Discussion Page for:

Frank R. Greening, Timothy N. Greening

Characterization of a World Trade Center Dust Sample

First Published: Scientific Method 9/11, August/2017, Version 1

View Author Details for: Greening F, Greening T


Discussion for Version 1, August/2017


Comment 1: - By: the Moderators, - Received: 08/04/17 - Posted: 08/04/17 - Added To: 08/29/17, 09/06/17

This previously-unpublished paper, Characterization of a World Trade Center Dust Sample, by F.R. Greening and T.N. Greening is listed here to encourage discussion and further research of the WTC dust or powder in the context of published results and analysis by other scientists and institutions. References [13] and [14] cited by the authors can be accessed using these links: [13] and [14].

Following September 11, 2001 (9/11), Congress in 2002 charged the National Institute of Standards and Technology (NIST) with determining how and why three steel-framed buildings in the World Trade Center (WTC) - the Twin Towers (WTC1/2) and Building 7 (WTC7) - collapsed. Never before or since 9/11 had steel-framed buildings been so completely destroyed purportedly by fire.

The NIST reports for the Twin Towers were published in 2005. In these reports, NIST violated the scientific method by failing to examine the actual fall of the Towers, as well as by ignoring other pertinent evidence from before and after the destructions. Observation and analysis of the way a building falls is usually the best indicator of the reason for its collapse or destruction. By the time NIST published its WTC1/2 reports, hundreds of highly-qualified scientists, engineers, architects and other scholars had concluded, after analyzing all available evidence, that the Towers (as well as WTC7) had been brought down by some form of controlled demolition.

Another major step in proper forensic investigations of completely-destroyed buildings is to analyze a building’s remains to determine whether explosives are present. National Fire Protection Association (NFPA) guidelines require this in cases of high-order damage. However, NIST itself never made such an examination. This examination was instead performed by others, such as the United States Environmental Protection Agency (EPA) [1], RJ Lee Company [2], the United States Geological Survey (USGS) [3] and independent scientists including Niels Harrit, Jeffrey Farrer, Steven E. Jones, and Kevin Ryan [4] who examined the WTC dust or powder. All of these studies found a high percentage of iron microspheres which require high temperatures for their formation. Harrit, Farrer et al.[4] also found red/gray chips where the red layer exhibited the properties of super-thermite incorporating nanotechnology, a material with explosive and incendiary properties.

Comments on the paper by F.R. Greening and T.N. Greening are invited.

Notes (Added 08/29/17, 09/06/17):

In considering the Greenings' paper for listing, we asked Frank Greening this question: "Did you look for any of the red-gray chips found in other WTC dust samples by Harrit et al.?" Frank Greening replied: "I spent a lot of time looking for red-grey chips, but found none. And I did find a few mono-layered iron-oxide chips." Regarding his work at McMaster University, Greening stated: "I paid $600/hour out of my own pocket for the SEM work." Greening also stated that this was the first WTC dust sample that he had analyzed, and that Ms. Sakoutis, who supplied the dust sample, heard of his interest in analyzing WTC dust samples after she saw Greening in the 2015 Smithsonian T.V. show "Missing Evidence".

References

[1] Paul J. Lioy et al., "Characterization of the Dust/Smoke Aerosol that Settled East of the World Trade Center (WTC) in Lower Manhattan after the Collapse of the WTC 11 September 2001," Environmental Health Perspectives, Volume 110, Number 7, July 2002.

[2] R.J. Lee Group, Inc., "Damage Assessment 130 Liberty Street Property - WTC Dust Signature Report," December, 2003.

[3] Gregory P. Meeker, Amy M. Bern, Heather A. Lowers, and Isabelle K. Brownfield, "Determination of a Diagnostic Signature for World Trade Center Dust using Scanning Electron Microscopy Point Counting Techniques," USGS Open File Report 2005 – 1031, (2005).

[4] Niels H. Harrit, Jeffrey Farrer, Steven E. Jones, Kevin R. Ryan, Frank M. Legge, Daniel Farnsworth, Gregg Roberts, James R. Gourley and Bradley R. Larsen, "Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe," The Open Chemical Physics Journal, 2009, 2,7-31.

See also a number of papers referenced in the paper under discussion.


Comment 2: - By: Christine Sakoutis, - Received: 08/03/17 - Posted: 08/09/17

I am the person who provided the 9/11 dust samples to Professor Frank Greening who has recently submitted a dust analysis to you. If anyone requires verification from me please refer to my email and ask them to write 9/11 in the title.

If you have any questions please do not hesitate to contact me. Thank you.

Chris Sakoutis

[Moderator Note: In response, the moderators wrote the following to Ms. Sakoutis:
"Dear Ms Sakoutis,
Thank you very much for contacting us and confirming the origin of the WTC dust sample that is the subject of the paper by F.R. Greening and T.N. Greening. Thank you for your thoughtfulness in preserving some of the dust you acquired that day. As you may know, our website engages in scientific discussion of submitted papers with the purpose of determining what took place on 9/11. We are in contact with other independent scientists who may be interested in examining WTC dust samples. Would you be able and willing to provide samples, similar to the one you gave Dr. Greening, for examination by other scientists? Thanks again for contacting us, this is an important part of the ongoing 9/11 research."]


Comment 3: - By: Frank R. Greening, - Received: 08/10/17 - Posted: 08/24/17

[Moderator Note: In this comment, Frank Greening is addressing the paper cited in reference [4] of Comment 1.]

As described in an Open Chemical Physics Journal article published in April, 2009, N. Harrit and S. Jones, (H&J), and seven additional authors, claim to have found “nanothermite” residues in samples of WTC dust. The authors base their study on the analysis of four samples collected at different locations in Lower Manhattan shortly after September 11th, 2001. The sampling locations are described in the paper as follows:

  1. Sample No. 1: Cedar and Liberty Streets, about 200 meters from Ground Zero
  2. Sample No. 2: Brooklyn Bridge, near Pearl Street, about 1000 meters from Ground Zero
  3. Sample No. 3: Hudson and Duane Streets, about 750 meters from Ground Zero
  4. Sample No. 4: Hudson and Chambers Streets, about 700 meters from Ground Zero

It is claimed in the Harrit et al. paper that an active thermitic material has been found "in all four samples" in the form of red/grey chips "with major dimensions of roughly 0.2 to 3 mm". Figure 2 of the Harrit paper shows examples of red/grey chips from each of the four dust samples. The single red/grey chip from sample No 1, with a length of ~ 2.5 mm, is stated to be one of the largest removed from any of the samples. Certainly, this is consistent with the examples of red/grey chips in Samples 2, 3 and 4 which exhibit lengths mostly ~ 200 microns. Nevertheless, other relatively large red/grey chips, not from Sample 1, are also discussed in Harrit et al. Some of these particles are from Sample 2, as shown in Harrit’s Figures 3 and 12. Several particles with major dimensions in excess of 300 microns are visible in Figure 3; in addition, the single particle shown in Figure 12, also from Sample 2, is approximately 750 microns in length. And finally, Figure 31 in the Harrit paper shows a particle from Sample 3 that is over 800 microns in length.

What is quite striking about the red/grey “chips” described in the Harrit et al. paper is that the authors do not consider the size of a given particle in relation to the distance of its sampling location from Ground Zero. However, aerodynamic stresses acting on particles falling in air dictate that particles with diameters greater than 1 mm fall rapidly, (with terminal velocities > 5 m/s), while very small particles, e.g. those with diameters 1 micron or less, may be held in suspension for periods greater than 10 minutes. As I have shown in my WTC Dust Characterization paper, WTC dust found at increasing distances from Ground Zero would have been significantly size-segregated as it was dispersed and gravitationally settled over Lower Manhattan; therefore, samples collected well away from Ground Zero cannot be representative of average WTC dust with respect to their particle size distribution and chemical composition. And, indeed, particles with diameters > 500 microns found in dust collected at distances > 500 meters from ground zero, could not be debris from the collapse of WTC 1, 2 or 7. Nonetheless, Harrit and Jones have, at different times, made very questionable estimates of the amount of nanothermite they believe was pre-planted in the Twin Towers using linear extrapolations from the concentrations of alleged nanothermite fragments found in WTC dust samples. (See for example: "Question No. 1" on page 23 of the Harrit paper.).

The record shows that in all their public declarations and writings on the red/grey chips, Harrit and Jones have completely ignored the size-segregating effects of gravitational settling. In truth, however, Harrit and Jones’ own data shows that the red/grey chips found in WTC dust samples, (which were collected at an average distance of 600 meters from Ground Zero), are typically in the size range 300 +/- 200 microns. However, calculations of the dispersion of dust particles in the size range 10 – 1000 microns, show that about 90 % of the 300-micron diameter particles created by the collapse of the Twin Towers would have settled well within a 600-meter radius of Ground Zero. This means that Harrit et al’s hypothesis suggesting that 10 – 100 ton of nanothermite was pre-planted in the WTC complex prior to 9/11, would have to be revised and increased by a factor of ~ 10 to allow for the size-dependent dilution effects that control dust cloud dispersion and deposition; thus, Harrit’s hypothesis requires the use of unreasonable amounts of pre-planted explosive in the destruction of the Twin Towers.

In view of the obvious logistical problems with the use of massive amounts of nanothermite it is necessary to reject Harrit and Jones’ controlled demolition hypothesis and seek alternative explanations for the nature of the iron-rich red/grey chips found in the WTC dust. One possibility is that the chips are flakes of spalled iron oxide from so-called weathering steels such as A-242 or A-588 – steels frequently used in the construction of high-rise buildings, bridges, etc. Iron oxide fragments from these steels would be quite common in the particulate matter found in any large urban center such as New York City. Recent research by Japanese scientists such as T. Nishimura has revealed the presence of nano-scale network structures of Fe(O,OH)6, incorporating surface layers enriched in alloying elements such as Al, Si, Ni and Cu, in oxide films on a number of long-exposure weathering steels. (See for example: Materials 2017, 10, 199).


Comment 4: - By: Christine Sakoutis, - Received: 08/14/17 - Posted: 08/24/17

I have more dust. Plenty of it. I promised Frank Greening that he would be in charge of distribution so please contact him. He too has more dust.

[Moderator Note: The comment previously here has been moved to the Notes section in Comment 1.]


Comment 5: - By: John D. Wyndham, - Received: 09/10/17 - Posted: 10/10/17

This paper by F.R. Greening T.N. Greening, herein referred to as the “Greenings’ paper” or “G&G,” presents several main issues:

  1. An examination of a WTC dust sample and the particles found therein.
  2. A discussion of temperatures in the Twin Towers during the event.
  3. A theory of how the WTC dust or powder was created.
  4. A theory of how the dust was dispersed and settled over lower Manhattan.

Main issue #1 which makes up the bulk of the paper will be of particular interest to those who have actually examined WTC dust samples using SEM/EDX equipment. Main issues #2 through #4 play important roles in the Greenings’ analysis of the results and the conclusions they reach in the paper. These specific issues will be discussed in later comments.

At a more general level, the paper raises questions about G&G’s research approach and the study of WTC dust samples now and in the future. These general issues are discussed in this comment.

Limited Scope of the Greenings' Paper

G&G’s paper makes no mention of the work of independent scientists such as Niels Harrit, Jeffrey Farrer, Steven Jones, Kevin Ryan and their collaborators who have studied WTC dust samples and written papers on their findings [1]. G&G also omits to mention studies of the air and temperatures at the WTC site (Ground Zero) by these researchers [2] [3]. At no point do G&G mention the controlled demolition theory for the WTC building destructions, although in their references [13] and [14] controlled demolition is mentioned in passing and by way of a reference to the work of Eric Hufschmid. The controlled demolition theory is held by thousands of independent scientists, architects, engineers and other scholars. See, for example, the articles in the Journal of 9/11 Studies and Architects & Engineers for 9/11 Truth [4] [5].

An internet search for F.R. Greening (and also comment 3) shows that author F.R. Greening is well-acquainted with the large body of research that supports the controlled demolition of WTC1/2, yet the G&G paper avoids any mention of it [6]. G&G's paper and references neither establish their gravity-driven theory nor do they effectively refute controlled demolition. By failing to deal adequately with the controlled demolition theory or establish their own theory, G&G’s paper does not conform with the scientific method which requires all evidence and possible hypotheses be considered.

Greenings' Omission of Results

The accurate logging and reporting of what took place during an experiment is essential to good science. According to F.R. Greening, the G&G authors spent considerable time searching for the red/gray chips reported by Harrit, Farrer et al., yet omitted to include any mention of this search in their paper. See Notes in Comment 1. A description of the methods used in their search might provide some insights into why G&G failed to find any red/gray chips. The details of G&G’s search for red/gray chips are an important part of their experiment and for completeness warranted inclusion in the paper.

The Control of Dust Samples

This is the first WTC dust sample that F.R. Greening has studied (see Notes in Comment 1). In Harrit el al., Steven Jones recounts how he obtained dust samples from Tom Breidenbach, Frank Delessio, Jody Intermont, Janette MacKinlay, and Steve White, and from an anonymous collector. Harrit et al. then states (p. 9): “Samples of WTC dust from these and other collectors have been sent directly from collectors to various scientists (including some not on this research team) who have also found such red/gray chips in the dust from the World Trade Center destruction.” If Greening was not one of the scientists to receive such samples, could he and other scientists like him obtain samples directly from the named collectors at this time? A sharing of samples, especially in cases where conflicting results are reported, would benefit this research.

According to Christine Sakoutis, F. R. Greening has control of the distribution of dust samples owned by her (see Comment 4). This raises an important issue. To avoid all conflicts of interest and even the appearance of such a conflict when distributing samples, it would be preferable if no one but the collector and the requestor were involved in the transaction. It is likely that most scientists, if they were to seek a dust sample for study, would prefer to obtain it directly from a collector who has no special relationship with any other scientist, rather than from one who has such a relationship.

The provenance of WTC dust samples is a major concern. In the interests of fair and open inquiry, how dust samples are stored and distributed without creating real or apparent conflicts of interest is of importance. There may be no easy solutions here, but the scientific community should attempt to rise above partisan considerations to ensure a credible supply of samples.

The Need for Additional Independent WTC Dust Analyses

According to Harrit et al., other scientists besides the authors of that paper have studied WTC dust samples and confirmed the presence of the red/gray chips. However, none of these scientists have as yet published their results. It would be highly important for them to publish their results without further delay. This is the only valid way to confirm or dispute the findings of Harrit et al. Theoretical arguments as to why a laboratory result should not have been observed must defer to the results of actual experiments. According to Harrit et al. (p. 9) the red/gray chips are “typically small but readily discernible by eye due to their distinctive color.”

It would be important to know at this time who else has confirmed the presence and properties of the red/gray chips. It is surprising that no major effort to confirm Harrit el al.’s findings through independent scientists publishing other studies of the red/gray chips has occurred in the period since 2009, the year Harrit et al. was published. Perhaps lack of expertise in this area, lack of access to the required equipment, time constraints and possible costs (F. R. Greening quotes a cost to himself of $600/hour - see Notes in Comment 1) have been deterrents in the confirmation process.

In their writings, both Steven Jones and Frank Legge called for the submission of WTC dust samples by collectors to interested scientists [7] [8]. At this time, it's appropriate to call for a fair distribution process for dust samples, and the publication of dust studies by as many independent scientists as possible.

References

[1] Niels H. Harrit, Jeffrey Farrer, Steven E. Jones, Kevin R. Ryan, Frank M. Legge, Daniel Farnsworth, Gregg Roberts, James R. Gourley and Bradley R. Larsen, "Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe," The Open Chemical Physics Journal, 2009, 2,7-31.

[2] Kevin R. Ryan, James R. Gourley and Steven E. Jones, "Environmental anomalies at the World Trade Center: evidence for energetic materials," The Environmentalist, 29 (2009): 56-63. (Also online August 4, 2008).

[3] Steven E. Jones, Jeffrey Farrer, Gregory S. Jenkins, Frank Legge, James Gourley, Kevin Ryan, Daniel Farnsworth, and Crockett Grabbe, "Extremely high temperatures during the World Trade Center destruction," Journal of 9/11 Studies, January, 2008.

[4] Journal of 9/11 Studies, "Journal of 9/11 Studies"

[5] Architects & Engineers for 9/11 Truth, "Architects & Engineers for 9/11 Truth"

[6] 911Blogger, "Dr. Frank Greening Agrees to Debate 9/11 Skeptics" National 9/11 Debate, 2006.

[7] Steven E. Jones, "Why Indeed Did the WTC Buildings Completely Collapse?" Journal of 9/11 Studies, Vol 3: September, 2006.

[8] Frank Legge, "Science of 9/11" The Case, Introduction: Notes on NIST.


Comment 6: - By: Christine Sakoutis, - Received: 10/10/17 - Posted: 11/05/17

I'm just a court clerk. I know nothing about scientific protocol which is why I wanted Prof. Greening to handle such things.

There are 2 choices: arrange with him to obtain a sample or arrange THROUGH him to have me send a sample. I'm fine with that. Either way, he's the conductor of this chorus.

Please post. Thank you.


Comment 7: - By: Niels Harrit, - Received: 10/10/17 - Posted: 11/05/17

I suggest that Dr. Greening explain:

I remind him: ”An object moves in the direction of the force” and ask him to take a look at the collapses of the twin towers again.


Comment 8: - By: Frank R. Greening, - Received: 10/10/17 - Posted: 11/05/17

[Moderators’ Note: To keep the discussion on track, and in accordance with our stated Policy for lengthy comments (see Acceptance of Comments), we list here F.R. Greening's response to Comment 5 without its two footnotes. Greening’s full response with footnotes can be viewed at F.R. Greening’s Full Response to Comment 5.]

[In response to Comment 5 by John D. Wyndham, Frank R. Greening writes:]

Thank you for your email [with link to comment 5] concerning my paper (with T. N. Greening as co-author), on the characterization of a WTC dust sample. I must say at the outset that my first reaction ... is one of concern that I am being criticized for things I didn’t do, rather than the scientific content of my paper. For example, I am being judged on something I didn’t say, but was said by the person who collected the sample - Ms. Sakoutis. I think your comment on this should be directed to, and answered by, Ms. Sakoutis.

Now, as to what appears to be your main complaint about my paper, namely that I did not refer to the work of Harrit et al. anywhere in my paper, my response is as follows:

My paper is first and foremost about the chemical characterization of a WTC dust sample. And, to put my results into perspective, I compared my analytical data to other published analyses. Thus, I refer to work by Lioy, McGee, Clark, Meeker and Lee (among others), who each provided tables of quantitative data on the chemical composition of their WTC dust samples. By comparison, Harrit et al’s paper includes no such data, so there is no basis for me to compare my results to theirs. And significantly, all the authors mentioned above failed to find any red/gray chips, as was the case for my sample. And I should also mention that one of these authors has now published an entire book on the subject of WTC dust – See: P. J. Lioy: Dust: The Inside Story of its Role in the September 11th Aftermath, Rowman & Littlefield Publishers Inc, Lanham, Maryland, USA, (2010). In 260 pages of discussion of WTC dust there is no mention of red/gray chips.

An additional topic addressed in my paper is the particle size and morphology of WTC dust. I carry out a full particle size analysis of my WTC dust sample. Here again, Harrit et al. fail to do any such analysis on their samples, but offer only the vague statement that the red/gray chips “are of variable size with major dimensions of roughly 0.2 to 3 mm”.

You complain that my paper makes no reference to Harrit et al’s paper as if this is a prerequisite of any paper on WTC dust. Worse yet, you accuse me of failing to “deal adequately with the controlled demolition theory”. I would ask you to consider the title of my paper: Characterization of a World Trade Center Dust Sample, and this is indeed what my paper is all about. It’s precisely because I found no red/gray chips in my sample that I saw no need to address the absence of such particles, and focus on the particles I did find!

I have dealt with Ryan et al’s paper (your reference [2]) previously – See my footnote 1 below:

I offer my response to Jones et al’s paper on the high temperatures in the WTC rubble pile, (your reference [3]) in footnote 2 below:

... [Y]ou appear to see the destruction of the WTC as an EITHER/OR situation, thereby creating a false dichotomy. In your universe there are only two alternatives: The Twin Tower’s destruction was by a gravity-driven collapse – the “Official Story” – or, a thermite-assisted controlled demolition – the A&E for 9/11 Truth Movement’s view. This does not allow for any other options/theories such as aluminum-assisted collapse; ammonium perchlorate-assisted collapse; advanced technology weaponry collapse, micro-nuke collapse, etc, etc.

So, please do not claim that I do not follow the scientific method. The scientific method is about evidence obtained by observation. This is what my report on Christine Sakoutis’ WTC dust sample is all about – nothing more, nothing less.


Comment 9: - By: John D. Wyndham, - Received: 10/14/17 - Posted: 11/05/17

With regard to comment 6 by Christine Sakoutis, scientfic protocol is not at issue here, but chain of custody is.

Those individuals who collected samples of the WTC dust or powder become, in effect, evidence custodians in an ongoing investigation and case of major importance. As such, they have special obligations which include the storage and equitable distribution of evidence samples, and the maintenance of the chain of custody.

Evidence custodians in criminal cases normally operate under the jurisdiction of law enforcement systems including the courts. Similarly, those who collected WTC dust samples are de facto evidence custodians presently under the jurisdiction of the court of public opinion, and best operate impartially with respect to the distribution of dust samples to interested parties. Of course, this role can be assigned to someone else, but, to avoid conflicts of interest, it would be best to choose someone who is not arguing the case.


Comment 10: - By: Steven Jones, - Received: 10/24/17 - Posted: 11/05/17

In response to Comment 5, Steven Jones writes:

I strongly agree that “it would be important to know at this time who else has confirmed the presence and properties of the red/gray chips.” I understand that Mark Basile has confirmed the presence of red/gray chips and has analyzed their behavior upon heating. Those two results would be well worth publishing right away.

Mark Basile is also performing other tests including Fourier-transform infrared spectroscopy (FTIR) analysis which is evidently very time-consuming. Perhaps these other tests could be published separately, to allow a first paper as outlined above to be published more quickly.


Comment 11: - By: John D. Wyndham, - Received: 10/26/17 - Posted: 11/05/17

Thank you, Dr. Greening, for your comment 8 and for your two footnotes on papers that I suggested you mention. Regarding my comment 5, you write: "... my first reaction ... is one of concern that I am being criticized for things I didn’t do, rather than the scientific content of my paper." Let me address that concern with this observation and explanation: omission of pertinent facts or evidence is a common problem that affects every human activity. For example, the 9/11 Commission Report omitted to mention the destruction of Building 7 (WTC7), with the result that the public's understanding of 9/11 has suffered. In science, omission is frequently the primary means by which the scientific method is violated. My continuing intention, as in comment 5, is to bring all pertinent facts into the discussion.

Here are some more responses to statements in your Comment 8. Each statement or response is numbered in the order in which it appears, prefixed by the author's initials and the number of the comment in which the statement or response first appears.

FRG Statement 8-1: "I am being judged on something I didn’t say, but was said by the person who collected the sample - Ms. Sakoutis. I think your comment on this should be directed to, and answered by, Ms. Sakoutis.

JDW Response 11-1: In comment 4, Ms. Sakoutis states that she "promised Frank Greening that he would be in charge of distribution [of her dust samples]" and in comment 6, Ms. Sakoutis designates Frank Greening as the "conductor" for her dust samples. Unless you explicitly declare otherwise, it appears that you have accepted the role that Ms. Sakoutis has assigned to you. See my response to Ms. Sakoutis' comment 6 in my comment 9.

FRG Statement 8-2: "And significantly, all the authors mentioned above [Lioy, McGee, Clark, Meeker and Lee] failed to find any red/gray chips, as was the case for my sample." "In 260 pages of discussion of WTC dust [in a book by Lioy] there is no mention of red/gray chips".

JDW Response 11-2: A lack of mention does not prove there were no red/gray chips present.

FRG Statement 8-3: "You complain that my paper makes no reference to Harrit et al’s paper as if this is a prerequisite of any paper on WTC dust. Worse yet, you accuse me of failing to “deal adequately with the controlled demolition theory." I would ask you to consider the title of my paper: Characterization of a World Trade Center Dust Sample, and this is indeed what my paper is all about."

JDW Response 11-3: The context of these studies is not purely academic, since G&G's paper has bearing on the details of what has been termed "the crime of the century." Those details have affected, and continue to affect, the lives of millions. NIST neglected to study the WTC dust or seriously consider the use of explosives, as required by NFPA 921 guidelines in cases of catastrophic building collapses. Harrit el al.'s experimental finding of highly-engineered red/gray chips containing thermitic material is therefore of the highest interest, and warrants the attention of anyone who studies the WTC powder. G&G's paper implicitly and explicitly relies on a theory of gravity-driven collapse, as seen, for example, in their discussion of particles and temperatures, and in their theoretical analysis of the generation and dispersion of the dust cloud. G&G's conclusions are based on this gravity-driven collapse theory, and ignore the many lines of evidence that point to high temperatures and violent, high-speed lateral ejections of material that are best explained by the controlled demolition theory. While presenting a study of a WTC dust sample, G&G's paper offers the reader a collapse theory that is speculative and that ignores the large body of evidence pointing to controlled demolition as the cause of the Towers' destructions. Considering all these aspects, I believe my assessment of G&G's paper in the above regard is accurate and warranted.

FRG Statement 8-4: "It’s precisely because I found no red/gray chips in my sample that I saw no need to address the absence of such particles, and focus on the particles I did find!

JDW Response 11-4: The fact that G&G looked for the red/gray chips makes their search worthy of mention, especially since their paper was submitted for discussion to this "website ... established to serve a need in the 9/11 truth movement ... ."

FRG Statement 8-5: "I have dealt with Ryan et al’s paper (your reference [2]) previously – See my footnote 1 below:

JDW Response 11-5: Footnote 1 focusses on the presence of 1,3-diphenylpropane (1,3-DPP). Footnote 1 does not adequately explain the sudden VOC emission spikes of benzens and propylene nearly five months after 9/11 which are arguably much more than "acute." Also, Ryan et al mention a number of important observations, such as the un-extinquishable fires, molten metal, explosions, and extremely high temperatures in the WTC rubble, observations that footnote 1 does not deal with.

FRG Statement 8-6: "I offer my response to Jones et al’s paper on the high temperatures in the WTC rubble pile, (your reference [3]) in footnote 2 below:

JDW Response 11-6: Footnote 2 is part of a 2006 article by Frank Greening on an aluminum-assisted collapse theory that can be found at Aluminum and the World Trade Center Disaster. This article is, in my opinion, highly speculative for many reasons. However, it does attempt to explain some of the other observations of Ryan et al mentioned above. In order to keep the focus at the moment on G&G's paper on the WTC dust sample, I will defer any further comment on footnote 2 at this time.

FRG Statement 8-7: "In your universe there are only two alternatives: The Twin Tower’s destruction was by a gravity-driven collapse – the “Official Story” – or, a thermite-assisted controlled demolition – the A&E for 9/11 Truth Movement’s view. This does not allow for any other options/theories such as aluminum-assisted collapse; ammonium perchlorate-assisted collapse; advanced technology weaponry collapse, micro-nuke collapse, etc, etc.

JDW Response 11-7: While there is a so-called "Official Story," perpetuated by its supporters and the media, of a gravity-driven collapse, there is no official scientific account of the total collapse that is based on an examination of the evidence provided by the actual "collapses" and their aftermaths. NIST failed to perform its Congressionally-directed mission and, by omission, presented the public with a scientifically-fraudulent report. NIST ended its investigation of the Towers' destructions at the point where NIST claimed collapse was imminent. NIST's claim of imminent collapse is based on speculation and a few dubious tests, not on actual observations. In contrast, there is copious eyewitness, photographic and physical evidence of what took place during and after the "collapses" but NIST did not go there. The actual observations strongly indicate controlled demolition as the cause of the "collapses." Though charged by the U.S. Congress to fully explain how and why the Towers collapsed, NIST, with all its resources of money, equipment and personnel, did not venture to study the actual "collapses." Into this scientific vacuum early on walked Bazant and Zhou with a theoretical model of a gravity-driven collapse mechanism that has not been replicated experimentally. But few have followed these authors with scientific papers on this fire-induced gravitational collapse theory. The vast majority of scientists, engineers, and scholars who have examined the actual evidence have concluded, many in scientific papers, that some form of controlled demolition brought down the Towers. Except for "aluminum-assisted collapse," the other options/theories you cite are different forms of controlled demolition. None of these hypotheses has gained any significant traction because they cannot address all the available evidence. As mentioned above (response 11-6), the aluminum-assisted collapse hypothesis is highly speculative. In my view there is at present only one viable theory for the Towers' destructions, namely, controlled demolition using some sort of explosives that include nano-thermite.

FRG Statement 8-8: "So, please do not claim that I do not follow the scientific method. The scientific method is about evidence obtained by observation. This is what my report on Christine Sakoutis’ WTC dust sample is all about – nothing more, nothing less."

JDW Response 11-8: The scientific method is about evidence obtained by all observations, including one's own, and about determining which of the different possible hypotheses best fits the observations. For example, G&G's study suggests that "iron-rich spherical particles [found] in the WTC 2 sample are from on-site cutting and grinding operations that were carried out during the construction of the Twin Towers." However that is highly speculative since there is no comparative analysis as to the composition of “on site cutting and grinding” residue from the structural steel used in the towers, and the chemical composition of the spheroids you analyzed. In contrast, RJ Lee's report on their dust studies concluded that "Various metals (most notably iron and lead) were melted during the WTC Event, producing spherical metallic particles. Exposure of phases to high heat results in the formation of spherical particles due to surface tension…". G&G's paper does not consider potential sources of this "high heat" during the WTC event. See reference [3].