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Post has been Killed

Revised Analysis of Downward Acceleration of WTC 7

submitted by schmawy

1 decade 6 years ago

[YT] NIST has reversed its earlier denial of freefall and acknowledged a period of freefall comparable to this analysis in their final report on WTC7 released in November 2008. They did their own measurement with a point near the center of the roof line and came up with an acceleration of 9.81 for approximately 2.25 sec. Their report did not, however, face the consequences of this acknowledgment: that ALL RESISTANCE was instantaneously removed across the width of the building, supporting pre-planted explosives as the cause of the collapse.
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(Original comment comments follow)
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Contrary to the August 2008 NIST report on WTC7, the acceleration of Building 7 is measured and is found to be indistinguishable from the acceleration of gravity over a period of about 2.5 seconds of fall.

During the first round of questions in the Aug 26, 2008 NIST Technical Briefing (at 1:01:45 into the presentation) the following question was asked by David Chandler:

"Any number of competent measurements using a variety of methods indicate the northwest corner of WTC 7 fell with an acceleration within a few percent of the acceleration of gravity. Yet your report contradicts this, claiming 40% slower than freefall based on a single data point. How can such a public, visible, easily measurable quantity be set aside?"

Dr. Shyam Sunder replies:

"Could you repeat the question?"

[the question is repeated by the moderator, leaving out the word, "competent" as well as the last sentence]

"Well...um...the...first of all gravity...um...gravity is the loading function that applies to the structure...um...at...um...applies....to every body...every...uh...on...all bodies on...ah...on...um... this particular...on this planet not just...um...uh...in ground zero...um...the...uh...the analysis shows a difference in time between a free fall time, a free fall time would be an object that has no...uh... structural components below it. And if you look at the analysis of the video it shows that the time it takes for the...17...uh...for the roof line of the video to collapse down the 17 floors that you can actually see in the video below which you can't see anything in the video is about...uh... 3.9 seconds. What the analysis shows...and...uh...the structural analysis shows, the collapse analysis shows that same time that it took for the structural model to come down from the roof line all the way for those 17 floors to disappear is...um... 5.4 seconds. It's...uh..., about one point...uh...five seconds or roughly 40% more time for that free fall to happen. And that is not at all unusual because there was structural resistance that was provided in this particular case. And you had...you had a sequence of structural failures that had to take place and everything was not instantaneous."
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Note that:
--He acknowledges that freefall can only occur if there is no structure under the falling section of the building.
--He acknowledges that their structural modeling predicts a fall slower than freefall.
--He acknowledges that there was structural resistance in this particular case.
--He acknowledges that there was a sequence of failures that had to take place and that this process was not instantaneous.

Thus, he acknowledges that their model is at variance with the observable fact that freefall actually occurred. Their response is to hold to their model, deny that freefall occurred, and put up a smokescreen of irrelevant measurements that obscure the reality.