The AIA disowns Richard Gage "AIA" and few architect want to have anything to do with him.

[Len Colby]

If a "top down" demolition were implemented in the WTC's Twin Towers on 9/11, then it would have been necessary to plant explosives on floors below the impact zone. From a novice perspective, it would seem ideal to have planted such explosives at regular intervals below the impact area, around floor 50, for example, and below that around floors 25 to 35, and lower. Videos show "squibs" emanating in these general areas of each tower, at levels spaced between the mechanical floors on 41-42, and 75-76.

LOL!!

So did Ryan base this on his own engineering expertise or the conclusions of qualified experts, or did he pull it out of his sphincter? Let's review, he has no applicable expertise and didn't cite anyone who does so that only leaves us with the latter.

It's hilarious that like all the qualified engineers who've looked at this he says collapsing floors would have destroyed the undamaged floors below them. What makes this so funny is that from day one the truther party line has been that the undamaged floors should have withstood the collapses. Accepting that damaged floors falling on undamaged ones could have led to the collapses of the later eliminates the 'necessity' for explosives to have been used. Since it gained mass and velocity the avalanche of debris became more and more energetic as it progressed to ground level.At least in the excerpt you posted Ryan never justified the floors he selected.

[Steven Gaal]

_{I always thought gravity part of the mix. Supercomputers helped get the demolition device #number low.}

_{Force 10 from Navarone (film)}

_{Mallory and Barnsby set their charges within the dam but realize that they are out of time. With the German assault only minutes away - they are forced to set a short fuse, leaving them no time to escape. Mallory and Barnsby are caught in the explosion, yet nevertheless survive. At first, the dam appears undamaged, but soon it begins to disintegrate. With its fragile structural integrity disrupted, the dam wall collapses, releasing millions of tons of water in a wave that topples the real target, the impregnable bridge. The German assault is thwarted, saving the Partisans.}

_{==========================================================}

Edited February 21, 2013 by Steven Gaal

[Len Colby]

If one accepts that collapsing floors would bring down the floors below them eliminates the 'logic' for claiming explosives were need; some FDNY commanders expected localized collapses. This also contradict other notions you've pushed such as claiming gravity would not have provided enough energy to have "pulverized" the concrete, how could explosives explain that if they were only placed if a handful of locations on 8 floors?

[Steven Gaal]

[Len Colby]

WOW a video from an anonymous YTer whose engineering expertise is unknown, how compelling!

[Steven Gaal]

WOW a video from an anonymous YTer whose engineering expertise is unknown, how compelling!

// end COLBY

++++++++++++++++++++++++++++++++++++++++++

I would be concerned not with the 'WHO' but the what of the video (of above post # 199). It shows that NIST'S scientific thoroughness and methodology are flawed. It gives cogent and strong evidence that the theories of NIST are incorrect. NIST is thus debunked.

Video at 911 blogger Posted by gerrycan1 on Thu, 02/21/2013 - 7:34pm.

Part 4 in a series of videos examining the collapse of WTC7: NIST and WTC7 - maladmiNISTratio

================================== the rest plus comments =============

Part 1: WTC7 and NIST - Shear Ignorance

Part 2: WTC7 and NIST - The Expanding Lie

Part 3: WTC7 and NIST - Tangled Webs

================================================

Great series

I have just a few questions about NIST's entire theory but I didn't want to sound too daft, but here goes.

1. Why would beams in WTC 7 expand, but the beams in the towers bowed? (outside of NIST's convenience.) Obviously with enough tensile strength to bend

2. Why wouldn't the beams in question expand in both directions? Is it reasonable to even think they would expand nearly 6" in one direction?

3. Wouldn't a beam need to be heated in the center or over its entirety to get such expansion?

4. How much time would it really take to expand a steal beam of this size over 6"? ( I see the premise of another Jon Cole experiment.)

5. None of the animations included concrete. And we know NIST fraudulently opted to not heat the concrete to create "differential expansion." How much more impossible does this make NIST's theory if it could even be quantified and will this fact be included in the final video?

These questions seem like common sense to me from my layman's point of view, but I've haven't seen them raised before. It would seem that these issues would have kept NIST from ever trying to make such nonsensical theory work, but maybe they had no other choice since diesel fuel and building damage was too easy to disprove.

Out of curiosity, are the producers of this series structural engineers? (not that it matters much to me, but just curious) and were the construction plans shown here obtained via FOIA? I truly appreciate the responses.

Again.. great work to all involved with this series. I look forward to seeing the cumulative final video. Major KUDOS!!!

peace everyone

dtg

Expansion vs length .

One thing that I have trouble with regarding the expansion of supporting beams is that the total length of a given steel beam once heated to a given temperature assumes the TOTAL LENGTH of said beam is heated to said temperature ? What would the likelihood of the beams being this uniformly heated be ?

Therefore if you heat a few meters in the center of a given beam you would get a large Delta T along the total length, perverting your calculations on total expansion/temperature .

mick on Sat, 02/23/2013 - 5:41pm.

The fall of WTC7 and NIST's statements about it

continue to amaze me as a physicist.

In their preliminary report summer 2008, NIST stated that they assumed the building came down at constant speed. This was far from the truth, for the building is seen in videos to be ACCELERATING, not constant speed at all.

David Chandler and I independently challenged NIST on their mistake in the report. It is fun to review how they hemmed and hawed at the public hearing (via video) and finally agreed to re-check the video data. Finally!

In their final report, they found what we had found from measurements taken using the video evidence -- the building is accelerating at FREE FALL acceleration, 9.8 m/s^2! This means that NO MASS was in the way of the falling upper floors seen in the videos.

But how does NIST explain the MISSING MASS? Answer -- they don't! They merely refer to their opaque computer model which is NOT available to the public! And when we look at the simulation-video produced by the computer model (that much was made public), we find that the upper floors (in their own computer model) do NOT accelerate downward at 9.8 m/s^2.

This is just one of the glaring discrepancies/problems found in NIST's final report on the fall of WTC7. Their "official narrative" that this building came down due to Al Qaeda's actions on 9/11 when the building was NOT even hit by a jet, just does not hold water, scientifically.

I have discussed these issues in several of my talks, available on youtube and elsewhere. Thank you for continued emphasis on WTC7 -- our community needs to keep bringing attention the official mistakes and lies/cover-up regarding WTC7 and its fall -- which fall was not even MENTIONED in the 9/11 Commission report.

ProfJones

Thank you

Thank you for your input, Professor Jones.

I find Chandler's measurement of the acceleration of the roof line of WTC 1 at a constant acceleration of 64% of free fall to be of near equal significance -- do you agree? The reason I ask is that I see these two events as completely implausible in and of themselves (or so improbable as to be impossible), and that the two taken together amounts to absolutely astronomical odds against the official 9/11 narrative.

Edited February 25, 2013 by Steven Gaal

[Len Colby]

WOW a video from an anonymous YTer whose engineering expertise is unknown, how compelling!

// end COLBY

++++++++++++++++++++++++++++++++++++++++++

I would be concerned not with the 'WHO' but the what of the video (of above post # 199). It shows that NIST'S scientific thoroughness and methodology are flawed. It gives cogent and strong evidence that the theories of NIST are incorrect. NIST is thus debunked.

No they showed that any anonymous apparently with no relevant expertise doesn't agree with their findings. One has to wonder why after over 4 years if there were such obvious discrepancies so few engineers have said anything. After 7 years or so of hard selling his petition Gage has only signed up less than 0.1% of US As & Es and much lower %s of such professionals from other nations.

I don't have time to go through all this so I'll just address the 1st " Why would beams in WTC 7 expand, but the beams in the towers bowed? (outside of NIST's convenience.) Obviously with enough tensile strength to bend"

The guy obviously never read the reports the floor assemblies did expand but they were seated in such a way that they couldn't move horizontally so were forced to bow down.

[Steven Gaal]

The guy obviously never read the reports the floor assemblies did expand but they were seated in such a way that they couldn't move horizontally so were forced to bow down. // end Colby

NO NO NO Mr. Colby

PART 1

The Truss Failure Theory

Fanciful Theory Doesn't Begin to Explain Total Collapse

Figure 2-20 from FEMA's Building Performance Study gives the impression that floors spanned the entire width of the Towers. The fine print indicates that the illustration depicts only a section of floors spanning the perimeter (left) and core (right).

The truss failure theory, a key ingredient of the better known floor pancake theory, was endorsed by FEMA in its 2002 World Trade Center Building Performance Study . It invites us to imagine the floors assemblies detaching from their connections to the columns of the core and perimeter walls, precipitating a chain reaction of floors falling on one another. Without the lateral support of the floors, the columns, FEMA tells us, buckled and precipitated total building collapse.

The truss-failure/pancake theory offered a way around the obvious problem with the column failure theory: the need for all the columns to be heated to 800º C. It offered instead prerequisite conditions that were far less implausible: that trusses holding up the floor slabs were heated to that temperature, and began to experience some combination of expansion and sagging. Floor trusses are much easier to heat because, unlike the columns, they are not well thermally coupled to the rest of the steel structure.

The Truss Failure Theory was was abandoned by NIST's investigation in 2004 because NIST was unable to get floor assemblies to fail as required by the theory. Documentaries that had promoted the truss failure theory became obsolete, and were quietly replaced with updated versions.

The Missing Steel

Some critics of FEMA's theory attacked the truss failure theory for the wrong reasons. One assumption of the theory is that the floor sections that spanned the Towers' cores and perimeter walls were undergirded only by the light web trusses. Although many structural details remain mysterious thanks to the unavailability of detailed engineering drawings, this assumption appears to be mostly true, modulo the observation that some floors appeared to be framed entirely with solid I-beams.

However, the anonymous Guardian author suggested that the idea that so many of the floors rested only on web trusses was a lie concocted to sell the pancake theory, arguing in a 2002 article that:

• FEMA's building description leaves 32,000 tons of steel unaccounted for in each tower, given that the towers were known to each use 96,000 tons of steel.
  
• A truss-only-based floor construction system would leave the floors too weak to transfer loads between the core and perimeter walls.
  

Guardian's conclusion about the extent of web trusses in the Towers appears to be mistaken: Between construction photographs and 60s-era articles in the Engineering News Record, there appears to be sufficient evidence to establish that floors outside of the cores, with the exceptions of top-most, bottom-most, and mechanical equipment floors, were supported entirely by web trusses. However, Guardian's calculations about the quantities of steel accounted for by FEMA's building description underline the failure of the official reports to provide a truthful and complete picture of the Towers' construction.

Deceptive Propaganda

Since the failure of a few trusses on a floor wouldn't automatically lead to a whole floor falling and starting the pancake syndrome, some fine tuning in the theory was needed. Dr. Thomas Eagar provided us with the zipper theory to explain how the failure of one truss could cause adjacent ones to fail. A horizontal domino effect of unzipping would precede the vertical one of pancaking. NOVA created a website to feature Eagar's promotion of the pancake theory which included a misleading animation of falling trusses, which failed to show either the transverse trusses or the steel floor pans.

From Sagging Trusses to Leveled Building

The unverified assumptions of the truss theory listed above are the least of its problems. It pretends that a few truss failures would automatically lead to the entire steel building crushing itself. What would be the likely chain of events following a floor failure envisioned by the truss theory?

Let's accept Dr. Eagar's zipper scenario (despite the clear evidence that fires did not cover a whole floor in either tower) and imagine that all the trusses of a floor failed in rapid succession and the whole floor fell. Then what? It would fall down about ten feet, then come to rest on the floor below, which was designed to support at least five times the weight of both floors, the fall cushioned by the folding of the trusses beneath the upper floor. But let's imagine that the lower floor suddenly gave up the ghost, and the two floors fell onto the next, and that failed, and floors kept falling. Then what? The floor diaphragms would have slid down around the core like records on a spindle, leaving both the core and perimeter wall standing.

Truss theory proponents hold that the core and perimeter wall lacked structural integrity without mutual bracing provided by the floor diaphragms. That may have been true in the event of a 140 mph wind, but not on a calm day. Note that the core had abundant cross-bracing, and would have been perfectly capable of standing in a hurricane by itself. And even if one imagines the outer wall buckling without that support, it does not begin to explain how it shattered into thousands of pieces, many of the column sections ripped from the spandrel plates at the welds, and how it shattered so quickly that no part of the wall remained standing above the falling dust cloud.

Edited February 26, 2013 by Steven Gaal

[Steven Gaal]

PART 2

PM claims that “professors and investigators contend it’s not surprising that [the Towers’] collapse-time estimates are close to would-be free-fall results” (pg. 44), and then proceeds to quote several of these said people. One of the people is MIT professor Dr. Thomas Eagar, who said it was not surprising that each Tower collapsed in ten seconds. PM writes:

[Eager’s] analysis explains that as exterior columns bowed and joists on the most heavily burned floors gave way, the mass of the collapsing floors created a cascade of failures

. (pg. 44)

This first thing that should be noted about PM’s citation of Dr. Eagar is that his analysis actually contradicts NIST’s analysis of the Towers’ collapses. PM cites Dr. Eagar’s paper, Why Did the World Trade Center Collapse? Science, Engineering, and Speculation, but when one actually reads what he wrote it is apparent that his analysis doesn’t promote NIST’s theory of collapse at all. In his paper, Dr. Eagar writes:

As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell.

⁶

Whereas NIST told us that the exterior columns bowed inward, Dr. Eagar’s paper asserts that the exterior columns bowed outward. By not quoting this section of his paper correctly, PM gives the impression that Dr. Eagar’s analysis is in total agreement with the NIST investigators (though Eagar’s paper currently provides a link to another article in the Journal of the Minerals, Metals and Materials Society that promotes NIST’s theory⁷). Instead, PM proceeds to directly quote from Eagar’s paper:

The floor below (with its 1,300 ton design capacity) could not support the roughly 45,000 tons of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an estimated speed of 200 km per hour.

⁸

However, this analysis is flawed by the fact that actual measurements of the collapse of the Towers show that the upper sections of the Towers never exerted massive forces on the lower sections, due to the fact that the upper sections accelerated through the lower section. As physicist David Chandler has shown, the upper section of the North Tower fell into the lower section, and

.⁹ Hence, there was no dynamic load being exerted on the lower section to cause it to collapse.

The next alleged expert PM cites is Dr. Keith Seffen, a senior lecturer in the engineering department at the University of Cambridge. They cite his paper, Progressive Collapse of the World Trade Center: A Simple Analysis, published in the Journal of Engineering Mechanics,¹⁰ as evidence that the Towers could have collapsed as quickly as they did as a result of the jet fuel and office fires. Instead of mentioning the technical refutations of Seffen’s claims, PM quotes a non-technical writer, Peter Wakefield Sault, who cites that “Dr. Seffen is an accessory after the fact to mass murder”. Dr. Keith Seffen has yet to respond to questions surrounding his defense of the official explanation for the Twin Towers’ collapse

PM’s citation of Sault’s comments highlights their obvious ploy to cherry-pick supporters of the 9/11 Truth movement to quote. Although a direct source for this quote is not provided (like most of the 9/11 Truth advocates quoted by PM), this statement is found not on the website PM provides, but on an obscure website. Sault is only commenting on a blog post about Keith Seffen.¹¹ The fact that PM quotes from such an obscure source reveals their determination to portray anyone who questions the WTC collapses as a “crazy conspiracy theorist”. On the contrary, the study of the destruction of the Twin Towers entered the realm of laboratory research years ago with published articles in scientific and academic journals. The critique of Seffen’s WTC paper written by University of Iowa Physics Professor Dr. Crockett Grabbe points out the many unscientific arguments that Seffen made

Evidently, PM’s writers and investigative journalists somehow missed an article written by Dr. Crockett Grabbe which refutes the arguments made in Seffen’s questionable paper even though Grabbe’s article was published in the very same journal as Dr. Seffen’s paper.¹² Though PM touts Dr. Seffen and his paper as providing excellent analysis of the WTC collapses, there is no mention of Grabbe’s peer-reviewed response, even though Grabbe is a credentialed scientist. Instead, PM chose to cite an inflammatory remark on an obscure internet site.

Dr. Seffen never responded to Dr. Grabbe’s discussion paper, which was published over three years ago. In addition, PM felt no need to quote Dr. Grabbe, who says on his website, “Seffen is an applied mathematician from Cambridge whose paper was on BBC News. I ripped his paper apart, and he never made any reply to my very critical comments.”¹³

PM finishes this section by quoting a section of NIST’s report on the collapse of the Twin Towers that discusses the rate of collapse. The section reads:

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increases, further increasing the demand of the floors below, which were unable to arrest the moving mass.

¹⁴

PM also quotes from NIST’s FAQ on the WTC collapses:

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2… Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.

¹⁵

However, engineer and 9/11 researcher Jim Hoffman addressed both of NIST’s assertions. In regards to the first point, Hoffman writes:

This does not explain either why the structure below failed to arrest the falling mass or how the structure failed to appreciably slow the falling mass. As in the preceding paragraphs, NIST begs these questions using a kind of circular argument: The towers fell rapidly because the stories below could not resist the tremendous energy of the falling mass. Videos clearly show that the upper section fell essentially in free-fall. Therefore the structures below offered minimal resistance to and were destroyed by the falling mass. The argument pre-supposes the conclusion that the force that overcame the resistance of the structures below was the falling mass, not some other force such as energy of explosives.

¹⁶

As for the second point, Hoffman writes:

To the contrary, video records, such as

this record of the North Tower's fall

, clearly establish upper boundaries on the times that it took for the vast majority of each tower to be destroyed.

¹⁷

While citing several experts who support their assertion that the collapse rates of the Towers were nothing unusual, PM failed to acknowledge numerous other experts who say that the collapse rates clearly violated the laws of physics. The rate in which the Towers came down cannot be explained by the combined effects of fire and gravity.

For more on the subject of the Towers’ collapse rates, the following articles are recommended:

Twin Towers Evidence Blows Away Fire Theory

by James Smith

The Missing Jolt: A Simple Refutation of the NIST-Bazant Collapse Hypothesis

, by Prof. Graeme MacQueen and Tony Szamboti

Destruction of the World Trade Center North Tower and Fundamental Physics

by David Chandler

Showing that the South Tower of World Trade Center Collapsed from Forces More Powerful than Gravitation

by Crockett Grabbe

**************************************************************************************************

⁶Quoted from: Why Did the World Trade Center Collapse? Science, Engineering, and Speculation, by Thomas W. Eagar and Christopher Musso http://www.tms.org/p...agar-0112.html

⁷See: http://www.tms.org/p...novic-0711.html

⁸Quoted from: Why Did the World Trade Center Collapse? Science, Engineering, and Speculation

⁹This analysis is shown in David Chandler’s paper: Destruction of the World Trade Center North Tower and Fundamental Physics http://www.journalof...ationOfWTC1.pdf (David Chandler also outlines this point in this video:)

¹⁰Seffen’s paper can be read here: http://winterpatriot...e_analysis.pdf

¹¹See: http://laura-knight-...ecial-wtc.html

¹²The paper can be read here: http://www.sealane.o...ffenrevpub.pdf

¹³Quoted from: http://www.sealane.o..../research.html

¹⁴Quoted from: NCSTAR 1, pg. 146 http://www.nist.gov/...?pub_id=909017

¹⁵Quoted from: http://www.nist.gov/..._wtctowers.cfm

¹⁶Quoted from: http://911research.w...ist/index.html

¹⁷Quoted from: http://911research.w..._FAQ_reply.html

[Len Colby]

The guy obviously never read the reports the floor assemblies did expand but they were seated in such a way that they couldn't move horizontally so were forced to bow down. // end Colby

NO NO NO Mr. Colby

PART 1

The Truss Failure Theory

Fanciful Theory Doesn't Begin to Explain Total Collapse

[...]

LOL

1) there were two groups of "official" reports regarding the WTC collapses:

- the 1st were prepared by the American Society of Civil Engineers (

ASCE

) and Structural Engineers Association of New York (SEAoNY) in conjunction with other engineering associations and sponsored by

FEMA

,

- these were latter supplanted by the far more through

NIST

reports.

My previous post referred to the latter, your "response" to the former.

2) I won't waste my time going through Hoffman's errors, he is a computer programmer, his area of speciality is computer graphic and visualisations, he has no relevant experience or expertise.

[Steven Gaal]

The Missing Jolt: A Simple Refutation of the NIST-Bazant Collapse Hypothesis, by Prof. Graeme MacQueen and Tony Szamboti

Three essential elements of NIST’s hypothesis of total collapse are made explicit in the Final Report and the companion volumes of the study:

1. Because of damage to stories 93 to 98, and especially because of column buckling due to fire, the top 12 stories of the North Tower (99-110) plus the roof were, in effect, separated from the rest of the Tower and began to behave as a unit. [2]

2. This "rigid block" of 12 stories plus the roof began to move. First it tilted, and then it abruptly fell onto the stories beneath it. [3]

3. The fall of the rigid block caused such damage to the lower structure that "global collapse began."[4]

The rigidity of the upper block of stories is crucial to this explanation. If the upper block were to break, disintegrate or flow on impact it would certainly not threaten the 92 intact floors beneath it.

In addition, the rigid block had to fall onto the rest of the building. Although this seems obvious, the NIST authors are often shy about saying it. We hear about the rigid block’s "descent."[5] We hear of tilting and "downward movement."[6] We have to look carefully to find the NIST authors using the language of falling. Whatever the reasons for their reticence, it is clear that it will not do for the upper block to ease itself onto the building beneath it, with a gradual creaking of buckled columns and sagging floors. If this were to happen, why would the structure beneath collapse? Journal of 911 Studies January 2009/Volume 24 2

There was nothing special about the weight of the upper block, rigid or otherwise. The lower part of the Tower had held up this weight without difficulty since 1970. The lower block had 283 cold steel columns, with less than 30% of their total load capacity being utilized for gravity loads, because of the factors of safety designed into the structure and the need to withstand high winds—and gravity loads were essentially the only loads the columns would have been subject to on a day such as 9/11 with little wind. The lower block was not weak, nor (excluding stories 93-98) was it damaged by plane impact or fire. The weight of the upper block posed no threat to it. If there were to be a threat, it had to come from the momentum of the upper block. But momentum is a product of mass and velocity, and since the upper block could not increase its mass it had to increase, if it were to become a threat, its velocity. Since NIST’s theory assumes the only energy at play at this stage of events was gravitational, the upper block had to fall, and the greater its velocity the greater its momentum. The longer and the less impeded its fall, the greater would be its impact on the lower structure. So it is no surprise that the NIST authors, however shy they are about affirming it, eventually come out in favour of the falling of the upper block. [7]

Zdenek Bazant and Yong Zhou, with whose September 13, 2001 back-of-the-envelope theory (with subsequent revisions and additions) NIST largely agrees, have never hesitated to say that the upper block fell. [8] Bazant has likewise been frank about the need for severe impact as the upper and lower structures met: he believes the impact may have been powerful enough to have been recorded by seismometers. [9] In his view, collapse initiation of the lower structure required "one powerful jolt."[10] Of course, if there was a powerful jolt to the lower structure there must also have been a powerful jolt to the upper falling structure, in accord with Newton’s Third Law.

In order to keep a sense of reality as we discuss NIST’s theory it may be useful to label the three interacting parts of the North Tower, as they are pictured by NIST, as RB-12+, DS-6 and RB-92. Where RB stands for rigid block, DS stands for damaged structure, and the numbers following the letters refer to the number of stories in each structure. The upper block comprised the 12 stories of 99-110 as well as the roof structure with antenna and hat truss; the intermediate area was damaged by plane impact and fire and was six stories high (93-98 inclusive); and the lower block was rigid and comprised, in addition to subterranean levels, the first 92 stories of the building.

These designations actually underestimate the contrast between RB-12+ and RB-92, because the latter was not only largely undamaged by fire but was more massive per story. It was also stronger: the Tower’s columns tapered as they ascended. [11] Yet the fall of RB-12+, we are supposed to believe, put a catastrophic end to DS-6 and RB-92.

What NIST essentially says, agreeing with Bazant, is that the lighter and weaker part initially fell with a powerful jolt onto the heavier and stronger part, which could not withstand its momentum, and that this caused a progressive collapse to initiate smashing the lower block to bits all the way to the ground.

The NIST Final Report does not tell us what happened to RB-12+ after its impact with the two structures beneath it. Did it fall through them all the way to the ground (that is, to the rubble heap on the ground), maintaining considerable mass and rigidity the whole time--as Bazant argued in 2001 and has continued to argue? [12]

=======

On this the NIST authors are silent.

NIST also does not tell us how far RB-12+ fell before its impact with intact structure. Did it fall one story (roughly 12 feet), or several stories? We are left in the dark. Once again Bazant comes to the rescue. It fell "at least one story," he says. [13]

To his credit, Bazant is willing to state the essential elements of the hypothesis. If this hypothesis is to hold any water at all there must be substantial impact: RB-12+ has a lot of work to do, so it had better fall at least one story.

As we will show, for the purposes of the present refutation it does not matter whether RB-12+ fell one story, six stories, or somewhere in between.

The Necessary Jolt:

As Bazant has said, when the top part fell and struck the stories beneath it, there had to be a powerful jolt. While a jolt entails acceleration of the impacted object it requires deceleration of the impacting object. Even a hammer hitting a nail decelerates, and if the hammer is striking a strong, rigid body fixed to the earth its deceleration will be abrupt and dramatic.

Although NIST does not explicitly speak, like Bazant, of a "jolt", and may therefore be thought to evade this paper’s refutation, it is impossible for NIST to escape the implications of its own assertions. The NIST report speaks of a strong, rigid structure (the upper structure or rigid block) falling freely onto another strong, rigid structure (the intact part of the building below the damaged area): the jolt cannot be avoided. [14]

This was a necessary jolt. Without it the required work could not have been done.

Testing for Deceleration:

GO TO LINK ABOVE AND SEE ANALYSIS

#####################################

#####################################

#####################################

Debunking the Debunkers

From this point we get a discussion of the inward bowing seen happening in the videos of the Towers. Mr. Power parrots the explanations provided by NIST; that the fires in the buildings caused the floor trusses to sag downward, causing the exterior columns to bow inward and eventually breaking, initiating the collapse. The inward bowing of the Towers perimeter columns has been a subject of much debate regarding the controlled demolition of the Towers. As we have already established, NIST has no evidence of high temperatures in the buildings in the first place, and this sort of phenomenon has never caused the total collapse of a steel-framed high-rise before.[10] All NIST has is evidence that the columns bowed inward, but they have no evidence that fire alone is what caused it. Though Mr. Power asserts that controlled demolition cannot cause this event either, those in the Movement have proposed ways it can be done.[11] As noted by mechanical engineer Tony Szamboti:

It is instructive that the first visible signs of failure on the North Tower are when the antenna mast moves downward by ten to twelve feet before the perimeter roof line moves. This is indicative of the central core suddenly and completely failing first. If you haven’t seen this watch it frame by frame at the link below.

http://911research.wtc7.net/wtc/evidence/videos/wtc1_close_frames.html

These frames don’t show slow creep, they show sudden failure of the central core itself. They certainly don’t show the perimeter walls failing first. If the central core failed first it would cause the floor trusses, not to sag, but to follow them downward. In this situation the other end of the floor trusses would apply a tremendous force and bending moment to the perimeter wall columns, causing them to bow inwardly and ultimately to fail. Some of the NIST photos of WTC1, showing inwardly bowed perimeter columns, are frozen frames taken from video. In these photos the roof of the building and antenna mast are not shown. It would be interesting to see these videos, without cropping of the roofline and antenna mast, to determine if the bowing of the perimeter columns occurs after the antenna mast starts moving downward.[12]

The inward bowing of the Towers’ columns in no way disproves the notion that they were destroyed through controlled demolition.[13]

Free-fall speed

The next issue Mr. Power discusses is the fall rates of the Towers. He explains that the Towers did not collapse at free-fall rate, noting that a) the collapses took longer than 10 seconds; parts of the cores were still standing after the collapses; and c) the debris falling outside the footprint of each building fell faster than the actual structure.

a) Here I actually agree with Mr. Power, as more accurate measurements indicate that the Towers collapsed in approximately 15 seconds in either case.[14] While the Towers clearly did not collapse at free-fall, this is the case for most controlled demolitions as well. It has been established that the fall times for the Towers is consistent with the fall times of other controlled demolitions, and had the buildings really collapsed through natural causes, their collapses should have taken much longer.[15]

Although parts of the cores of each Tower were standing after the collapses, analyses done by mechanical engineer Gordon Ross demonstrate that the cores were attacked first in the collapses, and that critical sections of them collapsed along with the rest of the structures.[16]

c) It’s true that the debris fell faster than the actual structure. However, close inspection of the videos show that the debris actually falls at around the same rate as the wave of ejections seen travelling down the faces of each building.[17]

Mr. Power also questions why truthers count the full height of the Towers when timing the collapses instead of counting only where the collapses started at the plane-impact areas. The reason for counting the full height of each building is rather simple. The videos show that the lower sections of the Towers do not even begin to start collapsing until the upper sections are completely destroyed.

[11] See: A Hypothetical Blasting Scenario A Plausible Theory Explaining the Controlled Demolition of the Twin Towers Using Aluminothermic Incendiaries and Explosives with Wireless Ignition Means, by Jim Hoffman http://911research.wtc7.net/essays/thermite/blasting_scenario.html

[12] Quoted from: The Sustainability of the Controlled Demolition Hypothesis for the destruction of the Twin Towers, by Tony Szamboti http://www.journalof911studies.com/volume/200704/SzambotiSustainabilityofControlledDemolitionHypothesisForDestructionofTwinTowers.pdf

[13] For more on the subject of the inward bowing issues, see: WTC Pre-Collapse Bowing Debunks 9/11 “Controlled Demolition” Theory? by John-Michael Talboo http://911debunkers.blogspot.com/2010/07/wtc-pre-collapse-bowing-debunks-911.html

Edited February 27, 2013 by Steven Gaal

[Steven Gaal]

GRABBE IS AN EXPERT <YOUR HOFFMAN IS STRAWMAN

====================================================

Debunking the Real 9/11 Myths: Why Popular Mechanics Can't Face up to Reality - Part 3

Evidently, PM’s writers and investigative journalists somehow missed an article written by Dr. Crockett Grabbe which refutes the arguments made in Seffen’s questionable paper even though Grabbe’s article was published in the very same journal as Dr. Seffen’s paper.¹² Though PM touts Dr. Seffen and his paper as providing excellent analysis of the WTC collapses, there is no mention of Grabbe’s peer-reviewed response, even though Grabbe is a credentialed scientist. Instead, PM chose to cite an inflammatory remark on an obscure internet site.

Dr. Seffen never responded to Dr. Grabbe’s discussion paper, which was published over three years ago. In addition, PM felt no need to quote Dr. Grabbe, who says on his website, “Seffen is an applied mathematician from Cambridge whose paper was on BBC News. I ripped his paper apart, and he never made any reply to my very critical comments.”¹³

PM finishes this section by quoting a section of NIST’s report on the collapse of the Twin Towers that discusses the rate of collapse. The section reads:

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increases, further increasing the demand of the floors below, which were unable to arrest the moving mass.

¹⁴

PM also quotes from NIST’s FAQ on the WTC collapses:

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2… Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.

¹⁵

However, engineer and 9/11 researcher Jim Hoffman addressed both of NIST’s assertions. In regards to the first point, Hoffman writes:

This does not explain either why the structure below failed to arrest the falling mass or how the structure failed to appreciably slow the falling mass. As in the preceding paragraphs, NIST begs these questions using a kind of circular argument:

The towers fell rapidly because the stories below could not resist the tremendous energy of the falling mass

. Videos clearly show that the upper section fell essentially in free-fall. Therefore the structures below offered minimal resistance to and were destroyed by the falling mass. The argument pre-supposes the conclusion that the force that overcame the resistance of the structures below was the falling mass, not some other force such as energy of explosives.

¹⁶

As for the second point, Hoffman writes:

To the contrary, video records, such as

this record of the North Tower's fall

, clearly establish upper boundaries on the times that it took for the vast majority of each tower to be destroyed.

¹⁷

While citing several experts who support their assertion that the collapse rates of the Towers were nothing unusual, PM failed to acknowledge numerous other experts who say that the collapse rates clearly violated the laws of physics. The rate in which the Towers came down cannot be explained by the combined effects of fire and gravity.

For more on the subject of the Towers’ collapse rates, the following articles are recommended:

Twin Towers Evidence Blows Away Fire Theory

by James Smith

The Missing Jolt: A Simple Refutation of the NIST-Bazant Collapse Hypothesis

, by Prof. Graeme MacQueen and Tony Szamboti

Destruction of the World Trade Center North Tower and Fundamental Physics

by David Chandler

Showing that the South Tower of World Trade Center Collapsed from Forces More Powerful than Gravitation

by Crockett Grabbe

[in Part 4 of this monthly series, Taylor challenges Popular Mechanics’ misleading claims regarding the violent ejections of dust and building materials during the collapse of the Twin Towers. Look for Part 4 in the May edition of the Blueprint newsletter. For Part 2 click here]

¹²The paper can be read here: http://www.sealane.o...ffenrevpub.pdf

¹³Quoted from: http://www.sealane.o.../research.html

¹⁴Quoted from: NCSTAR 1, pg. 146 http://www.nist.gov/...?pub_id=909017

¹⁵Quoted from: http://www.nist.gov/..._wtctowers.cfm

¹⁶Quoted from: http://911research.w...ist/index.html

¹⁷Quoted from: http://911research.w..._FAQ_reply.html

Edited February 27, 2013 by Steven Gaal

[Steven Gaal]

Washington's Blog

The chief electrical engineer who wired the World Trade Centers (Richard Humenn) says that people working on the elevators could have planted explosives:

Mechanical engineer Gordon Ross, in his talk on the destruction of the Twin Towers,

that:

“Those [core] columns which were situated adjacent to and accessible from inside the elevator shafts failed at an early stage of the collapse.

Those columns which were remote from the elevator shafts, and not accessible from the elevator shafts, survived the early stages of the collapse.”*

Indeed, a top demolition expert says that with access to the elevator shaft, a team of loading experts would have access to the columns and beams:

According to USA Today: “On Sept. 11, ACE Elevator of Palisades Park, N.J., had 80 elevator mechanics inside the World Trade Center“.

And NIST itself says that, on 9/11, “Elevators 6A and 7A were out of service for modernization“. (NIST NCSTAR 1-8, p.97).

In addition, Ace worked in and around structural steel:

A run of approximately 80 vertical feet, employed over 300 running feet of 2-1/2″ x 8″ and 2″x 2″ trough raceway. This run traveled through plaster ceilings, concrete floors and around structural steel.

Indeed, there had been numerous elevator renovation and and asbestos removal projects in the 6 years prior to 9/11 which allowed access to core building structures, including:

• 1995
  

• 1997
  

• 1998
  

• 1998
  

• 2000
  

These are just a few of the known, public examples of opportunities to plant bombs. There were undoubtedly many additional opportunities available to skilled operatives.

And as experts such as one of the world’s top structural engineers – Hugo Bachmann, Professor Emeritus and former Chairman of the Department of Structural Dynamics and Earthquake Engineering, Swiss Federal Institute of Technology – notes, there could have been tenants of the World Trade Centers who planted bombs in their own, rented space, before moving out and vacating their office spaces.

[Len Colby]

GRABBE IS AN EXPERT <YOUR HOFFMAN IS STRAWMAN

====================================================

Huh? I was responding to post 203 in which you cited Hoffman. Grabbe is NOT an expert his area of expertise is optics, he believes the top block of the south tower fell at 3 times gravitational rate, impossible even if explosives had been used.

Debunking the Real 9/11 Myths: Why Popular Mechanics Can't Face up to Reality - Part 3

Evidently, PM’s writers and investigative journalists somehow missed an article written by Dr. Crockett Grabbe which refutes the arguments made in Seffen’s questionable paper even though Grabbe’s article was published in the very same journal as Dr. Seffen’s paper.¹² Though PM touts Dr. Seffen and his paper as providing excellent analysis of the WTC collapses, there is no mention of Grabbe’s peer-reviewed response, even though Grabbe is a credentialed scientist. Instead, PM chose to cite an inflammatory remark on an obscure internet site.

We've already been over this.

The Missing Jolt: A Simple Refutation of the NIST-Bazant Collapse Hypothesis, by Prof. Graeme MacQueen and Tony Szamboti

LOL a structural engineering paper by a theologian and a mechanical engineer who works in aerospace, the former is unqualified the latter not especially. Here's another aerospace engineer's take.

https://sites.google.com/site/911guide/ryanmackey

Destruction of the World Trade Center North Tower and Fundamental Physics by David Chandler

High school physics teacher, I'm impressed!

Showing that the South Tower of World Trade Center Collapsed from Forces More Powerful than Gravitation

by Crockett Grabbe

Like I said "his area of expertise is optics, he believes the top block of the south tower fell at 3 times gravitational rate, impossible even if explosives had been used."

[Len Colby]

Washington's Blog

The chief electrical engineer who wired the World Trade Centers (Richard Humenn) says that people working on the elevators could have planted explosives:

Citation?

Mechanical engineer Gordon Ross, in his talk on the destruction of the Twin Towers,

that:

“Those [core] columns which were situated adjacent to and accessible from inside the elevator shafts failed at an early stage of the collapse.

Those columns which were remote from the elevator shafts, and not accessible from the elevator shafts, survived the early stages of the collapse.”*

And the evidence for these claims is? I contacted someone who graduated the same year from the same degree program as Ross he said it would NOT have especially prepared them to analyse the collapses.

Indeed, a top demolition expert says that with access to the elevator shaft, a team of loading experts would have access to the columns and beams:

Name? Citation?

According to USA Today: “On Sept. 11, ACE Elevator of Palisades Park, N.J., had 80 elevator mechanics inside the World Trade Center“.

And NIST itself says that, on 9/11, “Elevators 6A and 7A were out of service for modernization“. (NIST NCSTAR 1-8, p.97).

In addition, Ace worked in and around structural steel:

Yeah they obviously were 'in on it'.

And as experts such as one of the world’s top structural engineers – Hugo Bachmann, Professor Emeritus and former Chairman of the Department of Structural Dynamics and Earthquake Engineering, Swiss Federal Institute of Technology – notes, there could have been tenants of the World Trade Centers who planted bombs in their own, rented space, before moving out and vacating their office spaces

.

LOL the only source indicating he said this was an article written by a truther.