Sunday, 11 September 2011

911 : Can Physics Rewrite History?




A compilation of physical impossibilities & overlooked evidence
in the official explanations for the destruction of the
World Trade Center Complex

by C. Thurston
updated 08/08/11


This report is divided into the following sections:



Introduction:

I feel a sense of urgency over this issue because it involves the dangerous influence of a powerful and highly organized, but factually incorrect, set of beliefs that continues to have a strong hold on the minds of many Americans, as well as others around the world. These beliefs inherently create an unconscious mental disconnect from reality, while provoking misdirected feelings of fear and anger. This result has unfortunately been exploited as an opportunity for drastic changes in law and policy that would have been impossible otherwise.

I am wary of any important belief — whether it is mine or someone else's — if it is promoted and accepted with little or no substantial verification. I am learning to consider the possibility that a tempting new belief may have been engineered to serve the purposes of others unknown to me.

My independent research efforts into this matter are of a volunteer nature and are motivated by a desire to learn the truth about these events. Even if you disagree with my conclusions I hope you can at least share my intentions. This report is primarily intended as an information assist for others who may also be looking into these questions on their own.

The information presented here can be easily verified and/or expanded upon with simple internet searches. I have provided many relevant links to good sources of data and analysis on both sides of the issues. Independent research is a healthy exercise for anyone's critical and logical faculties — it is also a profound opportunity to reclaim possession of our understanding and perspective. How can we hope to control our future if our beliefs about the past and the present are the products of deliberate deception?

How were three steel frame high-rise structures completely destroyed on 9/11? Many conflicting theories have been put forward, but unlike most of history's unanswered puzzles, the destruction of the WTC Towers and the mysterious collapse of WTC Building 7 are matters of physics. We cannot even begin to define the crime of 9/11 until we have a basic understanding of the physical events that we all witnessed. The consideration of who had the means, motive and opportunity can only begin once we know what actually happened!


Existing photographic and video evidence that has undisputed authenticity and is a part of the public record presents a number of striking problems with the belief that the airplane impacts initiated a chain of events that ultimately destroyed the Towers, and of course WTC Building 7 was not hit by an airplane.

To clearly see these problems, it is helpful to first have a basic understanding of materials behavior and the design of the Towers, and then become aware of the distinct and remarkable features of the events themselves. This report includes a critical evaluation of the leading "official" explanations, followed by an examination of the compelling forensic evidence that is consistently either ignored or misrepresented by these explanations.


The Structures:

Structural steel has been used in the construction of buildings, bridges, towers, etc., for well over 100 years and its characteristics and behavior under adverse conditions have been well tested and analyzed over this long period of time. The greatest risks to modern highrise buildings (apart from military attacks and severe earthquakes) are fire, high winds and accidental airplane collisions. Consequently, the engineering and design of tall buildings must guarantee that they can successfully withstand these adversities.

The World Trade Center Towers were the world's tallest buildings when they were officially dedicated on April 4th, 1973. Historic innovations in high-rise design were conceived and implemented in order to safely reach such unprecedented heights.

Structural steel buildings up to this time had typically been designed with vertical columns evenly spaced in a grid-like arrangement in order to support the horizontal beams that would carry the floor above. This would be repeated from one floor to the next to create a tall building. One undesirable consequence of this type of design is that the interior office spaces in these buildings are periodically interrupted by the support columns.

The Towers were designed using a type of architecture that was relatively new at the time and is referred to as a "tube within a tube." Closely-spaced columns are positioned around the perimeter of the structure while other columns are concentrated in a heavily reinforced central core. The photos below show the dense spacing of the columns that make up the perimeter walls and the relative size of the core structure, which also contained the elevator shafts.


The office floors were suspended in between with no other vertical support. This provided a column-free office environment and also produced a very strong, flexible and relatively lightweight structure with tremendous sheer strength. The Towers could be 100 stories high and still withstand hurricane force winds and multiple high-speed collisions from large commercial jet aircraft.

Engineering News-Record reported in 1964 that the specially manufactured high strength steel perimeter columns had strength significantly greater than the 5 X load requirement of standard building codes, stating that "live loads on these columns can be increased more than 2000% before failure occurs." 

From the book City in the Sky (Times Books, Henry Hold and Company, LLC, 2003,  page 133), we're told that the calculations of the engineers working on the Tower design showed that ALL the columns on one side could be cut, along with the two corners and some of the columns on each adjacent side, and the building would still be strong enough to withstand a 100-mile-per-hour wind!

Post-9/11 assertions that the Towers were either poorly designed or poorly built do not square with the historic record. They were built to be incredibly strong and were considered to beengineering marvels. John Skilling, the lead designer, won prestigious awards for their design excellence.



Considerations Regarding Fire:

1) In order for structural steel to literally melt and change state into a flowing liquid, its internal temperature (as opposed to the surrounding temperature) must be raised to 1538˚C (2800˚F).

2) The strength of steel is determined by its internal temperature (regardless of fire temperature) at a given moment. While internal temperature will gradually rise during prolonged exposure to constant high temperature, if the temperature stabilizes, the steel will not continue to weaken as a cumulative effect. As its temperature changes — either up or down — its strength also changes accordingly.

3) At high internal temperatures below the melting point, steel can lose its load bearing strength and rigidity and become subject to bending, sagging, etc. Much well documented testing has been done over the years to determine this temperature threshold. The ability to predict the behavior of steel during intense fires is fundamental to its use as a construction material. To summarize the significant consensus of these tests, the strength of steel is reduced to 20% of normal when it reaches an internal temperature of around 720˚C (1328˚F).

This is significant because, as mentioned above, standard building design specifications require that structures be able to bear five times their maximum theoretical load (20% = 1/5). This means that even if all the steel in a building reaches an internal temp of 720˚C, the building will still be able to carry its maximum load. Since maximum theoretical loads rarely occur (extremely large crowds of people or concentrations of heavy equipment, for example), the steel temperature in a typical situation could probably go significantly higher before failure would occur.

4) Fire tests carried out in the 1990's at the Building Research Establishment test facility at Cardington in Bedfordshire, UK showed that the performance of whole buildings can exceed the performance of its parts, when tested separately. An 8-story closed test structure was subjected to atmospheric temperatures of 1200˚C (2192˚F), causing unprotected steel beams to eventually reach internal temperatures over 1100˚C (2012˚F). This caused deformations in some of the steel, but the structure did not collapse. Keep in mind that real fires in closed spaces cannot be sustained due to oxygen starvation.

5) In addition to being relatively lightweight in proportion to its strength, one of steel's best qualities and a major reason why it is used so commonly in building construction is its ability todissipate heat quickly and stand up unscathed in even the worst "towering inferno" conflagrations on record. The steel at the location of a fire within a building will be constantly cooled as the heat is drawn away into the surrounding framework.

Open test structures were subjected to prolonged and intense fires of up to 1200˚C (2192˚F) in an international study of structural steel car parks, but internal steel temperatures never reached higher than 360˚C (680˚F).

Fire temperature and internal steel temperature are NOT the same. This is why meat thermometers were invented. Remember 360˚C for later when we look at the various theories and claims based on the unproven assumption that the Towers "collapsed."

6) The Towers were designed to withstand impacts from the largest commercial aircraft that were in use at the time they were built. Contrary to initial reports, the airplanes on 9/11 were not significantly larger than this, and the jet aircraft of those days carried jet fuel just like they do now. Building survival is accomplished through redundancy and dynamic redistribution of loads to the surviving parts of the structure.

According to John Skilling, the lead designer of the Twin Towers (from a Seattle Times interview from February 27, 1993), an impact from a Boeing 707 travelling at 600 mph "would result in only local damage" and that “our analysis indicated the biggest problem would be the fact that all the fuel (from the airplane) would dump into the building. There would be a horrendous fire. A lot of people would be killed.” But, he says, “The building structure would still be there.”

7) Prior to 9/11 (or since) no steel-frame highrise has ever collapsed from fire. There have been numerous cases of high-rise fires far more severe than those observed on 9/11. Here are a few examples:

• Caracas, Venezuela, Oct, 2004, 56 story building burned for 17 hours over 26 floors
• LA, May 1988, 1st Interstate Bank, 62 stories, 5 floors burned for 3.5 hours
• Philadelphia, Feb, 1991, Meridian Plaza, 38 stories, 8 floors burned for 18 hours
• New York, Aug, 1970, New York Plaza, 50 stories, burned for six hours
• Madrid, February 2005, Windsor Bldg, 32 stories, burned for 24 hours, total loss


 

All of these fires were true "towering infernos" with dramatic, raging emergent flames bursting out from entire floors of the building through shattered windows. None of these buildings collapsed.

8) In 1975, an arson fire burned for three hours in the North Tower of the World Trade Center, eventually spreading to portions of six floors. 132 firefighters were involved in the effort to bring it under control and the fire captain reported that it was "like fighting a blow torch." The fire began in a wiring closet in the central core area and grew until the flames burst out through the windows on the 11th floor. The steel structure was not damaged by this fire, which was longer lasting and arguably more severe than the fires in the South Tower on 9/11.


Fuel for the Fires:

Jet fuel (refined kerosene) is a hydrocarbon and will burn at a maximum temperature of approximately 1000˚C (1832˚F) in an open fire when supplied with unlimited amounts of air (as opposed to pure oxygen). This information is easily available from any physics desk reference. Temperatures are lower if the fire is oxygen-starved, as evidenced by black smoke. Significantly higher temperatures are possible only with forced mixing of pure oxygen.

Early reports on 9/11 wildly overestimated the amount of jet fuel involved based on tank capacity. The planes were designed for intercontinental flight, but carried only the fuel needed for their domestic flight plans.

It is now acknowledged, even by the government's theories, that most of the jet fuel was consumed in the first few minutes by the huge fireballs at the time of impact. The idea that large pools of jet fuel could be burning for the entire 1-2 hours preceding the Towers' destruction is not consistent with the behavior of a volatile and highly flammable liquid in a high temperature environment. It would have either ignited, or — if inadequate oxygen was available to support combustion — it would have left the building as a vapor along with the smoke. The smell of jet fuel was indeed reported over a wide area. 

The burning jet fuel did of course start the fires inside the buildings, which were more severe in the North Tower where more of the jet fuel was carried inside the building. But the jet fuel could not have been a significant ongoing fuel for the fires. Known combustible materials within the buildings (carpets, desks, paper, plastics, etc.) are also mostly hydrocarbon in nature and can produce combustion temperatures no higher than jet fuel. House fires typically produce temperatures in the 500 - 650˚C range.


The Tower Impacts:

1) The airplane impacts were quite dramatic, with the huge fireballs that we all saw over and over again on TV. After the first few minutes, however, we simply had office building fires with some amount of structural damage. Interior damage is hard to determine based on visual evidence. The investigative report released by NIST in 2005 claims that 14-15% of the core columns in each Tower were severed. While sometimes repeated as fact, this is an estimate derived from questionable computer simulations. Even if true, this amount of damage would leave the buildings well within their load-bearing redundancy. More on the NIST Report later. 

2) Airplanes are made of aluminum, which is a much lighter and weaker material compared to structural steel. Airplanes may look big and substantial, but they are actually made to be aslightweight as possible. The thickness of their aluminum skin is only 2 mm.

3) Both buildings quickly re-stabilized after impact and showed no observable signs of instability or evidence of structural failure prior to the sudden onset of their destruction.



4) The North Tower, unlike the South Tower, took a direct hit with the airplane completely disappearing inside the building. If the load bearing central core of the building (see construction photos, above) had been severed by the impact of the plane, structural distress would have been evident almost immediately. Apart from the fires, the North Tower remained stable until the sudden onset of destruction, almost two hours after impact.

5) The South Tower took a glancing blow at the corner which created a very dramatic fireball, but this apparently did little damage to the structural core (in spite of speculations to the contrary from the NIST report). Less fuel was taken inside the building compared to the North Tower, and people were evacuating from the upper floors through the impact zone via stairwells in the central core area prior to the onset of destruction. The fires were smaller in this Tower, but its destruction occurred first, 56 minutes after impact. Firefighters who reached the 78th floor sky lobby reported only "two pockets of fire."


The Official Theories:

The destruction of the WTC Towers has been attributed by official investigators, and various "experts" promoted by the mainstream media, primarily to fire — causing one form or another of structural failure leading to "total progressive collapse." While most of these theories allow that impact damage was probably a contributing factor, few have suggested that this damage alone caused the total failure of the buildings.

While we look at these so-called "collapse" theories, it must be clearly understood that the use of the word "collapse" is a misnomer. What these theories are REALLY saying is that the upper part of the building above the impact zone CRUSHED the lower undamaged portion of the building. Remember that the structural integrity of the Towers was undiminished below the impact zones and much heavier and stronger materials were used in the lower parts of the building in order to support the much lighter upper floors.

1) One of the first explanations was put forward only two days after 9/11 (on September 13, 2001) by the American Society of Civil Engineers in a paper titled "Why Did the World Trade Center Collapse? — A Simple Analysis," by Zdenek Bazant and Yong Zhou. One might wonder how they were able to come up with such a seemingly confident and fully developed theoretical explanation for a shocking, unprecedented and inexplicable occurrence within such a short period of time. Like the voluminous and complex "USA Patriot Act," which appeared full blown inOctober 2001, it almost seems to have been prepared ahead of time.

In any case, their theory depends on the simultaneous failure of at least half the support columns on a "given floor," which they say would allow the upper part of the building to fall freely onto the lower part, thus allegedly triggering a sequence of events that would "doom" the entire tower.

They claim that this "triggering" condition would be achieved if more than half of the column steel on a "given floor" reached temperatures exceeding 800˚C (1472˚F), but they fail to distinguish between fire temperature and internal steel temperature and offer no explanation for how this could possibly occur. This assertion (based on the failure of only half the support strength) also reveals that they are either unaware of or are ignoring the 5 times maximum load strength requirement for building design. This is surprising, considering that they are representing the American Society of Civil Engineers.

An obvious fallacy with theories of this type is that column strength and heat conductivity in the Towers were NOT segmented by the vertical spacing of the office floors. During a fire, the heat produced by burning material on a particular office floor would be dissipated by the steel framework over a multi-story region of the building.

Also, the load-bearing strength of the columns was vertically continuous over many "floors" for any region of the building. The columns in the core structure were specially fabricated to be multiple stories in height and were joined together by welded connections. Dense cross-bracing interconnected the core columns and created a monolithic entity that was structurally independent of the office floor attachment locations, which were on the outer perimeter of the core structure.

Therefore, it really makes no sense to talk about about column behavior on a "given floor." The columns didn't have "floors."

The clustering of the core columns in the center of the building also places most of them at a significant distance away from the vicinity of any conceivable office fire. Bazant and Zhou's theory apparently assumes that the Towers were built according to the old-fashioned "post and beam" column grid arrangement. Like others to follow, they use complicated equations and obscure concepts to create an intimidating aura of authority, while overlooking or misrepresenting the fundamental features of the scenario.

In addition to these theoretical fallacies, we've already seen that high internal steel temperatures are very difficult to achieve over a wide area in a large structure. Not only is Bazant and Zhou's so-called triggering condition clearly impossible given the test data presented earlier, but the results of the examination of steel recovered from the fire zones, as reported by NIST in 8/04, shows no evidence of temperatures over 625˚C (1157˚F) and only rare instances of temperatures over 250˚C (482˚F)! This is consistent with the international fire test results mentioned earlier. (See the section below for more on the NIST report.)


A more detailed critique of Bazant and Zhou's paper can be found by following links from here:

2) Another theory was put forward by Thomas Eager, a professor of materials engineering from MIT. It appeared in JOM, the journal for the Minerals, Metals & Materials Society and was also presented in a NOVA interview that many people have seen. The transcript is available online. Eager claims to believe that the Towers were not designed to withstand a fire covering an entire single floor! He doesn't say where he gets this idea, but we know from the comments presented earlier that Skilling certainly DID allow for this possibility.

Because the spilling of the jet fuel may have caused this to happen, Eager suggests that the heat from this type of fire scenario caused the floor slab truss connections ("clips" he calls them) to fail — "unzipping" almost simultaneously around an entire floor — causing a pancaking sequence that also somehow pulled down the vertical support structures.

"Pancaking" collapses are sometimes seen in Third World countries where badly designed and poorly reinforced structures with heavy concrete floors are subjected to earthquakes. Modern American buildings (including the WTC Towers) are designed and built according to robust standards and specifications that require structural unification of horizontal and vertical assemblies. This is done specifically to prevent pancaking floor collapses under any circumstances.


Eager also ignores the continuous vertical strength of the core structure and its heavily cross-braced and unified design. Even if some of the floor connections had somehow broken loose, the more heavily built and potentially free-standing column structures would have remained in place. While the floor assemblies interconnected the core with the perimeter columns and added strength and flexibility to the structure as a whole, they were also designed to be as lightweight as possible.

A detailed evaluation of Thomas Eager's analysis can be found here:

3) Two highly produced, made-for-television specials have been particularly influential in determining many people's beliefs about the destruction of the WTC Towers. Unfortunately, the non-commercial reputation and credibility of PBS and NOVA have been exploited as a vehicle for the presentation of deliberately false information and analysis. To a traumatized television audience in 2001 this was not so apparent. But now, in the sober light of a better understanding, the fraudulent nature of these presentations is painfully obvious.

Below are two graphics used in the NOVA program "Why the Towers Fell." The one on the left misrepresents the structural core of the building to look like mysterious floating horizontal slabs with no vertical support! The one on the right is from an animated sequence of falling floor trusses that is also very misleading.

Missing from this animation are at least three major components that would have prevented this behavior: 1) the perpendicular cross trusses, 2) the welded-plate wall connections, and 3) the steel floor pan that is connected to the trusses, onto which the concrete slab is poured. The floor pan interconnects the trusses and provides stiffness and strength to the entire floor system.

                
This diagram shows a more truthful view of a typical truss assembly:


Another TV special titled "Anatomy of the Collapse" was produced for the Discovery Channel and also appeared shortly after 9/11. These two programs are similar and include numerous fraudulent statements. We are told, for example, that jet fuel had not been considered in the design of the Towers, that it had saturated the entire buildings and that steel temperatures had reached 2000ºF. None of these statements are true.

We are also told that the buildings would collapse without the floor trusses, that the floor trusses were connected by only two bolts, that the perimeter walls were comparable to sheets of cardboard and that the columns were like free-standing wobbly sticks. The perimeter and core column structures were, in fact, highly robust and independent structures unto themselves, each fully capable of standing on its own. And the biggest lie of all? We are told that total destruction was inevitable.

3) The first major government report was issued by FEMA, and it uses these misleading diagrams to make it look to the casual, non-technical reader like there was no central core at all!

           
A careful reading of the fine print says the vertical members on the right side of the diagrams are core columns and we are only looking at a detail of the structure, but this is not obvious at a glance. There is also no indication of the immense strength and dense cross bracing of the structural core of the building. Many people seem to believe that the Towers were supported only by the perimeter walls. It is easy to imagine that a building would collapse if it were built to look like this diagram!

Even the 9/11 Commission Report, on page 558, claims that: "The interior core of the buildings was a hollow steel shaft…" This is a blatantly false statement with no conceivable explanation other than the desire to intentionally deceive. The 9/11 Commission Report includes many other outright lies, distortions and critical ommissions. See David Ray Griffin's book, The 9/11 Commission Report: Ommissions and Distortions, for a comprehensive and thoroughly documented examination of over one hundred of these deliberate violations of truth.

Below is another view of one of the Towers during construction. Compare it to the diagrams above and to the statement by the 9/11 Commission. This gives a good look at how much of the footprint of the building was taken up by the core structure and its massive design.



America, who used to be so proud of her expertise and execution on every level, is nowpleading incompetence in new creative ways every day, including projecting that incompetence back into the past. Forgetting about the jet fuel and the possibility that an entire floor might catch fire was bad enough, but now there's this:

4) Hyman Brown, construction manager of the WTC and University of Colorado civil engineering professor said this in 2004 (quoting from the Boulder Weekly):

"It is correct that the towers did not collapse because of the airliners hitting it. But we do know how it collapsed and it has nothing to do with conspiracy," says Brown. "What caused the building to collapse is the airplane fuel and the fire-suppression system that we now have, which basically blocks off five-floor blocks, so the fire can’t go up and the fire can’t go down. You now have a fire confined to a five-floor area, burning at 2,000 degrees Fahrenheit. The steel in that five-floor area melts. All the tonnage above the five-floor area comes straight down when the steel melts. That broke all the connections, and that caused the building to collapse."

Who could have guessed that the fire suppression system, instead of causing the fires to die down from lack of oxygen and depletion of flammable material like everybody expected, actually caused the fires to become hotter! So hot that they melted all the steel in a five floor area of the building! To fuel this fire, Mr. Brown apparently assumes that unlimited quantities of jet fuel (and oxygen) were available on all five floors of both buildings for up to two hours in a 1093˚C (2000˚F) environment. The behavior of volatile flammable liquids in a high temperature environment would not allow this.

When Mr. Brown says that the steel "melted," I think he means to say that it failed — the melting point of steel, as we've seen, is 1538˚C (2800˚F). But failure is also a clear impossibility. Remember those open steel test structures? They were subjected for a longer time to a fire even hotter than the one he imagines, but the highest recorded steel temperature never went beyond than 360˚C (680˚F) — far below the temperature where failure could occur. Mr. Brown's fire may have been confined to a five story region, but the steel was still free todissipate heat throughout the entire building framework!

Also, to match his own description, this fire would have to fully engulf all five floors, with large emergent flames bursting from every window on all sides of the building. From photographic evidence we see only lots of black smoke with flames here and there. And the "tonnage" he's speaking of is simply the upper part of the structure that the lower part was designed to support.


I wouldn't spend so much effort examining Mr. Brown's highly improbable theory, except that he has been connected informally by the media to findings reported by NIST, the US government science agency that has recently completed a $20,000,000 investigation into the destruction of the WTC Towers. It was said in 2004 by the media that Mr. Brown's views were supported by the preliminary findings of the NIST investigation!

5) The final report released by NIST in 2005 (http://wtc.nist.gov/) does indeed start with the assumption that the Towers simply "collapsed" on their own, once impacted from above by a block of floors that allegedly "fell" through the impact zone. They depend on fire to "soften," "shorten," "buckle" and "snap" core and perimeter columns and floor trusses where necessary in order to create a plausible sounding "collapse initiation" sequence.

But they don't explain how the combustion of typical office contents could possibly produce enough heat at a high enough temperature to cause the extensive steel deformations necessary to support their hypothesis. And they also do not explain how they reconcile this hypothesiswith their own investigative data (mentioned earlier) from 8/04!




The NIST report also fails to explain or reconcile the fact that they were unable to duplicate failure in their post-9/11 floor model fire tests. They try to convince us that hypothetical damage to the fire-proofing of the steel explains everything, but they provide no scientifically verifiable data to support this conclusion or carry it beyond the status of pure speculation.

The following article by Kevin Ryan describes these issues in detail. He is a heroic whistle-blower who was fired from his senior position at Underwriters Laboratory for first attempting to resolve these problems through internal procedures, and then finally bringing them to the public's attention as a last resort. UL was responsible for the fire testing of steel assemblies used in the construction of the World Trade Center.

Like Mr. Brown, NIST simply assumes that once the alleged "collapse" begins, it will be obvious to everybody why it would crush the entire structure. This part is never explained. Out of all the thousands of pages in NIST's supposedly exhaustive report, the actual destruction of the buildings is dismissed with ONE SENTENCE: "Global collapse then ensued." That's it! That's all they have to say about it. This is the key issue and it should have been the focus of the entire report!

NIST's failure to look at evidence or to carry their analysis beyond the point of "collapse initiation" is extremely suspicious and highly unscientific. Their inability or unwillingness to PROVE their a priori assumption that the Towers were destroyed by a so-called progressive gravitational collapse invalidates the entire report.

Also in the October 2005 report (updated by a FAQ in August 2006), we find a stunning reversal that would put even a star NFL running back to shame. Not only has NIST officially backed away from the "pancaking collapse" theory (with no apology), but those much-maligned floor truss connections (remember the "two bolts"?) that were originally blamed for just about everything, are now somehow conspiring with alleged floor sagging to pull on the specially manufactured, high-strength steel perimeter columns (remember the 2000% load capacity?) with enough force to cause an entire face of the building to "snap" from inward bowing!

And they still don't explain how even this fantastic scenario would cause the inevitable destruction of the lower portions of the building.

After hearing the astonishing comments by S. Shyam Sunder, Ph D, the lead investigator for NIST, made during an interview about "conspiracy theories" with NOVA and available on their website, I feel compelled to question either his competence or his honesty, or both. Among other bizarre statements, he claims in a matter-of-fact sort of way that the Towers "fell" at the rate of free-fall because they were "70% just air in volume" (as if that explains anything) and because the columns weren't made of "solid steel" but were "steel boxes" with walls only 1/4" -  3/4" thick!

Buildings have NEVER been constructed with solid steel members. The very idea is absurd! They would be excessively and unnecessarily heavy. Box columns, I-beams and H-beams of comparable strength are much lighter. Large box columns were indeed used in the core structure. At the base of each Tower they measured 52" x 22" and the steel was, in fact, FOUR INCHES thick!



"NIST Data Disproves Collapse Theories Based on Fire," a paper by Frank Legge Ph D, uses data from the NIST report itself to show that NIST's conclusions contradict their own findings. This simple and straightforward refutation is presented purely within the terms and context of the NIST investigation. It is posted at this link, and also includes a number of useful reference links:

A detailed critique of the NIST Report can be found here:


6) Popular Mechanics magazine in its March 2005 issue attempted to discredit legitimate questioning of the WTC destruction by using intimidation tactics and presenting long lists of experts. This effort was continued in 2006 with the release of Debunking 9/11 Myths, a book length presentation of similar material. While the authors and their band of "experts" claim to have exhaustively debunked 9/11 skepticism, they have in fact only attacked long-discredited claims and "straw man" arguments while ignoring the serious questions. They fail, for example, to satisfactorily address any of the observations described in the next section of this paper. A detailed critique of the Popular Mechanics article can be found here:

Paul Craig Roberts has this to say about the origins of the Popular Mechanics article:

"Perhaps it is merely a coincidence that just prior to 9/11 Cathleen P. Black, who has family connections to the CIA and Pentagon and is president of Hearst Magazines, the owner of Popular Mechanics, fired the magazine’s editor-in-chief and several senior veteran staff members and installed James B. Meigs and Benjamin Chertoff, a cousin of Bush administration factotum Michael Chertoff. It was Meigs and Benjamin Chertoff who produced the Popular Mechanics report…"

All of the Popular Mechanics experts apparently forgot their high school physics since they, like gullible members of a new cult, "believe in" the free fall progressive collapse theory — a ridiculous impossibility. See "The elapsed time of the destruction" section, below. The Popular Mechanics experts also claim to believe (of course) that the Towers "collapsed" because fire weakened and distorted the steel.

I believe that all the above theories (and all similar ones) have to be rejected from the outsetfor at least two reasons:

a) They all depend on fire to do what fire is not able to do — and has never done before — that is, heat structural steel to the point of causing a total building failure.­

b) The intact lower portions of the buildings would have arrested or deflected any conceivable collapse (crushing) process. 


Dramatic Features of the Destruction that are Ignored by the Official Theories:

1) The Towers look like they are exploding, complete with enormous rising mushroom clouds before any debris reaches the ground (indicating tremendous heat release) and lateral ejection of material with great force to great distances. In the photo on the right, below, steel perimeter column sections are thrown into the air like toothpicks.

  
Massive sections of structural steel column assemblies were ejected as far as 500 feet — a distance equal to more than 1.5 football fields! The blast wave alone shattered windows in buildings 400 feet away and multi-ton sections of heavy steel column structures were lodged into the sides of neighboring buildings!


ABC News correspondent N. J. Burkett was standing more than a block away from the WTC Towers on 9/11 when the South Tower destruction suddenly began. He interrupted his live TV commentary by shouting as everyone ran for cover: "...A HUGE EXPLOSION NOW — RAINING DEBRIS ON ALL OF US!  WE"D BETTER GET OUT OF THE WAY!"


2) The destruction of each Tower began suddenly and was not preceded by obvious buckling or other dramatic visible deformations. There were no reports from firefighters of sagging, creaking or twisting steel that might signal impending failure.

3) One problem that everyone is having is that no one has ever seen a "natural" collapse of a steel frame high-rise building (because it has never happened), so no one knows what it oughtto look like! Earthquakes sometime topple modern buildings, but they retain their shape, even if distorted, and they don't explode or fall apart.

                

If the Towers did experience gravitational collapse due to global structural failure, you would expect to find a huge heap of identifiable parts of the building piled within and spilling outside of the original footprint. It would include sections of floor slabs, floor pans, large chunks of concrete, glass and the remains of identifiable building contents, including the bodies of the occupants.

This is not what happened — both Towers almost entirely disintegrated into rather short (30 ft or less) pieces of steel, dust and other metal debris. Hundreds of tiny human bone fragmentshave been discovered on the roofs of neighboring buildings, and the remains of over 1000 bodies disappeared completely. Were they vaporized out of existence? Or obliterated into particles too small even for DNA analysis? How could this possibly happen?



 

This photo was taken looking straight down within the footprint where one of the Towers once stood. The elevation of this area is not significantly higher than the original street level and shows only pieces of metal and dust. Search and rescue workers were stunned that so many bodies had apparently vanished — along with the desks, the computers, the glass and all the other building contents.

Joe Casaliggi of Engine 7, one of the early emergency workers who dug through the wreckage where the Towers once stood, put it this way:

"You have two 110-story office buildings: you don't find a chair, you don't find a telephone, a computer... the biggest piece of a telephone I found was half a keypad, and it was this big [holds up thumb and forefinger]. The buildings collapsed to dust."

Also note that the photo above includes no intact identifiable portions of the building itself. Of particular interest is the fact that the corrugated steel floor pans are all apparently missing— along with the concrete floors. There is no stack of "pancaked" floors piled up within the footprint of the former building.

4) Almost all of the non-steel building materials and contents were pulverized, much of it into talcum powder size (sub 100 micron) dust particles. This took the form of the dense pyroclastic dust clouds that expanded to enormous size as they raced down the surrounding streets at tremendous velocity and with clearly defined boundaries, depositing most of the mass of the buildings outside of the perimeter of their original footprints.


Concrete and gypsum, along with large amounts of asbestos and countless other dangerous materials, were all part of these huge toxic dust clouds that spread over lower Manhattan and poisoned the air at Ground Zero. All of the trained dogs and many of the rescue and cleanup workers have died or are now seriously and permanently ill.

If you dropped a large chunk of concrete from 1000 ft onto pavement far below, it would certainly break apart, but it wouldn't be pulverized into microscopic particles. In the case of the Towers, the disintegration into dust somehow took place in mid-air, long before any debris reached the ground.


5) Both the nearly total pulverization of the building materials and contents and the rapid expansion of the dust clouds (the photo on the right, below, was taken only 30 seconds after the start of the destruction of the North Tower) to great elevations and large distances from the building locations would require the release of tremendous amounts of heat energy. The only energy source presumed to be available to explain these phenomena is the elevated mass of the buildings themselves, which is inadequate by at least an order of magnitude according to conservative estimates.


       

6) The elapsed time of the destruction was nearly identical to the time it would take a free-falling object to reach the ground from the same height. Common sense would certainly suggest that if the lightweight upper part of the building had somehow dropped onto the intact structure below, the strength and resistance of the more heavily built lower portion of the building would not only slow the process, but would arrest it altogether or deflect it to one side. Several scientific papers supply proof for this conclusion — see the following websites for an abundance of bona fide analysis.

And IF the structural support for the upper part of the building actually DID give way because of damage and high temperature, it would have exhibited gradual deformations as it approached its failure threshold. The interconnected framework, even if it began to bend or sag, would still prevent a sudden drop of the upper floors. (See Cardington fire tests, mentioned earlied.) What we see instead looks as if the presence of structural support is instantly obliterated as the wave of destruction begins.

Based on video and photographic evidence, and FEMA's mapping of the widespread debris field, each Tower appears to have been progressively and systematically exploded from the top down, starting from the impact zone. The explosive sequence was timed to occur at a pace close to free-fall, thus allowing the falling debris to blanket over and partially hide the continuing explosions.


The Bazant & Zhou paper mentioned earlier, and other papers by Frank Greening and Manuel Garcia, all claim to have mathematical models that show how a high-rise steel structure can crush itself at the rate of free-fall.

These theoretical "pancaking" scenarios do not take into account the strength of specific structural features like the continuous verticality of the core column assemblies or the fact that much stronger and heavier materials were used in the lower part of the building. They also employ the entire mass of the structure to drive the process while ignoring the fact that most of this mass is actually landing outside of the original footprint and would therefore be unavailable.

In Garcia's article, for example, "We See Conspiracies That Don't Exist," available at the Counterpunch link above, he repeatedly makes reference to a falling "block of floors" that is supposedly impacting the structure below like a "hammer." Where is this alleged "block of floors"? All we can see in the photos above is an ever-expanding slurry of pulverized debris that is somehow being propelled far beyond the original perimeter of the structure.

Greening's paper is posted at 911myths.com (a "debunker" website, linked above) and, like Garcia, he tries to build a theory around the idea of "momentum transfer." The equations he uses assume impacts from solid masses like you see with billiard balls, but in the case of the Towers, a rigid falling mass is nowhere to be found.

But even if we forget all these objections, something else about the notion of a progressive collapse occurring at the rate of free fall defies intuition. The obvious problem with this idea is that it does not allow time or energy to overcome the INERTIA of the materials in the lower part of the building that must be instantly accelerated up to the rate of free fall in order to join the already falling material from above without slowing it down. In fact, each of these encounters with stationary mass WOULD require an energy expenditure from the falling material, which WOULD slow it down — and, when combined with the strength of the structure, quickly stop the process altogether.

There are only two ways a building can be destroyed at the rate of free fall:

a) All structural support is simultaneously removed at the foundation level — all parts of the building will then begin to fall at the same moment and at the same rate. This is the method that is typically used in the controlled demolitions that we see on TV. The advantage to this approach is that it minimizes damage to neighboring buildings (see WTC7).

b) Or, something (like timed explosives) progressively destroys the building from the top downat the rate of free fall, while simultaneously removing resistance in advance of the falling debris. This is NOT the way controlled demolitions are normally done, although tall chimneys are sometimes destroyed this way (see end of report).

See the following two links for thorough examinations of Garcia and his theories:

"Garcia not only works for the government, he works for a very interesting organization in terms of the best hypothesis for what happened that day. Lawrence Livermore National Laboratory (LLNL), Garcia's employer, appears to be where explosive thermite was invented, and it continues to be a focus of research there."


7) Oxidation, sulfidation and intergranular melting were observed by FEMA in their metallurgical examination of steel samples from the Towers. They describe this as "evidence of a severe high temperature corrosion attack." Edges of a one inch column were described as having been thinned to "almost razor sharpness," while a formerly solid flange had "gaping holes—some larger than a silver dollar."


These findings were reported in The New York Times, where they were described as "perhapsthe deepest mystery uncovered in the investigation." Deposits from a previously molten liquid mixture containing iron and sulfur have also been found in the same locations. These, according to Dr. Steven Jones, a PhD physicist from BYU, are the chemical signature for the types of reactions caused by thermite and Thermate — incendiaries and explosives sometimes used in building demolitions for cutting through heavy steel.


8) Intense hotspots persisted at sub-basement foundation levels at Ground Zero for weeks, in spite of 24/7 drenching of the site with water. The boots worn by workers at Ground Zero had to be constantly replaced due to the melting of the soles. Several days after 9/11, NASA conducted an infrared aerial survey of Ground Zero and detected hot spots in the rubble that were over 1300ºF! The image on the left, below, is from their report. Molten metal was later found at these locations. What was the source of this heat? Again, the use of incendiaries, or some other type of high energy method of destruction, appears to be the only plausible explanation.

         

9) Dr. Steven Jones has also discovered the presence of previously molten iron microspheres in the dust that blanketed lower Manhattan in the wake of the destruction. The "atomizing" of molten iron can be explained only as a byproduct of explosives and incendiaries.

Dr. Jones, a Physicist and Archaeometrist, has written a detailed scientific paper analyzing the destruction of the WTC buildings. It is available at this link:

10) The upper part of the South Tower begins to tip at the beginning of its destruction. Instead of continuing this rotation as would be expected from a rigid structure according to the law of conservation of angular momentum, the rotation stops as it begins to disintegrate beforefalling into the structure below. Without this unexplained disintegration, this upper block of floors would have toppled to the side and crashed to the ground as an intact structure.


11) The debris distribution from both Towers exhibited almost perfect radial symmetry as the wave of destruction moved rapidly down each building, spewing cladding, structural steel and pulverized material in all directions like a giant fountain.

                            


12) The huge outward arching dust plumes exhibited during the destruction of each Tower not only defy gravity, but are an unmistakable signature characteristic of the use of explosives.


13) The destruction followed the path of greatest resistance. In natural materials failures, like a broken window or the collapse of a burning wooden building­, even small variations in stresses and materials strength are amplified into highly asymmetrical breakage patterns, while the process inherently seeks the path of least resistance.

14) The tremendous size of the primary debris field (measured before hitting the ground) is not consistent with the downward pull of a gravity-driven event.



15) A number of small explosions with forceful lateral ejections can be seen occurring many floors below the leading edge of the destruction. These are visible in the photo below, and also in the right-hand photo on the first page. These have exactly the same signature appearance as cutter charges (squibs) used in controlled demolitions to remove structural supports within a building at strategic points in a timed sequence. Popular Mechanics would have us believe that this is just air being forced out as a bellows effect by pancaking floors. But where are the pancaking floors? And why would this occur so far down the building?



16) In aerial views of ground zero showing the immediate aftermath of the destruction, all we see are smoking craters where the Towers once stood, and debris scattered for blocks in all directions.



17) Many eyewitnesses reported explosions before and during the destruction. Firefighters, for example, recollected their experience as they were running from the South Tower:

fireman2: It was as if as if they had detonated, det..
fireman1: yea detonated yea
fireman2: as if they had planned to take down a building,
          boom-boom-boom-boom-boom-boom-boom-boom ...
fireman1: All the way down, I was watchin it, and runnin'

The New York Times, in August 2005, released over 12,000 pages of oral histories from 9/11. These included statements from 503 first responders, including firefighters, emergency medical workers and others. More than a hundred of these accounts included reports of explosions.

18) The Towers had stabilized after impact, the fires were no more serious than a typical office fire and no steel-frame highrise had ever collapsed from fire before — yet there were several reports of warnings that "collapse" was imminent. For example, from the 9/11 Commission Report:

"At about 9:57, an EMS paramedic approached the FDNY Chief of Department and advised that an engineer in front of 7 WTC had just remarked that the Twin Towers in fact were in imminent danger of a total collapse."

Who was this "engineer" and how or why did he know this? NY Mayor Rudi Giuliani also revealed in a live interview that he had been warned that the Towers would "collapse." Who could have told him this? And why didn't anyone bother to tell the firefighters inside the buildings?

19) Isolated pockets of inexplicably burned and melted vehicles were discovered at various distances from the site of the WTC. These two photos were taken on Barclay Street, about two blocks away from the Towers. Notice the small trees that appear to be unaffected.

   

The next two photos show melted cars that were found on FDR Drive, along the waterfront,seven blocks away from the WTC. The police car on the right is completely wilted in front with no tire remaining on the visible front wheel, yet the rear of the car and its tire appear to be undamaged. What possible explanation could account for these peculiar phenomena and their seemingly random locations at significant distances from the World Trade Center?  

   


The Mysterious Collapse of WTC Building 7:

And then of course there is Building 7, which many people have forgotten. It fell later in the day and from the beginning was treated like an insignificant footnote. WTC7 was an imposing 47-story structure and more modern than the Towers. It was not hit by an airplane and was a block away from the Towers with another lower building in between.

According to the debris distribution data contained in the FEMA report, WTC7 was not seriously battered by heavy debris from the Towers. The lighter orange rings in the diagram below indicate the range of light debris, while the darker orange areas indicate the reach of heavier debris, like steel column sections. WTC7 is the trapezoid-shaped darker blue building in the upper part of the diagram.


WTC7 did have fires of uncertain origin and extent. Official reports suggest that fires in WTC7 had been "raging out-of-control" all day, but there is no convincing photographic evidence of this. The fires in the photo above, taken on the afternoon of 9/11 shortly before the collapse, are minor, and clear images (below) from the moment of onset of the collapse do not even show emergent flames, let alone any other evidence of an all-consuming inferno.


WTC7 came down in 6.5 seconds, imploding perfectly within its footprint, collapsing straight downward from all points and looking just like a perfect controlled demolition. Even the "kink" in the roof line seen in the second image of the sequence above is evidence of a demolition technique that is used to make sure the walls collapse inward, thus minimizing damage to surrounding structures. The homepage of the website for "Architects and Engineers for 9/11 Truth" includes a video of the collapse of WTC7:

The straight-down, vertical collapse of Building 7 could not have happened and with such perfect symmetry unless all 58 perimeter columns and all 25 core columns were somehow cut almost simultaneously at the foundation level. In the three-image collapse sequence above, notice in the first image the light and dark mottled pattern of small clouds of smoke that appeared at the onset of the collapse. These look just like evidence of explosive cutter charges as used in controlled demolitions to break up the internal structure of a building as it begins to fall.

­
             
Large amounts of fuel oil were reportedly stored in the building, but even if this was burning it could not have caused the simultaneous structural failure of all the support columns — or any of them for that matter. As we have seen, open-air hydrocarbon fires are incapable of creating enough heat at a high enough temperature to cause the failure of steel-frame high-rise structures. The fact that WTC7 was built over a pre-existing three story substation also does not explain the perfect symmetry of the collapse, or the collapse itself.

Official investigators and "conspiracy theory debunkers" are now suddenly claiming that a section of the lower facade of WTC7 was "scooped out" by flying debris from the North Tower. This of course contradicts the detailed debris distribution mapping contained in the FEMA report produced shortly after 9/11. But even if true, this cannot account for the symmetry of the collapse since it would create an overhanging mass. And it can't explain the collapse itself since these new damage estimates still leave the building as a whole well within its load-bearing redundancy.

The site diagram above shows the distance that heavy steel would have to be propelled in order to cause serious damage to WTC7. More than anything else, this would be evidence ofexplosive force used in the destruction of the Towers!

This failure of WTC7 was attributed to "progressive total collapse" brought on by fire, in FEMA's report, but with the caveat that their hypothesis "has only a low probability of occurrence." WTC7 was not even mentioned in the 911 Commission Report!

And, most revealing of all, none of the official theories have been able to explain the live news coverage from British television announcing the collapse of WTC7 while it was still standing in the background of the live video feed from NYC! Somebody was reading their script a little too soon!


And Finally, Consider This:

What would it be like if every steel frame high-rise in existence was likely to collapse as a result of a not-too-serious fire, or even a serious fire? No one would set foot in them! As a matter of fact, no one would build them — they would be too dangerous. If the WTC buildings DID collapse from fire, these unprecedented failures would be extremely significant and ought to have aroused the most profound forensic analysis (the painstaking reassembly of crashed aircraft comes to mind).

This did not happen. The steel from all three buildings was quickly removed — over the strenuous objections of scientists, engineers, firefighters and the families of the victims — and most of it has been melted down in overseas markets. Access to Ground Zero was forcefully restricted and study of the final blueprints for the Towers has not been permitted.

Two groups have been extremely vocal in their protest of the destruction of evidence and lack of real forensic investigation: the families of those killed and firefighters. Fire Engineering Magazine — the primary journal for firefighters everywhere — ran a scathing editorial in January 2002 in which they referred to the official investigation blessed by FEMA and run by the American Society of Civil Engineers as a "half-baked farce that may already have been commandeered by political forces whose primary interests, to put it mildly, lie far afield of full disclosure."

This is obviously a big concern for firefighters because they have to go into burning buildings! Prior to 9/11 there was no precedent to caution them against entering the WTC Towers to go about their work of rescuing people and putting out the fires. Surviving audio recordings of firefighter communications from the South Tower, as mentioned earlier, show that they had reached the 78th floor sky lobby and found only "two pockets of fire." They called for "two lines" and began to implement their evacuation plan just before the destruction suddenly began!

Now what are firefighters supposed to do? In this new world, fires in high-rise steel structures can apparently trigger a "total progressive collapse" at any moment with no clear warning conditions. And this can happen not only in stable damaged structures, but in fully (or nearly) intact structures as well!

I wonder how much fear this adds to the lives of our firefighters and if high-rise fire rescue efforts have been curtailed in any way since 9/11, perhaps even causing unnecessary loss of life, due to this new uncertainty over entering burning steel structures.

And This:

If the government's story is true, then companies that offer controlled demolitions using explosives are clearly going to have some new competition. Thanks to those wily hijackers, we now have a much cheaper solution. If a structural steel high-rise needs to be removed, all that is necessary is to pick a floor somewhere in the upper portion of the building, saw off a few columns, flood the floor with jet fuel, light a match and stand back.

The building will then (about 1 or 2 hours later) miraculously explode, shattering all of the steel in the building into tidy 12-30 ft sections. The rest of the building and all of its contents will be conveniently converted into a fine dust that will be spread over a large area so that somebody else will have to pay to clean it up!


And This:

This photo shows the start of an explosive demolition of a large brick chimney.   

                                                   
Look familiar?

Characteristic features indicating the use of explosives:
1) Outward arching dust plumes
2) Formation of debris cloud that is symmetrical around the vertical axis of the structure
3) Heavier material is propelled out ahead of the dust


Conclusion:

We have to find the courage to think for ourselves, open our eyes and look — and keep looking. The truth will not go away. Once we see that most of what we were told about these events is actually false, we can finally get to work on discovering the real story of 9/11...


                        "...any ordinary person can tell an explosion from a collapse!"