The SINGLE MOST IMPORTANT ANALYSIS of the events of 9/11.

Lexyghot : Therefore, he can take away the entire core, and still have more than 100% of the intact column strength (PC and CC combined)
Overall, I'd estimate that he begins with a PC and CC combined strength that is roughly 2.5 - 3 times too strong, takes away a bunch of it, and STILL has more capacity than the towers ever had.
There's no reason to rebut it beyond that. It's on you to get some traction with this on something other than a forum board.

LT : TOTALLY wrong conclusion, lexyghot.
You are seriously trying to mislead ATS readers by intendedly avoiding linking your bogus arguments to any source, then quoting my source totally wrong, and come up with, at first glance for quick readers, reasonable looking conclusions, however based on fully biased and worse, misquoted arguments. Intendedly, or from your fantasy?
Or are you basically a very bad reader of academic sources. With no comprehension of what is really written and intended.

References for core columns dimensions :
911research.wtc7.net...
911research.wtc7.net... (Only WTC1N plans, look up floor plan 94)
femr2.ucoz.com...
ASCE journals refuse to correct fraudulent paper, (read both pages) :
the911forum.freeforums.org...
the911forum.freeforums.org...
The views of most members in the above interesting ASCE thread discussion are mine too.

More References :

Analysis of Mass and Potential Energy in the World Trade Center Twin Towers, by Gregory H. Urich

WTC 1 Collapse Time Calculations, by Prof. Kuttler

Momentum Transfer Analysis of the Collapse of the Upper Storeys of WTC 1, by Gordon Ross, 06-2006

Not sure at all if this is also a Gordon Ross site? From 2007.

The WTC Collapse Simulator from Femr2 and femr2.ucoz.com...

Core column cross-sections from LERA's SAP2000 structural reference model of WTC 1 and 2 developed for NIST, by Femr2.

And this is the latest engineering-based online 911-discussion at the Journal of 911 Studies.com and as also can be read at the911forums.org :

Journal of 9/11 Studies : ASCE Journals refuse to correct fraudulent paper they published on WTC collapses. By Tony Szamboti and Richard Johns. September 3, 2014.

The Szamboti and Johns paper showed the Journal of Engineering Mechanics editors, in a definitive way, that the Le and Bazant paper was grossly incorrect and that correction of their inputs gave results which were in complete opposition to their claims. Amazingly, the Le and Bazant paper still sits on the Journal of Engineering Mechanics uncorrected. Since nothing was done by them to correct it, after their being alerted to the inaccuracies, the ASCE editors and their Board of Governors are now in violation of their own ethics and complicit in what can only be considered a deliberate misleading of the engineering profession and the public in general regarding the WTC collapses.
The Le and Bazant January 2011 JEM paper can be found on the Internet at the link below
www.civil.northwestern.edu...
The Szamboti and Johns Discussion paper critiquing it, the JEM review comments and their rebuttal to it, and the resubmitted Discussion paper are included below on pages 3 through 17 for the reader to see just what the issues are for themselves.

I'll sum up the differences both parties, L&B contra S&J, have now from Jan 2011 up to Sept 2014 :

2. Inertia Resistance (page 3)
Le and Bazant (L&B) consider only the mass of the concrete floor slab in a falling story to be involved in the exchange of momentum = 0.627 Mkg and the velocity lost is then 1.1% as claimed.
While Tony Szamboti & Richard Johns (S&J) consider the mass of a single story = 3.870 Mkg for WTC 1 (from data from L&B 2008), and the velocity lost as ~ 7% of the original, rather than the ~1.1% claimed. (Note that this is already more than the ~3% total loss calculated later on by L&B)

3. Column resistance (page 4)
--3a. S&J also calculate the total cross-sectional area of the columns and obtain a total area A = 2.75 m², for all the 287 columns (PCs + CCs), which is much less than the L&B value of 6.05 m² (they however suppose all 287 columns to be of same size, while we all know that the core columns were much sturdier).
One is bound to wonder how this value of 6.05 m² was obtained, since no reference or calculation is given for it. S&J show further on, that the correct value is roughly A = 2.3 (perimeter) + 1.7 (core) = 4 m².
--3b. L&B use a value of Fy = 0.248 GN/m² (36 ksi) for the yield stress of the perimeter columns on the 97th story.
S&J recalculated that to be in fact a conservatively obtained value of 0.450 GN/m² (65ksi).
And thus also recalculated the column resistance Mp from L&B its value of 0.32 MNm upwards to a value of Mp for the perimeter columns of 0.58 MNm.
--3c. S&J then calculate their corrected total yield load for all the columns.
The 240 perimeter columns: P = 240 x 0.00675 x 4 x 0.3556 x 0.45 x 10^9 = 1.04 GN.
Using the same columns data, the total cross-sectional area of the core columns is found to be 1.69 m², and the maximum load is 0.46 GN.
Adding the resistive forces gives S&J's load-displacement curve in figure 1. Which shows that a column displacement of 0.38 m is needed, instead of the value of 0.065 m claimed by L&B in case the 54 Mkg top-section mass by Le and Bazant is used. That's 5.8 times more.
--3d. Up to this point S&J have used Le and Bazant’s mass value of 54 Mkg for the upper part of the tower, but this is probably an overestimate since it conflicts with the data provided in the NIST WTC report concerning their description of the floor structures, total steel weight found in contracts, and live and superimposed dead loads. A more reasonable estimate, based on these data, is 33 Mkg for the 12-story upper part, i.e. 2.75 Mkg per story. This lower estimate is also much closer to typical mass per square meter values for other buildings sharing this type of construction, such as the Sears Tower and John Hancock building. For a detailed treatment of these arguments, see Urich (2007).
Therefore, S&J calculate further using the 33 Mkg value as well as Le and Bazant’s 54 Mkg. For example, using the lower mass value of 33 Mkg, Ueq occurs at roughly 1.12m column displacement, as shown in Fig. 1. Instead of L&B their 0.065 m !
-- more --

4. Calculating the Velocity Curve. (page 6)
In order to verify the accuracy of the NIST/Bazant/lexyghot etc, gravity-driven model, S&J calculated that L&B 54 Mkg scenario its velocity curve, and the S&J 33 Mkg curve for the roof line descend velocity, and compared it with the real time behavior of WTC 1 its roof line itself.

""David Chandler, one of the “internet” sources that Le and Bazant presumably refer to, has analyzed this motion using Tracker, an open source video analysis tool. His graph is shown below, together with two velocity plots for a gravity-driven collapse.
The calculated velocity of the roof-line was obtained numerically using the load-displacement curve shown above in Fig.1.
We also assumed Le and Bazant’s free-fall acceleration during the collapse of the first story, and the two possible mass values, as mentioned above. The floors are treated as rigid and incompressible, so that no energy is lost deforming them, even though in reality this would be a significant energy drain. The upper part of the building is also modeled as a rigid block, which Le and Bazant regard as a reasonable approximation.""

Then "Measured and calculated velocity curves" Fig.2 is shown.



""It is questionable whether the velocity fluctuations seen on the graph in Fig. 2 (using the 54 Mkg mass value claimed by Le and Bazant) would be visible on the video, since the measurement error is +0.675 m/s. But it is clear that the calculated average downward acceleration is much less than the observed value by David Chandler's Tracker software.
With the 33 Mkg mass the calculated velocity decrease is roughly 2 m/s, and should be visible in a velocity plot obtained from the Sauret video footage. Also, the average acceleration after impact is negative (i.e. upward), which would be easy to observe.""

And then 10 pages more of rebuttals to the ASCE referees etc.

Here is a link to an ASCE Library search with terms "" WTC 2014 "", which delivers 12 results :
ascelibrary.org...

A search there with " WTC " delivers 163 results. Very old and discarded by the community ones included.
Its clear that 911 truth seekers with proven background in engineering have no chance at ASCE, they are obeying slaves of the system in place.

Explaining Inward Bowing via Core Failure.

Journal of 9/11 Studies - Attachment to Eastman/Cole, Volume 37, April 2013 - Table of Peer-reviewed Publications Focused on Mechanism of Collapse for WTC 1, 2, and 7

From David Chandler’s DVD, “9/11 Analysis”, the part called "A Little Physics Lesson", I took the liberty to slightly change Davids texts here and there, to hopefully improve the educational value of the texts for the readers who were less lucky in getting the right education, so they may understand the meat of the matter :

"" David + tiny bit LT :
Tower1N top section came down at nearly 2/3rd of the acceleration of gravity (2/3*g).
See my signature LINKS at the bottom of each of my posts, for the video made by David Chandler, where he measured with a software package called "Tracker", the descend speed of the roof line of Tower1N, which proved that constant acceleration.

Its top section was constantly accelerating, while falling downwards, that's the key observation.
Its top section exerts a force on the lower, still intact section, that's less than simply the weight of the top section by itself.
In other words, it was giving more force downward, in motion, than if it was simply sitting there.
That seems very counter-intuitive to most people.

In a free body diagram analysis in physics, we have a look at the top section of the building.
We have gravity working downward, which is the weight (w) of the building's top part, which has some amount of mass (m), times the acceleration of gravity (g), and that gives us this equation (w=m*g).
There's also an upward force (F) which is the resistive force of all the steel in the lower intact part of the building. Which prevents the top part of just free falling down.
The netto force is thus the downwards force minus the upwards force (m*g - F).
It's Newtons second law which says netto force is equal to mass times acceleration :
m*g - F = m*a.

We know what the acceleration (a) is, it is 2/3g (measured by "Tracker").
Thus : m*g - F = m*2/3g.
The resistive upwards force F, after reshuffling that above equation is thus equal to m*(g-2/3g). Which gives F = 1/3m*g.

Since m*g is the weight (w) of the top section, that value turns around according to Newtons third law. If the upwards force is 1/3rd of the top part's weight (since w=m*g, then F=1/3w), than the downward force is also 1/3rd of the top part's weight, says Newton.
Thus the top section is pushing down (F=1/3w) with 1/3rd of the resistive force (F), which is 2/3rd less than if it were simply sitting there on top of the lower sections of the tower, when the resistive force is at least equal to the top portion's weight, when F=w.

The top section is not slowing down, decelerating, but keeps picking up speed, accelerating, as if there is nothing there right under it.
If you hit a table with your fist, the table will slow your fist down.
However, that top section didn't slow down, it was doing the OPPOSITE, it was accelerating, picking up speed on the way down. As if there was a lot less resistance than normally would have been to be expected.

That happens only when explosives make room by disintegrating most resistance of the steel parts. Those steel parts being columns and their cross beams holding those columns normally solidly together.
That top portion can not crush the lower section with less force than its own total weight.
Only when it's falling through an already prematurely pulverized mass of material, it can. ""

View and listen to the rest of David Chandler's explanation from the 4:50 point on, in the video of 7:47 minutes length.
Basically, he and Tony Szamboni, a structural engineer, ask how the 47 core columns in the top section could crush the other 47 core columns in the tower's lower intact portion.
They say it could only happen when the upper columns spearheaded down, alongside the lower columns.
And what happened then to that very strong structure of cross-braced columns?

Their opponents will say that it was caused by buckling of those columns.
I say that buckling, and then breaking, and then sliding off and then down, of all those 47 columns, simultaneously, is not possible, and is not supported by the video evidence, where we see all 47 core columns and all 240 exterior columns failing already at the start of the collapse, in the first one of the first three seconds. While the collapse did not decelerate AT ALL.

Beck then proved that even when he deletes half of ALL core AND exterior columns out of his equations, still the rest of these columns delivered enough resistance to halt any eventual initiating buckling moment. The yield strain in every column was 3 times or more greater than the yield strain that could cause buckling.

The OS believers will say that it was one column first, that buckled. Thinking that in that case the whole weight of the upper tower's part rested on that column. Which means that that column must have stuck above the rest of the 46 other columns, otherwise that can't happen.
The moment it buckles far enough down, the other 46 columns will take over that top part's weight again, EVENLY.
Thus they must explain how the rest of the 46 core columns and the 236 exterior columns hereafter, EVENLY buckled too. Evidenced by the EVENLY sinking and constant acceleration of the tower's top roof line.

According to Becks equations, they never could buckle under normal conditions, even when he deleted 50 % of the CCs and PCs or, in other terms, 23 of 47 core columns and 120 of 240 exterior columns in his WTC1N equations.

Except when most resistance under that top portion which started to collapse, was constantly removed by externally introduced explosive forces, until the yield strain was low enough compared to the impacting mass, to not withstand that collapse force anymore.

The first three seconds of the North tower collapse were the most significant ones. After that, a natural floors collapse enfolded, as in every other demolition process, assisted by some sporadic other cutter charge explosives going off. To break f.ex. the resistance of the 3 mechanical floors, which were double floors with much sturdier floors and cross beams under them.
Evidence of those explosions inside the core were all those video-recorded high speed expulsions of material spitting out of one or a few windows, sometimes more than 10 to 15 floors under the approaching collapse fronts on all four sides of the North tower.
As shown in the already by me posted videos in this thread.

The demolition pace of shearing-off the floor connections to the core columns was maintained by the ignition of 4 ThermobaricBombs, on every facade-side one TB, per about every third floor story, thus blowing up/destructing all composite huge concrete floor-surfaces under and above these exploding TBs. And forcing all office material and all concrete-dust from the floors to spit out of the four exterior sides, as huge billowing dust clouds.

From David Chandler’s DVD, “9/11 Analysis”, the part called "A Little Physics Lesson" :
www.youtube.com...

Coming from the mouth of Tom Sullivan, a former explosives loader for Controlled Demolition,
Inc. (CDI Inc. ) :
""The story that just a few columns can cause a global collapse, well, that's just NONSENSE.
We have to let fail all of the support columns at a given floor at the same time, to do that.""

www.youtube.com...


HUGE explosion BEFORE the destruction of building WTC7, between 0:16 and 0:29 of 0:51 :
www.youtube.com...


Visible explosion at WTC, while a muffler-blanket spitted out from one exploding window, between 1:00 and 1:05 of 1:21 minutes :
www.youtube.com...


Physics - WTC7 free-fall calculations by David Chandler, measured with "Tracker" software :
Revised analysis, 9:29 min.
www.youtube.com...


North Tower acceleration by David Chandler, measured with "Tracker" software :
www.youtube.com...

a reply to: LaBTop

I see now, that it is probably not too clear, that you have to read my slightly altered text inside the "....", while you already have started the "Little_Physics_Lesson" YouTube video.

So, start that David Chandler video in my next post under that post, scroll up to my post above that post where the " "" David + tiny bit LT" text lines begin, and listen to David, while you read my posted text and keep pace with Davids lecture.

It will make it hopefully a tad bit clearer for the wealth of blue collar members here, jobless or not, who still have an unsatisfiable hunger for new explanations of things that seem so clear and obvious to some highly educated white collar workers.
Do never get stopped by lack of education !
You can and will educate yourself if the desire is big enough. 9/11 is BIG enough !

If you're jobless currently, you now have the time to educate yourselves.
Humans can reach unbelievable heights when the desire for real knowledge is strong enough.
And never shy away from asking, for fear of showing your, in your eyes, lower level of education.
We will help you to understand. In every possible manner.

PS : I will contact Charles M. Beck, since I think his remarks at page 19 of his Beck, Feb. 2013 : WTC 7 paper, indicate he is not aware of my seismic work (in my 3 LINKS under every post of mine, only to see for members, sadly enough not for lurkers) :

It can be shown that if the interior, core and floors, of the base and the core of the primary zone are destroyed prior to the release of the top section (Case 1) than the peak in the apparent weight of the building, δw from the first release (the top section being allowed to free fall) is comparable to, possibly weaker than, the peak of the first arrest (the top section reaching the ground).
On the other hand, if the destruction of the entire base marks the release of the top section (Case 2) then the peak of the first release is much stronger than the peak of the first arrest.
We believe it is the seismic signal of the collapse that can be used to deduce which of the two cases is more likely to have had occurred. We leave this analysis to future publications with our collaborators. Given our current knowledge [12], we favor Case 1.

It seems further thoughts have to go into the reasoning by Beck for Case 1, after he will read this thread and the following arguments :

My by LDEO registered, edited by me in 2005 already, WTC 7 seismogram that shows that the highest amplitude seismic peak started already seconds before we saw anything move in Manhattan's WTC 7 building and roof. The first sign was the denting of the east penthouse roof :

files.abovetopsecret.com...


and this very low explosion sound 1 to 2 seconds before the east roof penthouse sinks inside.
This HUGE explosion BEFORE the destruction of building WTC7, between 0:16 and 0:29 of 0:51 :

www.youtube.com...


It took about 8.3 + 2 seconds after that explosion, before the global collapse started, of which the first 2.3 seconds were in free fall acceleration.!
See also this WTC 7 seismogram its additional info from a few years later, by me :

files.abovetopsecret.com...


Beck, Oct. 2007 : WTC 1 + 2
Beck, April 2008 : WTC 1 + 2
Beck, Feb. 2013 : WTC 7

For the Lurkers, and especially Charles M. Beck, my 3 signature LINKS :
WISDOMwillWIN--->9/11=a LIE !--->EVIDENCE--->LIST

a reply to: LaBTop
With all due respect to your rights:
I personally feel your posts are too long for me to devote the time needed to digest what you are trying to get across.

< moderator snipped violation of T&C - Please be reminded of the enhanced rules for this forum >


Anyone interested in the by LDEO at Palisades N.Y. registered 9/11 seismograms, and their implications, can use these two terms in an ATS Search : LaBTop seismic
and then find 300+ posts about the subject. Choose not the laptop search proposal, click the LaBTop one. Terms like LaBTop thermobaric gives also lots of my posts on that subject, and contradictory to what GenRadek typed in his last post, there are lots of academic sources about that subject. Link to lots of them, a few pages back.


These are two of my multiple threads on the seismic subject from the past, where thorough researchers as f.ex. C.M. Beck can extract lots of valuable background information from :

WTC 7 was IMPLODED : irrefutable seismic evidence from LDEO and NIST itself :
www.abovetopsecret.com...
13 pages of 20 posts each, read up to page 11, then switch first to this Sequel of 2 pages long, then return back here at my post 6 on page 11)

SEQUEL : WTC 7 was IMPLODED : irrefutable seismic evidence from LDEO and NIST itself :
www.abovetopsecret.com...
Two pages, with my original outside-ATS posted material on page 1, from the long defunct StudyOf911.com forum, which can be checked for some info via the Wayback Machine website ( archive.org... ), of course. However, that precious site still has problems in saving old pages from especially Forum software.
If you then have reached and read the last Sequel-thread closing post at page 2, you can proceed at this post 6 at page 11 in my original thread.


Btw, this is also a wonderfull source of 9/11 and more, information,
historycommons.org...

And, Admins, moderators, have a look at their fundraiser app !
Perhaps a merger could be a best benefit for both of you, in a long term thinking tactic ?
To counter Googles AdSense throat-cutting techniques.

There are other good 9/11 sites who could be interested in merging too.
The best tactic could be to quarentee every merged forum or site, their own independently moderated and administrated niche in the new Super Conspiracies (911, Ufo's, NSA, CIA, etc) and Citizens News Sourcing site.
Old news and developing news alike.
Like NSA domestic spying, global warming, free trade, 9/11, “the war on terrorism,” civil liberties, the Iraq war, the Iran, Russia, China, North Korea, Syria, ISIS confrontations, and much more.

My above post regarding Tony Szamboti & Johns paper offers not sufficient importance to their rebuttals of the ASCE Journal referee/peer-reviewers.
In fact they (S&J) show that the chosen referee is strongly biased towards already accepted journal papers, and either doesn't know his math nor his engineering facts and publications/standard reference books, or is unworthy for the job and inadequately educated.

After reading pages 7 to the top of page 12, this is their criticism of the referee/reviewer.
See page 12, the S&J remarks about the professionalism of referee #2 :

In summary, Reviewer #2 has not found any error at all in our criticisms of Le and Bazant’s TN. We have correctly cited the TN itself, as well as Bazant’s earlier papers on the subject, and the NIST reports. Our criticisms, summarized below, are therefore still valid.

1. Le and Bazant do not adequately state their assumed specifications for the columns on story 97.

2. The values they do state, i.e. average Mp = 0.32 MNm and total XS area 6.05 m², are unsupported by any references or calculations, and not even consistent with one another, given the known number and external dimensions of the columns, their own value for the yield stress, and the standard textbook formula for Mp.

3. In calculating the momentum exchange between the falling upper block and the first stationary floor, Le and Bazant have incorrectly used the mass of the concrete slab only, rather than the full floor assembly.

4. Le and Bazant’s mass value of 54.18 Mkg for floors 99-110 (plus the roof) is unsupported by any evidence, and is much greater than the 33 Mkg value given by NIST.

5. Le and Bazant’s average value for the yield stress of the columns on story 97 contradicts the yield stresses provided by NIST.

6. With all these corrected data the value of Ueq, i.e. the downward displacement at which the resistive and gravitational forces balance, is roughly 1.12 m, not the 0.065 m they claim.

7. Using the corrected data, Le and Bazant’s own methods predict a velocity reduction that would be visible in a velocity plot derived from Etienne Sauret’s high-definition video footage of WTC 1. (Our discussion paper, unlike the TN, includes this necessary empirical data, and no such reduction is visible.) The conclusion of Le and Bazant’s TN is not supported by the available evidence.

And this was their conclusion about L&B their Jan. 2011 paper already on top of page 7 :

[The analysis of Le and Bazant, while sound theoretically, uses incorrect input values. These errors each have the effect of reducing the resistance of the lower part of the building. As a result, their calculated velocity drop on impact is too low, and the calculated acceleration following that drop is too high.

From page 13 to 17 they offer us their Resubmitted Discussion of the Jan. 2011 L&B paper, with a few minor adjustments to please the ASCE reviewers, which turned out to be fruitless, these guys defend their already published peers to the end of time. No elasticity present at all at the ASCE Journals submitting process.

Page 17, their Additional Comment:

The 2,000 word limit on Discussion papers, imposed by the ASCE Journal rules, kept the Discussion from addressing the inappropriate use of free fall through the 1st story in the Le and Bazant paper. If this erroneous assumption is replaced by the actual measured acceleration the below diagram would be the result, showing an arrest of the collapse in the second story of the fall.

files.abovetopsecret.com...

It is clear, that in addition to fraudulently minimizing the conservation of momentum loss, that Le and Bazant have also inappropriately embellished the kinetic energy of the falling upper section by using nearly double its actual mass and velocity contributions to it, while also diminishing the actual column energy absorption capacity by a factor of two.


Another paper, critiquing the WTC work of Zdenek Bazant published in the Journal of Engineering Mechanics since 2001, was submitted by Szuladzinski in 2012 with Szamboti and Johns as co-authors. The Journal of Engineering Mechanics also refused to publish that paper without being able to refute its points and conclusions and finally simply rejected it as “out of scope” also. The Szuladzinski, Szamboti, and Johns paper titled “Some Misunderstandings Related to WTC Collapse Analysis” was subsequently published by the International Journal of Protective Structures in June 2013 and since January 2014 has been available online without a fee by permission of the publisher. It can be viewed here :

911speakout.org...

David Chandler 2010 "9/11 Analysis" compilation DVD now at last, for free to watch.
www.youtube.com...



At the 4 to 7 min. point into the video, some North Tower collapse loops with David explaining the explosions visible much lower than the avalanche of advancing debris clouds.

Then, WTC 7 collapse and its second, revised, downward acceleration analysis from Aug. 2008 by David with the Tracker software up to 19 min. in this 58:27 min. long video.

Then David explains how he got access to the NIST technical briefing of the Aug. 26, 2008 WTC 7 Draft of their Final Report. He shows a video of what happened at that briefing after he was allowed to ask one question. It stops at the 28 min. mark.
Shyam Sunder, director of the NIST investigation : ""free fall time would be an object, that has no structural components below it"".
I.o.w., it appears as if there is no resistance of the structure below it.

David's response : "" What Dr. Sunder is saying is this :
For the 18 stories under consideration
1. Free fall would take 3.9 seconds
2. However their computer model simulating the collapse required 5.4 seconds
3. The slower collapse time was to be expected since
.....a. there was structural support in the building as it fell, slowing it in the fall
.....b. there was a progression of failures that had to take place
.....c. and that these were not instantaneous.
All of this makes sense as long as you don't look at the evidence. The evidence shows that free fall 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 very 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 countered up a 5.4 seconds measurement, to match. They had to stress themselves to do it, but they did it.!
They found a disappearance time, and then they went out of their way to pick an artificially early start time, exactly 5.4 seconds earlier. This they compare to free fall time.""

Then a question about the same subject came from Dr. Jones, and was badly answered by Mr Gross, then corrected by another NIST panel member there : that they would correct those sentences Dr. Jones pointed at, in their Final Report.

At 28:00 minutes into the video; the Nov 2008 release of the NIST WTC 7 Final Report.
And David discusses the change by NIST from 5.4 seconds of 40 % of free fall, to three stages that cover their computer modeled 5.4 seconds needed to fulfill their prediction of failure mode.
Note however that this was by NIST computed WITHOUT FREE FALL period in them.

Their second stage is then the 2.3 seconds of free fall, now AT LAST totally admitted by NIST.
Which means, according to Dr Sunder his earlier August 2008 statement : ""free fall time would be an object that has no structural components below it"".
Thus, building 7 had for 2.3 seconds (for about a 28 meter height drop, about 8 stories) no structural components left of any importance for structural resistance equations/calculations.

YOU CAN ONLY ACCOMPLISH THAT WITH explosives, a lot of them, or one big one, like that one you hear in this WTC 7 video :

HUGE explosion just 1-2 secs BEFORE the destruction of building WTC7, between 0:16 and 0:29 of 0:51. Then ~9 secs of further internal demolition, then the global collapse starts, with its first 2.3 seconds IN FREE FALL :

www.youtube.com...


From 30:00 min. on in David's video again.
David : "" For those of you that don't have a lot of Physics background, one of the concepts that might be a little tricky to understand is the difference between constant SPEED and constant ACCELERATION. So I like to elaborate a little on this here.
Constant speed is if you look at the speedometer in your car and it is holding steady. If you going down the highway with 60 miles an hour, that's constant speed.
But if you're at a stop sign, and you start accelerating, the speedometer needle is going to go increasingly upwards. If you do that at a uniform rate, that's constant acceleration.
In case of gravity, if you drop something from a certain height, it's accelerating.""

See/hear the rest of his lecture about that for yourself up to the 31:00 secs mark in the video.

Then David shows how NIST did their measurements of their 5.4 seconds three stage downward acceleration curve in a revised part 2 of his series. He added for better visuals, a clock in the right upper corner of the WTC 7 collapse video where NIST and David took their measurements from. Up to the 40 min. point in the video. He shows they added a ridiculous 1.5 seconds where no movement of WTC 7 can be observed, how hard you try.
NIST clearly worked up to a preconceived goal, to let their computer modeled 5.4 seconds outcome, fit into the video material.
Bogus science and in fact worth prison time, since it proves deliberate moves to deceive the public they should serve in total HONESTY.!
We do not for one second believe that scientists at NIST could ever made such childish "mistakes" in their presentation of the facts as they found them.

Thus, only ENORMOUS POLITICAL PRESSURE, OR ENORMOUS COMPENSATIONS COULD HAVE TRIGGERED THIS MONSTROUSLY MISLEADING BEHAVIOR by THE NIST decision makers.!!!

We have been taken over by the Paperclip People and their monstrous ideas.
I am as white as white can be, blue eyes and all, but I will see to it that my beautiful light brown offspring will NOT be put in concentration camps again, by a bunch of monstrous NAZI's. !
Then David shows in part 3 of his video series, the Selection Bias methods and computer simulations NIST used to come up with something that looked faintly alike we saw when WTC 7 collapsed. It did not match at all what we saw the roof line do. Their computer models DO NOT ALLOW for FREE FALL ! They do not give us their model data, thus they rely on FAITH.
REALLY? : ROTFLMLO (rollingonthefloorlaughingmylungsout).
Goes up to the 46:12 min. point in the video.

Then David recalls the Projectiles, spitting out of the sides of the Towers, from just under, to up to far below the falling debris fronts. With over 70 miles/hr ejective speeds.
In the first minutes, you see the collapse of the North Tower, filmed from a far distance.
This is a good moment to see for yourself, that the myth of the shortly surviving North Tower SPIRE being core columns, is just a myth.
It were a few of the northwest corner columns..!
Hold your mouse pointer steady at the start of the video, on that corner, at the level of the roof of the WTC 7. Now watch the spire come out of the dust clouds. You clearly see that it was first bend to the east, then veers back to the west, until it is straight in line with your mouse pointer again, then it starts to sink reasonably-straight down. I have a much better video that shows that spire much much sharper, and one of its vertical columns first bends on its own to the west, crosses through the original corner line, and then the other 4 columns start to sink down, and the first one too.
That was definitely a corner structure, not a core structure, as so many parrot each other. The South Tower spire was a core remnant, by the way.
Up to 49:40 min. into the video.

Next, David talks about the amazing constant 64% of free fall roof line acceleration of the North Tower . He plots velocity as a function of time, and gets a straight angled diagram line of constant acceleration, as the result.
Strongly indicating that the top part of the building falling in on the lower part, was not doing the Work to destruct the lower part. You better call it, proof of it.
Up to the 54 min. point into this video, then come some Personal remarks from David.

These are the most important words spoken by a 9/11 researcher ever, in those 4 last minutes.
Every honest scientist, academic, or field based one, should introspect and decide if he or she can further live on, denying the simple facts spread out in front of them, and still stay silent.
Millions have died, and are going to die, because so many of us decide to choose for the status quo, take no risks, and stay silent.

THIS COWARDLY BEHAVIOR HAS TO STOP, or a once great nation will abort itself from its true laws and intentions. We need more HEROES.!


We have been taken over by the PAPERCLIP People and their monstrous ideas.
I am as white as white can be, blue eyes and all, but I will see to it that my beautiful light brown offspring will not be forced in concentration camps by these monstrous Nazi's, ever.!

I just told you halfway page 22 (REF.4, find the word "greed"), and look ...... what I found :

Title : Probabilistic Risk Assessment for Improvised Explosive Device Attacks That Cause Significant Building Damage.

--- snip ---. The analysis includes estimates of the probability of threat, hazard, and loss for large commercial buildings in the United States. It was found that annual fatality risk for building occupants is similar to acceptable risk criteria. This suggests that strengthening buildings against progressive collapse may not be warranted unless there is a specific threat against a building.
Read More: ascelibrary.org...
© 2014 American Society of Civil Engineers.

GREED is a subjective commodity in a capitalistic society...its value depends on the beholder.

a reply to: LaBTop

I like your information but who needs all of that

All you need is implosion of Building 7

How is money crime or any of that bigger evil than killing 3000 Americans and demolishing the buildings

I presume I owe you all still these :

1. North Tower corner spire, a few seconds seen
files.abovetopsecret.com...


2. South Tower core remains, shortly seen
files.abovetopsecret.com...


3. South Tower core spire, a few seconds seen
files.abovetopsecret.com...

Now that's an interesting evaluation scenario, comparing this video with the C.M. Beck, Feb. 2013 : WTC 7 paper at the Cornell University Library.
Use very good audio equipment, but for best hearing, (more expensive) quality earphones.!

www.youtube.com...


I hear that huge very low sound of the first huge explosion at 18 secs into the above WTC 7 collapse-video :
ttT H U M Ppp

files.abovetopsecret.com...


Two seconds after that ..ttT H U M Ppp.. (red arrow in above picture), you see the eastern penthouse roof start to dent and topple down into the roof, followed by the western penthouse.
Then, 9 secs after that first huge thump, at the 27 secs position, you see the parapet of the whole roof line start to sink (start of global collapse).
Then, 5 secs later, at 32 secs, you faintly hear a softer THUMP , followed 2 secs later, at the 34 secs point with another much softer double thump--thump and 1 sec later at the 35 secs point another soft thump.

Count all the bold-printed dots and 2 bold-printed movements "v"' and "V"s and thumps below, as passing seconds :

Video starts showing WTC 7 at 16 secs into the 51 secs video duration, you hear :

(16s) . (18s)ttT H U M Ppp . (20s)v . . . . . . (27s)V . . . . (32s)THUMP . (34s)thump--thump (35s)thump . . . . . . . . . . . . . . . (51s)

This above multiple THUMPs time line fits well with in the paper by Charles M. Beck,Feb. 2013 : WTC 7 , page 29, proposed 4 stages of collapse :

files.abovetopsecret.com...


(LT : (16s) . (18s)ttT H U M Ppp . (20s)v . . . . . . (27s)V . . . . (32s)THUMP . (34s)thump--thump (35s)thump . . . . . . . . . . . . . . . (51s) )

Beck's 2013 Collapse explanation :
Given the descent curves, the results of physical modeling, some video evidence and the damage review by the NIST investigators we conclude that the collapse of WTC 7 is comprised of four phases :

‹o› Phase N: Null or Preparatory phase, starts 8, or so, seconds before the collapse.
(LT : at the 1 sec before my above bold-printed .(20s)v.)
During that phase, we argue, the core between H2 ~/= 68 m (15th floor) and H1 ~/= 28 m is destroyed together with the base interior.
The appearance of the building during that period, which features, among others, sinking of the penthouses on the top into the building, is consistent with severing of the core columns below H2. The sinking results from the sections of the core columns above H2 being left suspended from the hat truss and the perimeter columns.
That these hanging sections of core columns in the secondary zone are not destroyed becomes apparent during Phase III when the top section in its last moments regains its full (local) strength.

(LT : (16s) . (18s)ttT H U M Ppp . (20s)v . . . . . . (27s)V . . . . (32s)THUMP . (34s)thump--thump (35s)thump . . . . . . . . . . . . . . . (51s) )

‹o› Phase I: Free Fall phase begins at t = 0 with a sudden and total annihilation of the base (part of the building between the ground level and H1). This allows the top section (part of the building above H1) to free fall to the ground.
(LT : at my above bold-printed (27s)V.)

‹o› Phase II: “Crush-up” begins t ~/= 2.3 s into the collapse when the top section reaches the ground. For the next ~42 m the primary zone of the top section, which was compromised during Phase N, is destroyed in collision with the ground.

(LT : (16s) . (18s)ttT H U M Ppp . (20s)v . . . . . . (27s)V . . . . (32s)THUMP . (34s)thump--thump (35s)thump . . . . . . . . . . . . . . . (51s) )

‹o› Phase III: “Crush-up” of the top section continues for the next t ~/= 3.8 s as the
secondary zone is being destroyed. While the top section now begins to decelerate,
this, in itself, is not sufficient to arrest the collapse. The phase continues some 7.8-8.8 s
into the collapse when the last remains of the building fall on the ground.
We conclude that the building was destroyed in a highly controlled fashion and, contrary
to the common sentiment, did not spontaneously collapse.

See for the time stamps of the 4 Phases the THINLY underlined v and V and dots in my included blue thumps lines.

EDIT : Enhance your ATS screen-window size, by holding the CTRL button down, while you push seven times the plus (+) sign. Otherwise you can't see those thinly underlined dots and v and V at all.
Hold CTRL and press one time zero (0) to turn back to the standard screen format (at least in Firefox, try other OS's if it works the same).
You can also use CTRL plus seven times the minus (-) keyboard buttons to minimize one by one screen size setting.

I can't (yet) exactly correct sound and sight for the tripod + camera/microphone position.
Sound travels at 333 m per second. I propose 400-500 meter away from WTC 7.
Why? WTC1N has 100 m sides = 12 mm on my map. Distance to the Greenwich St corner with one to two streets further north than Murray St is +/- 50 to 60 mm on my map. 50/12 = 4.16 and 60/12 = 5.00 See further on for my rationale for that spot)
CBS or we could know the actual position of that camera-man from their archives.

It's interesting to know the camera-tripod spot, since from 2 secs after that huge THUMP sound, we must rely on vision combined with sound for collapse time events in this video, while both, building nor camera, change position.

I guess by looking at a well-known online map of the 2001 WTC area in my hand and at the video where I see the NW and NE top-corner of that stepped-up building, situated NE of the Verizon (NY Telephone) building, the tripod stood somewhere on Greenwich St., between the first and second corner north of Murray St.
Or even further up northwards. That's possibly minimal 400 to 500 meters northwestwards of WTC 7.
That's then a ~1.2 to ~1.5 seconds air travel delay in the video for that huge explosion sound.

You can also draw lines from the NW and NE roof-top corners of WTC 7 its roof line along both closer-by NW and NE roof-top corners of that stepped-up white building to find it out. And also draw lines from the NE top corner of WTC 7 to both roof-sides of the dark square sun shadow on the side of that lowest building in the left bottom corner of the video. That shadow (sun low in the west) already gives a strong indication where the camera stood, since there are no buildings on/along the west side of West St. around there. Only one smaller triangular one and a small thin one on the corner of Murray St. and West St. Which probably formed that square shadow on that side of that lowest building in the video. There's a strange star-formed structure in the lowest left corner of the video, on the visible side of that lowest building.
That will trigger the memory of a New Yorker, I suppose. Or assist in finding that building in the online 911/videos libraries.
A New Yorker will be able to quickly help me out on this, so we can place that camera man on a map, and know the distance that huge sound had to travel first through air, before the camera mike could register it.

That first huge sound will however more likely, ONLY have been picked up by the camera tripod through the ground, since it is such a very low sound. In soil or bedrock, explosive sounds travel much, much faster than through air. This is more logical, since we only faintly hear any following possible collapse sounds, which probably ain't any explosion sounds, after we see first the building start to sink. (See for the LOGICAL reason, the next post)
These were probably WTC 7 its faint building-debris collapse sounds, since the distance is so big, and lots of other buildings stood in the direct path of sound travel through air. It was more like a maze with narrow pathways for aerial sound.

Or a mixture of both, will some try to argue, which I think is not very likely, since I have the original CBS-Net Dub5 09 video in my library, not partially enhanced like AE member Ewing did in this video, he just rolled off the high end frequencies, and enhanced the low frequencies.
In the original CBS-version the sounds are even more faint, but still very well audible via professional earphones or - audio equipment.
Through those, I jump up, every time I hear that first huge deep sound, clear evidence of a huge demolition explosion.