Collapse of the Twin Towers

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Alchemist

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Let's see what was inside these buildings.








  • Each tower contained 96,000 tons of steel
  • 820 tons of steel per floor
  • 47 huge vertical steel core columns in the middle
  • 240 perimeter steel columns
  • 287 steel columns in total
Jet fuel doesn't burn anywhere near the temperature hot enough to melt steel. Steel weakens by 50% at only 1200 degrees.

This is directly from NIST report:
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… 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.
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(NIST, 2005, pp. 176-177; emphasis added.)

This is because jet fuel burns up QUICK and most of what you saw burning were office debris. In fact, MOST of the jet fuel exploded OUTSIDE when the 2nd plane hit as we can see here:



What we saw burning for most of the time were office debris which were controllable. We've all unfortunately seen the famous pictures of victims jumping out of the towers, but this happened during the first 15 minutes while the jet fuel was still burning. Later, we have photographs of victims STANDING in the impact holes.. BEGGING for help.. how could they survive heat that would melt through giant steel columns and girders? They wouldn't be able to...






And the firefighters were on record saying the fires were controlled. The temperatures had dropped dramatically, a lot of fires were extinguished, the people were in the open wounds begging for help.
9:52 a.m. Palmer surveys the damage on the 78th floor. He radios the men of Ladder Company 15 who are on their way up.

Battalion Chief Palmer: "Battalion Seven ... Ladder 15, we've got two isolated pockets of fire. We should be able to knock it down with two lines. Radio that, 78th floor numerous 10-45 Code Ones."
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9:48 a.m., September 11, 2001Ladder 15: “Battalion Fifteen to Battalion Seven.”
Battalion Seven: “Go Ladder 15.”
Ladder 15: “What do you got up there, Chief?”
Battalion Seven Chief: “I’m still in boy stair, 74th floor. No smoke or fire problems, walls are breached, so be careful.”
Ladder 15: “Yeah Ten-Four, I saw that on 68. Alright, we’re on 71. We’re coming up behind you."

Battalion Seven Chief: “Ten-four.”
Ladder 15: “Let me know when you see more fire.”
Battalion Seven Chief: “I found a marshall on 75.”
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"The buildings should have easily withstood the thermal stress caused by pools of burning jet fuel." - Kevin Ryan

Kevin Ryan is Site Manager at Environmental Health Laboratories (EHL) in South Bend, Indiana. This is a division of UL, the product-compliance and testing giant. This is directly from the UL which certified the WTC steel for its ability to withstand fires.

This is from Firefighter Engineering... one of the oldest engineering publication in United States... who went public as well calling for an investigation and criticizing the government for destroying the evidence:
Selling Out the Investigation
By Bill Manning

Did they throw away the locked doors from the Triangle Shirtwaist Fire? Did they throw away the gas can used at the Happyland Social Club Fire? Did they cast aside the pressure-regulating valves at the Meridian Plaza Fire? Of course not. But essentially, that's what they're doing at the World Trade Center.

For more than three months, structural steel from the World Trade Center has been and continues to be cut up and sold for scrap. Crucial evidence that could answer many questions about high-rise building design practices and performance under fire conditions is on the slow boat to China, perhaps never to be seen again in America until you buy your next car.

Such destruction of evidence shows the astounding ignorance of government officials to the value of a thorough, scientific investigation of the largest fire-induced collapse in world history. I have combed through our national standard for fire investigation, NFPA 921, but nowhere in it does one find an exemption allowing the destruction of evidence for buildings over 10 stories tall.

Hoping beyond hope, I have called experts to ask if the towers were the only high-rise buildings in America of lightweight, center-core construction. No such luck. I made other calls asking if these were the only buildings in America with light-density, sprayed-on fireproofing. Again, no luck-they were two of thousands that fit the description.

Comprehensive disaster investigations mean increased safety. They mean positive change. NASA knows it. The NTSB knows it. Does FEMA know it?

No. Fire Engineering has good reason to believe that the "official investigation" blessed by FEMA and run by the American Society of Civil Engineers is a half-baked farce that may already have been commandeered by political forces whose primary interests, to put it mildly, lie far afield of full disclosure. Except for the marginal benefit obtained from a three-day, visual walk-through of evidence sites conducted by ASCE investigation committee members- described by one close source as a "tourist trip"-no one's checking the evidence for anything.

Maybe we should live and work in planes. That way, if disaster strikes, we will at least be sure that a thorough investigation will help find ways to increase safety for our survivors.

As things now stand and if they continue in such fashion, the investigation into the World Trade Center fire and collapse will amount to paper- and computer-generated hypotheticals.

However, respected members of the fire protection engineering community are beginning to raise red flags, and a resonating theory has emerged: The structural damage from the planes and the explosive ignition of jet fuel in themselves were not enough to bring down the towers. Rather, theory has it, the subsequent contents fires attacking the questionably fireproofed lightweight trusses and load-bearing columns directly caused the collapses in an alarmingly short time. Of course, in light of there being no real evidence thus far produced, this could remain just unexplored theory.

The frequency of published and unpublished reports raising questions about the steel fireproofing and other fire protection elements in the buildings, as well as their design and construction, is on the rise. The builders and owners of the World Trade Center property, the Port Authority of New York-New Jersey, a governmental agency that operates in an accountability vacuum beyond the reach of local fire and building codes, has denied charges that the buildings' fire protection or construction components were substandard but has refused to cooperate with requests for documentation supporting its contentions.

Some citizens are taking to the streets to protest the investigation sellout. Sally Regenhard, for one, wants to know why and how the building fell as it did upon her unfortunate son Christian, an FDNY probationary firefighter. And so do we.

Clearly, there are burning questions that need answers. Based on the incident's magnitude alone, a full-throttle, fully resourced, forensic investigation is imperative. More important, from a moral standpoint, for the safety of present and future generations who live and work in tall buildings-and for firefighters, always first in and last out-the lessons about the buildings' design and behavior in this extraordinary event must be learned and applied in the real world.

To treat the September 11 incident any differently would be the height of stupidity and ignorance.

The destruction and removal of evidence must stop immediately.

The federal government must scrap the current setup and commission a fully resourced blue ribbon panel to conduct a clean and thorough investigation of the fire and collapse, leaving no stones unturned.

Firefighters, this is your call to action. Visit WTC "Investigation"?: A Call to Action, then contact your representatives in Congress and officials in Washington and help us correct this problem immediately.
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Frank Demartini, Construction Manager, specifies that the towers were specifically designed to withstand MULTIPLE impacts of jets


Yet we've been told that fire was able to cause the 47 huge core columns in the middle to fail in unison at close to free-fall acceleration via "pan cake theory". If it's correct that the weight of the floors above was responsible for the collapse, then how come the basement columns were still in tact?

 
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Mick West

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That's what is know as "an argument from personal incredulity".

See:
https://www.metabunk.org/threads/posting-guidelines.2064/

Guidelines for new threads
(guidelines, not rules - there are always exceptions).
  1. Focus on individual claims of evidence, not broader theories
  2. Title the thread with something that identifies that claim, preferably with an appropriate tag word/phrase describing what the first post does (e.g. "Claim:" , "Debunked:", "Fake:", "Need Debunking:" (only use descriptors that you can back up)
  3. Describe what the claim of evidence is, who made it, where they made it, what the known facts are, what are the disputed facts, and what is the broader theory that this claim is supporting
  4. Debunk it if possible. Explain what the problems with the claim are - both evidence and conclusions. Link to other sites that discuss the claim.
  5. Ask specific questions about what you don't know about the claim
 
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Mick West

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If you want to continue please pick one of the points in your OP, briefly discuss the standard debunker arguments, and then explain why you think they are wrong.
 

Alchemist

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NIST report admits that there is no evidence that temperatures reached anywhere close to what would be required to weaken or melt the steel. Most of the jet fuel burnt out very quickly.. most of it exploding outside of the 2nd tower in a giant fireball... and there were people standing in the impact holes along with firefighters confirming that fires were extinguished and controlled as high as 78th floor. NIST doesn't even understand what happened.

Only half of one page of this 10,000-page report is spent on the actual collapse, and it merely speculates that “the structure below the level of collapse initiation offered minimal resistance to the falling building mass” and that it “came down essentially in free fall as seen in the videos”.NIST’s response to formal Request for Correction filed by this author and five other concerned citizens stated “we are unable to provide a full explanation of the total collapse.
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This is what the WTC Construction Manager said about the design:
The building was designed to have a fully loaded 707 crash into it. That was the largest plane at the time... the building could probably sustain multiple impacts of jet liners because this structure is like the mosquito netting in your screen door - this intense grid - and the jet plane is just a pencil puncturing that screen netting - it really does nothing to the screen netting.

Despite this intense matrix netting of steel with HUGE 47 VERTICAL CORE COLUMNS in the middle, the towers came down with NO RESISTANCE crushing through more than 70,000 TONS OF STEEL. For this to occur all of those 47 vertical core columns would need to fail simultaneously. How is this possible as a result of fires and asymmetrical structural damage?
 
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Mick West

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NIST has a FAQ, which is a good starting point.
http://www.nist.gov/el/disasterstudies/wtc/faqs_wtctowers.cfm

The towers did not come down with no resistance, so your last question is moot. The resistance was about 0.1g, as I remember. And it's an average of a very complex system of millions of events.

The lower portion of the tower could hold up a large static load, but the dynamic load of the moving upper floors vastly, VASTLY exceeded that.

It's like the difference between resting a weight on something, and dropping the weight on something. Like, say, a 30lb weight on an empty coke can. It can easily support it, but once it's moving, it can't stop it.
 

Alchemist

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Their own report says it was free-fall. The airplane hit above 92 floor. How does that adequately explain how 14,760 pounds of steel crushes through 75,440 still-intact, highly robust tons of steel in lower part of the tower at almost no resistance (0.1g) as if falling through thin air?
 

Landru

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Their own report says it was free-fall. The airplane hit above 92 floor. How does that adequately explain how 14,760 pounds of steel crushes through 75,440 still-intact, highly robust tons of steel in lower part of the tower at almost no resistance (0.1g) as if falling through thin air?

NIST explains it in their report and here.


11. How could the WTC towers collapse in only 11 seconds (WTC 1) and 9 seconds (WTC 2)—speeds that approximate that of a ball dropped from similar height in a vacuum (with no air resistance)?

NIST estimated the elapsed times for the first exterior panels to strike the ground after the collapse initiated in each of the towers to be approximately 11 seconds for WTC 1 and approximately 9 seconds for WTC 2. These elapsed times were based on: (1) precise timing of the initiation of collapse from video evidence, and (2) ground motion (seismic) signals recorded at Palisades, N.Y., that also were precisely time-calibrated for wave transmission times from lower Manhattan (see NIST NCSTAR 1-5A).

As documented in Section 6.14.4 of NIST NCSTAR 1, these collapse times show that:

“The structure below the level of collapse initiation offered minimal resistance to the falling building mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that energy through energy of deformation.

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below, which were unable to arrest the moving mass.”

In other words, the momentum (which equals mass times velocity) of the 12 to 28 stories (WTC 1 and WTC 2, respectively) falling on the supporting structure below (which was designed to support only the static weight of the floors above and not any dynamic effects due to the downward momentum) so greatly exceeded the strength capacity of the structure below that it (the structure below) was unable to stop or even to slow the falling mass. The downward momentum felt by each successive lower floor was even larger due to the increasing mass.

From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.
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Mick West

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Their own report says it was free-fall. The airplane hit above 92 floor. How does that adequately explain how 14,760 pounds of steel crushes through 75,440 still-intact, highly robust tons of steel in lower part of the tower at almost no resistance (0.1g) as if falling through thin air?

It's very clearly not collapsing at free fall speed, as the bits that fall off it fall faster than the collapse. The black beams here are falling at free fall. The tower is not.
upload_2013-8-9_16-5-27.png
 

Landru

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Specific paragraph from above. Emphasis mine.

From video evidence, significant portions of the cores of both buildings (roughly 60 stories of WTC 1 and 40 stories of WTC 2) are known to have stood 15 to 25 seconds after collapse initiation before they, too, began to collapse. Neither the duration of the seismic records nor video evidence (due to obstruction of view caused by debris clouds) are reliable indicators of the total time it took for each building to collapse completely.
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Not exactly free fall the whole way.
 

Landru

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And for WTC 1&2 NIST examined the steel.


8. Why didn’t NIST consider a “controlled demolition” hypothesis with matching computer modeling and explanation like it did for the “pancake theory” hypothesis?

NIST conducted an extremely thorough three-year investigation that included consideration of a number of hypotheses for the collapses of the WTC towers.

Some 200 technical experts—including about 85 career NIST experts and 125 leading experts from the private sector and academia—reviewed tens of thousands of documents, interviewed more than 1,000 people, reviewed 7,000 segments of video footage and 7,000 photographs, analyzed 236 pieces of steel from the wreckage, performed laboratory tests, and created sophisticated computer simulations of the sequence of events that occurred from the moment the aircraft struck the towers until they began to collapse.

Based on its comprehensive investigation, NIST concluded that the WTC towers collapsed according to the scenario detailed in the response to Question 6.

NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers (the composite floor system—that connected the core columns and the perimeter columns—consisted of a grid of steel “trusses” integrated with a concrete slab; see diagram). Instead, the NIST investigation showed conclusively that the failure of the inwardly bowed perimeter columns initiated collapse and that the occurrence of this inward bowing required the sagging floors to remain connected to the columns and pull the columns inwards. Thus, the floors did not fail progressively to cause a pancaking phenomenon.









Diagram of the Composite WTC Floor System Credit: NIST


NIST’s findings also do not support the “controlled demolition” theory since there is conclusive evidence that:

  • the collapse was initiated in the impact and fire floors of the WTC towers and nowhere else, and;
  • the time it took for the collapse to initiate (56 minutes for WTC 2 and 102 minutes for WTC 1) was dictated by (1) the extent of damage caused by the aircraft impact, and (2) the time it took for the fires to reach critical locations and weaken the structure to the point that the towers could not resist the tremendous energy released by the downward movement of the massive top section of the building at and above the fire and impact floors.
Video evidence also showed unambiguously that the collapse progressed from the top to the bottom, and there was no evidence (collected by NIST or by the New York City Police Department, the Port Authority Police Department, or the Fire Department of New York) of any blast or explosions in the region below the impact and fire floors as the top building sections (including and above the 98th floor in WTC 1 and the 82nd floor in WTC 2) began their downward movement upon collapse initiation.

In summary, NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives. NIST also did not find any evidence that missiles were fired at or hit the towers. Instead, photographs and videos from several angles clearly show that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward until the dust clouds obscured the view.
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Alchemist

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Just like you can redirect questions pertaining to illegally wiretapping reporters to Eric Holder's FAQs. :)
 
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Landru

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Just like you can redirect questions pertaining to illegally wiretapping reporters to Eric Holder's FAQs. :)

If Eric Holder had 200 technical experts—including about 85 career NIST experts and 125 leading experts from the private sector and academia—reviewed tens of thousands of documents, interviewed more than 1,000 people, reviewed 7,000 segments of video footage and 7,000 photographs, analyzed 236 pieces of steel from the wreckage, performed laboratory tests, and created sophisticated computer simulations of the sequence of events that occurred from the moment the aircraft struck the towers until they began to collapse, then yeah.
 

Alchemist

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Of course when they were under the direction of authorities with an agenda...

 
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Mick West

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Hang on now. You can't just toss out points and then ignore the answers. What about the free-fall issue? Do the rebuttals above change anything for you?
 

Alchemist

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As I've posted above... even NIST admits that the fires were NOWHERE close to the temperatures required to WEAKEN the steel, let alone melt it. NIST's collapse conclusions don't fit observable facts. They can't account for the complete failure of the 47 IMMENSE vertical core columns in the middle.


In the case of the free-falling body, the two kinds of energy we are concerned with are kinetic energy and potential energy. Examples of potential (gravitational) energy are the water stored way up high in a water tower, or a boulder perched atop a hill. If whatever’s holding them up there is removed, they will come down, under the influence of gravity’s pull.

So, as an object falls, it gives up potential energy for kinetic energy.

It turns out that the equation for potential energy is as follows:
Potential Energy = Mass x Gravity x Height

It turns out that the equation for kinetic energy is as follows:
Kinetic Energy = 1/2 x Mass x Velocity(squared)

So let’s just say, for the sake of simplicity, that our falling object has a mass of 1. (Remember, the object’s mass will affect its energy, and its momentum, but not its rate of free-fall.)

The potential energy given up by falling 3 seconds (144 ft) is 1×32 x 144 = 4608

The kinetic energy gained after falling 3 secs is 1/2×1 x 96(squared) = 1/2×9216 = 4608

So, all of the available potential energy was converted to kinetic energy. Seeing that energy was, in fact, conserved is how we know that the answer in The Simplest Case, above, was correct. We’ve checked our work, using an independent analysis, based upon the sound principle of conservation of energy. Now, and only now, we can be certain that our answer was correct.
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One little complication...

Air resistance.

The free-fall equations reflect a perfect, frictionless world. They perfectly predict the behavior of falling bodies which encounter zero resistance, as in a vacuum. In fact, some of you may have seen a science class demonstration in which the air is pumped out of a tube and then a feather will fall, in that vacuum, as fast as will a solid metal ball.

That’s how parachutes work: much of the falling object’s potential energy gets expended doing the work of pushing a lot of air out of the way in order for the object to fall. As a result, not all of the potential gravitational energy can go towards accelerating the object downward at gravity’s maximal rate of 32 ft/sec/sec.

In other words, only when there is zero resistance can any falling object’s potential energy be completely converted into kinetic energy. Anything which interferes with any falling object’s downward progress will cause its acceleration to be reduced from the maximum gravitational acceleration of 32 feet per second per second, as some of gravity’s potential energy is consumed doing work overcoming resistance.

That’s why you may have heard the term “terminal velocity”. The free-fall equations predict that a falling object’s velocity will continue to increase, without limit. But in air, once a falling object reaches a certain speed, its propensity to fall will be matched by air’s resistance to the fall. At that point the object will continue to fall, but its speed will no longer increase over time.

A Quick Recap

Earth’s gravity causes objects to fall. They fall according to precise, well-known equations. The equations assume no (air) resistance. Any resistance at all will cause the object to fall less rapidly than it would have without that resistance.

It is that last sentence which bears repeating.

There is a maximum possible rate at which objects fall, and if any of gravity’s potential energy is consumed doing anything other than accelerate the object downward even just having to push air out of the way there will be less energy available to accelerate the object downward, and so that object’s downward acceleration will be diminished.

And if an object’s downward acceleration is diminished, it will be going slower along the way, and thus it will take longer to fall a given distance.

Free-falling from WTC heights

The towers were 1350 and 1360 feet tall. So let’s start by using our trusty free-fall equation to see how long it should take an object to free-fall from the towers’ former height.

Distance = 1/2 x Gravity x Time(squared)
or
2 x Distance = Gravity x Time(squared)
Time(squared) = (2 x Distance) / Gravity
Time(squared) = 2710 / 32 = 84.7
Time = 9.2

So our equation tells us that it will take 9.2 seconds to free-fall to the ground from the towers’ former height.

Using our simpler equation, V = GT, we can see that at 9.2 seconds, in order to reach the ground in 9.2 seconds, the free-falling object’s velocity must be about 295 ft/sec, which is just over 200 mph.

But that can only occur in a vacuum.

Since the WTC was at sea level, in Earth’s atmosphere, you might be able to imagine how much air resistance that represents. (Think about putting your arm out the window of a car moving half that fast!) Most free-falling objects would reach their terminal velocity long before they reached 200 mph. For example, the commonly-accepted terminal velocity of a free-falling human is around 120 mph. The terminal velocity of a free-falling cat is around 60 mph. (source)

Therefore, air resistance alone will make it take longer than 10 seconds for gravity to pull an object to the ground from the towers’ former height.
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Observations from 9/11

On page 305 of the 9/11 Commission Report, we are told, in the government’s “complete and final report” of 9/11, that the South Tower “collapsed” in 10 seconds. “quote”: At 9:58:59, the South Tower collapsed in ten seconds”(That’s the government’s official number) Videos confirm that it fell unnaturally, if not precisely that fast. See for yourself: QT Real)

But as we’ve just determined, that’s free-fall time. That’s close to the free-fall time in a vacuum, and an exceptionally rapid free-fall time through air.

But the “collapse” proceeded “through” the lower stories of the tower. Those undamaged floors below the impact zone would have offered resistance that is thousands of times greater than air. Recall that those lower stories had successfully supported the mass of the tower for 30 years.

Air can’t do that.

Can anyone possibly imagine the supposedly-undamaged lower floors getting out of the way of the upper floors as effortlessly as air would?

Can anyone possibly imagine the lower stories slowing any kind of fall of the upper floors less than would, say, a parachute? (And what energy source could have reduced the height of [most of] the columns, top-down, at the same rate?)

You can move your arms and legs, non-destructively, through water a liquid fluid but not anywhere near as rapidly as you can through air. You certainly can’t move your arms and legs through solids as rapidly as you can through air. And neither can gravity.
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Pete Tar

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Where's the bit admitting that 'even NIST admits that the fires were NOWHERE close to the temperatures required to WEAKEN the steel, let alone melt it.'?
And I don't think anyone thinks the steel needed to melt to cause the failure.
 

Alchemist

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Where's the bit admitting that 'even NIST admits that the fires were NOWHERE close to the temperatures required to WEAKEN the steel, let alone melt it.'?
And I don't think anyone thinks the steel needed to melt to cause the failure.
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… 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.
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(NIST, 2005, pp. 176-177; emphasis added.)
 

Alchemist

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Hang on now. You can't just toss out points and then ignore the answers. What about the free-fall issue? Do the rebuttals above change anything for you?
This is from the VERY LINK he posted of the FAQ's right above where he got that paragraph:

“Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos.
-NIST
 

Keef Wivanef

New Member
I'm not big on conspiracy theories BUT!

The columns supporting the building were massive.
Could the kinetic energy of the plane deliver enough energy to destroy enough of the columns to cause a collapse?
The engine parts would probably be the only parts substantial enough to do much damage but I've never seen any footage that shows any of those columns had been taken out.
The building didn't fall down right away so I think we can probably exclude that possibility.

Much of the fuel load was ejected from the building and exploded in a fireball.
Given the thermal mass of steel and concrete would act as a massive heat sink it seems unlikely that the fire would have weakened the structure sufficient to cause the collapse. ( I said unlikely not impossible)

The free fall argument doesn't bother me too much. If the entire supporting structure at the level of impact did suddenly collapse then it seems reasonable that the sledgehammer effect of the upper block dropping 10 foot or so onto the next floor would be pretty devastating on the floors below and the rate of fall probably be just a bit slower than free fall.

Chances of both towers (and WT7) falling perfectly vertically into their own footprint?
Not impossible but it would need a simultaneous failure of virtually all the supporting columns.

Now, how about those blobs of white hot metal dug out by the excavators two weeks 7/11?
That was a bit strange!

" Any molten steel in the wreckage was more likely due to the high temperature resulting from long exposure to combustion within the pile than to short exposure to fires or explosions while the buildings were standing."

I find that very hard to believe!
 
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