Critique of ENERGY TRANSFER IN THE WTC COLLAPSE
By
F. R. Greening

The paper is available at this link.





His introduction:

A good place to start unraveling the mystery of what caused the Twin Towers to collapse is to investigate the mechanics of the impact and collapse events. This involves following the energy transfer processes from the initial aircraft collisions, through the subsequent fires, to the final collapse and crushing of the steel, concrete and other materials used in the construction of these buildings. In this report we attempt to evaluate the energetics of the impact and collapse events of the September 11th WTC disaster. In this way it is hoped to decide if the observed collapse events could have occurred without the help of explosives or, indeed, without any input from other external sources of
energy.



How the author goes about deciding the statement in bold can be understood by looking at the layout of the paper. The sections are listed in order:


2.0 WTC COLLAPSE TIMES
3.0 MOMENTUM TRANSFER THEORY OF THE WTC COLLAPSE
4.0 ENERGETICS OF THE WTC COLLAPSE
4.1 KINETIC ENERGIES FROM INELASTIC COLLISION THEORY
4.2 IMPACT ENERGY REQUIRED TO COLLAPSE ONE WTC FLOOR
4.3 BOEING 767 AIRCRAFT IMPACT ENERGY DISSIPATION
5.0 ENERGY TO CRUSH THE WTC CONCRETE
6.0 DISCUSSION
7.0 CONCLUSIONS



From the quotes of Thomas Kuhn cited in section 4, these general approaches based on general momentum and energy considerations can be understood as "stock puzzle solutions" which may or may not match only the grossest observations and measurements of each collapse, loosely based on:


1) General collapse times
2) Comparison with a Momentum-only model
3) General energetics of WTC collapses
4) Energy required to pulverize concrete

while general building dynamics are examined by looking at the general impact energy required to crush one floor.




The unstated assumption within this very general approach is that these gross collapse characteristics by themselves allow an observer to distinguish between a CD case and a no CD case for the highly specific structural designs in question. Not a single observation is considered outside of the broadest context, using only the most generic observations like seismic data or degree of pulverization of concrete.


Kuhn: "Normal Science as Puzzle-solving. Doing research is essentially like solving a puzzle. Puzzles have rules. Puzzles generally have predetermined solutions."


This list also shows what Frank Greening means by "observables". The only observables worth considering are those that conform to the grossest stock puzzle solutions of his own choosing. As long as the grossest kinetic and energetic properties fall within a certain acceptable range, F. Greening, like Bazant, leaps to his respective conclusions.




Application of Generalized Block Mechanics as a puzzle solution results in an artificially narrowed false choice.


An EITHER-OR, all-or-nothing world view tends govern arguments that attempt to apply "block mechanics" to a building demolition in a literal way. Block mechanics phrases the question of demolition like a cartoon in which only 2 general scenarios are considered possible. Both "sides" phrase both question and answer in terms of simplified cartoons. One "side" says the "upper block" could not propagate downward without assistance while the other "side" says it could, but, in truth, both "sides" unwittingly phrase their questions and answers in terms of the grossest cartoons and feel that there is simply nothing more specific that need be considered and no more detailed observations need be made.


Kuhn: "One of the reasons why normal science seems to progress so rapidly is that its practitioners concentrate on problems that only their own lack of ingenuity should keep them from solving."





F. Greening sets up the stacked system puzzle conditions:

"We now apply this simple model to the WTC collapse. We assume that both WTC building collapses began with an upper block of n floors collapsing onto a series of lower floors as in the “domino effect”. We shall refer to this process as the first stage of collapse. For this stage, (see equation 1), we have an initial mass nmf falling onto the floor below and becoming mass (n+1)mf. This new, enlarged, block of floors descends with velocity v2 = {n/(n+1)}v1 through a distance hf at which point it strikes the floor below and becomes mass (n+2)mf moving at velocity {n/(n+2)}v2, and so on. This implies a first stage collapse sequence for WTC 1: all floors from 110 to 96 (= 14 floors) collapse onto floor 95; all these floors collapse onto 94  93  92 and so on to 3 2  1; for WTC 2 all floors from 110 to 81 (= 29 floors) follow the same sequential process.
At the end of each of these collapse events we envision a second stage of collapse involving the destruction of the upper block of the WTC buildings: for WTC 1 the 97th floor, plus all floors above, collapse onto the pile of rubble topped by floor 96; this is followed by floor 98 (plus all floors above) collapsing onto floor 97 and so on. The 2nd
stage sequence for WTC 1 ends with floor 110 collapsing on to all lower floors. For WTC 2 the 2nd stage involves floor 82 collapsing onto floor 81, followed by 83, 84, etc, collapsing on to the pile of rubble until floor 110 collapses onto all lower floors."



With the mappings assembled by independent researchers and available to the general public in 2012, it is easy to see that the ROOSD process was not well known when this paper was written. This is also evident in the Bazant papers BV, BL and BLGB, the last of which Frank Greening co-authored. The descriptions offered clearly demonstrate the basic concepts of a ROOSD propagation model were not well known to the authors as late as 2007, 2008.






General Energetics of One Floor Collapse: Early Stock Puzzle Solutions to ROOSD propagation



F. Greening asks:

"4.2. IMPACT ENERGY REQUIRED TO COLLAPSE ONE WTC FLOOR

A crucial question that is frequently asked concerning the collapse of the WTC towers is why did the localized damage near the impact levels in WTC 1 and 2 cause the collapse of the entire buildings? In order to answer this question we need to move beyond our simple momentum transfer collision theory and consider how much energy is needed to bring about the collapse of one floor. We call this energyE1."



This is a generic energetics approach to a complex question. It is a crucial question, which is why it deserves a more specific and mechanism-oriented response. For example, if the same question is taken from the point of view of a specific mechanism of material propagation, or from the viewpoint of the unique structural attributes of the twin towers, the twin towers progressive floor collapse model is the obvious lens through which such a crucial question can be approached with clarity.

When this paper was written the ROOSD propagation mechanism was obviously not well known. A general energetic approach was being used, which would be useless if details of the actual progression process were already mapped and known.



Consider the generic way the energies needed to collapse a single floor were being described at the time this paper was written:

The fact that the values of E1 derived from Wierzbicki's and Bažant's studies are quite similar is very significant because these author's calculations were actually undertaken for two different impact events: (i) The collision of a Boeing aircraft with one floor of a WTC tower, and (ii) The collapse of a block of WTC floors onto the floor below. Thus Wierzbicki considers floor support failure under lateral impact loading while Bažant's considers the failure of the floor supports under axial impact loading. The fact that the energy calculated in each of these cases is about the same suggests that the energy dissipated in a floor collapse is relatively insensitive to the mode of failure of the support structures. This is a common observation in studies of collisions of large objects involving complex structures such as aircraft, automobiles, trains, and ships.


Neither approach cited nor F. Greening seemed to have any conception of a specific ROOSD driving mechanism when this was written. By the mapping standards developed through the work of a few independent researchers, the quote shows how little was understood about the specifics of global mass and particulate flow at that time.

As F. Greening notes, it is significant that the E1 values from Wierzbicki’s and Bažant’s studies are similar. But what is just as significant is that all 3 researchers, Wierzbicki, Bazant or F. Greening, seemed to have no concrete conception of a specific collapse progression mode when guessing such values.




F. Greening asks:

Why Did the Towers Fall?


"We have shown in this report that because of the failure of just one floor, a sequential collapse of all remaining floors was inevitable. This, of course, brings us to the $64,000 question:

What caused the initial floor collapse?"


(This was written in 2006, so including changes in currency values the question is now valued at $154,000 in 2012 dollars.)

"Although some researchers apparently find it difficult to accept, I believe the answer to this question is essentially quite simple:

The initial floor collapse occurred due to the aircraft impact damage and the resulting eccentric loading of the core columns."



The NIST disagreed. This description directly contradicts the NIST claims that the most probable collapse initiation mechanism were due to sagging long span floor trusses.






The Manner In Which The Collapses Were Observed


From the conclusion:

An analysis of the energetics of the WTC collapse events has shown that the kinetic energy of the aircraft collisions and the subsequent gravitational energy released by the
descending blocks of floors were quite sufficient to destroy the twin towers in the manner observed.


Please consider the expression "in the manner observed" in light of the following. In the case of WTC1, for example,


The NIST "manner observed" is described in section 2.2 of my book, literally based on fictitious collapse features.

The Bazant "manner observed" is described in section 2.6 of my book, literally based on crushing blocks.

NASA engineer Ryan Mackey "manner observed" is described in section 2.7 and 6.1, which is a curious fusion between crushing blocks with a tilt as the NIST describes, none of which is actually contained in the visual record.



Whereas the actual "manner observed" as anyone can verify against the visual record of the events themselves, is given in section 3.1.


In retrospect, neither of the three parties could possibly have understood with clarity "the manner the twin towers were observed" to collapse without accurate mappings to which to compare various theories (guesses). Each party seems to claim their conceptions of the collapses match observables only in a tongue-in-cheek way.

The term "manner observed" is used quite casually, as if it can be assumed all observers are observing the buildings in the same manner. Their own quoted writings clearly show they are not.


Kuhn: "Normal science is "a strenuous and devoted attempt to force nature into the conceptual boxes supplied by professional education". Phenomena that will not fit the box are often not seen at all."



Both Bazant and Greening use the word "observation", but then compare their conceptions to observables in only the grossest meaning of the word. Gross observations are cited to check whether the buildings fall within the basic puzzle solutions they are utilizing. They are not using observation as "that which is observed". That which was actually observed is carefully logged in part 3 of my book and it is clearly quite different than what either Dr Bazant or Dr Greening or the NIST observed.







F. Greening Concludes:

From a consideration of the strength of the WTC columns, and the effective area of support they provided, it is demonstrated that the conditions necessary for the initial floor collapse were initiated by the aircraft impacts and made irrevocable by the subsequent eccentric loading of the core columns. The fires that were initiated by the jet fuel spilled within the towers certainly weakened steel in localized areas in the impact zones. However, it is suggested that the total collapse of both towers would have occurred even without the jet fuel fires.



The claim in bold contradicts the NIST explanation of how and why the towers collapsed.

Generalized argument through what are basically stock puzzle solutions applied to a highly complex system cannot possibly give justification to these statements. They can be addressed through highly sensitive, detailed mappings of structural behavior leading into and during the collapse process. The proper way to address the issue of collapse initiation is to see the buildings through the most accurate and detailed lenses possible. There is no generic substitute.



ON THE BRIGHT SIDE: the puzzle solution given as momentum transfer theory and general energetics provide use information.






Authors Conclusions


The author agrees with the opening sentences of the paper when F. Greening writes:

"A good place to start unraveling the mystery of what caused the Twin Towers to collapse is to investigate the mechanics of the impact and collapse events. This involves following the energy transfer processes from the initial aircraft collisions, through the subsequent fires, to the final collapse and crushing of the steel, concrete and other
materials used in the construction of these buildings."

The author agrees that it is a good place to start, but it is only a generic starting point based on the grossest collapse features. Generic stock puzzle solutions can help but they serve to set only the broadest parameters of the observed collapses. No amount of generic matching to stock puzzle solutions can substitute for careful and detailed observations and measurements of the events themselves.

It is a good place to start, but is it a sufficient place to end and draw a firm conclusion without more detailed and careful observation and measurement?





Kuhn: "A paradigm can, for that matter, even insulate the community from those socially important problems that are not reducible to the puzzle form, because they cannot be stated in terms of the conceptual and instrumental tools the paradigm supplies."

WIthin such an atmosphere phenomena more detailed than the grossest collapse features can easily go unnoticed.
Detailed observations and measurements may or may not be reducible to puzzle form, but one cannot know without trying and without careful observation using the most accurate mappings possible. There is no way to see without looking. There is no generic stock puzzle substitute for astute perception.






Kuhn: "The proliferation of studies that find the expected helps ensure that the paradigm/theory will flourish."


The latter 3 Bazant papers BV, BL and BLGB, along with the present paper by F. Greening and the NIST reports on the collapses all came to the same general conclusions and basically found what they expected to find. But in the case of WTC1, for example, the NIST misrepresented every visible feature of the collapse initiation process. Dr Bazant described the collapses literally in terms of crushing blocks, crushing down before any significant crush up can occur. All these papers can be considered part of the same "paradigm" or theory and their respective representations certainly have flourished, currently comprising the written collapse record as it is represented to the general public.



The F. Greening paper has another feature in common with the Bazant and NIST publication in that each author claims the general mechanics described "match observables".

The NIST claimed that their collapse initiation mechanism "matched key observables".

Dr Bazant, in the concluding remarks of BLGB, claimed his proposed progression model of crush down, then crush up "matched key observables", stating:

"One and the same mathematical model, with one and the same set of parameters, is shown capable of matching all of the observations, including: (1) the video records of the first few seconds of motion of both towers, (2) the seismic records for both towers, (3) the mass and size distributions of the comminuted particles of concrete, (4) the energy requirement for the comminution that occurred, (5) the wide spread of the fine dust around the tower, (6) the loud booms heard during collapse, (7) the fast expansion of dust clouds during collapse, and (8) the dust content of cloud implied by its size."






THE ACTUAL COLLAPSES APPEAR AS HIGHLY COMPLEX, ORDERED, MAPPABLE EVENTS


As demonstrated in sections 2.1 and part 3 that the collapsing buildings were largely mappable. The most detailed mappings available to the public are in section 3.1 of my book.

Once again, the question of CD can only be properly forumlated with a knowledge of the highly specific and unique stacked and caged structure of the twin towers and with correct, detailed mappings of the collapse progression mechanisms. No generic arguments which substitute for carefully logged observations and measurements are possible.



Carefully detailed mappings of the collapse processed demonstrate behond doubt that it is absurd to claim that any of these descriptions actually matched building behavior as preserved in the visual record of the events themselves. Even so, all 3 publications explicitly state the models and mechanisms presented within them "match key observables".

So, even though the claims are verifiably untrue, the proliferation of these studies (that find the expected) ensures that the claims made within these publications will flourish.





Unfortunately the paper as written reinforces the mindset of seeing the question of demolition through an artificially narrowed false choice. It is the same false formulation seen everywhere with respect to the collapses. All media organizations quoted in part 6.2 formulate the question in the same artificially narrowed set of false choices. This EITHER-OR false choice can be loosely thought of as the commonly accepted "paradigm" through which the collapses are commonly understood and portrayed through main stream media.



The qualities of a natural propagation mechanism and natural degrees of pulverization are taken to mean no CD occurred, while their opposite qualities are taken to represent CD. Such a formulation demonstrates no understanding of the actual propagation mechanisms as being highly specific to the twin towers structural design.