Metatheory and the NIST report

[jay howard]

To begin to have a dialogue about the adequacy of the NIST report, we cannot simply approach an interlocutor with a lump-sum of data that only corroborates itself from its own perspective. For the skeptics sake, this dialogue must begin at the beginning. With that, please read this whole thing, because pieces of it will come up again.

Without omnipotence, we will always fall short of absolute truth. There is no way around this. Anyone who doubts this needs to read and understand Kant before proceeding. That said, every bit of evidence is open to interpretation. However, at some point, if none of the evidence to support a position can be verified, or it turns out to be based on unverifiable claims, or is in contradiction to well-designed tests, then that evidence must be weighed against the entirety of the claim: what S. Pepper calls “danda corroboration.”

Because our human nature makes it difficult to admit when problems exist in our theories, we can appeal to a set of criteria from which all theories can be judged. These criteria do not care about anyone’s political agenda nor are they affected by tricks of logic.

These criteria exist in response to real-world epistemic conditions. That is, these criteria are not designed to be able to tell which theory is “true” and which is “false,” but which theory is better designed to answer the question at hand. In the real world, “truth” bears no capital “T”. If it did, we would need no such standards, and we would not need evidence and argument to bring us to conclusions. This epistemic problem goes much deeper than this introduction can even allude to, however, we can (and do, everyday,) make judgments regarding the probability of certain events: i.e., that the oxygen in the room will remain relatively evenly distributed; that our vehicle will not explode without forewarning; that our chair will sustain our weight, etc. These are reasonable probabilities on which most of us waste little deliberative thought. The fact remains that these judgments are probabilities, not guarantees.

Please bear with me.

Parsimony—also called Ockham’s Razor—states that of two competing theories with equal explanatory power, the simplest theory is more theoretically appealing than the more complicated one. Strictly defined, parsimony demands us not to “multiply entities beyond necessity.” In terms of JFK, the “lone assassin” theory (LAT) better meets this standard as it has fewest moving parts: crazy assassin, high-value target. Whereas the alternative theories require government-mobster collusion, coordination across time and space and through multiple levels within our own government, etc. Not very parsimonious.

Explanatory power: Simply put, the theory that explains the most phenomena and disregards the least evidence is the more powerful theory. Put another way, if theory A must disregard some evidence, and theory B does not, theory B is a better theory. This ties directly with the choices noted above to wit, evidence in contradiction to an explanation requires either the dismissal of the evidence or a shift to a more powerful theory—or a more powerful version of a theory. When taking into account the Zapruder film, we cannot deny the apparent snap of the President’s head toward the lone assassin. The (LAT) cannot account well for this evidence and is thus thrown into doubt despite its parsimonious nature.

Experimental repeatability: The events espoused by a theory should be repeatable or at least observable in analogous circumstances. Theories that hinge on results that are unrepeatable are suspect as unlikely. See “Falsifiability” below.

As a further explication of the above criteria, we should recognize that theories that fly in the face of long-standing, fundamental principles (otherwise known as “laws of physics and thermodynamics”), are highly questionable, and require very strong evidence to even consider as plausible, much less as likely explanations.

Falsifiability: If there do not exist any criteria by which a proposition might be false, then it is not really an explanation at all. That is, if there is no way a theory could be false, then there is no way that theory could be right. For a theory to be a contender explanation, it must be possible for the claim to be wrong. If I claim that you have a scorpion on your face, but you cannot see it, feel it, get stung by it or otherwise test for it in any way, then the claim is indistinguishable from its denial. There is no way to prove or disprove it, so functionally, it is meaningless. Undetectable scorpions play a larger role than for which we give them credit, however, they bring us no closer to discerning fruitful probabilities from wild speculation.

If we suspect a theory of being unfalsifiable, we may check to see what conditions would satisfactorily take it out of the running as a likely explanation. For instance, if the neighbor claims to have talked to a demon, what possible criteria could be employed to dissuade such a view? None exist. The statement is only useful science if our object of inquiry were our neighbor’s mental processes and should not be used to explain physical phenomenon. Such views should be quickly identified and sifted from plausible explanations of the world—or incorporated into theories that account for moon-bat neighbors. These all seem like things that don’t need to be pointed out, however, the emotional power of an American mass murder can be more persuasive than logic.

This is where the initial question for anyone’s theory needs to start. So let's do a thought experiment:

Take your favorite position on the cause of the WTC towers collapse and ask: "What conditions would need to be met in order to disprove my theory?"

If I believe mini-nukes brought down the WTC buildings, and I know that any fission reaction will produce high amounts of tritium or tritiated water, then my theory can be false if we only find background levels of tritium or strontium-90 or other by-products of a nuclear fission reaction. If any of these fission by-products are found, we do not have sufficient grounds to dismiss the mini-nukes theory altogether; however, if none are found (above background levels), then we need to just depart from that theory because it doesn't help us predict evidence or otherwise make sense of the situation.

If one must alter the evidence to fit the theory, there is a very good chance that the theory is either incomplete or completely wrong.

If I believe in the CD theory, and subsequent lab experiments show that floor trusses do, in fact, fail at the temperatures we have evidence for, then my CD theory fails in terms of parsimony because there's no need to throw in extra entities to account for the evidence.

Given all this, is there anyone who believes the NIST report meets these criteria as a good theory?

I’ve laid this all out before, but the conversation has only resulted in a lot of accusations of how ignorant I am of the NIST report. Thought I’d give you guys a shot at an adult discussion.

[slugmancs]

Why play the game? Can you please state your grievances against the report?

[R.Mackey]

I contend, as someone who has read the NIST report from cover to cover and defended it often, that the NIST theory is falsifiable. On that ground I claim it is a good theory.

If you don't think so, then we will need a few ground rules, of which the most important are these: Do you know what the NIST theory is? What do you think it is? Do you want to discuss it in whole or in part?

Also of critical importance is to understand that the NIST theory has only been tested twice -- by WTC 1 and WTC 2 -- and thus it is difficult to test it rigorously. Falsifiable in general is not the same as falsifiable by the evidence we have in hand. There are, therefore, a few rough spots in the NIST theory, and there always will be, as there are for any accident investigation. This in no way invalidates or even harms the theory. It is what it is.

As long as we can agree to these points, then I look forward to a productive discussion.

[jay howard]

First thing's first. Do you think these are fair standards by which to judge a theory?

[R.Mackey]

Parsimony, repeatability, falsifiability, and agreement with various observations? Yes, I'd say those are all excellent metrics to apply to a theory. Proceed.

[LashL]

Ignoring the Kant and Pepper philosophical fluff, this has the potential to be an interesting thread. I am looking forward to the discussion between RMackey and the noob, "jay howard".

(insert popcorn smilie here)

[slugmancs]

At this point I expected a 5 page copy and paste job, I guess this guy may have more class than most "truthers."

(joins with popcorn smilie)

[jay howard]

Originally Posted by R.Mackey

I contend, as someone who has read the NIST report from cover to cover and defended it often, that the NIST theory is falsifiable. On that ground I claim it is a good theory.

We will test your claim.

Originally Posted by R.Mackey

If you don't think so, then we will need a few ground rules, of which the most important are these: Do you know what the NIST theory is? What do you think it is? Do you want to discuss it in whole or in part?

NIST's theory is basically a heat-induced collapse theory (HICT). Without heat weakening the steel, there is no collapse. In their words,

"...the towers withstood the impacts and would have remained standing were it not for the dislodged insulation and the subsequent multifloor fires."(171)

We will likely discuss it in whole and in part.

Originally Posted by R.Mackey

Also of critical importance is to understand that the NIST theory has only been tested twice -- by WTC 1 and WTC 2 -- and thus it is difficult to test it rigorously.

Why don't the tests NIST did on the short lengths of the floor assemblies count as tests of their theory? The fires were hotter than any of the recovered steel NIST analyzed, and run for longer than it took for the towers to collapse.

Originally Posted by R.Mackey

Falsifiable in general is not the same as falsifiable by the evidence we have in hand.

Falisifiability, as I defined it above, makes no distinction. A theory is either falsifiable or it isn't. There is no wiggle room. Please clarify.

Originally Posted by R.Mackey

There are, therefore, a few rough spots in the NIST theory, and there always will be, as there are for any accident investigation. This in no way invalidates or even harms the theory. It is what it is.

I'm all right with "rough spots" so long as it has less "rough spots" than any other competing theory that's judged by the same criteria.



.

[jay howard]

Originally Posted by R.Mackey

Parsimony, repeatability, falsifiability, and agreement with various observations? Yes, I'd say those are all excellent metrics to apply to a theory. Proceed.

Don't forget explanatory power. It will undoubtedly come up.


.

[LashL]

Originally Posted by jay howard

We will test your claim.

Who is this "we" of which you speak?

[defaultdotxbe]

heh, good luck jay, these guys wont get sick of you as quickly as i did

but dont let that go to your head, im pretty much sick of all truthers at this point, and these guys dont let anyone get the last word, just look at malcom kirkmans thread

[Gravy]

Hello, Jay. Welcome to the forums.

Originally Posted by jay howard

Don't forget explanatory power. It will undoubtedly come up.

While we're alive?

[jay howard]

Originally Posted by LashL

Who is this "we" of which you speak?

The NIST report, the criteria outlined above and everyone reading.

[jay howard]

Originally Posted by Gravy

Hello, Jay. Welcome to the forums.



While we're alive?

Hello, all. Sorry for the rudeness.

[LashL]

Originally Posted by slugmancs

At this point I expected a 5 page copy and paste job, I guess this guy may have more class than most "truthers."

It's too soon to tell yet. I am not as optimistic as you, though, as regards the latter part of that sentence.

Originally Posted by slugmancs

(joins with popcorn smilie)

[R.Mackey]

Originally Posted by jay howard

NIST's theory is basically a heat-induced collapse theory (HICT). Without heat weakening the steel, there is no collapse. In their words,

"...the towers withstood the impacts and would have remained standing were it not for the dislodged insulation and the subsequent multifloor fires."(171)

We will likely discuss it in whole and in part.

Okay. That's not a complete characterization of the NIST theory, because (as your quote notes) NIST predicts without the impact damage, the Towers wouldn't have collapsed, either. (Also note that some dispute this result.) So I wouldn't call it a "heat-induced collapse theory." That is one facet of the NIST theory, but not the whole theory.

We can, however, restrict our observations to this part of the theory if you prefer.

Originally Posted by jay howard

Why don't the tests NIST did on the short lengths of the floor assemblies count as tests of their theory? The fires were hotter than any of the recovered steel NIST analyzed, and run for longer than it took for the towers to collapse.

You're getting a bit ahead of yourself. I can answer this question in detail, but first, why do you think they did this? And what do you think this means? Do you have a superior hypothesis on the basis of this information?

Originally Posted by jay howard

Falisifiability, as I defined it above, makes no distinction. A theory is either falsifiable or it isn't. There is no wiggle room. Please clarify.

No, there is wiggle room, namely precision in experimental design. On the basis of the fact that the WTC collapses are prohibitively expensive to repeat in full-scale, we are in some cases left to compare one theory versus another on the basis of their accuracy and uncertainty, rather than ruling one way or another outright. While the logical notion of falsifiability is a logical absolute, actually "disproving" one theory or another often comes down to statistics.

For instance, it is still possible that Morley was right, and Einstein was wrong -- our best measurements of the "aether" are null, but only to one part in 10¹¹ or so. This is statistically sound enough for us to discredit Morley, but it's not 100%, iron-clad, wiggle-room-less proof.

Originally Posted by jay howard

I'm all right with "rough spots" so long as it has less "rough spots" than any other competing theory that's judged by the same criteria.

Agreed. A theory that is equally good to NIST's but contains fewer unproven mechanisms is a superior theory, at least until new data arrives.

[Gravy]

Originally Posted by jay howard

Explanatory power: Simply put, the theory that explains the most phenomena and disregards the least evidence is the more powerful theory. Put another way, if theory A must disregard some evidence, and theory B does not, theory B is a better theory. This ties directly with the choices noted above to wit, evidence in contradiction to an explanation requires either the dismissal of the evidence or a shift to a more powerful theory—or a more powerful version of a theory. When taking into account the Zapruder film, we cannot deny the apparent snap of the President’s head toward the lone assassin. The (LAT) cannot account well for this evidence and is thus thrown into doubt despite its parsimonious nature.

Since JFK's head first moves forward, and then back, you are wrong. There are several reasons why you could be wrong. This is just one reason why you are.

Overall, as is usual with 9/11 deniers, a terrible start. Please put your best evidence forward as soon as possible. It's one thing to be wrong, quite another to be long-windedly wrong

[LashL]

Originally Posted by jay howard

The NIST report, the criteria outlined above and everyone reading.

So, when you said to RMackey, "We will test your claim," you meant, "The NIST report and everyone reading will test your claim"? Do I have that straight?

ETA: Never mind. No response necessary. Do carry on.

[R.Mackey]

Originally Posted by Gravy

Since JFK's head first moves forward, and then back, you are wrong. There are several reasons why you could be wrong. This is just one reason why you are.

Overall, as is usual with 9/11 deniers, a terrible start. Please put your best evidence forward as soon as possible. It's one thing to be wrong, quite another to be long-windedly wrong

Correct, of course, but I was ignoring that as it's not relevant to NIST.

For jay, we can cover (and have covered, in grim detail) this topic in another thread. Let's not derail this one with an explanation of spall.

[jay howard]

Originally Posted by Gravy

Since JFK's head first moves forward, and then back, you are wrong. There are several reasons why you could be wrong. This is just one reason why you are.

Are you saying I'm wrong about the concept of falsifiability or about its application to the JFK debate?

If it's the latter, I have no horse in that race. If it's a bad example, so be it.

If you have a problem with the concept, then there is a serious issue.

Which is it?

[uk_dave]

Hi Jay Howard, welcome to the forum.

No doubt better minds than mine will have already made this observation, but I'll continue anyway because I think it is something those on the 'truther' side of things fail to comprehend........

Originally Posted by jay howard

NIST's theory is basically a heat-induced collapse theory (HICT). Without heat weakening the steel, there is no collapse. In their words,

"...the towers withstood the impacts and would have remained standing were it not for the dislodged insulation and the subsequent multifloor fires."(171)

....this does not mean that the structural damage caused by the impact is to be discounted.

Yes, the tower performed well given that a large amount of damage was caused to the structure. It didn't collapse immediately.

But that damage didn't go away. The damage also wasn't just confined to removal of structural elements, but included removal of the system of protection to structural elements.

The subsequent fires, burning for a long period of time, TOGETHER with the redistribution of loads within the structure and the damage/removal of fire protection to the structural elements, is what doomed the towers.

[slugmancs]

Originally Posted by jay howard

Are you saying I'm wrong about the concept of falsifiability or about its application to the JFK debate?

If it's the latter, I have no horse in that race. If it's a bad example, so be it.

If you have a problem with the concept, then there is a serious issue.

Which is it?

Can you get on with your points or are you hoping we die of boredom before your "95 Theses" are posted on the JREF door?

[beachnut]

Originally Posted by jay howard

I’ve laid this all out before, but the conversation has only resulted in a lot of accusations of how ignorant I am of the NIST report. Thought I’d give you guys a shot at an adult discussion.

I think the mini nuke is the easiest to prove wrong, or right based on the blast effects would be so evident, there would not be any question. The air could be sampled for nuke material before the day was done to confirm the blast. The mini-nuke would be solved in one day.

Choosing CD is only something I think only weak minded fools would pick. As a pilot and engineer and seeing the WTC collapse on 9/11, I had no question it was impact and fire that made the steel weak. I know structural wood holds up better than steel. This is why steel is fire proofed to withstand fire for so many hours. Plus I have seen many examples of steel structures fail in fire and fall. I guess kids missed seeing 9/11 on live TV, but most of us witnessed it on TV, some first hand. There were no explosive reports (sounds) that CD would give you. If you like the thermite card, it took over 4 years for Dr Jones to go nuts enough to publish his paper/letter. I doubt he knew raw thermite was a gravity event itself. I think CD people have picked a challenging thesis, CD is so far out and with zero evidence, it has become a red flag to identify people who have no facts or evidence on 9/11. I have witnessed CD people bashing their head against the rough brick wall of CD ideas from 9/11 truth.

I think NIST is not needed to prove the WTC fell due to gravity after an aircraft impact, and fires. It is neat to learn what NIST did in a broad work that covers many goals besides why the towers began to collapse. But it is clear from just observation on 9/11, the impact, and fires, worked together to destroy the towers. Or you can use hundreds of other work which confirms the same. When I came up with my own ideas on the collapse, impact, fire, collapse I did not notice the idiots making up lies, like CD about 9/11. But then I did. But I found all the 9/11 truth movement to be based on lies and false information. No facts to back up the conclusions. I thought it was neat the chief structural engineer on the WTC agrees with me. It was even better when I found papers, even papers I would have to pay for, that support the what really happen on 9/11. Not one paper supports 9/11 truth. Dr Jones had to make a peer review out of 9/11 truth people to make up a journal to publish the lies, and some papers of woo.

Not only is there no need for CD, it would not of worked. The people who set the charges would have been caught, and the charges in the area of fire would cook off early after the impact. I do not see why someone needs to discuss NIST if they already support CD, a fantasy of the 9/11 truth movement. I always see truth movement people present CD information and then apply CD it to WTC7 (They can not explain why WTC7 would have to have CD,). I look forward to seeing CD people blasted away as they try to discuss the NIST report on a intellectual level, a level well above those who believe in CD. In fact, I view all who come equipped with belief of CD to be unable to think rationally or logically. I look forward to an exception but fear no one from 9/11 truth can.

Hope you have reviewed the thousands of post on the NIST report already. Good luck.

[Gravy]

Originally Posted by jay howard

Are you saying I'm wrong about the concept of falsifiability or about its application to the JFK debate?

If it's the latter, I have no horse in that race. If it's a bad example, so be it.

If you have a problem with the concept, then there is a serious issue.

Which is it?

It was a bad, but revealing, example.

[LashL]

Originally Posted by slugmancs

Can you get on with your points or are you hoping we die of boredom before your "95 Theses" are posted on the JREF door?

It looks like "jay howard" wasn't as prepared to argue his points as he thought he was. Big surprise, that.

[pomeroo]

Originally Posted by LashL

It looks like "jay howard" wasn't as prepared to argue his points as he thought he was. Big surprise, that.

Gregory Urich is striving to reach the 500-post mark before revealing that a vast, mathematically-impossible conspiracy brought down the Twin Towers with explosives. He is a strong contender to win the coveted JREF award for Slowest Telegraphed Punch in History.

Jay Howard will, I suspect, reveal the existence of that same mathematically-impossible conspiracy more expeditiously.

I mean, he will, won't he? My God! What if he doesn't?

[jay howard]

Originally Posted by R.Mackey

Okay. That's not a complete characterization of the NIST theory, because (as your quote notes) NIST predicts without the impact damage, the Towers wouldn't have collapsed, either.

I'd love to see a quote to back that up. Just because I haven't found it, certainly doesn't mean they didn't say it, but you sound like you're speaking from experience.

From every explanation they give, heat plays the vital role of inducing the collapse. Yes, I've read about the pathways produced from the crash debris, but like the quote above, they seem to think the crash alone would not have caused the collapse. I have yet to see anything otherwise in the official report.

Originally Posted by R.Mackey

You're getting a bit ahead of yourself. I can answer this question in detail, but first, why do you think they did this? And what do you think this means? Do you have a superior hypothesis on the basis of this information?

My theory is that the NIST report is a brochure on simulated fires. What matters about the tests are the parameters and the results. The rest is up for interpretation. Do you agree that they tried to replicate circumstances in the towers?

Originally Posted by R.Mackey

No, there is wiggle room, namely precision in experimental design.

We will disagree, but we shouldn't disagree over misunderstandings. Falsifiability is the ability of a theory to be wrong. Any reliable theory must have some criteria by which, if it obtains, we can safely say that theory cannot be true. Falsifiability can tell us nothing about the precision of competing (falsifiable) theories. Beyond what it can do, it is useless.

A theory is either false or possible. In your example, Morley's theory was still possible, and apparently, both theories were/are falsifiable. I don't know enough about that specific instance to make a good example, but the fact remains that if a condition is met that would demonstrate the falsity of a theory, then that theory is false and we can move on.
and
If no such conditions exist by which a theory can be false, then it is non-falsifiable, and hence useless as an explanation.

We must be clear on this to have a discussion.

Originally Posted by R.Mackey

Agreed. A theory that is equally good to NIST's but contains fewer unproven mechanisms is a superior theory, at least until new data arrives.

All right.

[Pardalis]

Give the runner a chance.

[jay howard]

Originally Posted by Gravy

It was a bad, but revealing, example.

Do you have a problem with the concept of "falsifiability" as I've defined it at top?

[pomeroo]

Originally Posted by Pardalis

Give the runner a chance.

"Do you agree that they tried to replicate circumstances in the towers?"


Nah, they tried to make the test conditions as different from the conditions in the towers as they could.

I know that Undesired Walrus has criticized me for nastiness, but, geez Louise, gimme a break!

[pomeroo]

Originally Posted by jay howard

Do you have a problem with the concept of "falsifiability" as I've defined it at top?

I'll bet you're a big fan of the Loose Change boys. Wanna guess how they responded when I asked them what could falsify their beliefs?

[R.Mackey]

Originally Posted by jay howard

I'd love to see a quote to back that up. Just because I haven't found it, certainly doesn't mean they didn't say it, but you sound like you're speaking from experience.

I am. From NIST NCSTAR1-6D, page 327:

Originally Posted by NIST

The structural damage alone did not cause the collapse of the towers, as they stood for periods of time and collapsed after fire-induced weakening of the cores, floor systems and exterior walls. In the absence of impact damage, there would have been no insulation damage and the likelihood of collapse of the towers under the intense fires would have been very small.

(Emphasis added)

Originally Posted by jay howard

From every explanation they give, heat plays the vital role of inducing the collapse. Yes, I've read about the pathways produced from the crash debris, but like the quote above, they seem to think the crash alone would not have caused the collapse. I have yet to see anything otherwise in the official report.

You're correct that without the heat, NIST predicts no collapse. But that doesn't mean that heat alone led to the collapse. Do you see the distinction?

Originally Posted by jay howard

My theory is that the NIST report is a brochure on simulated fires. What matters about the tests are the parameters and the results. The rest is up for interpretation. Do you agree that they tried to replicate circumstances in the towers?

No, NIST is a great deal more complicated than a "brochure" on simulated fires. The fires were relegated to a single project out of nine. I do agree, of course, that NIST attempted to replicate circumstances in the Towers.

Originally Posted by jay howard

We will disagree, but we shouldn't disagree over misunderstandings. Falsifiability is the ability of a theory to be wrong. Any reliable theory must have some criteria by which, if it obtains, we can safely say that theory cannot be true. Falsifiability can tell us nothing about the precision of competing (falsifiable) theories. Beyond what it can do, it is useless.

A theory is either false or possible. In your example, Morley's theory was still possible, and apparently, both theories were/are falsifiable. I don't know enough about that specific instance to make a good example, but the fact remains that if a condition is met that would demonstrate the falsity of a theory, then that theory is false and we can move on.
and
If no such conditions exist by which a theory can be false, then it is non-falsifiable, and hence useless as an explanation.

We must be clear on this to have a discussion.

Then let me clarify. For the purposes of our discussion, or any scientific discussion, "to be falsified" means that a theory is shown to be significantly inferior to at least one other theory. If you can show me that you have a theory superior to the NIST theory, even if the NIST theory still remains vaguely possible, I will consider it falsified.

If there are no theories that can plausibly explain a given phenomenon, then any given theory may simply be incomplete.

This sentiment is consistent with your opening post where you claimed that "we will always fall short of absolute truth." We will never reach a 100% confidence level in statistics. 95% is generally good enough for anyone, as it is for me.

Are we settled, then?

[Gravy]

Originally Posted by jay howard

I'd love to see a quote to back that up. Just because I haven't found it, certainly doesn't mean they didn't say it, but you sound like you're speaking from experience.

If you can't even make it as far as the second answer in NIST's Answers to Frequently Asked Questions about the WTC investigation, can you really expect anyone to engage in a discussion with you?

Quote:

2. Why did NIST not consider a “controlled demolition” hypothesis with matching computer modeling and explanation as it did for the “pancake theory” hypothesis? A key critique of NIST’s work lies in the complete lack of analysis supporting a “progressive collapse” after the point of collapse initiation and the lack of consideration given to a controlled demolition hypothesis.

NIST conducted an extremely thorough three-year investigation into what caused the WTC towers to collapse, as explained in NIST’s dedicated Web site, http://wtc.nist.gov. This included consideration of a number of hypotheses for the collapses of the 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 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 this comprehensive investigation, NIST concluded that the WTC towers collapsed because: (1) the impact of the planes severed and damaged support columns, dislodged fireproofing insulation coating the steel floor trusses and steel columns, and widely dispersed jet fuel over multiple floors; and (2) the subsequent unusually large jet-fuel ignited multi-floor fires (which reached temperatures as high as 1,000 degrees Celsius) significantly weakened the floors and columns with dislodged fireproofing to the point where floors sagged and pulled inward on the perimeter columns. This led to the inward bowing of the perimeter columns and failure of the south face of WTC 1 and the east face of WTC 2, initiating the collapse of each of the towers. Both photographic and video evidence—as well as accounts from the New York Police Department aviation unit during a half-hour period prior to collapse—support this sequence for each tower.

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 below). 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 Composite WTC Floor System

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 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 planted prior to Sept. 11, 2001. 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.

Edit: cross-posted with R. Mackey, who was more succinct.

[R.Mackey]

Originally Posted by Pardalis

Give the runner a chance.

Quiet, you! (Yes, I pulled that up two hours ago in preparation.)

[jay howard]

Originally Posted by pomeroo

I'll bet you're a big fan of the Loose Change boys.

You'd lose that bet.

Seriously, are you here for a real discussion or to chat?

I'm not interested in chatting with you. If you have something to add to the conversation, don't keep me in suspense.

[beachnut]

Originally Posted by jay howard

You'd lose that bet.

Seriously, are you here for a real discussion or to chat?

I'm not interested in chatting with you. If you have something to add to the conversation, don't keep me in suspense.

If you do not want to post to a post, do not post to it. You can save time and if off topic like this why would I care if you post to my post?

Yet it appears you are not prepared as you said you were; and posting to posts you have no interest in, shows your unprepared state. So get on to the good stuff, please. I expect an intellectual type discussion to kill off all Dr Jones and other 9/11 truth efforts toward CD. Do carry on, please. I hope the results to be shattering 9/11 truth's very foundation and show the dolts in 9/11 truth, how they make light of a serious event with lies and about 9/11 and do not hold the death of fellow citizens with any respect, but make up false information for monetary and political reasons out of ignorance.

[ref]

Originally Posted by pomeroo

I'll bet you're a big fan of the Loose Change boys. Wanna guess how they responded when I asked them what could falsify their beliefs?

I know the answer to that one, can I say can I say!

[jay howard]

Originally Posted by Gravy

If you can't even make it as far as the second answer in NIST's

You're apparently having a different discussion with different theories being addressed.

[slugmancs]

Originally Posted by jay howard

I'm not interested in chatting with you. If you have something to add to the conversation, don't keep me in suspense.

Take your own advice and put forth your beliefs... its been 3 hours since your OP and you have said little to nothing. Please, tell us what your problem is with NIST, what you have brought up to this point is on par with every other CT.

[Gravy]

Originally Posted by Pardalis

Give the runner a chance.

Excellent. I get to use my chemtrails "barium blockbuster baffler."