Demolition of WTC: Let’s not overstate the case, please

On the Truth Action board, we’ve been having an interesting discussion about the evidence for controlled demolition of the WTC buildings, starting on this page.

There is disagreement about how sure we should be about the idea that WTC 1, 2, and 7 were demolished with explosives and/or thermite. Some, including YT, are 100% sure, while others, such as John Doraemi and Nicholas, believe that it’s likely but not 100% proven. I’m in the latter camp, though not to quite the same extent as John and Nicholas. On the next page of the above Truth Action thread, I voiced some of my own opinions about the need for caution in how we present the case for controlled demolition of the WTC buildings. Below, I’ll voice more of my thoughts on this matter.

In my opinion, we shouldn’t be claiming that the WTC buildings definitely were demolished with explosives and/or thermite. Instead, our claim should be that there’s enough evidence for demolition to warrant a serious and truly independent investigation with subpoena power.

Furthermore, we need to be careful about how we argue for the likelihood of demolition. We need to make sure our arguments are sound; otherwise we risk discrediting ourselves.

To me it seems that a lot of people in the 9/11 Truth movement have overstated the case for demolition and have used some faulty arguments (as well as some good arguments) for the likelihood of demolition. Below is my assessment of various arguments that I’ve seen used:

• WTC 7: A very simple, genuinely strong argument
• The “Newton’s laws” argument: Incomplete without some details
• WTC 1 and 2: Size matters
• WTC 1 and 2: Focus on the need for a new investigation
• “Foreknowledge” by NYC officials – a bad argument
• WTC 1 and 2: The NIST report
• Thermite (or Thermate) – good so far, though not conclusive
• “Ready for shipment”? – just not true
• WTC 1: Core column failure and demolition
• A faulty objection to the “pile driver” hypothesis
• WTC 1 and 2: Flying perimeter column pieces
• Sounds of explosions heard by witnesses
• The “squibs” – more details needed
• More about the need for a new investigation

WTC 7: A very simple, genuinely strong argument

We do have a very solid, simple case for probable controlled demolition of WTC 7. The almost perfectly symmetical, straight-down, vertical collapse of WTC 7 is extremely unlikely otherwise, especially given the asymmetrical damage.

In my opinion, even this is not 100% proof of demolition. Experts have speculated on other maybe-possible hypothetical scenarios, e.g. in The Collapse of Building 7 (PDF) by Arthur Scheuerman, FDNY (Retired).

Nevertheless, in my opinion, the symmetry of collapse is still a solid argument for at least a very strong likelihood of demolition. And this argument has stood the test of time. As far as I am aware, no “debunker” has yet refuted it. (See my earlier blog post Straight-down collapse of WTC 7 – what do “debunkers” say?. See also 9/11 – Proof of Explosive Demolition without Calculations (PDF) by Frank Legge, in the Journal of 9/11 Studies, September 2007.)

But the issues for the Twin Towers are much more complex, more quantitative, and more iffy.

By the way, the symmetry argument for WTC 7 cannot be applied directly to WTC 1 and 2, because the collapse of WTC 7 was bottom-up, like most controlled demolitions, whereas the collapses of WTC 1 and 2 were top-down from the impact floors. Furthermore, the collapse of WTC 2 was not nearly as symmetric as the collapse of WTC 7. The top part of WTC 2 did tilt over quite a bit as it began to fall, a fact which, by example, strengthens the symmetry argument for WTC 7.

There may well be some valid symmetry arguments for WTC 1 and 2 too, but they would have to be a bit more subtle.

(P.S., 2/11/2008: I’ve recently encountered, for the first time, what may be a substantial counterargument against what I had thought of as the close-to-perfect symmetry of WTC 7’s collapse. See the comments after my post Review of Hardfire debates between Mark Roberts and Loose Change crew. But it all depends on the authenticity of a certain privately-made video, so I should wait for some corroborating evidence before drawing a definite conclusion. See my post Two WTC 7 collapse videos: Can both be real?.)

(P.S., 2/28/2008: For my current thoughts about WTC 7, including the symmetry argument, please see: Richard Gage’s avowed enemy, part 2 – and my thoughts about WTC 7.)

The “Newton’s laws” argument: Incomplete without some details

For an example of what I mean by overstating the case, a lot of folks have claimed that the sheer speed of collapse inherently violates Newton’s laws.

In fact, the towers did not fall with exactly free-fall acceleration. They fell a little bit slower than that.

The question is whether they fell slower enough to be consistent with an alleged purely “natural” collapse. That’s a quantitative question, not one that can be answered with simple hand-waving.

Zdnenek Bazant and other defenders of the official story have claimed that, once the collapse of either of the Twin Towers got going, the resistance of the columns to being shattered was “negligible” compared to the impact of the top part of the building falling on top of them.

If indeed this claim is true, then what should be the expected collapse time? Using my own oversimplified computer model for WTC 1, assuming a top-down collapse starting at the 95th floor, with totally inelastic collisions and no matter being ejected out of the building, I got 10.5 seconds for the time of descent of the collapse front. Adjusting my model to eject about 70% of the mass of each floor outside the building (probably an unrealistically high estimate), I was able to increase the fall time only to 12 seconds.

So, it seems to me that we can’t prove demolition based on collapse times alone. Based on my own calculations, the fall time might be consistent with the official story, if indeed it’s possible that the resistance of the columns to being shattered could be “negligible” compared to the impact of the top part of the building falling on top of them. Is the latter claim plausible? That too is a quantitative question. It can be answered only by people with an in-depth familiarity with the properties of steel, including how steel deforms.

Is it indeed physically possible that, once the collapse got going, the resistance of the columns to being shattered was “negligible” compared to the impact of the top part of the building falling on top of them. Zdnenek Bazant says yes, Gordon Ross says no.

Bazant’s claims can be found in his 2001 paper Why did the World Trade Center towers collapse? and again in the more recent paper Collapse of the World Trade Center Towers: What Did and Did Not Cause It? (PDF) by Bazant, Le, Greening, and Benson, June 22, 2007. Some brief comments by Thomas Spellman about the latter paper, but nothing substantial yet, can be found on the website of Architects and Engineers for 9/11 Truth. On Bazant’s earlier paper, Jim Hoffman wrote a commentary which may have misunderstood at least some of what Bazant and Zhou wrote, because Hoffman is not a structural engineer, but nevertheless caught what would seem to be some real errors in Bazant’s paper, such as an overestimation of the likely temperatures of the fires. (About fire temperatures, see also Why Did the World Trade Center Collapse? Science, Engineering, and Speculation by Thomas W. Eagar and Christopher Musso, 2001. Note, however, that Eagar’s and Musso’s explanation of the collapses has subsequently been rejected by nearly everyone including NIST. Note also that the steel temperatures would not be nearly as high as the fire temperatures, because steel conducts heat very well, so the steel frame would act as a big heat sink.)

Gordon Ross, a mechanical engineer, has written Momentum Transfer in WTC1, which was also published (PDF copy here) in Steven Jones’s Journal of 9/11 Studies, which also published a response by Frank Greening (PDF), to which Ross replied here (PDF), and an anonymous response to Ross’s paper (PDF), to which Ross replied here (PDF). Ross has also written a more general critique of Bazant’s hypothesis, Dr. Bazant – NIST’s 911 Fall Guy. (See also Ross’s detailed hypothesis on How the Towers were Demolished, an attempt to account for all the observed phenomena.)

Not having any expertise on the deformation of steel myself, I’m going to take an agnostic wait-and-see attitude on this particular issue for now. Bazant’s hypothesis about the mechanism of collapse seems very unlikely to me, but I don’t have the necessary background to disprove it. As far as I am aware, Gordon Ross is the only person in the Journal of 9/11 Studies crowd who has made a serious effort to refute Bazant’s hypothesis, but I don’t have the necessary background to evaluate all his arguments either. So, all I can do is wait and see what develops.

In the meantime, I will not claim that the towers’ fall times alone prove demolition, or that the collapses “violate laws of physics” merely because of the fall times or the acceleration. And, if you don’t have quantitative knowledge about the deformation properties of steel, then I don’t think you should make that claim either. There are other, better, yet still relatively simple arguments we can make.

(P.S., 11/22/2007: The ensuing discussion, both here and in the Truth Action forum, has made me aware of some important flaws in my computer model. I’ll revise my model later, and will discuss it in more detail in a future post.)

(Further P.S., 11/22/2007: As I’ve said, although I can’t prove it, it does seem to me that Bazant’s hypothesis is unlikely. An intuitive counterargument – admittedly not a proof – is simply to point to the thickness of the core columns, at least in the lower and middle parts of the building, as seen in this construction photo, for example.)

(Still further P.S., 12/8/2007: For some more reasons to doubt Bazant’s hypothesis, see the comment thread starting here, and see also my post Engineers were surprised by the WTC collapses, especially the section titled What this does and does not mean)

WTC 1 and 2: Size matters

One simplistic argument, which some people mistakenly believe is very sound, even incontrovertible qualitative proof of demolition of the Twin Towers, is just to point to the explosive appearance of the Twin Tower “collapses.” As Richard Gage has shown in his for-the-most-part excellent video presentation, the collapsing towers, with their enormous and explosive-looking dust clouds, look physically a lot more like volcanic eruptions and nuclear blasts than like any previous known building collapses. See also Jim Hoffman’s page about Other Building Collapses.

While the sheer qualitative resemblance to a huge explosion is worth pointing out, it is far from incontrovertible as an argument for the likelihood of demolition with explosives. The problem with it as an alleged proof of demolition is that the “collapses” of the Twin Towers were an utterly unique event, unique in many ways. Never before in the history of the world have any steel frame high-rise buildings anywhere near 110 storeys tall ever collapsed for any reason whatsoever. Therefore, we don’t know what the collapse of such a huge building “should” look like, if it were to collapse due just to airplane impact damage plus fire on upper floors. (Whether the latter is plausible is, of course, questionable on other grounds. For now we’re just exploring the question of what such a collapse “should” look like if it were to happen.) The examples of building collapses given in Richard Gage’s video presentation, and on websites such as Jim Hoffman’s, all involve much smaller buildings of very different construction.

What we can see with our own two eyes is sufficient for evaluating things within our everyday experience, but not sufficient for evaluating things outside our everyday experience. In science, there are many examples of failed generalizations. An example is the Michelson-Morely experiment, which disproved some common-sense beliefs about the speed of light. (Einstein formulated his Special Theory of Relativity in response to the Michelson-Morley experiment.)

Can a gravity-induced collapse cause something to look like it’s exploding? Actually, yes. To give an extreme example, the most powerful explosions known in the universe are supernova explosions, caused by the gravity-induced collapse of a large star which has run out of nuclear fuel. Of course, that’s a ridiculously extreme example, because the Earth’s gravitational force is much, much smaller than that of a collapsing star. But my ridiculously extreme example does illustrate a key point, which is that size matters.

In a commentary on Thomas Eagar’s collapse hypothesis, Jim Hoffman quotes Jeff King as saying:

He implies that the laws of gravitation are somehow not linear, that if a small object of the same proportions (6.5/1 height to base ratio) tends to topple, a much bigger object of the same proportions will not be similarly unstable. A wooden box 1′ square and 6 1/2′ tall has the exact same geometric relations of center of gravity to base as a big steel box 1300′ tall and 208′ on a side. Nothing changes with a change in absolute size, this is the most basic Newtonian physics.

It is true, as Jeff King says, that the geometric relation of center of gravity to base does not change with absolute size. But many other mechanical properties of an object do vary nonlinearly with “absolute size.” In particular, for objects of a given shape, the force of gravity on an object is a nonlinear function of the object’s height. The force of gravity on an object is the object’s weight, which is proportional to its mass, which (for objects of a given density) is proportional to volume, which, in turn, is proportional to the cube of the height.

In many areas of science, “absolute size” does matter. For example, in high school biology I learned that there are reasons why living cells must be microscopic. The bigger something is, the smaller its surface-to-volume ratio (because, for objects of different size but the same shape, the surface area is proportional to the square of a given linear dimension such as its length, whereas the volume is proportional to the cube of the linear dimension). Thus a too-big cell would have a too-small surface-to-volume ratio, so that, for example, the cell could no longer feed itself via osmosis across the cell membrane. Similarly there are reasons why all insects must be small, compared to most vertebrates. A too-big insect would not have the strength to move its too-heavy exoskeleton.

Back to buildings. As I said earlier, for a building with a given aspect ratio, the volume (and hence also the mass) is proportional to the cube of the height. So, whereas a pair of little toy scale models of the Twin Towers clearly would not be capable of crushing themselves, this, in itself, does not prove that the Twin Towers themselves would be incapable of crushing themselves.

It still seems to me unlikely that the Towers could crush themselves as per Bazant’s hypothesis. But this cannot be disproven with a scale model, or by simply referring to the history of collapses of much smaller buildings.

Might a gravity-induced collapse of a very large, massive building (if such a collapse were to occur) look very different from a gravity-induced collapse of a much smaller building? Quite probably, yes. Would it look at least somewhat like the “collapses” of the Twin Towers? We don’t know, because we’ve never seen a collapse of such a tall and heavy building before.

WTC 1 and 2: Focus on the need for a new investigation

In my opinion, regarding the Twin Towers, I think our best bet is to focus on the deficiencies of the investigations thus far.

Many of those deficiencies, which suggest a coverup, have been noted even by many people who do not otherwise dispute the official story. For example, according to Bill Manning, editor-in-chief of Fire Engineering magazine ($elling Out the Investigation, January 4, 2002):

Did they throw away the locked doors from the Triangle Shirtwaist Fire? Did they throw away the gas can used at the Happyland Social Club Fire? Did they cast aside the pressure-regulating valves at the Meridian Plaza Fire? Of course not. But essentially, that’s what they’re doing at the World Trade Center.

For more than three months, structural steel from the World Trade Center has been and continues to be cut up and sold for scrap. Crucial evidence that could answer many questions about high-rise building design practices and performance under fire conditions is on the slow boat to China, perhaps never to be seen again in America until you buy your next car.

Such destruction of evidence shows the astounding ignorance of government officials to the value of a thorough, scientific investigation of the largest fire-induced collapse in world history. I have combed through our national standard for fire investigation, NFPA 921, but nowhere in it does one find an exemption allowing the destruction of evidence for buildings over 10 stories tall.

…

Comprehensive disaster investigations mean increased safety. They mean positive change. NASA knows it. The NTSB knows it. Does FEMA know it?

No. Fire Engineering has good reason to believe that the “official investigation” blessed by FEMA and run by the American Society of Civil Engineers is 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. Except for the marginal benefit obtained from a three-day, visual walk-through of evidence sites conducted by ASCE investigation committee members- described by one close source as a “tourist trip” – no one’s checking the evidence for anything.

Bill Manning suspected a coverup, not of demolition but of possible deficiencies in the buildings’ construction:

The builders and owners of the World Trade Center property, the Port Authority of New York-New Jersey, a governmental agency that operates in an accountability vacuum beyond the reach of local fire and building codes, has denied charges that the buildings’ fire protection or construction components were substandard but has refused to cooperate with requests for documentation supporting its contentions.

Even so, we can certainly agree with his call for a better investigation and his denunciation of the destruction of evidence.

“Foreknowledge” by NYC officials – a bad argument

Manning’s Fire Engineering article ends with a link to WTC “Investigation”? A Call to Action, which contains a very interesting perspective on 9/11 from the viewpoint of firefighters, including another issue on which many of us in the 9/11 Truth movement may have overstated our case.

This page says that the editors have “always been leery” of the fireproofing used in the WTC and similar buildings: “Why do many firefighters say that they would rather fight a high-rise fire in an old building than in a modern one? Isn’t it because of the level of fire resistance provided?”

For more about this issue, see the September 11 archives page on the Progressive Review site, including a synopsis of a 1976 book by New York City Fire Commissioner John O’Hagan, High Rise Fire and Life Safety, in which O’Hagan worried about the possibility of the Twin Towers collapsing due to fire.

Whether or not these worries were in fact justified on the grounds given, it would seem that the hypothetical possibility of a steel high-rise building collapsing was not totally unheard of among fire fighters or among fire safety experts before 2001.

We can still argue that such a collapse is unlikely, given the WTC buildings’ highly redundant design, and given the history of more-severe and longer-lasting fires in similarly constructed buildings that did not collapse. (For examples, see Jim Hoffman’s page on Other Skyscraper Fires.)

However, city officials’ worries about the possibility of WTC 1 and 2 collapsing, before those collapses occurred, are not evidence of criminal foreknowledge.

Regarding “foreknowledge” of the collapse of WTC 1 and 2, see also 9/11 cops saw collapse coming by Paul H.B. Shin, New York Daily News, June 19th, 2004, as reprinted on the website of the Skyscraper Safety Campaign, which also contains a lot more information about 9/11 from the viewpoint of firefighters and families of victims.

Regarding “foreknowledge” of the collapse of WTC 7, see also this interview with Deputy Fire Chief Peter Hayden in Firehouse Magazine, April 2002.

(P.S., 12/9/2007: See my subsequent post WTC 7: FEMA report and NIST prelim report: What about pre-collapse leaning and the transit???)

WTC 1 and 2: The NIST report

Anyhow, after the FEMA report, there have been other “investigations.” For now I’ll skip over the 9/11 Commission report, which focussed on matters other than the scientific, but about which there have been many complaints too. Let’s look now at some critiques of the NIST report by scientists and engineers in the 9/11 Truth movement.

Kevin Ryan, a chemist and a former executive at Underwriters Laboratories, has made the following critique:

• Propping Up the War on Terror: Lies about the WTC by NIST and Underwriters Laboratories by Kevin Ryan
• Jim Hoffman’s review of a presentation by Kevin Ryan
• What is 9/11 Truth? The First Steps (PDF) by Kevin Ryan
• Kevin Ryan’s response to the NIST FAQ

Some people have tried to discredit Ryan’s critique on the grounds that he is a chemist, not a structural engineer. But the issues he raises are ones of basic scientific methodology, not requiring specialized knowledge of structural engineering.

In a comment on my post Reply to “Nerd World Order” about the page “The 9/11 Conspiracy guys are retarded”, I was challenged to read On Debunking 9/11 Debunking by Ryan Mackey. This article allegedly contains an indirect refutation of Ryan’s points, via a critique of David Ray Griffin’s book Debunking 9/11 Debunking. I have not yet managed to plow all the way through this very long article, but I do intend to, and will post about it here when I do.

The Journal of 9/11 Studies site has published a bunch of other critiques of the NIST investigation. Below I’ve listed them all, in forward chronological order:

• NIST Data Disproves Collapse Theories Based on Fire (PDF) by Dr. Frank Legge, August 2006
• The NIST WTC Investigation–How Real Was The Simulation? (PDF) by Eric Douglas, R.A., December 2006 (Word version)
• NIST and Dr. Bazant – Simultaneous Failure (PDF) by Gordon Ross, ME, May 2007
• 9/11 Family Members and Scholars: Request for Correction Submitted to NIST (PDF) by Bob McIlvaine, Bill Doyle, Steven Jones, Kevin Ryan, Richard Gage, Scholars for 9/11 Truth and Justice, June 2007
• Sept. 2007 Response to April 2007 RFC, from NIST (PDF)
• Appeal Filed with NIST, Persuant to Earlier Request for Correction (PDF) by James Gourley, Bob McIlvaine, Bill Doyle, Steven Jones, Kevin Ryan, Richard Gage, Scholars for 9/11 Truth and Justice, November 2007

See also Jim Hoffman’s commentary on the NIST report, and see also Reply to NIST by Gordon Ross.

I’ll comment on these in a future post, at some point.

As I said, regarding the Twin Towers, many of the issues are complex and quantitative, having to do with quantities like temperature of fire and strength of steel. That being the case, it’s probably best to emphasize flaws in the NIST report. There are other issues we can talk about, too, but we need to be careful that our arguments are sound.

(P.S., 12/9/2007: See my subsequent post about Fire temperatures and steel temperatures and the comment thread following it.)

(P.S. 12/16/2007: Frank Greening, a co-author of the latest Bazant paper, is nevertheless highly critical of the NIST report. See his fascinating post Confessions of a 9/11 Agnostic, on page 6 of the thread Debate! What debate? in the JREF forum. As far as I can tell, he suspects a coverup, not of 9/11 being an inside job, but of possible flaws in the design of the WTC. See also this post of his in the JREF forum thread Another engineer criticizes NIST & FEMA.)

Thermite (or Thermate) – good so far, though not conclusive

Some relatively simple points we can make have to do with Steven Jones’s evidence for the use of thermite/thermate. Although he has not conclusively proven his hypothesis, his evidence clearly does show the need for a truly independent investigation, without the conflicts of interest that have plagued all previous official investigations. See his paper Why Indeed Did the World Trade Center Buildings Completely Collapse? (PDF).

His strongest piece of evidence, in my opinion, is the iron-alloy spherules found in WTC dust – not just Jones’s samples, but other samples too. The spherules most likely were formed from molten iron flying through the air. The existence of molten iron, in turn, strongly suggests the presence of an incendiary such as thermite or thermate, because the fires in the WTC buildings were not otherwise hot enough to melt steel.

Another piece of evidence is the mysterious glowing yellow liquid that poured out of a window on the 82nd floor of WTC 2 just before its collapse. (A post by Danse on the Truth Action board contains this photo.) Obviously we can’t know for sure what this stuff was, but Dr. Jones did experimentally rule out a few possibilities other than molten iron. (See Dr. Jones’s paper, and see also Molten What? (PDF) by Jerry Lobdill, May 2007.)

Still another piece of evidence is the many eye-witness testimonies about molten steel (or at least a white-hot liquid of some kind) found in the rubble piles of all three towers. In the Truth Action forum, Danse put together a collection of quite a few of these testimonies. (See also Molten Metal: Workers Reported Molten Metal in Ground Zero Rubble on Jim Hoffman’s 9-11 Research site.)

However, as Nicholas pointed out in our discussion on the Truth Action board, most of these testimonies are about molten metal seen in the debris pile long after the collapse. Only one of them referred to “rivers of molten steel” that were encountered immediately after the collapse. So, perhaps this isn’t as strong evidence as the spherules in the dust.

But then again, there’s also the question of how the debris pile fires managed to get so extremely hot without the presence of an incendiary. While one might expect the pile fires to get hotter than the building fires in at least some places, should we expect them to get that much hotter?

The eye-witness testimony about “molten steel” is confirmed by the existence of the so-called “meteorites,” which contained previously molten iron.

One “debunker,” Frank Greening, has speculated that thermite reactions might have occurred spontaneously when the aluminum from the crashed airplanes melted. See his article Aluminum and the World Trade Center Disaster (PDF). This has been answered by Steven Jones in his video presentation. See also the following:

• Experiments with Molten Aluminum (Word document) by Steven E. Jones with Wesley Lifferth, Jared Dodson, Jacob Stevenson and Shannon Walch, circa June 2006
• A description of molten aluminum poured onto rusty steel (PDF) by Wes Lifferth, Journal of 9/11 Studies, March 2007
• Sorry Dr. Greening et al by Gordon Ross

For an answer to the NIST FAQ’s objections to the thermite hypothesis, see Statement Regarding Thermite, Part 1 (PDF) by Robert Moore, Journal of 9/11 Studies, January 2007.

For an answer to some other objections, see “Thermite Hypothesis” versus “Controlled Demolition Hypothesis”: a response to “The Scientific Method Applied to the Thermite Hypothesis” (PDF) by Arabesque.

(P.S., 12/9/2007: Another attempt to refute Jones is this page by Henry62, which I might critique sometime later. For now I’ll just note that it, like most attempts to refute Jones’s hypothesis, doesn’t deal with Jones’s strongest evidence, namely the iron spherules, which were found by the U.S. Geological Survey as well as by Jones. The latter is acknowledged even by at least one of the better-informed official-story defenders, e.g. Frank Greening a.k.a. “Apollo20,” in this post in the JREF forum and in another post quoted here. Note that Greening has some disagreements with NIST and refers disparagingly to “NISTians,” but basically supports the official story in other ways, such as by being a co-author of the most recent Bazant paper.)

(P.S., 12/17/2007: For an interesting variation on the thermite arson hypothesis, see also my post “The Adventures of Max Photon” – a review.)

(P.S., 1/3/2008: Another source on the iron spherules, besides the U.S. Geological Survey, is this report by the RJ Lee Group (PDF). For more about this report, please see my post He oughta know better: Mark Roberts and the iron spherules.)

Let’s look now at some other common arguments for the hypothesis that the Twin Towers were demolished with explosives and/or incendiaries.

“Ready for shipment”? – just not true

One particularly bad argument I’ve seen is the claim that the columns were all cut up into 30-foot pieces, “ready for shipment.”

In fact, there were many bigger pieces. Judy Wood’s Star Wars Beam Weapons paper, despite its on-the-whole wacky thesis, does contain lots of interesting photos of both the collapses and the rubble piles. In some of the photos, observe what Judy Wood calls “wheat chex,” i.e. large pieces of the perimeter wall skeleton, much too big to fit on a truck.

There were indeed a lot of pieces that were approximately 30 feet long too. But we should expect to see these in any case, because the prefabricated perimeter column assemblies were three storeys tall. In a sufficiently forceful “natural” collapse, if such were to occur, one would expect the columns to come apart at the welds between the prefab column assemblies.

My hunch is that thermite and/or explosive charges were placed at or near many of the welds in order to simulate this, or at least to make sure that it happened. But the existence of many 3-storey pieces is not, in and of itself, evidence of demolition as opposed to a “natural” collapse (if indeed a “natural” collapse could be sufficiently forceful).

(Note: I do not recommend Judy Wood’s claims or ideas, but only her collection of photos. For some of the reasons why her hypotheses are very unlikely, see the following Journal of 9/11 Studies pages: The Overwhelming Implausibility of Using Directed Energy Beams to Demolish the World Trade Center (PDF) by Dr. Gregory S. Jenkins, February 2007; A study of some issues raised in a paper by Wood & Reynolds (PDF) by Dr. Frank Legge, January 11, 2007; Scientific Critique of Judy Wood’s Paper “The Star Wars Beam Weapon” (PDF) by James Gourley, January 2007); Why the damage to WTC Bldgs. 3 and 6 does not support the beam weapon hypothesis and some correspondence with Dr. James Fetzer about it (PDF) by Tony Szamboti, March 2007; and Introduction to and Interview with Dr. Judy Wood conducted at the National Press Club in Washington D.C. regarding the use of Directed Energy Beams in the Demolition of the World Trade Center Towers (PDF) by Dr. Greg Jenkins, Febuary 2007.)

(P.S., 11/22/2007: A common “debunker” argument against the idea of explosive demolition of the WTC buildings is that it would require a too-huge number of explosive charges to be placed. The fact that the rubble is not “ready for shipment” cuts down on the number of explosive charges that would be needed to produce the observed results.)

WTC 1: Core column failure and demolition

Another bad argument I’ve seen is the claim that the North Tower must have been demolished with explosives because the fall of the roof antenna, just before the rest of the building began to collapse, implies that the core columns failed first, consistent with what we would expect in a controlled demolition.

It is true that, in a controlled demolition, the core columns are broken first. However, if a building’s core columns fail first, this does not, in and of itself, necessarily imply controlled demolition. In the case of the North Tower, it would have been logical to expect the core to fail first anyhow, if indeed the building were to have collapsed due just to the fires and structural damage (which is questionable on other grounds, as noted elsewhere on this page). Why should we expect the core columns to fail first, at least on or near the 95th floor? For the following combination of reasons:

1. The core columns supported more than 50% of the total weight.
2. There were a lot fewer core columns than perimeter columns; hence the core columns (especially the core’s outermost columns, which were attached directly to the floors) supported a lot more weight per column than the perimeter columns did.
3. At least some of the core columns were damaged by the plane crash, resulting in even more weight per remaining column. (The plane crash probably damaged a larger proportion of the core columns than of the perimeter columns.)
4. The core columns were tapered. Up at the 95th floor, the core columns were not nearly as thick as they were down on the lower floors. On the other hand, the perimeter columns were not tapered; they were as thick as ever at the 95th floor.

(P.S., 11/27/2007: On the other hand, what does seem very suspicious to me is the witness reports I’ve seen about floors failing far lower in the towers than the impact zone (well before the final “collapse,” that is). This suggests to me some sort of non-natural attack on the core columns in lower parts of the towers. Alas, I don’t have these witness testimonies handy at the moment, so I can’t comment yet on how reliable or well-corroborated they are, but I will keep an eye out for them.)

A faulty objection to the “pile driver” hypothesis

Another flawed argument concerns the alleged “pile driver” effect, which Bazant and other defenders of the official story claim to have been the mechanism of ongoing progressive collapse of the Twin Towers. Some people in the 9/11 Truth movement have claimed that “there’s no pile driver” because the top part of the building is in process of disintigrating too.

But this means that the top part of the building is now a descending pile of rubble, much (though not all) of which is still falling on top of the remainder of the building. Given the huge amount of falling matter, the descending rubble pile does not need to be solid in order to have at least somewhat of a “pile driver” effect on whatever it falls on top of. (Imagine a several-ton pile of rocks falling directly on top of your car all at once. While they might not cause as much damage as a falling solid stone wall, they could still cause plenty of damage.)

The fact that the upper part is not in one piece would indeed cause a significant softening of the impact as it hits the lower part. But, to prove that this rules out progressive collapse, one would need to quantify the effect of the softening. And then, one would still need to determine whether there is enough mass, falling fast enough, to cause the observed effects in the observed amount of time, despite the softening. For now, all that can be said is that the failure even to notice – let alone quantify – this softening is a significant error in Bazant’s papers. This error does cast doubt on Bazant’s progressive collapse hypothesis, but, without further quantitative analysis, we can’t be sure whether this error disproves the progressive collapse hypothesis. Alas, I don’t know how to do all the relevant quantitative analysis.

To me it seems prima facie unlikely that Bazant’s “pile driver” could be sufficiently forceful. But it’s an exaggeration to say that there’s no “pile driver.”

(P.S., 12/8/2007: See the comment thread starting here, where, in a debate with “anonanonanon,” I voice what I think may be the beginnings of a solid scientific argument on this matter, although I don’t have all the necessary technical background to flesh it out.)

WTC 1 and 2: Flying perimeter column pieces

Another bad argument is the claim that only an explosion could have sent pieces of the perimeter columns all the way across West Street.

But flying projectiles are consistent with Bazant’s alleged “pile driver” effect. Imagine yourself shattering something with a hammer. Pieces could well go flying out in all directions.

The only question is whether the descending top parts of the towers could have hit the bottom parts hard enough to send pieces out that far. This is yet another quantitative question.

Offhand, to me it doesn’t seem completely implausible that some pieces could have been flung that far, given the height of the towers, compared to the distance the pieces were flung. If indeed Bazant’s “pile driver” could crush the towers (and that’s the big if, of course), then surely it could also send pieces flying all over the place too.

Sounds of explosions heard by witnesses

Some people believe that our best evidence for demolition is the oral histories and other witness testimonies about explosions.

However, as I’ll explain in a future post, many though not all of these testimonies can be explained away in terms of the official story. So, while some of the testimonies are worth quoting, on the whole they’re not nearly as strong evidence for demolition as some people think they are.

One thing that’s worth pointing out about the oral histories is not just the content of the testimonies themselves, but also the reluctance of the New York City government to release them to the public. The New York Times had to get a court order to get the oral histories released. This fact isn’t really evidence for demolition per se, but it does suggest, at the very least, that someone had something to hide, hence another reason why we need a truly independent investigation.

(P.S., 11/23/2007: The witness testimonies are valid counterevidence in the event that anyone tries to claim something along the lines of: “nobody heard or saw explosions; therefore, there were no explosions.”)

(P.S., 11/25/2007: There’s still the question of whether the explosive sounds heard by many witnesses were loud enough that they could possibly be explosions of demolition charges. That’s another one of those pesky quantitative questions.)

The “squibs” – more details needed

Now for a very complicated matter, whose soundness as an argument for demolition I’m not yet sure of: the “squibs.” See the following Journal of 9/11 Studies articles:

• High Velocity Bursts of Debris From Point-Like Sources in the WTC Towers (PDF) by Kevin Ryan, July 2007
• Direct Evidence for Explosions: Flying Projectiles and Widespread Impact Damage (PDF) by Dr. Crockett Grabbe, August 2007

See also Squibs: High-Velocity “Demolition Squibs” Are Visible in the Twin Towers’ Collapses on Jim Hoffman’s 9-11 Research site.

One error I notice on some of the above pages: It is argued that the rubble from the disintegrating upper floors cannot act as a “piston” because it is not airtight. Perhaps it can’t act as a full-fledged “piston,” but it does seem to me that a suddenly descending pile of rubble, even if it has lots of holes and is not very compact, still could cause a huge and sudden downward gust of wind. Perhaps it still couldn’t produce enough of a downward gust of wind to cause the effects claimed by defenders of the official story. But how much sudden downward wind could it cause? And what would be the resulting increases in pressure on lower floors? These are quantitative questions. I’m not sure how to answer them. I would encourage those with relevant expertise, on both sides of the debate, to do some computations. (If anyone reading this knows of such computations having already been done, please let me know via a comment.)

Even more sudden gusts of wind could perhaps be produced if the core columns (or at least the outermost core columns, the ones attached directly to the floors) are failing first, before the perimeter columns. In that case, it seems to me that the suddenly tipping floors could force quite a bit of air out of one or more broken windows on a floor lower than where the perimeter columns have failed. Still they might not be able to blow the dust out as fast as has been observed, but that’s another quantitave question. To prove this, one would need to compute just how fast one should expect air to be blown out of a window if, for example, the floor just above the window were suddenly to lose its core-column support.

The above points do not invalidate the other arguments regarding “squibs.” I personally don’t know how to evaluate most of these arguments.

One possibly good defense of the “squibs” idea is the argument that if windows are being blown out on a given floor, all the windows on that floor should break at once, not than just a few of them, so, if dust were being blown out just by air pressure from the collapse, then it should have come out of a lot more windows. I’m not absolutely sure that this argument is valid, but it does seem to me to be prima facie plausible. It is true that when windows are blown out by a fire, typically many windows are broken all at once, not just a few of them.

Anyhow, if one is going to use the “squibs” as an argument for the likelihood of demolition, then one needs to be prepared to answer the obvious counter-hypothesis that the “puffs of dust” are being ejected merely due to pressure from falling debris on higher floors. This can get very complicated. For example, if your answer is that the puffs are being ejected too fast, then you need to be able to estimate how fast they should be ejected if the sole cause were pressure from falling debris on higher floors.

The too-few-windows argument is probably a better defense than the speed argument. The speed argument definitely needs more quantitative analysis. On the other hand, we’ve all seen windows blown out by a fire, and we saw how the dust clouds from the World Trade Center “collapses” broke not only the WTC buildings’ own windows, but also the windows of many other buildings even several blocks away.

However, to be sure that the too-few-windows argument is valid, it would be necessary to check the floor plans of the floors from which the “squibs” were seen bursting. For example, might the windows that ejected the “squibs” be at the ends of corridors leading directly from the elevators? If so, then perhaps that might explain how a gust of dust from one of the elevator shafts could be blown out from only those particular windows and not from the windows of enclosed offices. (I’m assuming that the offices, even if very big, had walls and doors and were not directly open to the elevators.)

Anyhow, whether or not the “squibs” idea is valid on the whole (which I’m not sure of yet), I personally would hesitate to bring it up in street actions or on a pamphlet. It’s just too complicated, requiring a detailed response to an obvious and simple counterargument.

(P.S., 11/22/2007: Some claims about the speed of air being ejected from the towers can be found in the latest Bazant paper, Collapse of the World Trade Center Towers: What Did and Did Not Cause It? (PDF) by Bazant, Le, Greening, and Benson, June 22, 2007. These claims should be checked.)

More about the need for a new investigation

Even if we can’t be 100% sure that the WTC buildings were brought down by controlled demolition, we do have a 100% solid case for the need for a new investigation. Even many people who do not otherwise support the 9/11 Truth movement would agree that we need a new and truly independent investigation.

When a friend of mine committed suicide back in the late 1980’s, her husband was locked out of their apartment for about three months, if I remember correctly, while the police investigated the possibility of foul play. In other words, murder is something that gets investigated even when it’s very doubtful that a murder has even occurred.

We do know for sure that, on 9/11, at least three thousand people were murdered. What many people question is whether all the perpetrators have been correctly identified. Likewise all the means of murder.

Even more people have questioned how and why the planes were allowed to hit their targets, especially the Pentagon. On the latter question, we’ve gotten a series of conflicting stories from the government.

All the official investigations thus far have been conducted by people who either were employed directly by the Bush administration or otherwise had strong ties to the Bush administration. Obviously this is a conflict of interest. We need a new and truly independent investigation, with subpoena power, by a panel without conflicts of interest.