I recently but somewhat accidentally ran across something interesting in the NCSTAR report.

On the matter of mass distribution of the towers the NIST says this:

2.4.3 Single Impulse Excitations

Accurate estimation of the tower’s motion during the airplane impact required detailed knowledge of the geometry, weight distribution, and impact velocity of the aircraft, as well as detailed knowledge of the geometry, weight distribution, and structural strength of the tower. At the time of this test series (fall 2003), much of this information was unknown, and the impact motion could only be roughly estimated. To allow this estimate to be made quickly, many simplifying assumptions were made regarding the nature of the impact.
http://wtc.nist.gov/NISTNCSTAR1-5D.pdf page 74


Since people don't just accidentally decide how much steel and concrete to put on every level of a 1360 foot building that can withstand 100 mph winds the above statement is not surprising. The peculiar thing is that this was not discussed A LOT in preparing to analyze the event back in 2001.

I don't understand why they couldn't have had that info on the building by fall 2003 though and I certainly don't understand why we don't have it now. WTF

I love the jargon they have to come with for these kind of reports, " Single Impulse Excitations". You have to stop and think, "What the hell does that mean?" Oh. it was hit real hard one time and started vibrating. DUH! 500 mph airliners do that, but only once.

The south tower moved 12 inches at the 70th floor which was 130 feet below the impact at the 81st floor. The tower oscillated for FOUR MINUTES.



These are physical data, showing a characteristic nearly exponential decay (damping) of the oscillation. Observed oscillation of the WTC 2 Tower provides compelling empirical evidence that it was hit by a fast-moving jetliner. Any claim to the contrary must confront these published data or the analysis thereof.
http://wtc.nist.gov/NISTNCSTAR1-5.pdf p. 26 It will not do in scientific inquiry to ignore data like this – even if one does not trust the source for some reason. In other words, the argument must be to the DATA, not to the source (ad hominem).
http://stj911.org/jones/Jones_Replyt...olds_Wood.html

So that Single Pulse Excitation was caused by a lot of kinetic energy from the plane and the amount of energy which produced structural damage cannot be computed from the total energy of the aircraft without calculating how much produced this behavior in the building and that requires reasonably accurate distribution of steel and concrete information. And where does the NIST show that data and do those calculation?

psik