WTC7: NIST Finally Admits Freefall (Part I)
In August, 2008, after a seven year delay, NIST, the government agency charged with investigating the World Trade Center collapses released the Draft of their Final Report on the Collapse of World Trade Center Building 7 for public comment.
In that report, they claim that the time for the building to fall the first 18 stories, that's the part of the collapse visible on many videos, was 40 percent longer than it would have taken had it been in freefall.
I responded with a video posted on YouTube, called "WTC 7 in Freefall", in which I showed that for approximately 2.5 seconds, Building 7 fell at a rate indistinguishable from free fall. Furthermore, in that video I showed that NIST's methodology was not a valid way to analyze the true motion of the building. NIST's measurement was not just wrong, it was fraudulent. Then on August 26th, NIST staged a technical briefing in which engineers and others with technical credentials could pose questions. I'm a high school physics teacher so I figured I would be excluded. However, I went ahead and registered citing my membership in the American Association of Physics Teachers as my professional affiliation. By the way, I am not speaking for AAPT; that was just my passport into the briefing. To my surprise, my credentials were accepted and I was able to pose a question. Here's a little of how it went.
Our next question comes from David Chandler, of the American Association of Physics Teachers. "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 percent slower than freefall, based on a single data point. How could such a publicly visible, easily measurable quantity be set aside?"
"Can you repeat the question, please?"
Sure, "Any number of 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 the report contradicts this, claiming 40 percent slower than the free fall, based on a single data point."
"Well, um. the... First of all, gravity is the loading function that applies to the structure ...applies to, applies to everybody, every, all bodies on uh, on uh, on this particular, on this planet, not just in Ground Zero."
Dr Shyam Sunder
Whoa! I'm used to responses like that on a physics exam when a student hasn't even bothered to open the book. But this is NIST speaking, so let's continue.
"The analysis showed there's a difference in time between a freefall time, a free-fall time would be an object that has no structural components below it, and if you look at the analysis of the video, it shows that the time it takes for the 17, for the the roof line of the video to, uh, collapse down to 17 floors that you can actually see in the video below which you can't see anything in the video, is about 3.9 seconds.
Dr Shyam Sunder
What the analysis shows, and the structural analysis shows, or 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 5.4 seconds. It's about 1.5 seconds or roughly 40 percent 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 a sequence of structural failures that had to take place. Everything was not instantaneous."
For the 18 stories under consideration:
Buried in all that verbage, what Dr Sundar is saying is freefall, for the 18 stories under consideration would've taken 3.9 seconds. However, their computer model simulating collapse required 5.4 seconds. The slower collapse time was to be expected, since there was structure supporting the building as it fell, slowing the fall, but there was a progression of failures that had to take place, and that these were not instantaneous. - Freefall would take 3.9 seconds
- Their computer model predicted 5.4 seconds
- The slower time is to be expected since
- there was structural support
- there was a progression of failures
- they were not instantaneous
All of this makes sense as long as you don't look at the evidence. The evidence shows that freefall actually occurred, but since their computer modeling could not come up with a scenario that would allow for free fall, they had to declare free fall out-of-bounds, and try to cover up the evidence.
The problem is, unlike the columns and girders buried deep inside the building, the motion of the building is right out in plain view. Since their model predicted 5.4 seconds for the 18-story collapse, they dutifully conjured up a 5.4 second measurement to match. They had to stretch themselves to do it, but they did it. They found the disappearance time, and then they went out of their way to pick an artificially early start time exactly 5.4 seconds earlier. This, they compared with freefall time.
This next question comes from Dr. Stephen Jones.
"NIST discusses the fall time for WTC 7 on page 40 of the summary report, where it's stated, 'assuming that the descent speed was approximately constant'. However, observations by others of the descent show that the building is accelerating rather than being at constant speed. So the question is, why did NIST assume that the descent speed was approximately constant?"
The correct response should have been "Whoops, we'll fix that." But no, here's how they handled that question.
I didn't hear a "Whoops" in there, did you?"The force of gravity obviously is, the acceleration of gravity is what's the driving force and our calculation was based on the amount of time from the top of the parapet to fall til it disappeared from view between the two buildings seen in the video. That time was established from the video, by a single frame. Search of the time, so that was down to 1/30th of a second, and then we did the same thing for when the top of the parapet disappeared. We found that time to be a 5.4 seconds."
Dr John Gross
This is John Gross, one of the lead engineers for the NIST report on the Collapse of the Twin Towers. He has a PhD in structural engineering from Cornell University. He taught engineering at the University of Colorado in Boulder; he has long resume on top of that.
Don't you think he probably knows the difference between speed and acceleration?
Don't you think he could explain it with perfect clarity if he wasn't so preoccupied trying to cover his tracks?
Don't you find it interesting that the 5.4 seconds he measured for the collapse time just happens to exactly match the theoretical prediction of their model? That kind of precision is incredibly rare when modeling real world events. Incredible is the right word - it's not credible!
This measurement has all the characteristics of what we call "dry-labbing", manipulating the data to fit a pre-determined outcome. It's an ethics violation in science on a par with plagiarism. Any engineers engaging in this kind of sleight of hand should lose their licenses. The larger implication, of course, is dry labbing in this kind of investigation would constitute a criminal cover-up.
After another round of quibbling, someone had to step in and bail out poor John.
"Can you clarify that?"
"I think it's something that we need to clarify and correct in the final version of the report."
"OK"
That was August. This is November. The final version of the NIST WTC 7 report just came out. And guess what? We have a revised analysis of the building collapse rate.
Constant speed is out. Constant acceleration is out.
Instead we have three phases of collapse, with a whopping 2.25 seconds of absolute free fall. The irrelevant 5.4 seconds is still defended in the wording, but it plays no apparent role other than CYA for John Gross and associates. So freefall is, hereby, official dogma. How are they going to handle all the ramifications of that inconvenient fact? Read on. It says:
That's it!"The three stages of collapse progression described above are consistent with the results of the global collapse analysis discussed in Chapter 12 of NIST NCSTART 1-9."
Freefall went from an impossibility that required backflips in logic to obfuscate to a simple fact to be measured, then declared consistent with their fire-induced collapse hypothesis. Apparently they have now decided that freefall okay as long as it is seen as a part of a longer stretch of time that covers the required 5.4 seconds.
In other words, they dropped the bullying tactic of blowing smoke to obscure the facts and adopted an alternate bullying tactic, cover it with a lie, and walk away. However, NIST cannot walk away from free fall.
Now that NIST has certified freefall as fact, take a look at the implications.
[The WTC7 series has elicited a number of questions from people unclear on the details of how I did the measurements, compared to how NIST did them and how the representatives of NIST described their measurements. I have therefore created a WTC7 Measurement FAQ page: http://www.911speakout.org/WTC7-Measurement-FAQ.pdf . I will also use this FAQ as a place of reference for other questions that arise as well.]
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