# The clock is ticking, but I don't see WTC 7 moving yet

#### Boston

##### Active Member
For the purposes of this thread I think it prudent to discuss what is visible rather than what is invisible. I can't help but notice that some people seem hell bent on arguing something they have no evidence for. For WTC 7 ( which will be the focal point of this thread ) we have a very clear rate of descent. It starts when we can see the four corners of the building collapse straight down and it ends as the building disappears behind obstructions in the film evidence.

I present the following two films as examples, one of how not to measure the rate of descent and one of how to measure that rate of descent. I'll ask that people stick to discussing what we can see as there is no other evidence available other than a few minor scraps of material and some dust samples. ( site was pretty darn thoroughly scrubbed before any investigation was conducted and before any mapping of the debris pile could occur. )

Video A

As you can see the clock starts when the first penthouse structure fails, keeps running till the second starts and is at least several seconds on, into the start of the corners descent. This is no way to judge the rate of descent of the overall structure. What NIST and these guys are doing is attempting to include an assumed collapse of the interior with the timing of the visible collapse. Thus artificially inflating the collapse time.

There is an admission that we can't know what was going on inside the building but the presenter then goes on to assume that "something" must be going on. This is not the scientific method in action. Using this logic, the collapse time could be started when the first fire blew out the first window.

Lets look at another video

Video B

In this video a known pair of measurements are used to define a distance in which multiple data points can be developed to establish an exact rate of acceleration. A far far better representation of the scientific method. Nothing invisible is argued, there are no ambiguities, just a solid group of measurements which establish a known acceleration for a known distance.

I think it important to compare these two methodologies and establish why any scientific investigation would consider taking such an important measurement by dry labbing, working back from an assumption and using that assumption to base ones data on. NIST "assumes" there was an internal collapse which "may" have started with the collapse of one section of the penthouse structure and then carried there time of collapse on from there.

Video B assumes nothing and takes the available data and discovers that the rate of descent was free fall for some significant period of time.

So the question becomes, "why would NIST dry lab there results ?

#### jvnk08

##### Senior Member.
Kay, it's in free fall for some portion of its collapse, so what's the point? Is that out of line with the assertion that the interior collapsed first, or is the conclusion being drawn here that the interior did not collapse?

What does this prove? Let's get to the meat of the matter - if the interior didn't collapse, what does this mean? One of the dozens of conspiracy narratives is correct?

#### Boston

##### Active Member
I'm not sure how you could have drawn the conclusion that anyone is suggesting that the interior did not collapse. We have some pretty good photographic evidence that both the interior and the exterior both collapsed

I guess my only response can be to go back and sloooooooowly reread the initial post.

#### Mick West

Staff member
Define "collapse time".

#### Pete Tar

##### Senior Member.
Are you saying there was no interior collapse beyond the penthouse? Can you see the windows that have daylight in them in unison with that collapse, at least the first two floors?
Do you not think those floors interior collapsed, or just the floors out of sight that can't be confirmed?

I'm not sure how you could have drawn the conclusion that anyone is suggesting that the interior did not collapse. We have some pretty good photographic evidence that both the interior and the exterior both collapsed

Is this a snarky way of saying the interior did not collapse first? Just be clear.

#### Boston

##### Active Member
How long it takes a measurable and visible portion of the building to drop from point A to point B. Point A and B also requiring to be a measurable and visible set of points between which this portion of the building must pass

Oh and something else that explains some of the problems with the "official" timing of the collapse.

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#### Boston

##### Active Member
Are you saying there was no interior collapse beyond the penthouse? Can you see the windows that have daylight in them in unison with that collapse, at least the first two floors?
Do you not think those floors interior collapsed, or just the floors out of sight that can't be confirmed?

Is this a snarky way of saying the interior did not collapse first? Just be clear.

Again I'd recommend going back and rereading the initial posting which outlines the parameters of this discussion. We should be considering what we can directly ascertain from the data available. Which in this case is highly restricted. We have video and photographic evidence from the outside of the building and a few bits and pieces of rubble along with some dust samples. Beyond that there is only assumptions, which IMHO are hardly the basis for a scientific investigation.

There is no telling when or for what reason the interior fell, other than that it either fell before, or during the collapse of the exterior. We can observe portions of the penthouse falling, until they disappear behind the parapet wall. What might have caused any reflective variations in the window characteristics that "may" have occurred is purely speculative. Passing clouds, flock of birds, smoke, water vapor, any number of things could be responsible for what few if any variations are seen in the buildings reflection.

What I am saying is that for the purposes of a scientific investigation no assumptions will be made. You don't know what happened inside that building.

#### jvnk08

##### Senior Member.
What I am saying is that for the purposes of a scientific investigation no assumptions will be made. You don't know what happened inside that building.

Alright. So, again, what are we getting at here? This lends credence to a particular conspiracy narrative? I think we can all agree that we don't know what happened inside the building, but we can say with a fair degree of confidence that, per Occam's razor, the interior collapsed first.

Or, perhaps what you're getting at is that NIST initially lied about their conclusions or something along those lines? You haven't exactly built a compelling case for that. Neither does that video.

I just don't understand this about the fixation on WTC7. We're to believe that the government orchestrated some planes to collide with both towers, but their actual intended objective was to destroy a building hours later with the collateral damage of those collisions? Then, they cover up this obvious gaffe with an investigation which reached a conclusion regarding the length of collapse that is only marginally different from the one the conspiracists later did.

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#### Boston

##### Active Member
I"m betting you didn't reread the original post. Please do so before posting any more of these kinds of assumption and fallacy based arguments. We are discussing the two different methodologies for measuring the rate of collapse. One based off an arbitrary hypothetical starting point and the other based off verifiable evidence. Only one represents the scientific method. Want to guess which one that is ?

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#### jvnk08

##### Senior Member.
I was under the impression we were on a conspiracy theory debunking forum and that this was a part of a larger discussion. Sorry. I'm not so sure that the A&E9/11 video "represents the scientific method". As it stands, are they only using the testimony of this one guy? Is there not more concrete documentation about how NIST arrived at the duration they did? Are we sure they were talking about the same footage?

#### Boston

##### Active Member
No apologies necessary, but no, this isn't part of a larger discussion. I prefer to isolate each questionable analysis and treat it individually. That way maybe we can at least find common ground to engage from. In this particular case we have on the one hand NIST at least appearing to dry lab data to fit a hypothesis. VS a the analysis of actual data without presupposition.

Your right in that we are on a debunking site of course, but your mistaken about whats being debunked. The original NIST hypothesis of the fall time of this structure is IMHO false, based off the verifiable evidence I see being presented.

See

http://journalof911studies.com/volume/2010/ChandlerDownwardAccelerationOfWTC1.pdf

as well as

#### Boston

##### Active Member
I would also add some notes from the NIST site itself as evidence of there having improperly measured the collapse time which corroborate the above complaint.

see
http://www.nist.gov/public_affairs/factsheet/wtc_qa_082108.cfm

In the draft WTC 7 report (released Aug. 21, 2008; available at http://wtc.nist.gov/media/NIST_NCSTAR_1A_for_public_comment.pdf), NIST stated that the north face of the building descended 18 stories (the portion of the collapse visible in the video) in 5.4 seconds, based on video analysis of the building collapse. This time period is 40 percent longer than the 3.9 seconds this process would have taken if the north face of the building had descended solely under free fall conditions. During the public comment period on the draft report, NIST was asked to confirm this time difference and define the reasons for it in greater detail.

To further clarify the descent of the north face, NIST recorded the downward displacement of a point near the center of the roofline from first movement until the north face was no longer visible in the video. Numerical analyses were conducted to calculate the velocity and acceleration of the roofline point from the time-dependent displacement data. The instant at which vertical motion of the roofline first occurred was determined by tracking the numerical value of the brightness of a pixel (a single element in the video image) at the roofline. This pixel became brighter as the roofline began to descend because the color of the pixel started to change from that of the building façade to the lighter color of the sky.

The approach taken by NIST is summarized in Section 3.6 of the final summary report, NCSTAR 1A (released Nov. 20, 2008; available at http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR 1A.pdf) and detailed in Section 12.5.3 of NIST NCSTAR 1-9 (available at http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR 1-9 Vol 2.pdf).

The analyses of the video (both the estimation of the instant the roofline began to descend and the calculated velocity and acceleration of a point on the roofline) revealed three distinct stages characterizing the 5.4 seconds of collapse:

* Stage 1 (0 to 1.75 seconds): acceleration less than that of gravity (i.e., slower than free fall).
* Stage 2 (1.75 to 4.0 seconds): gravitational acceleration (free fall)
* Stage 3 (4.0 to 5.4 seconds): decreased acceleration, again less than that of gravity

This analysis showed that the 40 percent longer descent time—compared to the 3.9 second free fall time—was due primarily to Stage 1, which corresponded to the buckling of the exterior columns in the lower stories of the north face. During Stage 2, the north face descended essentially in free fall, indicating negligible support from the structure below. This is consistent with the structural analysis model which showed the exterior columns buckling and losing their capacity to support the loads from the structure above. In Stage 3, the acceleration decreased as the upper portion of the north face encountered increased resistance from the collapsed

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