Achilles, the son of King Peleus of Thessaly and the shape-changing nymph
Thetis, is the central character of Homer's great poem, the Iliad. The
Achilles' heel is named for the only part of the body of the Greek hero that
was vulnerable.
Stretching the metaphor a bit, the collapse time, i.e. the time from the
beginning of collapse to total collapse, is the Achilles' heel of the
official 9/11 conspiracy theory. The official theory is also vulnerable to
other challenges.
The National Institue of Standards and Technology (NIST) -- U.S. government
department assigned the job of explaining what "The 9/11 Commission Report"
does not -- estimates (October 5, 2007 FAQ) "the
elapsed times for the first exterior panels to strike the ground after the
collapse initiated in each of the towers to be approximately 11 seconds for
WTC 1 and approximately 9 seconds for WTC 2. These elapsed times were based
on: (1) precise timing of the initiation of collapse from video evidence,
and (2) ground motion (seismic) signals recorded at Palisades, N.Y."
NIST adds that "significant portions of the cores of both buildings (roughly
60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to
25 seconds after collapse initiation before they, too, began to collapse.
Neither the duration of the seismic records nor video evidence . . . are
reliable indicators of the total time it took for each building to collapse
completely."
"The 9/11 Commission Report" puts it more simply (p. 322): "the South Tower
collapsed in ten seconds".
These collapse times are close to that of a billiard ball dropped from the
top of WTC 1 or 2. The time is calculated using the equation taught in high
school physics
classes: Distance = 0.5 X Acceleration X Time Squared.
Using this equation a billiard ball dropped from the top of the 1368 feet
tall WTC 1 or 2 would travel 1296 feet in 9 seconds -- it would reach the
ground in 9.2 seconds (assuming acceleration due to gravity of 32 feet per
second per second, and no wind resistance).
The South towers' collapse in 10 seconds -- at near free-fall speed, due
solely to airplane impact and the resulting fires, defies logic.
In Section 6.14.4 of NIST NCSTAR 1, NIST states: ". . . the structure below the
level of collapse initiation offered minimal resistance to the falling
building mass at and above the impact zone. The potential energy released by
the downward movement of the large building mass far exceeded the capacity
of the intact structure below to absorb that energy through energy of
deformation."
NIST (a) offers no calculations to support this theory, (b) does not explain
how "falling building mass" which explodes into powder retains enough energy
to dislodge the floors below, and (b) does not explain the symmetry of
collapse.
Prof. Kenneth L. Kuttler, who has done the calculations concludes:
"Clearly, fall times of over 25 seconds are expected with reasonable
assumptions, yet the observed fall time for the Tower is less that that."
A letter
from Dr Frank Legge in the Journal of 9/11 Studies observes that the
downward acceleration of Building 7's roof was "very close to free fall
right from the start . . . tells us that the steel supports went from
adequate strength to virtually no strength in an instant." This is
inconsistent with the behavior of steel heated to the point that it could no
longer support the structure.
And there are other
errors and inconsistencies in NIST's explanation.
Regarding the molten
metal reported in the WTC debris pile more than three weeks later, NIST
says: "The condition of the steel in the wreckage of the WTC towers (i.e.,
whether it was in a molten state or not) was irrelevant to the investigation
of the collapse since it does not provide any conclusive information on the
condition of the steel when the WTC towers were standing."
The molten steel may not provide "any conclusive information on the
condition of the steel when the WTC towers were standing", but it is very
relevant to the evaluation of hypotheses of why the towers collapsed. The
steel at the bottom of the debris pile did not spontaneously get hot and
melt after collapse.
"NIST's findings do not
support" the "pancake theory" for the collapse, but NIST lead
investigator Shyam Sunder explains the squibs (puffs or jets of smoke and
dust caused by the detonation of explosives used to demolish buildings) seen
in videos of the collapse: "Those clouds of dust may create the impression
of a controlled demolition but it is the floor pancaking that leads to that
perception."
NIST did not evaluate the use of explosives. NIST writes that an assisted
collapse would require many thousands of pounds of explosives, yet their
explanation of a gravity only collapse requires none.
Earlier this year researchers at Purdue
University claimed to have the answer. They stated, "the weight of the fuel
acted like a flash flood of flaming liquid, knocking out essential
structural columns within the building and removing fireproofing insulation
from other support structures."
These researchers simulated the "top 20 stories" for "3/4 seconds real-time".
By extrapolation, flawed yet illustrative, a simulation of the 102 real-time
minutes from impact to collapse, using Purdue's computers, could take
652,800 hours -- (102 x 60 / 0.750) x 80 hours, or about 75 years.
A NIST letter dated September 27, 2007, in response to a
"request for correction", states: "NIST carried its analysis to the
point where the buildings reached global instability. . . . we were unable
to provide a full explanation of the total collapse." (emphasis added)
Independent analysts claim that "it is impossible that the jet fuel,
by itself, raised the temperature of this floor more than 257° C
(495° F). . . . It is not even close to the first critical temperature
of 600° C (1,100° F) where steel loses about half its strength."
They add that "In the mid-1990s British Steel and the Building Research
Establishment performed a series of six experiments at Cardington to
investigate the behavior of steel frame buildings. These experiments were
conducted in a simulated, eight-story building. Secondary steel beams were
not protected. Despite the temperature of the steel beams reaching
800-900° C (1,500-1,700° F) in three of the tests (well above the
traditionally assumed critical temperature of 600° C (1,100° F), no
collapse was observed in any of the six experiments."
Architects & Engineers for 9/11
Truth state that "controlled demolition with explosives was involved in the
destruction of the Twin Towers on 9/11." They offer the following evidence:
- Rapid onset of destruction
- Symmetrical and near-freefall speed of collapse
- Virtually complete pulverization of concrete
- 20-ton beams hurled 500 feet
- 700, half inch, bone fragments on top of adjacent buildings
- Molten metal "flowing like lava"
- Iron-rich microspheres
- Chemical evidence of the incendiary thermate
- Ends of columns and beams exhibiting rapid oxidation, sulfidation and intergranular melting
- 118 first-responders reporting sounds of explosions and flashes of light
- Squibs, or mistimed explosions 40 stories below collapse wave
Richard Gage, architect, in a letter to Mark Weitzman of the
Simon Wiesenthal Center who, in testimony before the Homeland Security
Subcommittee on Intelligence, Information Sharing, and Terrorism Risk
Assessment, referred to AE911Truth.org as an "Incubator of 9/11 Conspiracies
and Disinformation", has demanded a retraction of Weitzman's "false, defamatory,
outrageous and insulting statements".
Regarding the 47-story WTC 7 -- whose
collapse in under 7 seconds is not even mentioned in "The 9/11 Commission
Report" -- NIST writes that "a draft report will be released for public
comment by the end of 2007 and that the final report will be released in
early 2008."
NIST, and the 9/11 Commission, refuse to debate their findings with
independent researchers.
Mr. Masud, an engineer, managed the National Power Grid Study for the U.S.
Dept. of Energy (26 multidisciplinary teams, a total of 150 persons), has
consulted for USAID and the World Bank, is a contributing author of "9/11
and American Empire: Christians, Jews, and Muslims Speak Out," and the
moderator of the 9/11 Special Interest
Group blog.