9/11

Never said it was

Seriously, what is wrong with you? We have been through this, 360 feet, your "actual upper block is 10 floors into your "lower intact structure" anyway

Stop stalling, it just comes down to the very first initiation of collapse anyway, how many parts of that steel structure you need intact for it not to at least collapse down to the bottom of the aircraft impact

No energy is consumed, all energy is conserved

Forget the Sun, Moon, Earth itself, the component of Jupiters gravity on 1kg mass on earth is 0.1 Newtons. Get way out past the solar system the effect will be negligable, but there is no such thing as a stationary object near the earth. Plane into the building is a moment of inertia calculation (angular momentum) not an inertia one, even with collisions you think directly oppose each other because, there is always gravity, and the sum gravitational force on earth doesnt just come from the direction of earth. There is no real world example where newtons theoretical laws apply

Not all of the plane slowed down,. The landing gear especially, there is a point in the arc it travelled from the point of impact to where it hit the ground, where it exceeded the speed the plane was travelling at becuase it was also accelerating due to gravity downwards. If it collided with anything and the retarding force was less than the force from gravity that was going to accelerate it again. Then there is at least one example where the moving body did not slow down.....until it hit a building on the earth, which is a different collision


Any collision fast enough, where the moving object gets to the stationary objects centre of mass faster than the stationary object moves. Newtons laws cant be applied.
Two snooker balls one travelling at 500mph the other stationary relative to the earth, they will obliterate each other. it is an inelastic collision. Much like American 11s right wingtip into the steel perimeter column. material deforms before the centre of mass moves

 

First of all, you're lying when you deny saying that the photo of the core structure I provided was something from the 1930s. It was a lie when you said it, and your denial of saying it is another lie.

For your edification:

I said: "And this photo shows the core and perimeter structures that the hat truss was tied into."

You replied: "As for that second picture, I was unaware they started construction on the wtc in the 1930s"

So, there you are. You're either extremely dimwitted and forgetful, or you're a liar. Which would you prefer to be known as?

Anyway, the NIST believes that only 8 core columns, and only 33 perimeter columns were severed. That leaves you with the problem explaining how the entire remainder of the cross-braced core and perimeter columns just suddenly gave way and started to fall at virtual freefall speed without so much as a jolt, to say nothing of having to explain how the lower intact structure offered little more resistance than air for at least the first 360 feet.

You're reaching for straws that aren't even there when you say that there's no such thing as a stationary object on earth in order to explain why the core structure below the impact zone offered virtually the same resistance as air. The core was a stationary structure, and as such, had an effect on the upper block's descent. As I've said before, you believe the upper block was a cause with an effect, but that the intact structure below it was a cause without an effect.

 

Uh huh, so it doesnt say I said the photo was taken in the 1930s, as I said, i knew what you would do, 5 pages of pettyness. You think anyone is going to believe I didnt know when construction started

And cross braced with what?

And there is that phrase again, virtual freefall.

"That leaves you with the problem" - how is it my problem?

You are the one arguing it there wasnt enough damage for it collapse. It then follows that either it didnt collapse, or it was assisted quote unquote "somehow"

Now here is the most important point of the last 71 pages. You are not going to go down that road of assisted "somehow" because just about everyone else, 99% of everyone else will roll their eyes and think , oh here comes the thermite thing. Most of them not realising any explosive (with the exception of nuclear) would have slowed down the collapse not speed it up, and would have resulted in much less force reaching the ground, even explosives all pointed down would have broken up the buildings translational inertia before collapse.

That is, as long as that initial point of collapse happened and successive floors were never going to be able to hold more than 80 pounds per sq ft. Explosive were never going to be able to do more damage.

Best one can ever claim is a small explosion helped initiate the collapse. But given how pissy those floor trusses were, you can still claim an explosion assisting initiation wouldnt have mattered

What can I tell you, those are the answers you are looking for, assuming you have any actual interest in working out why.

The collapse was never a single collision, newtons laws dont spply the way you think they should, every little molecule is under a gravitational force stationary or not. Centre of the building was never designed to stay up without the outside of the building and vice versa. It didnt fall at freefall the first 5 seconds, or 40 foot shy of freefall because part of the interior had already collapsed a second or two before that.

Upper block, lower block, virtual freefall....these terms are all irrelevant, still all comes down to what initiated collapse. How many bits of steel going across, how many bits of steel up and down do you need for it not to collapse

 

Oh everyone, including you, knows when the Towers were constructed. But when presented with an image of the actual core structure, you didn't recognize it. That's why you made the comment implying that it was a photo from the 1930s. You can try to turn your mistake into something else, but trust me when I tell you that your explanation comes across as a farfetched tale designed to help you save face.

Why are you asking what the core columns were braced with? Are you blind?





The bottom pic shows one of the smaller box columns. And if you don't close your eyes, you can see the cross bracing going off in different directions from it. Have you been believing that the core columns were just standing disconnected from each other? That would explain a lot of your confusion.

And according to the NIST, there wasn't enough damage to the core and perimeter structures to account for an instant total loss of structural integrity.

You say that part of the interior had already collapsed a second or two before. Really? I'd like to see you cite something to that effect. So what do you got?

 

Oh, i can smell the butthurt

Pettyness, butthurt, aggression. The truther side are they. Once you start down the truther path forever will it dominate your destiny

Yeah, see, you are not here for any resolution.

A picture of a column ooooh that looks strong, great, useless if the floor has disppeared already, the centre is trying to stand up by itself, gets pulled in

Quit stalling, you know what the NIST report says, i dont need to copy and paste it yet again. How much of all that steel is supposed to be where it should be for it not to collapse.

You are just going to keep stalling

 

You asked what the core columns were cross-braced with, and I just showed you. And your response is rather childish.

I showed you a photo of the WTC core structure during construction, you brushed it off, saying that you were unaware that they started construction on the WTC in the 1930s. When I pointed out your failure, you decided to insult the intelligence of readers by claiming that you did not mean to imply that the structure in the photo was not the WTC.

So just to close this out, what did you mean to convey when you responded to a photo of the core structure by saying that you were unaware that they started construction of the WTC in the 1930s?

This should be good.

 

So we can ad this photo to the list now.

Storch believes this twisted hunk of metal proves the buildings didnt fall down

 

To induce 5 pages of butthurt and pettyness



Can...... you feel..... the butthurt to...night
The pettyness.... the evening brings

 

Earlier you claimed that you didn't say that the photo was of something from the 1930s, even though you did say it, which is a matter of public record now. But now you admit to saying it. You seem incapable of keeping track of what you post. You're going to have to make up your mind as to whether you said it or didn't say it. So which of your diametrically opposed statements would you like to settle on? If I were you, I'd go with admitting that I said it. That way you can avoid being labelled a liar.

 

Every little trick in the book to avoid what it all comes down too. That initial point of collapse.

We dont need any bloody equations, you dont need to quote what damage NIST lists at the aircraft impact and try make out it stayed that way...again.

Just how much steel going across ways, up and down, under the floor etc for that intial collapse to occur or not.

Thats all it comes down to.

But, by all means, keep stalling

 

Indeed! One such trick in the book is to argue the limitations of something when you don't even recognize what that something is; not even when it's shoved in your face. Your ignorance of what the core structure looked like is a good case in point here. You verified your ignorance when you claimed that this:

is a photo of something from the 1930s.

I know you were hoping that your ignorance regarding the very object being discussed would be overlooked, but that's not the way it works. And to further compound your ignorance, and degrade your credibility and integrity, you then claimed that your ignorance was not really ignorance, but a ruse designed to induce five pages of pettiness. Sure it was . . .

And I'm sure that your failure to produce the segment of the FEMA report that you claim says: "the WHOLE structural intergrity of wtc 1, including all the columns in that " intact core structure" were compromised by the collapse of wtc 2" is also a ruse designed to serve your purposes here in some strange, twisted way.

 

NIST NCSTAR-1

"2.3 IMMEDIATE DAMAGE (of impact of AA 11 on wtc 1)

The aircraft flew almost straight toward the north tower, banked approximately 25 degrees to the left (i.e., the right wing elevated relative to the left wing) and descended at an angle of about 10 degrees at impact.

Moving at about 440 mph, the nose hit the exterior of the tower at the 96"^ floor. The aircraft cut a gash that was over half the width of the building and extended from the 93'^'' floor to the 99"" floor (Figures 2-2
and 2-3). All but the lowest of these floors were occupied by Marsh & McLennan, a worldwide insurance company, which also occupied the 100* floor. Marsh & McLennan shared the 93^^*^ floor with Fred Alger Management, an investment portfolio management company.

There was relatively little impact damage to the 93"^*^ floor, hit only by the outboard 10 ft of the left wing.

Containing no jet ftiel, the wing tip was shredded by the perimeter columns. The light debris did minimal damage to the columns or to the thermal insulation on the trusses of the composite floor system supporting the 94* floor.'' The trusses supporting the 94* floor were impacted by flying debris on the
93'*^ floor.

The 94* floor was more severely damaged. The midsection of the left wing, laden with jet ftael, and the left engine cut through the building facade, severing 17 of the perimeter columns and heavily damaging four more. The pieces of the aircraft continued inward, severing and heavily damaging core columns.

The insulation applied to the floor trusses above and the columns was scraped off by shrapnel-like aircraft debris and building wall fragments over a wedge almost 100 ft wide at the north face of the tower and 50 ft wide at the south end of the building core.

The 767-200ER aircraft had two fuel tanks that extended through most of the interior of the wings and a center tank between the wings

In the bottom of the fuselage. A full fuel load would have filled all three tanks.

The aircraft did the most damage to the 95"' and 96* floors. The fuel-heavy inner left wing hit the 95* floor slab, breaking it over the fiall 60 ft depth of tenant space and another 20 ft into the building core. The fuselage was centered on the 96* floor slab and filled the 95* and 96* floors top to bottom. The
severity of the impact was clear. A wheel from the left wing landing gear flew through multiple partitions, through the core of the building, and became embedded in one of the exterior column panels on the south side of the tower. The impact severed the bolts connecting the panel to its neighbors, and the panel and tire landed on Cedar Street, some 700 ft to the south. A second wheel landed 700 ft further south. Within the two floors, 15 to 18 perimeter columns and five to six core columns were severed, and
an additional one to three core columns were heavily damaged. A 40 ft width of the 96* floor slab was broken 80 ft into the building. TTie insulation was knocked off nearly all the core columns and over a 40 ft width of floor trusses from the south end of the core to the south face of the tower

The right wing of the aircraft was fragmented by the perimeter columns on the 97 ' floor. In the process, 12 of those columns were severed. The debris cut a path through the west and center array of trusses and
core columns, stripping the insulation over a 90 ft wide path. The insulation was stripped from a 50 ft wide path on the south side of the floor space.

On the 98"' and 99"^ floors, the outboard 30 ft of the starboard wing was sliced by the perimeter columns,of which five were severed. The debris cut a shallow path through the west and center array of trusses,
damaging the insulation up to the north wall of the building core.

This devastation took 0.7 s. The structural and insulation damage was considerable (Figure 2-4) and was
estimated to be:
• 35 exterior columns severed, 2 heavily damaged.
• 6 core columns severed, 3 heavily damaged.

43 of 47 core columns stripped of insulation on one or more floors.
Insulation stripped from trusses covering 60.000 ft' of floor area

Even with all this damage, the building still stood. The acceleration from the impact had been so severethat people even on lower floors were knocked down and furniture was thrown about. Some survivors reported fallen ceiling tiles throughout the building, all the way down to the Concourse Level. The pipes
that fed the automatic fire sprinkler system were severed. At least 166 windows were broken. Damage to interior walls was reported from the Lobby to the 92"'' floors. However, the building was designed with
reserve capacity: it could support significantly more load than the weight of the structure and its people and contents. The building redistributed the load from the severed perimeter columns, mainly to their
neighboring columns. The undamaged core columns assumed the remaining load, as well as the load from their damaged neighbors. WTC 1 still stood, and would have continued to do so, if not for the fires that followed.

NIST could not determine how many occupants were in the path of the aircraft as it entered the tower.

Those in the direct collision path were almost certainly killed instantly. Many more would have lost their lives from the burst of heat from the burning jet fuel. Fatal injuries were reported on floors as low as the
Concourse Level, where a fireball swept through the lobby

In the impact region was further damage that would cost the lives of all the 1,355 people from the 92 floor to the 1 10''^ floor. The crash and flying debris had collapsed the walls of all three stairwells and interrupted all elevator service to the upper 60 floors. All opportunity for escape had been eliminated."

 

2.4 The Jet fuel

To the wings of the 767-200ER, the perimeter columns acted like knife blades, slashing the aluminum fuel tanks and atomizing much of the 10,000 gal ofjet fuel liquid into a spray of fuel droplets.

Atomized jet fuel is highly flammable (similar to kerosene), so both the hot debris and the numerous pieces of electrical and electronic gear in the offices were more than sufficient as ignition sources.

A surge ofcombusting fuel rapidly filled the floors, mixing with dust from the pulverized walls and floor slabs. The pressure created by the heated gases forced the ignited mist out the entrance gash and blown-out windows on the east and south sides of the tower. The resulting fireballs could be seen for miles, precipitating many 9-1-1 calls.

Less than 15 percent of the jet fuel burned in the spray cloud inside the building. A roughly comparable amount was consumed in the fireballs outside the building. Thus, well over half of the jet fuel remained in the building, unbumed in the initial fires. Some splashed onto the office furnishings and combustibles
from the aircraft that lodged on the impacted floors, there to ignite (immediately or later) the fires that would continue to bum for the remaining life of the building. Some of the burning fuel shot up and down the elevator shafts, blowing out doors and walls on other floors all the way down to the basement.

Flash fires in the lobby blew out many of the plate glass windows. Fortunately, there were not enough combustibles near the elevators for major fires to start on the lower floors.

 

Yeah, we've already gone over this back when I found that you didn't look into exactly how much jet fuel made it into the impact floors. According to the NIST, there were 6,947 gallons of fuel after the initial fireball. Of that 6,947 gallons of fuel, 3,474 gallons remained on the impact floor, while an equal number of gallons flowed away.

http://www.journalof911studies.com/letters/e/VisualizationAidsWTCTowers.pdf

You can also scroll down to the bottom of that page to see a visual comparison of the Tower and the volume of jet fuel that we're talking about.
________________________________________________________________________________________________

So, having been exposed as a person who makes shit up and then tries to cover up by claiming that their lies were all part of a plan to induce pettiness, you now reduce yourself to copying and pasting from the NIST report. First of all, you're lucky. Most people wouldn't listen to another word coming out of your mouth, since you've now established yourself as one who will lie in order to get around the facts. But not me. I'm fine with that. I couldn't do this without you.

First of all, the NIST's theory about the effects of the plane impact and the fires has problems. Its assumption that collapse initiation automatically leads to global collapse is exactly that--an unfounded assumption. And they assert that assumption without any supporting argument. The scope of their report is limited to the time between plane-impact and the beginning of collapse. And the same is true about their speculation concerning core column damage; it's . . . speculation. As I've said before, they seem to have started with a conclusion, and then proceeded to make whatever speculation was necessary to arrive at the conclusion.

Here is how they characterize their own Report:

This is the final report on the National Institute of Standards and Technology (NIST) reconstruction of the collapses of the World Trade Center (WTC) towers, the results of an investigation conducted under the National Construction Safety Team Act. This reports [sic] describes how the aircraft impacts and subsequent fires led to the collapses of the towers after terrorists flew jet fuel laden commercial airliners into the buildings . . . (p xiii/15).

Furthermore, they say:

The focus of the Investigation was on the sequence of events from the instant of aircraft impact to the initiation of collapse for each tower. For brevity in this report, this sequence is referred to as the "probable collapse sequence," although it does not actually include the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable. (p xliii/45)

They're saying that they're presenting a probable collapse scenario, but that they have nothing to say about anything concerning the mechanics of the collapse; only their presumption that, once collapse initiation was reached, collapse was inevitable. That's quite of leap. And the only reason they give for their assumption that collapse was inevitable is the fires that followed. However, later in their report, they admit that there is no visual evidence for fires close to or in the cores.

About that, they said this:

Fires deeper than a few meters inside the building could not be seen because of the smoke obscuration and the steep viewing angle of nearly all the photographs. (p 124/178)

So they say that the Tower would have continued standing if not for the fires that followed, but then they basically say that their speculation concerning the fires is just that--speculation. They state that fires raged in the cores of the Towers even though they themselves say that they have no evidence to support it. I'll have more about the fires and what the NIST did not include in their calculations later.

 

11:00
Earth magnetic field on 9/11

 

Still trying to avoid what initiated collapse I see.

And this time by implying in an intentionally misleading way that no photographic evidence from the outside means they were saying there were no fires in the core.

Another lame and desperate truther trick.

Everyone else can just scroll up to the bolded part with the jetfuel down the elevator shafts (which are in the core) and fireball down to the lobby

 

NIST NCSTAR 1-6D

5.2 WTC 1 collapse sequence

The aircraft impacted the north wall of WTC 1 at 8:46 a.m. The aircraft severed exterior columns and floors on the north side of the tower and core columns and floor members between Floor 93 and Floor 98.

The subsequent fires weakened structural subsystems, including the core columns, floors, and exterior walls. The core displaced downward, the floors sagged, and the south exterior wall bowed inward.

At 10:28 a.m., about 102 min after the aircraft impact, WTC 1 began to collapse.
The sequence of main structural events that led to the collapse of WTC 1, starting from aircraft impact, and the causes and effects of these structural events along with key observations, are discussed below.

The WTC 1 collapse sequence consists of five main events, listed in Table 5–1, which are discussed below. Actual observations are summarized in Table 5–2, which are based on NIST’s examination of photos and videos (NIST NCSTAR 1-6).

Table 5–1.
Summary of main events that led to the collapse of WTC 1.

Event Number Event

1 Aircraft impact
2 Unloading of core
3 Sagging of floors and floor/wall disconnections
4 Bowing of south wall
5 Buckling of south wall and collapse initiation

Table 5–2. Observations on WTC 1 provided by NIST.
Time Time from Impact (min) Observation

8:46:26 0 Aircraft impact on the north wall of WTC 1 between Floor 93 and Floor 99 and Columns 112 and 151.

9:25:28 39 Fire on west side of south wall.

9:40 54 No bowing of columns was observed between Columns 301 and 323 on the east side of south wall.

10:18:43 92 Smoke suddenly expelled on Floor 92 north wall, Floor 94 east side of north wall, Floor 95 to Floor 98 on west side of north wall, Floor 95 and Floor 98 on north side of west wall, lower floor on south side.

10:22:59 97 Inward bowing from Floor 95 to about Floor 99 between Columns 308 and 326 (maybe to 340) on the south wall,maximum amplitude approximately 55 in. at Floor 97.

10:28:18 102 Smoke puff out of north edge and center of west wall; smoke and debris clouds out of the north, east, and west walls on Floor 98. Fire out of windows on the north, east, west, and south walls between
Floor 92 and Floor 98, and on Floor 104.

10:28:20 102 WTC 1 began to collapse. First exterior sign of collapse was at Floor 98. Rotation of at least 8 degrees to the south occurred before the building section began to fall vertically under gravity.

Aircraft Impact

The aircraft impacted WTC 1 at the north wall. The aircraft severed or heavily damaged Columns 112 to 151 between Floors 94 and 98 on the north wall. After breaching the building’s perimeter, the aircraft continued to penetrate into the building. The north office area floor system sustained severe structural damage between Columns 112 and 145 at Floors 94 to 98. Core Columns 503, 504, 505, 506, 604, 704, 706, 805, and 904 were severed or heavily damaged between Floor 92 and Floor 97.

The aircraft also severed a single exterior panel at the center of the south wall from Columns 329 to 331 between Floor 93 and Floor 96. In summary, 38 of 59 columns of the north wall, three of 59 columns of the south wall, and nine of 47 core columns were severed or heavily damaged. In addition, thermal insulation on floor
framing and columns was also damaged from the impact area to the south perimeter wall, primarily through the center of WTC 1 and over one-third to one-half of the core width.

Figures 2–2, 2–14, and 2–18 summarize aircraft impact damage to exterior and core columns and floors of WTC 1.

Gravity loads in the columns that were severed were redistributed, mostly to the neighboring columns. Due to the severe impact damage to the north wall, the wall section above the impact zone moved
downward as shown in Figs. 4–9 and 4–13.

The hat truss resisted the downward movement of the north wall and rotated about its east-west axis, which reduced the load on the south wall. As a result, the north
and south walls each carried about 7 percent less gravity loads at Floor 98 after impact, the east and west walls each carried about 7 percent more loads, and the core carried about 1 percent more gravity loads at
Floor 98 after impact (Table 5–3).

Column 705 buckled, and Columns 605 and 804 showed minor buckling.

Unloading of Core

Temperatures in the core area rose quickly, and thermal expansion of the core was greater than the thermal expansion of the exterior walls in early stages of the fire.

This increased the gravity loads in the
core columns until 10 min after impact (Table 5–3). The additional gravity loads from adjacent severed columns and high temperatures caused high plastic and creep strains to develop in the core columns in
early stages of the fire.

More columns buckled inelastically due to high temperatures. Creep strain continued to increase to the point of collapse (see Fig. 4–81). By 30 min, the plastic-plus-creep strains
exceeded thermal expansion strains. Due to high plastic and creep strains and inelastic buckling of core columns, the core columns shortened, and the core displaced downward.

At 100 min, the downward displacement of the core at Floor 99 became 2.0 in. on the average, as shown in Fig. 4–37.

The shortening of core columns was resisted by the hat truss, which unloaded the core over time and redistributed the gravity loads from the core to the exterior walls, as can be seen in Table 5–3.

As a result, the north, east, south, and west walls at Floor 98 carried about 12 percent, 27 percent, 10 percent, and 22 percent more gravity loads, respectively, at 80 min than the state after the impact, and the core
carried about 20 percent less loads as shown in Table 5–3.

The net increase in the total column load on
the south wall, where exterior wall failure initiated, was only about 10 percent due to the downward displacement of the core (see Fig. 5–3).

At 80 min, the total core column loads reached their maximum.
As the floor pulled in starting at 80 min on in the south side, the south exterior wall began to shed load to adjacent walls and the core.

 

NIST NCSTAR 1-6D continued

Sagging of Floors and Floor/Wall Disconnections

The long-span trusses of Floor 95 through Floor 99 sagged due to high temperatures.

While the fires were on the north side and the floors on the north side sagged first, the fires later reached the south side, and the floors on the south side sagged. Figure 5–4 shows vertical displacements of Floors 95 through 98 determined by the full floor models at 100 min. Full floor models underestimated the extent of sagging because cracking and spalling of concrete and creep in steel under high temperatures were not included in
the floor models, and because the extent of insulation damage was conservatively estimated.

The sagging floors pulled in the south wall columns over Floors 95 to 99. In addition, the exterior seats on the south wall in the hot zone of Floors 97 and 98 began to fail due to their reduced vertical shear capacity at
around 80 min, and by 100 min about 20 percent of the exterior seats on the south wall of Floors 97 and 98 failed, as shown in Figs. 5–4 and 5–5.

Partial collapse of the floor may have occurred at Floors 97 and 98, resulting from the exterior seat failures, as indicated by the observed smoke puff at 92 min (10:19
a.m.) in Table 5–2, but this phenomenon was not modeled.

Bowing of South Wall

The exterior columns on the south wall bowed inward as they were subjected to high temperatures, pull-in forces from the floors beginning at 80 min, and additional gravity loads redistributed from the core.

Figure 5–6 shows the observed and the estimated inward bowing of the south wall at 97 min after impact (10:23 a.m.). Since no bowing was observed on the south wall at 69 min (9:55 a.m.), as shown in Table
5–2, it is estimated that the south wall began to bow inward at around 80 min when the floors on the south side began to substantially sag.

The inward bowing of the south wall increased with time due to continuing floor sagging and increased temperatures on the south wall as shown in Figs. 4–42 and 5–7.
At 97 min (10:23 a.m.), the maximum bowing observed was about 55 in. (see Fig. 5–6).

Buckling of South Wall and Collapse Initiation

With continuously increased bowing, as more columns buckled, the entire width of the south wall buckled inward. Instability started at the center of the south wall and rapidly progressed horizontally toward the
sides. As a result of the buckling of the south wall, the south wall significantly unloaded (Fig. 5–3), redistributing its load to the softened core through the hat truss and to the south side of the east and west walls through the spandrels.

The onset of this load redistribution can be found in the total column loads
in the WTC 1 global model at 100 min in the bottom line of Table 5–3. At 100 min, the north, east, and west walls at Floor 98 carried about 7 percent, 35 percent, and 30 percent more gravity loads than the state after impact, and the south wall and the core carried about 7 percent and 20 percent less loads, respectively.

The section of the building above the impact zone tilted to the south (observed at about 8˚, Table 5–2) as column instability progressed rapidly from the south wall to the adjacent east and west walls (see Fig. 5–8), resulting in increased gravity load on the core columns.

The release of potential
energy due to downward movement of building mass above the buckled columns exceeded the strain energy that could be absorbed by the structure. Global collapse ensued.

 

Um, I just showed you that the NIST admitted to not knowing the extent of fires beyond a few meters inside the Tower, but you nevertheless believe them when they say that it was the fire that did the Tower in. You seem unaware that there was really nothing combustible in the core area. You also seem to be totally unaware that no steel members were found to have been subjected to anything beyond 600 degrees Celsius.

You also seem to not understand what the NIST means when they say: "For brevity in this report, this sequence is referred to as the "probable collapse sequence," although it does not actually include the structural behavior of the tower after the conditions for collapse initiation were reached and collapse became inevitable.

That means that when they say: The aircraft severed or heavily damaged Columns 112 to 151 between Floors 94 and 98 on the north wall. After breaching the building’s perimeter, the aircraft continued to penetrate into the building. The north office area floor system sustained severe structural damage between Columns 112 and 145 at Floors 94 to 98. Core Columns 503, 504, 505, 506, 604, 704, 706, 805, and 904 were severed or heavily damaged between Floor 92 and Floor 97, they are speculating. That's why despite their extreme detail in certain areas, they do so without any detail or supporting evidence. Go ahead and find the supporting evidence for the above. You won't find it. But for some reason, you and others just buy into their detailed explanation that could have only been gotten if they were inside the Tower at the time taking notes. But they weren't. Plus, their assessment of the heating of columns ignores the effect of the thermal conductivity of steel. And yet they say that it was the fires that caused the failure of the structure, even though other steel towers did not collapse after burning for 20 hours.

And of course the NIST totally disregards the resistance that the rest of the Tower would have offered to the upper block.

But you can start by producing the NIST's evidence that supports their speculation concerning what they call the "probable collapse sequence." Maybe you should first look up the word, "probable."
______________________________________________________________________

Let's go further:

From the NIST Report: Observations of paint cracking due to thermal expansion. Of the more than 170 areas examined on 16 perimeter column panels, only three columns had evidence that the steel reached temperatures above 250 ºC: east face, floor 98, inner web; east face, floor 92, inner web; and north face, floor 98, floor truss connector. Only two core column specimens had sufficient paint remaining to make such an analysis, and their temperatures did not reach 250 ºC. ... Using metallographic analysis, NIST determined that there was no evidence that any of the samples had reached temperatures above 600 ºC. (p 88/142)

So, the highest temperatures they estimated for the samples was 250 degrees Celsius (482 degrees Fahrenheit ). That's consistent with the results of fire tests in uninsulated steel-framed parking garages, which showed maximum steel temperatures of 360 ºC (680 ºF). How interesting that the NIST's sagging truss model has the truss heated to 700 degrees Celsius (1292 degrees Fahrenheit).

From the NIST Report: A floor section was modeled to investigate failure modes and sequences of failures under combined gravity and thermal loads. The floor section was heated to 700 ºC (300 ºC at the top surface of the slab) over a period of 30 min. Initially the thermal expansion of the floor pushed the columns outward, but with increased temperatures, the floor sagged and the columns were pulled inward. (p 96/150)

So the NIST asserts that steel temperatures should be more than 450 degrees Celsius (or 842 degrees Fahrenheit) higher than their own evidence indicates. Funny, huh?

 

So thats it? Thats all you got after 72 pages?

Corrobirating evidence for the columns that wouldnt stand up by themselves anyway?

And....

"Plus, their assessment of the heating of columns ignores the effect of the thermal conductivity of steel"

Their assesment of the heating of the columns ignores the effect of how the columns conduct heat.

Are you freakin serious???