Why Indeed did the WTC Buildings Collapse?

http://www.informationclearinghouse.info/article11017.htm

[see URL for several important photos]

Steven E. Jones, (2006). "Why Indeed did the WTC Buildings Collapse?," The
Hidden History of 9-11-2001, Research in Political Economy, Volume 23, P.
Zarembka, editor, Amsterdam: Elsevier, 2006.

DRAFT

Why Indeed Did the WTC Buildings Collapse?
By Steven E. Jones
Department of Physics and Astronomy
Brigham Young University
Provo, UT 84604


ABSTRACT

In writing this paper, I call for a serious investigation of the hypothesis
that WTC 7 and the Twin Towers were brought down, not just by damage and
fires, but through the use of pre-positioned explosives. I consider the
official FEMA, NIST, and 9-11 Commission reports that fires plus damage
alone caused complete collapses of all three buildings. And I present
evidence for the explosive-demolition hypothesis, which is suggested by the
available data, testable and falsifiable, and yet has not been analyzed in
any of the reports funded by the US government.

Let's start with the collapse of the 47-story WTC 7, which was never hit by
a jet. I ask you to take a minute to look at the collapse of this building
as a basis for discussion.

[photos]
WTC 7: 47 - Story, steel-frame building..

WTC 7 on afternoon of 9-11-01. WTC 7 is the tall

sky-scraper in the back-ground, right. Seen from WTC 1 area.

WTC 7 collapsed completely, onto its own footprint


Now that you have seen the still photographs, it is important to the
discussion which follows for you to observe video clips of the collapse of
this building, so go to:

http://911research.wtc7.net/talks/wtc/videos.html Click on the three
photos at the top of this web-site page in order to see the videos of the
collapse of WTC 7. It helps to have sound.

Then consider a video close-up of the same building (SW corner) as its
demise begins:

squibs

What did you observe?

Symmetry: did the building collapse straight down (nearly symmetrically) ­
or did it topple over?

Speed: How fast did the building fall? (Students and I measure less than
6.6 seconds; time it!)

Smoke/debris-jets: Did you observe puffs of smoke/debris coming out of the
building? Please note for yourself the sequence and fast timing of
observed puffs or "squibs." Note that reference to web pages is used in
this paper due largely to the importance of viewing motion picture clips,
thus enhancing consideration of the laws of motion and physics
generally. High-quality photographs showing details of the collapses of
WTC 7 and the WTC Towers can be found in books (Hufschmid, 2002; Paul and
Hoffman, 2004), magazines (Hoffman, 2005; Baker, 2005) and at
http://911research.wtc7.net/wtc/evidence/photos/collapses.html.

My reasons for advancing the explosive-demolition hypothesis while
challenging the "official" fire-caused collapse hypothesis are these:

1. As you observed, WTC 7 collapsed rapidly and symmetrically -- even
though fires were randomly scattered in the building. WTC 7 fell about
seven hours after the Towers collapsed, even though no major persistent
fires were visible. There were twenty-four huge steel support columns
inside WTC 7 as well as huge trusses, arranged asymmetrically, along with
approximately 57 perimeter columns. (FEMA, 2002, chapter 5.) A symmetrical
collapse, as observed, evidently requires the simultaneous "pulling" of
most or all of the support columns. The Second Law of Thermodynamics
implies that the likelihood of complete and symmetrical collapse due to
random fires as in the "official" theory is small, since asymmetrical
failure is so much more likely. On the other hand, a major goal of
controlled demolition using explosives is the complete and symmetrical
collapse of buildings.

Concluding remarks in the FEMA report on the WTC 7 collapse lend support to
my arguments:

The specifics of the fires in WTC 7 and how they caused the building to
collapse ["official theory"] remain unknown at this time. Although the
total diesel fuel on the premises contained massive potential energy, the
best hypothesis [fire/damage-caused collapse] has only a low probability of
occurrence. Further research, investigation, and analyses are needed to
resolve this issue. (FEMA, 2002, chapter 5; emphasis added.)

That is precisely my point: further investigation and analyses are needed,
including consideration of the controlled-demolition hypothesis which is
neglected in all of the government reports (FEMA, NIST and 9-11 Commission
reports). Note that the 9-11 Commission report does not even mention the
collapse of WTC 7 on 9-11-01. (Commission, 2004) This is a striking
omission of data highly relevant to the question of what really happened on
9-11.

2. A New York Times article entitled "Engineers are baffled over the
collapse of 7 WTC; Steel members have been partly evaporated," provides
relevant data.

Experts said no building like it [WTC7], a modern, steel-reinforced
high-rise, had ever collapsed because of an uncontrolled fire. (Glanz,
2001; emphasis added.)

That's correct ­ no such steel-beam building had ever before (or since)
completely collapsed due to fires! However, such complete, symmetrical
collapses have indeed occurred many times before -- all of them due to
pre-positioned explosives in a procedure called "implosion" or controlled
demolition. What a surprise, then, for such an occurrence in downtown
Manhattan- three skyscrapers completely collapsed on the same day,
September 11, 2001.

Engineers have been trying to figure out exactly what happened and whether
they should be worried about other buildings like it around the country.
Most of the other buildings in the [area] stood despite suffering damage of
all kinds, including fire... 'Fire and the structural damage .would not
explain steel members in the debris pile that appear to have been partly
evaporated', Dr. [Jonathan] Barnett said. (Glanz, 2001; emphasis added.)

The observed "partly evaporated" steel members is particularly upsetting to
the official theory, since fires involving paper, office materials, even
diesel fuel, cannot generate temperatures anywhere near the 5,000+ oF
needed to "evaporate" steel. However, thermite, RDX and other
commonly-used explosives can readily slice through steel (thus cutting the
support columns simultaneously in an explosive demolition) and reach the
required temperatures. (It is possible that some other chemical reactions
were involved which might proceed at lesser temperatures.) This mystery
needs to be explored ­ but is not mentioned in the "official" 9-11
Commission or NIST reports.

3. There are several published observations of molten metal in the
basements of all three buildings, WTC 1, 2 ("Twin Towers") and 7. For
example, Dr. Keith Eaton toured Ground Zero and stated in The Structural
Engineer,

'They showed us many fascinating slides' [Eaton] continued, 'ranging from
molten metal which was still red hot weeks after the event, to 4-inch thick
steel plates sheared and bent in the disaster'. (Structural Engineer,
September 3, 2002, p. 6; emphasis added.)

The observation of molten metal at Ground Zero was emphasized publicly by
Leslie Robertson, the structural engineer responsible for the design of the
World Trade Center Towers, who reported that "As of 21 days after the
attack, the fires were still burning and molten steel was still
running." (Williams, 2001, p. 3; emphasis added.)

Sarah Atlas was part of New Jersey's Task Force One Urban Search and Rescue
and was one of the first on the scene at Ground Zero with her canine
partner Anna. She reported in Penn Arts and Sciences, summer 2002,

'Nobody's going to be alive.' Fires burned and molten steel flowed in the
pile of ruins still settling beneath her feet. (Penn, 2002; emphasis added.)

Dr. Allison Geyh was one of a team of public health investigators from
Johns Hopkins who visited the WTC site after 9-11. She reported in the Late
Fall 2001 issue of Magazine of Johns Hopkins Public Health, "In some
pockets now being uncovered they are finding molten steel." Further
information on the subject is available at
HERE.

Thus, molten metal was repeatedly observed and formally reported in the
rubble piles of the WTC Towers and WTC 7, metal that looked like molten
steel. However, scientific analysis, using for example X-ray fluorescence,
would be needed to ascertain the actual composition of the molten metal.

I maintain that these published observations are consistent with the use of
the high-temperature thermite reaction, used to cut or demolish
steel. Thermite is a mixture of iron oxide and aluminum powder. The end
products of the thermite reaction are aluminum oxide and molten iron. So
the thermite reaction generates molten iron directly, and is hot enough to
melt and even evaporate steel which it contacts while reacting. On the
other hand, falling buildings (absent explosives) have insufficient
directed energy to result in melting of large quantities of metal. The
government reports admit that the building fires were insufficient to melt
steel beams -- then where did the molten metal come from? Metals expert
Dr. Frank Gayle (working with NIST) stated:

Your gut reaction would be the jet fuel is what made the fire so very
intense, a lot of people figured that's what melted the steel. Indeed it
did not, the steel did not melt. (Field, 2005; emphasis added.)

None of the official reports tackles this mystery. Yet this is evidently a
significant clue to what caused the Towers and WTC 7 to collapse. So I
would very much like to see an analysis of the elemental composition of the
metal, and could do this myself if a small sample were made available
according to scientific courtesy. Any reader who knows of chemical
analyses or even photographs of this molten metal found below the rubble
piles of WTC 1, 2 and 7 is invited to speak out and contact the
author. This could lead to an experiment crucis.

4. Horizontal puffs of smoke and debris are observed emerging from WTC-7 on
upper floors, in regular sequence, just as the building starts to
collapse. (The reader may wish to view the close-up video clip
again.) The upper floors have not moved relative to one another yet, as
one can verify from the videos. In addition, the timing between the puffs
is less than 0.2 seconds so air-expulsion due to collapsing floors is
excluded. Free-fall time for a floor to fall down to the next floor is
significantly longer than 0.2 seconds: the equation for free fall, y = ½
gt2, yields a little over 0.6 seconds, as this is near the initiation of
the collapse.

However, the presence of such "squibs" proceeding up the side of the
building is common when pre-positioned explosives are used, as can be
observed at http://www.implosionworld.com/cinema.html. The same site shows
that rapid timing between explosive squibs is also common. (It is
instructive to view several of the implosion videos at this web
site.) Thus, squibs as observed during the collapse of WTC 7 going up the
side of the building in rapid sequence provide additional significant
evidence for the use of pre-placed explosives. Regarding this
highly-secure building, a NY Times article entitled "Secretive C.I.A. Site
in New York was Destroyed on Sept. 11," provides an intriguing puzzle
piece:

The C.I.A.'s undercover New York station was in the 47-story building at 7
World Trade Center. All of the agency's employees at the site were safely
evacuated. The intelligence agency's employees were able to watch from
their office windows while the twin towers burned just before they
evacuated their own building. (Risen, 2001)

5. The official FEMA 9-11 report admits a striking anomaly regarding the
North Tower collapse:

Review of videotape recordings of the collapse taken from various angles
indicates that the transmission tower on top of the structure began to move
downward and laterally slightly before movement was evident at the exterior
wall. This suggests that collapse began with one or more failures in the
central core area of the building. (FEMA, 2002, chapter 2; emphasis added.)

[photo] North Tower showing antenna (top) at beginning of
collapse.


Yes, we can see for ourselves that the antenna drops first from videos of
the North Tower collapse. (See
HERE;
also http://home.comcast.net/~skydrifter/collapse.htm.) A NY Times article
also notes this behavior:

The building stood for more than an hour and a half. Videos of the north
tower's collapse appear to show that its television antenna began to drop a
fraction of a second before the rest of the building. The observations
suggest that the building's steel core somehow gave way first. (Glanz and
Lipton, 2002; emphasis added)

But how? What caused the 47 enormous steel core columns of this building
(which supported the antenna) to give way nearly simultaneously? That
mystery was raised by the FEMA report (FEMA, 2002, chapter 2) and the New
York Times (Glanz and Lipton, 2002) yet not solved in any official report
(FEMA, 2002; Commission, 2004; NIST, 2005). The odd behavior was not even
mentioned in the final NIST report (NIST, 2005), but some of us have not
forgotten.

Could random fires burning office materials in the building account for a
near-simultaneous "pulling" of these core supports? Certainly such an event
would have exceedingly low probability. Again, use of pre-positioned
explosives to cut the core columns first (standard demolition practice)
provides a simple yet elegant explanation for the observation, satisfying
the "Occam's razor" test (Jones, 2005).

6. Multiple loud explosions in rapid sequence were heard and reported by
numerous observers in and near the WTC Towers, consistent with explosive
demolition. Firemen and others described flashes and explosions in upper
floors near where the plane entered, and in lower floors of WTC 2 just
prior to its collapse, far below the region where the plane had struck the
tower (Dwyer, 2005). For instance, at the start of the collapse of the
South Tower a Fox News anchor reported:

There is an explosion at the base of the building. white smoke from the
bottom. something happened at the base of the building! Then another
explosion." (De Grand Pre, 2002, emphasis added.)

Firefighter Edward Cachia independently reported:

[We] thought there was like an internal detonation, explosives, because it
went in succession, boom, boom, boom, boom, and then the tower came down.It
actually gave at a lower floor, not the floor where the plane hit. (Dwyer,
2005; emphasis added.)

And assistant fire commissioner Stephen Gregory provides additional insights:

When I looked in the direction of the Trade Center before it came down,
before No. 2 came down, ..I saw low-level flashes. In my conversation with
Lieutenant Evangelista, never mentioning this to him, he questioned me and
asked me if I saw low-level flashes in front of the building, and I agreed
with him because I thought -- at that time I didn't know what it was. I
mean, it could have been as a result of the building collapsing, things
exploding, but I saw a flash flash flash and then it looked like the
building came down.

Q. Was that on the lower level of the building or up where the fire was?

A. No, the lower level of the building. You know like when they demolish
a building, how when they blow up a building, when it falls down? That's
what I thought I saw. And I didn't broach the topic to him, but he asked
me. He said I don't know if I'm crazy, but I just wanted to ask you because
you were standing right next to me. He said did you see any flashes? I
said, yes, well, I thought it was just me. He said no, I saw them,
too. (Dwyer, 2005, Assistant Commissioner Stephen Gregory FDNY WCT2 File
No. 91 10008; emphasis added.)

It is highly unlikely that jet fuel was present to generate such
explosions especially on lower floors, and long after the planes hit the
buildings. Dr. Shyam Sunder, Lead Investigator for NIST stated: "The jet
fuel probably burned out in less than 10 minutes." (Field, 2005) On the
other hand, pre-positioned explosives provide a plausible and simple
explanation for the observations, satisfying Occam's razor (Jones,
2005). Thus, it cannot be said that "no evidence" can be found for the use
of explosives. This serious matter needs to be treated as a plausible
scientific hypothesis and thoroughly investigated.

7. The horizontal ejection of steel beams for hundreds of feet and the
pulverization of concrete to flour-like powder, observed clearly in the
collapses of the WTC towers, provides further evidence for the use of
explosives ­ as well-explained in
http://911research.wtc7.net/talks/towers/index.html. (See also, Griffin,
2004, chapter 2.)

[photo] North Tower during top-down collapse.

Notice mysterious squibs far below pulverization region.

Unlike WTC7, the twin towers appear to have been exploded "top-down" rather
than proceeding from the bottom ­ which is unusual for controlled
demolition but clearly possible, depending on the order in which explosives
are detonated. That is, explosives may have been placed on higher floors of
the towers and exploded via radio signals so as to have early explosions
near the region where the plane entered the tower. Certainly this
hypothesis ought to be seriously considered in an independent investigation
using all available data.

8. I totally agree with the urgent yet reasoned assessment of expert
fire-protection engineers, as boldly editorialized in the journal Fire
Engineering:

Respected members of the fire protection engineering community are
beginning to raise red flags, and a resonating [result] has emerged: The
structural damage from the planes and the explosive ignition of jet fuel in
themselves were not enough to bring down the towers.

Fire Engineering has good reason to believe that the "official
investigation" blessed by FEMA. 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.

Some citizens are taking to the streets to protest the investigation
sellout. Sally Regenhard, for one, wants to know why and how the building
fell as it did upon her unfortunate son Christian, an FDNY probationary
firefighter. And so do we.

Clearly, there are burning questions that need answers. Based on the
incident's magnitude alone, a full-throttle, fully resourced, forensic
investigation is imperative. More important, from a moral standpoint, [are
considerations] for the. present and future generations. (Manning, 2002;
emphasis added).

9. The occurrence of nearly symmetrical, straight-down and complete
collapses of the WTC 7 and the Towers is particularly upsetting to the
"official" theory that random fires plus damage caused all these
collapses. Even with explosives, achieving such results requires a great
deal of pre-planning and expertise.

The main challenge in bringing a building down is controlling which way it
falls. Ideally, a blasting crew will be able to tumble the building over on
one side, into a parking lot or other open area. This sort of blast is the
easiest to execute [favored by the Law of Increasing Entropy]. Tipping a
building over is something like felling a tree. To topple the building to
the north, the blasters detonate explosives on the north side of the
building first.

Sometimes, though, a building is surrounded by structures that must be
preserved. In this case, the blasters proceed with a true implosion,
demolishing the building so that it collapses straight down into its own
footprint (the total area at the base of the building). This feat requires
such skill that only a handful of demolition companies in the world will
attempt it. [Again, consistent with the Second Law of Thermodynamics.]

Blasters approach each project a little differently... [A good] option is
to detonate the columns at the center of the building before the other
columns so that the building's sides fall inward. (Harris, 2000; emphasis
added.)

Careful observation of the collapse of WTC 7 (video clips above)
demonstrates a downward "kink" near the center of the building first,
suggesting "pulling" of the support columns, then the building's sides pull
inward such that the building "collapses straight down into its own
footprint" (Harris, 2000). FEMA admitted that WTC 7 collapsed onto a
well-confined footprint:

The collapse of WTC 7 had a small debris field as the facade was pulled
downward, suggesting an internal failure and implosion. The average debris
field radius was approximately 70 feet. (FEMA, 2002, chapter 5.)

Evidently we agree that this was a beautifully done implosion in the
collapse of WTC 7, and yet:

This feat requires such skill that only a handful of demolition companies
in the world will attempt it. (Harris, 2000; emphasis added.)

Consider: Why would terrorists undertake straight-down collapses of WTC7
and the Towers, when "toppling-over" falls would require much less work and
would do much more damage in downtown Manhattan? And where would they
obtain the necessary skills and access to the buildings for a symmetrical
implosion anyway? The "symmetry data" emphasized here, along with other
data, provide strong evidence for an "inside job." Proof would require
additional investigation and questioning of suspects outside of Al Qaeda.

One of the people a thorough investigation should question under oath would
be demolition expert Mark Loizeaux, president of Controlled Demolition,
Inc. Speaking of the way the WTC buildings came down, he said in an
interview: "If I were to bring the towers down, I would put explosives in
the basement to get the weight of the building to help collapse the
structure." (Bollyn, 2002; emphasis added.)

Just right ­ "explosives in the basement" agrees with eyewitness reports of
explosions down low in the buildings (point 6 above). Also, this would be
the way to effectively sever the support columns, consistent with both the
initial drop of the communication tower (WTC Tower 1) and the "kink" in the
middle of WTC 7 as its collapse began. Yes, and as president of Controlled
Demolition, Inc., Mr. Loizeaux would know the "handful of demolition
companies in the world [that] will attempt" a symmetrical controlled
demolition. (Harris, 2000) His company is certainly one of these and was
hired to do the rapid clean-up work following the building collapses. A
thorough investigation might also query the owner of WTC7, who received
billions in insurance monies due to the demise of the WTC buildings on
9-11. (Paul and Hoffman, 2004, p. 17)

If you still haven't looked at the rapid symmetrical collapse of WTC7 for
yourself, why not do so now? Watch for the initial "kink" or drop in the
middle, and for the "squibs" blowing in sequence up the side of the
building, and notice the symmetrical, straight-down collapse -- all so
common in controlled demolitions. See for yourself
at: http://911research.wtc7.net/talks/wtc/videos.html. A great deal of
further information is presented from a serious scientific point-of-view at
this site (http://911research.wtc7.net/).

10. I presented my objections to the "official" theory at a seminar at BYU
on September 22, 2005, to about sixty people. I also showed evidence and
scientific arguments for the explosive demolition theory. In attendance
were faculty from Physics, Mechanical Engineering, Civil Engineering,
Electrical Engineering, Psychology, Geology, and Mathematics ­ and perhaps
other departments as I did not recognize all of the people present. Two
local universities were represented (BYU and Utah Valley State College).

The discussion was vigorous and lasted nearly two hours. It ended only
when a university class needed the room. After presenting the material
summarized here, including actually looking at and discussing the collapses
of WTC 7 and the Towers, all except one attendee agreed (by hand-vote) that
further investigation of the WTC collapses was called for. The next day,
the dissenting professor said he had further thought about it and now
agreed that more investigation was needed. He joined the others in hoping
that the 6,899 photographs and 6,977 segments of video footage held by NIST
plus others held by the FBI would be released for independent scrutiny;
photos largely from private photographers (NIST, 2005, p. 81). We call
for the release of these data to a cross-disciplinary, preferably
international team of scientists and engineers.

11. One attendee to the BYU Seminar on 9-11 anomalies suggested I review
the paper by Bazant and Zhou, which I did. Quoting:

The 110-story towers of the World Trade Center were designed to withstand
as a whole the forces caused by a horizontal impact of a large commercial
aircraft. So why did a total collapse occur? (Bazant and Zhou, 2002, p. 2.)

Correct ­ jet collisions did not cause collapses ­ we can agree on
that. MIT's Thomas Eager also concurs "because the number of columns lost
on the initial impact was not large and the loads were shifted to remaining
columns in this highly redundant structure" (Eager and Musso, 2001).

We continue with Bazant & Zhou:

The conflagration, caused by the aircraft fuel spilled into the structure,
causes the steel of the columns to be exposed to sustained temperatures
apparently exceeding 800oC. (Bazant and Zhou, 2002, p. 2.)
But here we note from the recent NIST report that: "The initial jet fuel
fires themselves lasted at most a few minutes" and office material fires
would burn out within about 20 minutes in a given location. (NIST, 2005; p.
179, emphasis added.) Certainly jet fuel burning was not enough to raise
steel to sustained temperatures above 800oC. But we continue:

Once more than half of the columns in the critical floor.. suffer buckling
(stage 3), the weight of the upper part of the structure above this floor
can no longer be supported, and so the upper part starts falling down onto
the lower part below."(Bazant and Zhou, 2002, p. 2.)

Hold on ­ Bazant & Zhou do not explain how "more than half of the columns
in the critical floor [can] suffer buckling" at the same time to
precipitate the complete and nearly symmetrical collapse observed. There
were 47 huge steel core columns in each Tower, and 24 such support columns
in WTC 7 (NIST 2005; NISTb, 2005).



[photo] The WTC towers were solidly constructed with 47 steel core

columns and 240 perimeter steel beams. 287 steel-columns total.

Many doubt that random fires/damage could cause them to

collapse straight down (official theory), and suspect explosives.

Steel-frame: Huge core (left), enormous Heat Sink. Notice workers
standing on floor pan which is firmly attached to the interconnected core
columns.


They do NOT explain how steel-column temperatures above 800oC were achieved
near-simultaneously due to burning office materials. NIST notes that
office materials in an area burn for about 15-20 minutes, then are consumed
away (NIST, 2005, pp. 117, 179). This is evidently not long enough to
raise steel column temperatures above 800oC as required in the Bazant &
Zhou model, given the enormous heat sinks of the structures. And to have
three buildings completely collapse due to this unlikely mechanism on the
same day strains credulity. Moreover, the Final NIST report on the Towers
admits:

Of the more than 170 areas examined on 16 perimeter column panels, only
three columns had evidence that the steel reached temperatures above 250ºC.
Only two core column specimens had sufficient paint remaining to make such
an analysis, and their temperatures did not reach 250 ºC. ... Using
metallographic analysis, NIST determined that there was no evidence that
any of the samples had reached temperatures above 600 ºC. (NIST, 2005, pp.
176-177; emphasis added.)

As for WTC 7, Bazant & Zhou say little but mention in a separate "addendum"
that burning natural gas might have been a source of the needed heat
(Bazant and Zhou, March 2002, p. 370). The FEMA report (FEMA, 2002)
addresses this issue:

Early news reports had indicated that a high pressure, 24-inch gas main was
located in the vicinity of the building [WTC 7]; however, this proved not
to be true." (FEMA, 2002, chapter 5; emphasis added)

12. I have read through the hundreds of pages of the Final NIST report on
the collapses of the WTC Towers. (NIST, 2005) It is interesting to note
that NIST "decoupled" and delayed their final report on WTC 7, which is
overdue as of this writing (NIST, 2005; NISTb, 2005) I agree with some of
the NIST report; for example:

Both WTC 1 and WTC 2 were stable after the aircraft impact, standing for
102 min and 56 min, respectively. The global analyses with structural
impact damage showed that both towers had considerable reserve
capacity. This was confirmed by analysis of the post-impact vibration of
WTC 2. where the damaged tower oscillated at a period nearly equal to the
first mode period calculated for the undamaged structure. (NIST, 2005, p.
144; emphasis added.)

At any given location, the duration of [air, not steel] temperatures near
1,000oC was about 15 min to 20 min. The rest of the time, the calculated
temperatures were near 500oC or below." (NIST, 2005, p. 127, emphasis added.)

NIST contracted with Underwriters Laboratories, Inc. to conduct tests to
obtain information on the fire endurance of trusses like those in the WTC
towers. All four test specimens sustained the maximum design load for
approximately 2 hours without collapsing." (NIST, 2005, p. 140, emphasis
added.)

However, I along with others challenge NIST's collapse theory. NIST
maintains that all three building collapses were fire-initiated despite the
observations above, particularly the fact that fire endurance tests with
actual models did not result in collapse. In a paper by fire-engineering
experts in the UK, we find:

The basis of NIST's collapse theory is. column behaviour in
fire... However, we believe that a considerable difference in downward
displace between the [47] core and [240] perimeter columns, much greater
than the 300 mm proposed, is required for the collapse theory to hold true.
[Our] lower reliance on passive fire protection is in contrast to the NIST
work where the amount of fire protection on the truss elements is believed
to be a significant factor in defining the time to collapse. The [proposed
effect] is swamped by thermal expansion . Thermal expansion and the
response of the whole frame to this effect has NOT been described as yet
[by NIST]. (Lane and Lamont, 2005.)

I agree with these pointed objections, particularly that the "response of
the whole frame" of each building should be considered, especially heat
transport to the whole frame from localized fires, and that the "core
columns cannot pull the exterior columns in via the floor." (Lane and
Lamont, 2005)

The computerized models of the Towers in the NIST study, which incorporate
many features of the buildings and the fires on 9-11-01, are less than
convincing. The Final report states:

The Investigation Team then defined three cases for each building by
combining the middle, less severe, and more severe values of the
influential variables. Upon a preliminary examination of the middle cases,
it became clear that the towers would likely remain standing. The less
severe cases were discarded after the aircraft impact results were compared
to observed events. The middle cases (which became Case A for WTC 1 and
Case C for WTC 2) were discarded after the structural response analysis of
major subsystems were compared to observed events. (NIST, 2005, p. 142;
emphasis added.)

The NIST report makes for interesting reading. The less severe cases based
on empirical data were discarded because they did not result in building
collapse. But 'we must save the hypothesis,' so more severe cases were
tried and the simulations tweaked, as we read in the NIST report:

The more severe case (which became Case B for WTC 1 and Case D for WTC 2)
was used for the global analysis of each tower. Complete sets of
simulations were then performed for Cases B and D. To the extent that the
simulations deviated from the photographic evidence or eyewitness reports
[e.g., complete collapse occurred], the investigators adjusted the input,
but only within the range of physical reality. Thus, for instance,.the
pulling forces on the perimeter columns by the sagging floors were
adjusted... (NIST, 2005, p. 142; emphasis added.)

The primary role of the floors in the collapse of the towers was to provide
inward pull forces that induced inward bowing of perimeter columns. (NIST,
2005, p. 180; emphasis added.)

How fun to tweak the model like that, until the building collapses -- until
one gets the desired result. But the end result of such tweaked computer
hypotheticals is not compelling, sorry gentlemen. Notice that the "the
pulling forces on the perimeter columns by the sagging floors were
adjusted" (NIST, 2005, p. 142; emphasis added) to get the perimeter columns
to yield sufficiently ­ one suspects these were "adjusted" by hand quite a
bit -- even though the UK experts complained that "the core columns cannot
pull the exterior [i.e., perimeter] columns in via the floor." (Lane and
Lamont, 2005; emphasis added.)

I also agree with Kevin Ryan's objections regarding the NIST study. Kevin
Ryan, at the time a manager at Underwriters Laboratories (UL), makes a
point of the non-collapse of actual WTC-based models in his letter to Frank
Gayle of NIST:

As I'm sure you know, the company I work for certified the steel
components used in the construction of the WTC buildings. In requesting
information from both our CEO and Fire Protection business manager last
year. they suggested we all be patient and understand that UL was working
with your team. I'm aware of UL's attempts to help, including performing
tests on models of the floor assemblies. But the results of these tests.
indicate that the buildings should have easily withstood the thermal stress
caused by. burning [jet fuel, paper, etc.]. (Ryan, 2004)

That models of WTC trusses at Underwriter Laboratories (UL) subjected to
fires did NOT fail is also admitted in the final NIST report:

NIST contracted with Underwriters Laboratories, Inc. to conduct tests to
obtain information on the fire endurance of trusses like those in the WTC
towers.. All four test specimens sustained the maximum design load for
approximately 2 hours without collapsing. The Investigation Team was
cautious about using these results directly in the formulation of collapse
hypotheses. In addition to the scaling issues raised by the test results,
the fires in the towers on September 11, and the resulting exposure of the
floor systems, were substantially different from the conditions in the test
furnaces. Nonetheless, the [empirical test] results established that this
type of assembly was capable of sustaining a large gravity load, without
collapsing, for a substantial period of time relative to the duration of
the fires in any given location on September 11. (NIST, 2005, p. 141;
emphasis added.)

So how does the NIST team justify the WTC collapses, when actual models
fail to collapse and there are zero examples of fire-caused high-rise
collapses? Easy, NIST concocted computer-generated hypotheticals for very
"severe" cases, called cases B and D (NIST, 2005, pp. 124-138). Of
course, the details are rather hidden to us. And they omit consideration
of the complete, rapid and symmetrical nature of the collapses.

Indeed, NIST makes the startling admission in a footnote on page 80 of
their Final Report:

The focus of the Investigation was on the sequence of events from the
instant of aircraft impact to the initiation of collapse for each tower.
For brevity in this report, this sequence is referred to as the "probable
collapse sequence," although it does not actually include the structural
behavior of the tower after the conditions for collapse initiation were
reached...(NIST, 2005, p. 80, fn. 12; emphasis added.)

Again, on page 142, NIST admits that their computer simulation only
proceeds until the building is "poised for collapse", thus ignoring any
data from that time on.

The results were a simulation of the structural deterioration of each tower
from the time of aircraft impact to the time at which the building became
unstable, i.e., was poised for collapse. ...(NIST, 2005, p. 142; emphasis
added.)

What about the subsequent complete, rapid and symmetrical collapse of the
buildings? What about the observed squibs? What about the antenna
dropping first in the North Tower? What about the molten metal observed in
the basement areas in large pools in both Towers and WTC 7 as well? Never
mind all that: NIST did not discuss at all any data after the buildings
were "poised for collapse." Well, some of us want to look at ALL the data,
without computer simulations that are "adjusted" to make them fit the
desired outcome.

13. Kevin Ryan, the whistleblower from Underwriters Laboratories, did his
own statistical analysis in a recent letter regarding the NIST report,
arguing that probabilities of collapse-initiation needed to be calculated
(Ryan, 2005). NIST nowhere provides such a likelihood analysis for their
non-explosive collapse model. Ryan's analysis is that the probability that
fires and damage (the "official theory") could cause the Towers complete
collapse is less than one in a trillion, and the probability is much less
still when the complete collapse of WTC7 is included (Ryan, 2005). Nor
does NIST (or FEMA or the 9-11 Commission) even mention the molten metals
found in the basements of all three buildings (WTC 1, 2 and 7).

So where does that leave us? I strongly agree with Kevin Ryan,

This ["official"] story just does not add up.. That fact should be of
great concern to all Americans.. There is no question that the events of
9/11 are the emotional driving force behind the War on Terror. And the
issue of the WTC collapse is at the crux of the story of 9/11. (Ryan, 2004;
emphasis added.)

14. The NIST team fairly admits that their report "does not actually
include the structural behavior of the tower after the conditions for
collapse initiation were reached." (NIST, 2005, p. 80, fn. 1; emphasis
added.) Quite a confession, since much of the external evidence for
explosive demolition typically comes after collapse initiation, as seen in
cases of acknowledged controlled demolition. (Harris, 2000.)

The rapid fall of the Towers and WTC7 has been analyzed by several
engineers/scientists
(http://911research.wtc7.net/wtc/analysis/proofs/speed.html; Griffin, 2004,
chapter 2). The roof of WTC 7 (students and I are observing the southwest
corner) falls to earth in less than 6.6 seconds, while an object dropped
from the roof would hit the ground in 6.0 seconds. This follows from t =
(2H/g)1/2. Likewise, the Towers fall very rapidly to the ground, with the
upper part falling nearly as rapidly as ejected debris which provide
free-fall references
(HERE; Griffin, 2004,
chapter 2). Where is the delay that must be expected due to conservation
of momentum ­ one of the foundational Laws of Physics? That is, as
upper-falling floors strike lower floors ­ and intact steel support columns
­ the fall must be significantly impeded by the impacted mass. If the
central support columns remained standing, then the effective resistive
mass would be less, but this is not the case ­ somehow the enormous support
columns failed/disintegrated along with the falling floor pans.

How do the upper floors fall so quickly, then, and still conserve momentum
in the collapsing buildings? The contradiction is ignored by FEMA, NIST
and 9-11 Commission reports where conservation of momentum and the fall
times were not analyzed. The paradox is easily resolved by the explosive
demolition hypothesis, whereby explosives quickly remove lower-floor
material including steel support columns and allow near free-fall-speed
collapses (Harris, 2000).

And these explosives also readily account for the turning of the falling
Towers to fine dust as the collapse ensues. Rather than a piling up with
shattering of concrete as we might expect from non-explosive-caused
progressive collapse ("official theory"), we find that most of the Towers
material (concrete, carpet, steel, etc.) is converted to flour-like powder
WHILE the buildings are falling. The Towers' collapses are not a typical
implosions, but quite possibly series of "shock-and-awe" explosions ­ at
least the evidence points strongly in this direction. The hypothesis ought
to be explored further.

Those who wish to preserve as inviolate fundamental physical laws may wish
to take a closer look. Consider the collapse of the South WTC Tower on
9-11:
HERE FOR VIDEO

[photo] Top ~ 34 floors of South Tower topple over.

What happens to the block and its angular momentum?

We observe that approximately 34 upper floors begin to rotate as a block,
to the south and east. They begin to topple over, as favored by the Second
Law of Thermodynamics. The torque due to gravity on this block is
enormous, as is its angular momentum. But then ­ and this I'm still
puzzling over ­ this block turned mostly to powder in mid-air! How can we
understand this strange behavior, without explosives? Remarkable, amazing
­ and demanding scrutiny since the US government-funded reports failed to
analyze this phenomenon. But, of course, the Final NIST 9-11 report "does
not actually include the structural behavior of the tower after the
conditions for collapse initiation were reached." (NIST, 2005, p. 80, fn.
1; emphasis added.)

Indeed, if we seek the truth of the matter, we must NOT ignore the data to
be observed during the actual collapses of the towers, as the NIST team
admits they did. But why did they do such a non-scientific procedure as to
ignore highly-relevant data? The business smacks of political constraints
on what was supposed to be an "open and thorough" investigation. (See
Mooney, 2005.)

So I with others call for an open and thorough investigation. I hope the
international community will rise to the challenge. The field is wide open
for considering the alternative hypothesis outlined here, due to its
neglect by studies funded by the US government.

15. Finally, and by way of review, we consider the variations and
inconsistencies in the fire/damaged-caused collapse models with time. The
earliest model, promoted by various media sources, was that the fires in
the towers were sufficiently hot to actually melt the steel in the
buildings, thus causing their collapse. For example, Chris Wise in a BBC
piece spouted out false notions with great gusto

"It was the fire that killed the buildings. There's nothing on earth that
could survive those temperatures with that amount of fuel burning. The
columns would have melted, the floors would have melted and eventually they
would have collapsed one on top of the other." (quoted in Paul and
Hoffman, 2004, p. 25)

But as we have seen from later serious studies, the jet fuel burned out
within minutes following impact. Recall the statement of expert Dr. Gayle
refuting the notion that fires in the WTC buildings were sufficiently hot
to melt the steel supports:

Your gut reaction would be the jet fuel is what made the fire so very
intense, a lot of people figured that's what melted the steel. Indeed it
did not, the steel did not melt. (Field, 2005; emphasis added)

Then we have the model of Bazant and Zhou, which requires the majority of
the 47 huge steel columns on a floor of each Tower to reach sustained
temperatures of 800oC in order to buckle (not melt) ­ at the same
time. But as we've seen, such temperatures are very difficult to reach
while burning office materials, in these connected steel structures where
the heat is wicked away by heat transport. (Paul and Hoffman, 2004, p.
26) And then to reach the 800oC at the same time, well, no, this scenario
is far too improbable.

So that approach was abandoned by FEMA in the next effort (FEMA,
2002). The FEMA team largely adopted the theory of Dr. Thomas Eager (Eager
and Musso, 2001), which was also presented in the NOVA presentation "Why
the Towers Fell" (NOVA, 2002). Instead of having the columns fail
simultaneously, FEMA has floor pans in the Towers warp due to fires, and
the floor connections to the vertical beams break, and these floor pans
then fall down onto the floor pans below, initiating "progressive collapse"
or pancaking of one floor pan on another. Very simple. But not so fast ­
what happens to the enormous core columns to which the floors were firmly
attached? Why don't these remain standing like a spindle with the floor
pans falling down around them, since the connections are presumed to have
broken away? This interconnected steel core is founded on bedrock. FEMA
does not totally ignore the core:

As the floors collapsed, this left tall freestanding portions of the
exterior wall and possibly central core columns. As the unsupported height
of these freestanding exterior wall elements increased [no mention of the
huge central core anymore!], they buckled at the bolted column splice
connections and also collapsed." (FEMA. 2002; emphasis added)

This approach finally fails to account for the observed collapse of the 47
interconnected core columns which are massive and designed to bear the
weight of the buildings, and it has the striking weakness of requiring the
connections of the floor pans to the vertical columns to break, both at the
core and at the perimeter columns, more or less simultaneously.

That didn't work out, so NIST goes back to the drawing
board. They require that the connections of the floor pans to vertical
columns do NOT fail (contrary to FEMA's model), but rather that the floor
pans "pull" with enormous force, sufficient to cause the perimeter columns
to significantly pull in, leading to final failure (contrary to objections
of ARUP Fire experts, discussed above). Also, NIST constructs a computer
model -- but realistic cases do not actually lead to building collapse. So
they "adjust" inputs until the model finally shows collapse initiation for
the most severe cases. The details of these "adjustments" are hidden from
us, in their computerized hypotheticals, but "the hypothesis is
saved." NIST also has Underwriters Laboratories construct models of the
WTC trusses, but the models withstand all fires in tests and do NOT
collapse. (See above for details.)

We are left without a compelling fire/damage model, unless one
blindly accepts the NIST computer simulation while ignoring the model
fire-tests, which I'm not willing to do. And none of the "official" models
outlined above accounts for what happens to the buildings AFTER the
building is "poised for collapse" (NIST, 2005, p. 142) ­ namely the rapid
and symmetrical and complete (no tall-standing central core)
collapses. Reports of explosions, heard and seen, are not
discussed. And they ignore the squibs seen ejected from floors far from
where the jets hit ­ particularly seen in WTC 7 (where no jet hit at
all). Finally, what about that molten metal under the rubble piles of all
three WTC skyscrapers?

Remarkably, the explosive demolition hypothesis accounts for
all the available data rather easily. The core columns on lower floors are
cut using explosives, near-simultaneously, along with explosives detonated
up higher so that gravity acting on now-unsupported floors helps bring down
the buildings quickly. The collapses are thus symmetrical, rapid and
complete, with accompanying squibs -- really very standard stuff for
demolition experts. Thermite (whose end product is molten iron) used on
some of the steel beams readily accounts for the molten metal which then
pooled beneath the rubble piles.

I believe this is a straightforward hypothesis, much more probable than the
official hypothesis. It deserves scientific scrutiny, beyond what I have
been able to outline in this treatise. It is quite plausible that
explosives were pre-planted in all three buildings, and set off after the
two plane crashes ­ which were actually a diversion tactic. The science is
sound. The implications are paradigm-shifting: Muslims are (probably) not
to blame for bringing down the WTC buildings after all.


CONCLUSIONS

I have called attention to glaring weaknesses in the "final" reports funded
by the US government and shown evidences for a likely alternative
hypothesis. In particular, the official theory lacks repeatability in that
no actual models or buildings (before or since 9-11-01) have been observed
to completely collapse due to the proposed fire-based mechanisms. On the
other hand, dozens of buildings have been completely and symmetrically
demolished through the use of pre-positioned explosives. The "explosive
demolition" hypothesis better satisfies tests of repeatability and
parsimony and therefore is not "junk science." It ought to be seriously,
scientifically investigated and debated.

A truly independent, international panel would consider all viable
hypotheses, including the pre-positioned-explosives theory, guided not by
politicized notions and constraints, but rather by observations and
calculations, to reach a scientific conclusion. Questioning (preferably
under oath) of officials who approved the rapid removal and destruction of
the WTC steel beams and columns before they could be properly analyzed ­
and others as outlined above ­ should proceed in the United States.

None of the government-funded studies have provided serious analyses of the
explosive demolition hypothesis at all. Until the above steps are taken,
the case for accusing ill-trained Muslims of causing all the destruction on
9-11-01 is far from compelling. It just does not add up.

And that fact should be of great concern to Americans and to all those
threatened by American military and security units in the wake of the 9-11
events (Ryan, 2004). Use of powerful, pre-positioned explosives in the WTC
buildings would imply an "inside job" (Griffin, 2004, chapter 2). Clearly,
we must find out what really caused the WTC skyscrapers to collapse as they
did.

To this end, NIST must release the 6,899 photographs and over 300 hours of
video recordings ­ acquired mostly by private parties ­ which it admits to
holding (NIST, 2005, p. 81). In particular, photos and analyses of the
molten metal (probably not molten steel) observed in the basements of both
Towers and WTC7 need to be brought forth to the international community of
scientists and engineers immediately. Therefore, along with others, I call
for the release of these and all relevant data for scrutiny by a
cross-disciplinary, international team of researchers. The
explosive-demolition hypothesis will be considered: all options will be on
the table.


AFTERWARD

In writing this paper, I call for a serious investigation of the hypothesis
that WTC7 and the Twin Towers were brought down, not just by damage and
fires, but through the carefully planned use of explosives. I have
presented ample evidence for the explosive-demolition hypothesis, which is
testable and falsifiable and yet has not been seriously considered in any
of the studies funded by the US government.

At the same time, I acknowledge that other notions have sprung up in the
near vacuum of official consideration of this very plausible
hypothesis. These notions must be subjected to careful scrutiny. I by no
means endorse all such ideas. For example, the video "In Plane Site"
promotes the theory that a "pod" holds a missile under the wing of the 757
which hit WTC 2 (see Hoffman, 2005; Chertoff, 2005). Careful inspection of
the undercarriage of a standard 757 leads to the explanation that the
so-called "pod" was merely a reflection from the bulged undercarriage
(Hoffman, 2005; Chertoff, 2005). I find that the "pod theory" is very weak
and distracts from central issues.

Again, there is a notion that something other than Boeing jetliners hit the
WTC Towers (see Hoffman, 2005; Chertoff, 2005). Scrutiny of photographs
and videos provides compelling evidence that jets did in fact hit these
buildings (Hoffman, 2005; Chertoff, 2005). A March 2005 article in Popular
Mechanics focuses on poorly-supported claims and proceeds to ridicule the
whole "9-11 truth movement" (Chertoff, 2005). Serious replies to this
article have already been written (Hoffman, 2005; Baker, 2005;
HERE).

Those espousing weak or untestable claims should realize that they may be
damaging the effort to achieve a rational debate of important issues by
poisoning the process with "junk science". Likewise, the notion that the
"explosive demolition" hypothesis should not be debated since it would
imply a "conspiracy theory" departs from good science as well as from
numerous historical precedents of empirical conspiracies (Jones,
2005). Scientific inquiry is not or should not be dictated by politics
(Mooney, 2005).



ACKNOWLEDGMENTS

I gratefully acknowledge comments and contributions by Jim Hoffman and
Jeff Strahl, and Professors Jack Weyland, David Ray Griffin, Steven
Benzley, Bryan Peterson and Harold Stokes.


REFERENCES

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