The questions Mr. Watts asked are, in some instances, quite specific and lengthy, requiring multiple diary entries to address the responses adequately. When reviewing the questions, please refer to the link above for my initial response to Mr. Watts' summary questions.
(1) Core column damage
"Tom: In the following NIST report you reference, on page 21 it says 6 core columns in WTC1 and 10 core columns in WTC2 were severed. Do you know how they "know" that? And, of course, they are saying the airplanes did the severing. Is that correct?"
NIST NCSTAR- 1-2 (Baseline Structural Performance and Aircraft Impact Damage Analysis if the World Trade Centers) details the modeling assumptions - http://wtc.nist.gov/NISTNCSTAR1-2.pdf . Section 7.6.2 (Tower Structural Damage) details the damage to the exterior (perimeter) and core columns in WTC 2.
Three scenarios were presented for each model and run in multiple. Using available data (existent and observed), the scenarios addressed the less severe internal damage, base damage, and more severe internal damage approaches. Once run, the model output was compared to observed exterior damage for alignment to reality. The linked report displays images of observed external damage vs. modeled external damage.
The scenarios that tended to better align with the observed damage (95% confidence level) were the base and more severe cases. Given the close alignment between the exterior observed and modeled damage, the likelihood that internal damage align with modeled damage was high. It is from this modeling, then, that NIST "knows" which core columns were damaged and with what severity. Review of debris from the pile did reveal core column damage from the impacted floor consistent with the model outputs.
A discussion on the model assumptions and limitations is presented in the Preface of the report.
Regarding what caused the damage to the core columns, Section 7.6.1 (Impact Response) states:
"[Within 0.2 seconds of impact...] The aircraft was severely broken into thousands of debris fragments of various sizes and mass as a result of the impact with WTC 2. Larger fragments occurred for specific components, such as the engines and landing gear components," (p. 224).
Also, portions of the exterior wall and internal components were gathered into the fast and forward moving debris cloud. Therefore, it's incorrect to say that the aircraft was the sole sources of the severing. Larger pieces of debris (both aircraft and internal in origin), as well as the mass associated with the wing fuel, were the sources of the resulting core column damage.
(2) Tom: Regarding "footprint"
"Tom: you say.... 'Therefore, their own 'footprint' statement is... silly.'... How does a gravitational collapse project heavy missiles farther away (1600 feet) than the buildings were tall (1368 feet?)? And, I would presume that at least some, if not all, of the "missiles" came from points in the building below 1000 feet above the ground -- the approximate points where the collapses began... By the way, do you know where the antennae did end up?"
The debris found 1,600 feet away did not include "heavy" missiles. Small pieces of aluminum cladding, pieces of interior building components, and paper were prevalent in this debris field. The pressure wave generated by the falling upper part of each tower onto the stationary lower part was partially channeled horizontally across each floor immediately prior to the resisting floor's collapse; the remainder of the wave was forced downward through the core. By the time the falling upper section had reached ground level, this pressure eave had generate a wind of about 200 mph. Falling debris that encountered the horizontal component of this pressure wave was pushed further away from the towers and were prone to the air resistance and the winds/eddy currents caused by the other high-rise structures in the area.
If you watch the video snippet in this link - http://www.debunking911.com/overp.htm , you'll note that as the topmost debris at center falls diagonal and outward, the windows on the underlying floors blow out and horizontal – into the path of the falling debris. Note the change in the debris in the lower left corner of the video as it is pushed farther away from the tower. The same is also observed with the dust cloud behind the leading edge of the debris fall.
The remains of the antennae landed atop the debris pile of the tower that housed it – WTC 1 - click here and http://nymag.com/news/articles/wtc/gallery/16.htm . Remains of the antenna's base have been stored at Hanger 17 at JFK International Airport, awaiting final disposition - http://www.amny.com/media/photo/2006-08/24928682.jpg .
(3) Path of least resistance
"Tom: I don't believe you addressed the point in question #1 regarding the 'path of most resistance.' The collapses did take the paths of "most resistance" and NOT the paths of 'least resistance' -- a fundamental law that governs our universe. The significantly tilting top section of the south tower it was should have kept 'toppling' off to the side -- and therefore take the path of least resistance -- and not symmetrically crush the entire building through the path of most resitance [sic]."
I believe you missed the point in my response. The path of least resistance between two bodies (i.e., the Earth and the falling upper part of the tower) is the line that connects the two at center mass for each. While the upper part was tilted, it's center mass was NOT along the exterior but rather the interior. Therefore, once a line is drawn that connects the two bodies and where the mass of the Earth far exceeds that of the upper part, the upper part will fall along that line.
Once the collapse initiated, the upper part was in freefall with an initial velocity of about 8.5 m/s. With nothing to "fix" it, the upper part followed the path of least resistance, traversing the space occupied by the lower part of the tower. While this path appears counter to expectation, the upper part entering freefall at the initiation of collapse permits the Law of Gravity to be applied - http://www.debunking911.com/collapse.htm .
"The Law of Gravity, when applied to the WTC towers' collapses, dictates that masses of the Earth and the collapsing portion of each tower define the observed path of least resistance – even though these paths traversed through the spaces of the underlying structures. And once the potential energy from the impacted floors and above was released as kinetic energy, the resistance of the underlying structures in the form of friction became negligible with respect to the Gravity Index and Conservation of Momentum - click here ."
(4) Mass
"Tom: "'...... both processes use mass and speed (as either a velocity or constant). Why is this so difficult for Truthers to comprehend...? [...] I addressed the 'mass' issue in two different debates hosted by Larry King. Please read the debate about NIST and 'heavy dust.'"
I addressed this issue of mass and velocity within a recent comment to meremark - http://www.opednews.com/maxwrite/diarypage.php?did=6509 . The set of equations I offered attempted to explain the tower collapses and demonstrated that the energy input essentially matches the energy output. I readily admit that the equations only describe the energy balance and collapses at the macro level. Additional forces did influence the debris scattering and floor crushing (and associated energy flows) but not to the point where it invalidates the Conservation of Momentum and concept of mass balance.
The dust cloud paper that you referenced by Mr. Hoffman was thoroughly debunked shortly after it was issued by Dr. Greening - http://www.911myths.com/Energy_Transfer_Addendum.pdf . The energy dependencies that were concluded by Mr. Hoffman failed to account for expansion ratios of the debris within the cloud as it expanded in volume. Therefore, the paper assumed uniform dust cloud temperatures of 700 degrees C in order to arrive at its mass and velocity conclusions; I do not recall persons caught in the dust cloud being burned that day. As a result, the dust cloud mass conclusions were significantly incorrect.
More Q&A to follow in Parts 2 and 3.
