University engineer demonstrates that once the collapse of the twin towers began, it was destined to be rapid and total. One of many conspiracy theories proposes that the buildings came down in a manner consistent with a "controlled demolition". The study suggests a different explanation for how the towers fell. Over 2,800 people were killed in the devastating attacks on New York. After reviewing television footage of the Trade Center's destruction, engineers had proposed the idea of "progressive collapse" to explain the way the twin towers disintegrated on 11 September 2001. This mode of structural failure describes the way the building fell straight down rather than toppling, with each successive floor crushing the one beneath (an effect called "pancaking"). Resistance to collapse Dr Keith Seffen set out to test mathematically whether this chain reaction really could explain what happened in Lower Manhattan six years ago. The findings are to be published in the Journal of Engineering Mechanics. Previous studies have tended to focus on the initial stages of collapse, showing that there was an initial, localised failure around the aircraft impact zones, and that this probably led to the progressive collapse of both structures. Man stands amid rubble of the World Trade Center, AFP/Getty Once the collapse began, it was destined to be "rapid and total" In other words, the damaged parts of the tower were bound to fall down, but it was not clear why the undamaged building should have offered little resistance to these falling parts. "The initiation part has been quantified by many people; but no one had put numbers on the progressive collapse," Dr Seffen told the BBC News website. Dr Seffen was able to calculate the "residual capacity" of the undamaged building: that is, simply speaking, the ability of the undamaged structure to resist or comply with collapse. His calculations suggest the residual capacity of the north and south towers was limited, and that once the collapse was set in motion, it would take only nine seconds for the building to go down. This is just a little longer than a free-falling coin, dropped from the top of either tower, would take to reach the ground. 'Fair assumption' The University of Cambridge engineer said his results therefore suggested progressive collapse was "a fair assumption in terms of how the building fell". "One thing that confounded engineers was how falling parts of the structure ploughed through undamaged building beneath and brought the towers down so quickly," said Dr Seffen. The south tower of the World Trade Center collapses, AP Conspiracy theorists see evidence of a "controlled detonation" He added that his calculations showed this was a "very ordinary thing to happen" and that no other intervention, such as explosive charges laid inside the building, was needed to explain the behaviour of the buildings. The controlled detonation idea, espoused on several internet websites, asserts that the manner of collapse is consistent with synchronised rows of explosives going off inside the World Trade Center. This would have generated a demolition wave that explained the speed, uniformity and similarity between the collapses of both towers. Conspiracy theorists assert that these explosive "squibs" can actually be seen going off in photos and video footage of the collapse. These appear as ejections of gas and debris from the sides of the building, well below the descending rubble. Other observers say this could be explained by debris falling down lift shafts and impacting on lower floors during the collapse. Dr Seffen's research could help inform future building design.
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Begin Trace Mode for Comment # 181.
#2. To: buckeroo (#0)
Two problems: 1. The videos that show the collapse. 2. The reason the collapse was initiated. There is no proof that the aircraft, or fires, are what set it off. As well an explosive demolition would show basically the same signature, and the theory does not explain why one tower took about 14 seconds to collapse and the other identical tower 22-23 seconds. For a theory to be valid it must account for all of the observed phenomena.
The two towers were "hit" differently and the central core supports were damaged differently as a result. Check this out: Impact to Collapse by NOVA.
What type of plane hit WTC 7 again? You know, the one that the BBC reported had collapsed 25 minutes before it did. Check this out: THE WTC WAS DESIGNED TO SURVIVE THE IMPACT OF A BOEING 767
Of course no aircraft struck WTC7. But it was damaged from the collapse of the twin towers earlier in the day.
Of course no aircraft struck WTC7. But it was damaged from the collapse of the twin towers earlier in the day. How so? And don't try and dredge up the Pop Mechanics piece because it has already been proven false - they used a picture of WTC 6 which was damaged by debris, and did not fall - it was later demolished at great expense, and then reversed and falsely represented as "secret photos" of WTC 7.
ROTFL How about, Final Report on WTC7 - NIST, ever read it? If so, please comment.
Cite your specific reference - not the totality of a multi-thousand page report.
Hold on there pardner! WHOA! Have you read that document at anytime?
Hold on there pardner! WHOA! Have you read that document at anytime? You cited an entire document as a reference. That is not a refutation. It is an evasion. Cite where in the report your refutation comes from - page and paragraph(s). My reading habits are not the question. You attempted to evade the point and I am not going to let you.
And I am not evading you or anyone. That is why I chose to initiate a thread with the title banner you see.
And I am not evading you or anyone. That is why I chose to initiate a thread with the title banner you see. I do believe you are running a circuit of what Gerard Holmgren calls "The Fruit Loop". So, you agreed that no plane hit WTC 7. Then you cited unspecified damage from the collapse of the other 2 towers. When asked to cite why you believe that, not including the discredited Pop Mechanics Disinfo piece you replied with a vague reference to the NIST Report (which itself has been shredded). When asked to cite what and where specifically in the report you gave me the above. More evasion.
the only way any of the crap bucky copies and paste as part of his duties as a ranking member of the liar movement to have even a shred of accuracy is if that crap started out "once upon a time"
LOL! I've been reading an interesting analysis of the NIST Report and it is an eye opener. They played some neat hanky panky with it complete with unsupported assumptions, unlabeled speculation mixed in with factual statement, and it made no analysis at all of how the collapse proceeded once it began. They just wave their magic wand and say it fell. Here's a link if you're curious: 911research.wtc7.net/essays/nist/index.html
The entire NIST theory rests upon the removal of all 80,000 square feet of the fireproofing/SFRM in each of the impact zones of the towers. The problem is, NIST never provides any credible evidence of substantial testing and research of this said phenomenon. Cartoon computer models are only as reliable as the data put in.
The problem is, NIST never provides any credible evidence of substantial testing and research of this said phenomenon. In addition to providing no validating data for the assumptions on the fireproofing or the angles at which the aircraft hit the building they provide no validation for the number of central column support beams severed, show them as smaller than the perimeter columns (which the were not they were substantially LARGER), and provide no sound justification for the internal temperatures that they allege existed in the core prior to collapse. And they are only as honest as the person running the model. You could make the model sing "The Battle Hymm of The Republic" with the right input parameters. NIST, very unscientifically for a purported investigation, assumes a conclusion and then sets out to validate that conclusion. Their supposed validation has so many flaws, half truths, and outright subterfuge that one cannot escape the conclusion that their modeling DID NOT validate their concluision and so they had to "adjust" the parameters to make the real world fit the model.
>> Cartoon computer models are only as reliable as the data put in. And they are only as honest as the person running the model. You could make the model sing "The Battle Hymm of The Republic" with the right input parameters. NIST, very unscientifically for a purported investigation, assumes a conclusion and then sets out to validate that conclusion. Their supposed validation has so many flaws, half truths, and outright subterfuge that one cannot escape the conclusion that their modeling DID NOT validate their concluision and so they had to "adjust" the parameters to make the real world fit the model. Both of you are genuinely well read on Griffin's article, of which I reference here: The Mysterious Collapse of WTC7 by David Ray Griffin, yet there are no FACTS other than spinning this charlatan around in a vacuous washtub with old soap. Do you guys have the capability to stand on your own feet and discuss the original article as opposed to hiding behind the wild cover-ups of a cheap, charlatan?
>> Cartoon computer models are only as reliable as the data put in. And they are only as honest as the person running the model. You could make the model sing "The Battle Hymm of The Republic" with the right input parameters. NIST, very unscientifically for a purported investigation, assumes a conclusion and then sets out to validate that conclusion. Their supposed validation has so many flaws, half truths, and outright subterfuge that one cannot escape the conclusion that their modeling DID NOT validate their concluision and so they had to "adjust" the parameters to make the real world fit the model. Both of you are genuinely well read on Griffin's article, of which I reference here: The Mysterious Collapse of WTC7 by David Ray Griffin, yet there are no FACTS other than spinning this charlatan around in a vacuous washtub with old soap. Do you guys have the capability to stand on your own feet and discuss the original article as opposed to hiding behind the wild cover-ups of a cheap, charlatan? Instead of engaging in attacking the man i.e., Argumentum Ad Hominem, perhaps you could specify exact what factual issue you take with the analysis. Otherwise all you post is vacuous drivel which avoids facts and focuses only on unsubstantiated personal attacks. Since you know what you are doing it can only be classified as intentionally dishonest.
The first casualty of war is the truth.
#183. To: James Deffenbach (#181)
Mad Uncle Sugar. He'll leave his bones to bleach in that desert, I'll warrant. It's all the fault of the kind that bloviate crap on this forum, and you know who the hell I'm talking about. I find it abhorrent to draw a breath in the same country as those that propagate old lies. I have nothing to say to them. This country is going the way of Germany of the 1930s, and the innocent will be punished with the guilty.
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#43. To: Original_Intent (#2)
As well an explosive demolition would show basically the same signature, and the theory does not explain why one tower took about 14 seconds to collapse and the other identical tower 22-23 seconds.
#48. To: buckeroo (#43)
The two towers were "hit" differently and the central core supports were damaged differently as a result. Check this out: Impact to Collapse by NOVA.
#51. To: Original_Intent (#48)
What type of plane hit WTC 7 again?
#52. To: buckeroo (#51)
What type of plane hit WTC 7 again?
#57. To: Original_Intent (#52)
And don't try and dredge up the Pop Mechanics piece because it has already been proven false
#58. To: buckeroo (#57)
#60. To: Original_Intent (#58)
Cite your specific reference - not the totality of a multi-thousand page report.
#89. To: buckeroo (#60)
Cite your specific reference - not the totality of a multi-thousand page report.
#92. To: Original_Intent (#89)
You attempted to evade the point and I am not going to let you.
#118. To: buckeroo (#92)
You attempted to evade the point and I am not going to let you.
#125. To: Original_Intent (#118)
#128. To: IRTorqued (#125)
the only way any of the crap bucky copies and paste as part of his duties as a ranking member of the liar movement to have even a shred of accuracy is if that crap started out "once upon a time"
#137. To: Original_Intent (#128)
#143. To: Kamala (#137)
The entire NIST theory rests upon the removal of all 80,000 square feet of the fireproofing/SFRM in each of the impact zones of the towers.
Cartoon computer models are only as reliable as the data put in.
#145. To: Original_Intent, Kamala, AGAviator (#143)
In addition to providing no validating data for the assumptions on the fireproofing or the angles at which the aircraft hit the building they provide no validation for the number of central column support beams severed, show them as smaller than the perimeter columns (which the were not they were substantially LARGER), and provide no sound justification for the internal temperatures that they allege existed in the core prior to collapse.
#179. To: buckeroo, Kamala (#145)
In addition to providing no validating data for the assumptions on the fireproofing or the angles at which the aircraft hit the building they provide no validation for the number of central column support beams severed, show them as smaller than the perimeter columns (which the were not they were substantially LARGER), and provide no sound justification for the internal temperatures that they allege existed in the core prior to collapse.
#181. To: Original_Intent (#179)
Replies to Comment # 181.
End Trace Mode for Comment # 181.