Metatheory and the NIST report [Archive] - Page 5

jay howard

5th September 2007, 04:37 PM

NIST's base assumption of 4 lb/ft2 of fuel load was an estimate and was known to be low compared to similar office layouts.

So what? Does that mean they get to increase it at will?

It was an average figure.

Thanks for pointing out the obvious again. Do they get to increase it at will because it was an average? What kind of sense does that make?

Only case A assumed an even distribution of the fuel load throughout the affected floors.

Again, so what? Case B weighted combustibles towards the core--for what reason? Aircraft impact would not have pushed an increased pile of it towards the interior. They admit they didn't count the aircraft because the thermal modeling would only accept one fuel source, so how does one justify an increased fuel concentration in the core area? It's no secret the vast majority of combustible mass was between the core and the exterior. But you not only accept this as "good science," you use it to try to JUSTIFY the NIST report's manipulation of the data.

That figure also ignores combustibles within the aircraft. They appear to ignore paper in filing cabinets, although a greater range of cases could reasonably assume impact damage liberating some of this paper. They appear to have taken the conservative approach here. Cases B, C and D assume some redistribution of the fuel load, yet case C still - conservatively - assumes 4 lb/ft2

No, they appear to have increased the fuel load against their own estimates without any clear reason why. In their words:

"NIST estimated the combustible fuel loading on these floors to have been about 4 lb/ft2 (20 kg/m2)."(NCSTAR 1, 77)

“Simulations performed with doubled fuel loads slowed the fire spread well below the observed rates. Combined with the above results, this suggested that the estimated overall combustible load of 4 lb/ft2 was reasonable.”(NCSTAR 1, 129)

This one is particularly troubling for anyone who thinks NIST was justified in increasing the fuel load:

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

And

“The fact that the simulated fires encircled the building in roughly the same amount of time as the actual fires supported the estimate of the overall combustible load, 20 kg/m2 (4 lb/ft2). The fires burned for roughly 20 min to 30 min in any one location, consistent with the visual evidence (NIST NCSTAR 1-5A) and the multiple workstation fire experiments performed at NIST (Chapter 4).”(NCSTAR 1-5F, 107)

And what reasons do they give for the increase?

“For WTC 1, the changes made were designed to create a ‘more severe’ fire.”(NCSTAR 1-5F, 78)

Oh. That makes perfect sense.

In short - varying the figure from 4 lb/ft2 to 5 lb/ft2 across the 4 cases is perfectly reasonable.

Maybe you should read the reports before you say something completely unsubstantiated.

NIST could not possibly have known the precise fuel load.

So what? Does that mean they can increase it by 25% from their "reasonable" estimate at will and without any clear justification?

Your paranoid outlook, however, requires this approach to be viewed as conspiratorial and unscientific and labelled as "beefing up". It's no such thing.

Do you have any reason to say that other than you want it to be true?

Tell me, jay, if NIST consciously fiddled the 4 lb/ft2 to achieve a desired outcome why the hell wouldn't they just start with 5 lb/ft2 ?? Nobody would have had any grounds to doubt it.

Because "they" were several groups who were assigned a set of tasks. The leaders of those groups set out to do their jobs. This all fits into a straight-forward hierarchical-style framework. There is nothing unusual about this. When it was determined that under the "middle cases" the buildings would likely remain standing, someone was indeed tasked with increasing the fuel load.

Did that person/group ask why?

It doesn't matter what they asked. It was their job to do as they were told. Boss wants to increase the fuel loads in the scenarios; therefore they increased the fuel loads in the scenarios.

Can you find me reasonable explanation as to why? No. Should you be able to? Yes. Does that mean all the science in the NIST report is null and void? No. Does that mean the data was manipulated? It certainly looks that way. If the data was manipulated, does that mean all the people who worked on it are guilty of murder? Of course not. Are they guilty of bad science? Not likely. The people guilty of bad science are those who structured the argument.

For the very little it's worth, it strikes me that case A in particular is very conservative.

How would you know what conservative is? From what the NIST report says? Did you read the other things the NIST report said about Case A? Apparently not.

beachnut

5th September 2007, 04:46 PM

twinstead

5th September 2007, 04:55 PM

Jay are you implying that these 'groups' were simply automatons doing their master's bidding and following orders without understanding what they were doing?

JimBenArm

5th September 2007, 05:16 PM

Considering I've had to explain the concept of falsifiability to the same group of engineers here in this thread several times since the beginning, and even now, some just don't get it, it should come as no surprise that "scientific thought" has to be disambiguated from salesmanship on a regular basis. The NIST report has plenty of rigorous scientific findings in it. It does not follow from that, that the report is therefore a thoroughly scientific work. Sales brochures for this year's new Hyundai (or whatever) are filled with facts about it. Are you saying the scientific facts (0-60mph, fuel consumption, bhp, etc) make the brochure a bona fide scientific report?

So now you compare the NIST report to a sales brochure?:dl:
Science really isn't your strong suit, is it?
Cynicism and paranoia, however...

They're not allowed to lie in the brochures, either. Doesn't mean they don't manipulate the data to present an image.
They also don't have the international community ready to pounce on any misstatement or misrepresentation, either. Your point is rejected yet again! So sorry!

If you think my criticisms of the report are unfair in some way, please point out why.
I already did. You just are unable to understand it. Sorry, not my problem.

Of course you will.
Yeah, and of course you skipped the part where I asked for some kind of actual evidence to back up your slander of the people that worked so hard on the NIST report. Not that I actually thought you could...

Crungy

5th September 2007, 06:09 PM

Maybe you could try reading a post or two that I've written on the ways in which the report doesn't pass basic standards of theoretical adequacy.

They are all here for you to pick at in any order you wish.

Sorry, but I, like others here, do not agree with the arguments which you have presented here to support your statement above and you have been reapetedly called out for this.

beachnut

5th September 2007, 08:50 PM

Maybe you could try reading a post or two that I've written on the ways in which the report doesn't pass basic standards of theoretical adequacy.

They are all here for you to pick at in any order you wish.
Jay, you have failed to do what you said. Anyone who has the ability to think rationally knows you are wrong and have failed to show what you said.

What you are saying is a lie, you have no shown anything yet. Looking at all of your posts as an engineer, you have failed. F. If this was a student defending a thesis you would have to try again.

rwguinn

5th September 2007, 08:50 PM

jh:
:dl: :dl: :dl: :dl:

rwguinn

5th September 2007, 08:51 PM

Jay, you have failed to do what you said. Anyone who has the ability to think rationally knows you are wrong and have failed to show what you said.

What you are saying is a lie, you have no shown anything yet. Looking at all of your posts as an engineer, you have failed. F. If this was a student defending a thesis you would have to try again.
Nope-
They'd flunk him out, permanently. Not even back to Freshman level...

PhantomWolf

5th September 2007, 10:07 PM

I just haven't seen a convincing model that can fall down in 12 sec.

Well that's okay, because neither of the Towers fell in 12 seconds. WTC 2 took at least 16 and more likely 18, and WTC 1 took at least 18 seconds more likely closer to 20.

jay howard

6th September 2007, 07:16 AM

So, does anyone have a real response to why NIST increased the fuel loads?

Their words:

"NIST estimated the combustible fuel loading on these floors to have been about 4 lb/ft2 (20 kg/m2)."(NCSTAR 1, 77)

“Simulations performed with doubled fuel loads slowed the fire spread well below the observed rates. Combined with the above results, this suggested that the estimated overall combustible load of 4 lb/ft2 was reasonable.”(NCSTAR 1, 129)

This one is particularly troubling for anyone who thinks NIST was justified in increasing the fuel load:

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

And

“The fact that the simulated fires encircled the building in roughly the same amount of time as the actual fires supported the estimate of the overall combustible load, 20 kg/m2 (4 lb/ft2). The fires burned for roughly 20 min to 30 min in any one location, consistent with the visual evidence (NIST NCSTAR 1-5A) and the multiple workstation fire experiments performed at NIST (Chapter 4).”(NCSTAR 1-5F, 107)

What reasons do they give for the increase?

Skibum

6th September 2007, 07:27 AM

What reasons do they give for the increase?

I would guess that they were testing different amounts of fuel to see what matched up best with what was observed in real life on 9/11.

jay howard

6th September 2007, 09:49 AM

I would guess that they were testing different amounts of fuel to see what matched up best with what was observed in real life on 9/11.

Then why do they go against those observations in order to form the more severe cases?

jay howard

6th September 2007, 02:50 PM

I already did. You just are unable to understand it. Sorry, not my problem.

You already presented a counterargument to my criticisms of the NIST report?

Could you link to it?

jay howard

6th September 2007, 02:52 PM

Sorry, but I, like others here, do not agree with the arguments which you have presented here to support your statement above and you have been reapetedly called out for this.

Well thanks for sharing your agreement. Do you have any legitimate reasons for believing what you do, or do you believe things in order to identify with a group?

Drudgewire

6th September 2007, 03:19 PM

Well thanks for sharing your agreement. Do you have any legitimate reasons for believing what you do, or do you believe things in order to identify with a group?
Yes, that's it. You're the very first person on this forum to ever bring up the points you're making. They've NEVER been discussed thoroughly time and time again or anything. The only reason we believe what we do is because we're all a bunch of fuddy-duddies who don't like people exposing our hero and master George Bush for the fraud we prefer to pretend he isn't.

That's it, it has nothing to do with being able to look at the evidence as a whole instead of pick and choosing it, using the scientific method and having it stand up to rigorous peer review, taking personal agendas out of the equation before poring over it, and having all the top legitimate experts in their various fields take it at face value.

You've hit the nail on the head. Show's over kids. Pack up and go home. I TOLD you we should have used youtube and Bible experts instead. :mad:

jay howard

6th September 2007, 03:57 PM

That's it, it has nothing to do with being able to look at the evidence as a whole instead of pick and choosing it, using the scientific method and having it stand up to rigorous peer review, taking personal agendas out of the equation before poring over it, and having all the top legitimate experts in their various fields take it at face value.

Can you answer the question of why NIST appealed to the higher fuel load of 5 lb/sq ft in WTC 1 after pointing out repeatedly that 4 lb/sq ft was the best estimate of the fuel load in the towers?

They also clearly state that increasing the fuel load would not produce the observed effects, nor would it allow for the fire to travel to the south side in time to initiate global collapse.

So why don't you question the accuracy of their "more severe case"?

Do you have a real reason? How do you reconcile the increase?

No one here can answer this question. There is no good answer in any of the NIST literature. Whether you or anyone else here likes it or not, there is no good reason to increase the fuel load in the towers by 25%, yet the NIST authors do so, and claim they've answered the question of why the buildings collapsed.

If someone created a simulation that demonstrated the buildings could NOT have collapsed from the fires and impacts, and they clearly appealed to unsubstantiated data, would you call it a good argument?

Of course not. You would dismiss it immediately as crap science. Yet, when they do exactly this to make the case that impacts/fires caused the buildings to collapse, not only don't you question the veracity of their science, you DEFEND it.

So again, if you've got a good explanation, please show me. If someone else has already given a good reason for it somewhere, please link to it. (I know this isn't going to happen. More likely there will be a fevered attempt to change the subject, or a bunch of vacuous posts, and of course, beechnut saying "Your thermite lies won't cut it around here. You fail. F" Wow. Good retort.)

The real question in all this seems to be, Why do you still believe the NIST report answered the questions posed from the collapse? It's not because of the solid case they make in the report. Is it the fear that you may have been fooled this whole time? The fear that people in official positions are not looking out for your best interests? The peace of mind that only official reports can produce? What exactly keeps you clinging to the results of a report that no one can properly make sense of?

The entire report hinges in these simulations producing this "global collapse" event from heat. No forensic evidence recognized by NIST substantiates temperatures that could weaken steel to the degree necessary in the time constraints. Yet the simulations must use increased inputs in order to show "collapse initiation". Of course, we don't get to see if the initiation actually caused the entire building to collapse because 1. they haven't released their simulations, 2. the "middle case" which uses their own reasoned estimates do not demonstrate "collapse initiation", 3. whatever happened after "initiation" was outside the scope of the report and 4. the fuel load increase is never justified.

pomeroo

6th September 2007, 07:39 PM

[snip] Much drivel

The entire report hinges in these simulations producing this "global collapse" event from heat. No forensic evidence recognized by NIST substantiates temperatures that could weaken steel to the degree necessary in the time constraints. Yet the simulations must use increased inputs in order to show "collapse initiation". Of course, we don't get to see if the initiation actually caused the entire building to collapse because 1. they haven't released their simulations,

Whoops! Sorry, the simulations have been released.

[snip] more drivel

jay howard

7th September 2007, 04:07 PM

Whoops! Sorry, the simulations have been released.

So, you have absolutely no response to why they increased the inputs to the collapse scenarios?

You cite one thing you disagree with--without any link or substantiation--and think this overcomes my criticisms.

Weak tits--not unlike a canine with 4 sets of weak tits.

jay howard

7th September 2007, 04:09 PM

No one here can honestly claim they "know" that the NIST simulations are good science, because no one here can justify NIST's increased inputs for their simulations.

twinstead

7th September 2007, 06:11 PM

No one here can honestly claim they "know" that the NIST simulations are good science, because no one here can justify NIST's increased inputs for their simulations.

Talk to NIST. Their website has every contributor. Whining about it on a relatively obscure web forum does nothing to further your movement. In fact, considering that YOU aren't any more qualified to judge the 'good science' of NIST than I am, it just makes your movement look kind of kooky.

While you're at it, you can contact the scientists at Purdue University and the experts consulted by Popular Mechanics and ask them their opinions.

You are interested in 'official' second opinions, right? I mean you wouldn't NOT contact the people actually directly involved in the development of the official version of 911 for any reason, right?

TellyKNeasuss

7th September 2007, 07:46 PM

I will preface my comments by acknowledging that I only skimmed parts of the NIST report. I am just throwing out some ideas to get the dialogue moving again, and my impressions may be way off. I don't even understand the context in which the simulations were used to describe the collapse mechanism. I also am not an engineer of any sort, nor am I a numerical modeler.

Can you answer the question of why NIST appealed to the higher fuel load of 5 lb/sq ft in WTC 1 after pointing out repeatedly that 4 lb/sq ft was the best estimate of the fuel load in the towers?

My interpretation was that the 4 lbs/sq ft was a guestimate based on a simple model of the layout of furniture, etc. The 4 lbs./sq ft most likely did not generate enough heat to match the observed temperatures (I could be wrong, but I probably won't have time to thoroughly read the section in the near future). If you make a rough guess at the input to any kind of model and your results don't match the observations, do you: 1) assume that the observations are wrong; 2) assume that your guess as to what the input should be is wrong. The inputs to the model are not that precise; for instance they were unable to include heat from the burning aluminum in the airplane. I doubt that this sort of adjustment is unheard of in situations where the baseline data is not known.

They also clearly state that increasing the fuel load would not produce the observed effects, nor would it allow for the fire to travel to the south side in time to initiate global collapse.Do I misunderstand this statement, or are you acknowledging that increasing the fuel load from 4 lb/sq ft to 5 lb/sq ft wasn't important anyway. Because it was just an adjustment needed to generate the heat that was indicated by the observations?

No one here can answer this question. There is no good answer in any of the NIST literature. Whether you or anyone else here likes it or not, there is no good reason to increase the fuel load in the towers by 25%, yet the NIST authors do so, and claim they've answered the question of why the buildings collapsed. Yet they published this in a publicly available document. If they were fudging numbers, why wouldn't have they just published the 5 lb/sq ft data? And just because no one here can answer a question, does that prove that the question cannot be answered by anyone?

The real question in all this seems to be, Why do you still believe the NIST report answered the questions posed from the collapse? It's not because of the solid case they make in the report. Is it the fear that you may have been fooled this whole time? The fear that people in official positions are not looking out for your best interests? The peace of mind that only official reports can produce? What exactly keeps you clinging to the results of a report that no one can properly make sense of?No one can properly make sense of? You know for sure that here isn't a single structural engineer or fire protection engineer in the whole world that can make sense of the report? And I suppose that the reason why nobody has mentioned it is because every single one is too embaressed to admit it.

twinstead

7th September 2007, 07:52 PM

It appears that Jay claims that NO ONE can make sense of the NIST report.

cmcaulif

7th September 2007, 09:37 PM

For WTC 1, the changes were designed to create a "more severe" fire.

<snip>

The intent of these changes was to span the probable range of gas temperatures in the core area by considering a more severe case. The Case A simulation showed that the model was replicating the basic fire behavior at the building exterior, but there was no way to confirm the behavior deep within the building.

The rest of the page provides further details. This should be noted as well:

The assumptions made for all Cases fell within the range of uncertainty resulting from the impact analyses; the objective of the parameter changes was to generate results that would span as much as possible the set of probable outcomes given the range of plausible initial and boundary conditions

GlennB

8th September 2007, 03:53 AM

The rest of the page provides further details. This should be noted as well:

Yep, and jay howard knows all this perfectly well.

He seems to be obsessively clinging to the 4lb figure, apparently believing that any variation from it somehow consigns NIST to the dustbin. Of course it doesn't.

cmcaulif

8th September 2007, 09:32 AM

Yep, and jay howard knows all this perfectly well.

He seems to be obsessively clinging to the 4lb figure, apparently believing that any variation from it somehow consigns NIST to the dustbin. Of course it doesn't.

Especially given the nature of the FDS software, which can be downloaded for free here (http://www.fds-smv.net/downloads), just as an aside.

FDS is sensitive to a number of inputs, including fuel load, and after the first case was done for WTC 1, the NIST wanted to examine a case with higher temperatures at the core. Increasing the fuel load was one of the ways they achieved this through the FDS software.

jay howard

8th September 2007, 03:30 PM

And yet, no one here can squarely reconcile the fuel load increases.

cm,

you quote the NIST report as if their "answers" justified the increase:

The intent of these changes was to span the probable range of gas temperatures in the core area by considering a more severe case.

And how would they know what the "probable range of gas temperatures in the core" are? From estimating the a reasonable fuel load--which they do on several occasions in the report as 4 lb/sq ft.

Now, if 4 lb/sq ft is a reasonable estimate given all the info known about the towers, what possible reason do they suppose that they underestimated this by 25%? That's a significant increase. That's 60 tons per floor versus 75 tons per floor. Where do you suppose an extra 15 tons of fuel per floor came from? Wouldn't you think they'd give some kind of justification for an extra 15 tons per floor?

The Case A simulation showed that the model was replicating the basic fire behavior at the building exterior, but there was no way to confirm the behavior deep within the building.

So they clearly admit that Case A fits the available evidence. However, they must contradict the visual evidence in favor of an estimate that "there was no way to confirm."

Not only is this an argument from ignorance--in that they appeal to an unknown factor to increase the fuel load--they must actually contradict the available visual evidence to make this appeal.

If a "twoofer" was making this kind of a case for ...whatever, you'd jump his **** so fast, he'd get a headache. And rightfully so. This is a weak argument for not only appealing to an unknown in order to justify what appears to be a predetermined conclusion, but contradicting the evidence at hand. The real question is "why doesn't this argument bother you?"

The assumptions made for all Cases fell within the range of uncertainty resulting from the impact analyses; the objective of the parameter changes was to generate results that would span as much as possible the set of probable outcomes given the range of plausible initial and boundary conditions

So what? Maybe you'd like to try to interpret this sentence in such a way that would justify the fuel load increase? I do not see any real answer here. Please help. The “set of probable outcomes” should be bound by reasonable estimates of fuel loads. This doesn’t explain why they decided to increase these estimates willy-nilly. Please help.

And just because no one here can answer a question, does that prove that the question cannot be answered by anyone?

Not necessarily, but it does make clear that you are willing to believe something that you cannot logically justify, i.e. you are treating the NIST theory on the same grounds that creationist treat the age of the universe: on Faith.

You admit that you can't find a reason for the increase, yet you still believe. The fuel load issue is not tangential: the entire argument hinges on it. Yet you cannot come to terms with the possibility that you've been sold a pile of *****.

Twinstead,

Yes, I am indeed saying that no one here can make sense of the fuel load increase or the fuel load redistribution in Cases C and D. If they could, I would like them to make their case, please.

Because no one here seems to be able to make sense of these pivotal problems, it is strikingly clear that you and others are clinging to the NIST report like a safety blanket. The fact is that despite the evidence that the NIST report could only get the steel to fail in exaggerated simulations, you will not even accept the possibility that the NIST report might be wrong.

You are not operating on logic and reason, you are making your judgments in this particular case on faith.

You cannot find fault with my reasoning--in which I show that the lynch pin of the NIST explanation is based on an unjustified assumption--yet you cling to it for dear life.

Again, this is exactly the kind crap thinking that you are all too happy to point out when it applies to a different conclusion. When it applies to your own conclusion, you tell me to take it up with the experts--so long as I leave you alone.

Your (and others') faith in the NIST report is a psychological issue: not a logical one. No one here can justify the fuel load increase, (because there is no justification for it) yet you refuse to come to terms with even the possibility that a government-funded agency would try to sell you something. Wake up.

TellyKNeasuss

8th September 2007, 05:55 PM

And yet, no one here can squarely reconcile the fuel load increases.
.
.
.
Now, if 4 lb/sq ft is a reasonable estimate given all the info known about the towers, what possible reason do they suppose that they underestimated this by 25%? That's a significant increase. That's 60 tons per floor versus 75 tons per floor. Where do you suppose an extra 15 tons of fuel per floor came from? Wouldn't you think they'd give some kind of justification for an extra 15 tons per floor?

So they clearly admit that Case A fits the available evidence. However, they must contradict the visual evidence in favor of an estimate that "there was no way to confirm."

Not only is this an argument from ignorance--in that they appeal to an unknown factor to increase the fuel load--they must actually contradict the available visual evidence to make this appeal.

You're assuming that because they didn't specifically state the reason for re-running the simulation with a higher fuel load that there must be something sinister about it. Did you consider any other possibilities? Such as that people knowledgeable about fire simulation modeling would not need the reasoning spelled out? That it might be common in situations in which the true input data is not known to essentially work both forwards and backwards from the middle to try to find realistic estimates of the proper input data that enable the model to produce results that match the observations? That it might be acceptable to increase the fuel load to compensate for other heat sources (e.g., Dr. Greening's PVC reactions, the heat from burning aircraft parts) that could not be input into the model? Do you have any experience in numerical simulations that would enable you to answer these questions? Have you researched fire simulations or contacted any fire engineering experts? Have any experts complained about the way NIST handled the simulations?

It might be just my strange way of thinking, but if I were fudging input data into to produce a desired result, when I wrote the paper I would portray my fudged data as the best values for the input.

I will consider posing this topic to my niece, who is working on a Ph.D. in structural engineering and has taught steel design classes. However, when I've mentioned conspiracy theories in the past she has said that she considers them so ludicrous that she has no interest in discussing them.

cmcaulif

9th September 2007, 12:07 AM

jay howard

9th September 2007, 11:08 AM

you missed the point entirely jay. You are clinging to the fuel load increase, but you forget this, along with the other adjusted factors for the more severe case, were done to produce a scenario with higher temps at the core, within the limits of the FDS software. They specifically wanted to see what would happen if heat was trapped in the core(the added fuel load actually slowed the spread of fire as well), which is why they made these decisions.The fuel load increase is merely a way to produce a desired environment with the available resources.

So ****** what? What is your point? That they wanted to play a $20M game of "Rampage"?

The salient point in all this is that the "most influential factor" in the simulations had to be arbitrarily and significantly increased in order to produce the white whale of their explanation: collapse initiation.

Without increasing these values 25%, there is no simulated collapse. It's possible their entire assessment is fundamentally wrong. However, if their fundamental assessment is acceptable, then why do they go against it in order to simulate the collapses?

You are on the horns of an uncomfortable dilemma: either

1. NIST's assessment of the conditions in the towers is flawed--in which case, we can't say whether 4 lb/sq ft is a reasonable estimate of the fuel load or not,

or

2. NIST's assessment of the conditions in the towers is reasonable, however, they must ignore and contradict data regarding the "most influential factor" in the simulations in order to produce a collapse.

So, either you have no simulated collapse with their reasonable data, or you have incompatible data with collapse initiation. You seem to want to say that they have good data AND they get to ignore their good data without any justification to produce a simulated collapse initiation. If this is what you mean to say, then you have removed their approach entirely from the scientific realm by making their conclusion irrefutable.

Despite the alluring sound of "irrefutable," it is not a desirable quality of theories. Astrology is irrefutable. Marxism is irrefutable. T.v. psychics are irrefutable. You do not want your cherished theory to be grouped in with these by making it irrefutable.

cmcaulif

9th September 2007, 11:47 AM

Once again, you have ignored what I said, kept clinging to the fuel load increase despite this, and have thrown in more snide and pointless comments. This of course, is why most posters don't bother with you anymore.

The temperatures produced by in the core were within the ranges that they found in the any experiments they did within the subproject. To recreate a more severe case, using the FDS software, which has limitations, they decided to increase the fuel load. They are not claiming that an increased fuel load is needed for collapse, the load is only increased because that produced the sort of outputs the NIST wanted to examine, outputs which still remain within experimental uncertainty. So they have a simulation with reasonable data, albeit with limitations and uncertainties, which they are quite clear about.

If you are going to simply ignore what I'm saying and continue to repeat yourself, don't bother to respond, like many other posters here, I have no interest in talking to a brick wall. You can drop your snide remarks as well(my cherished theory is the one proposed by Arup/Edinburgh, not the NIST by the way)

jay howard

9th September 2007, 11:49 AM

You're assuming that because they didn't specifically state the reason for re-running the simulation with a higher fuel load that there must be something sinister about it.

It's not a matter of "something sinister". That is a moral assessment. I'm making a determination about the structure of the NIST theory for the collapses. If I've been unclear about this, let me disabuse you of any misunderstandings on this: at some point, someone involved with the NIST Report on the WTC collapses probably knew that their theory hinged on unsubstantiated speculation. But that's speculation on my part. I'm speculating that the people who compiled the data and created the conclusions were smart enough to know that their data did not support their conclusions.

Is that an "unsubstantiated speculation"? Not really, and it's not pivotal to my criticisms anyway. Why they went ahead with the report without any clarification about the nature of these assumptions is unclear. I cannot make a good determination about their motivations. Are they morally flexible? It's possible. It's also possible that they were manipulated or coerced by more powerful forces. However, it's not very likely that they just didn't understand that the data did not support the conclusions. People are complicated. But it doesn't change the fact that their data does not support their conclusions.

Did you consider any other possibilities? Such as that people knowledgeable about fire simulation modeling would not need the reasoning spelled out? That it might be common in situations in which the true input data is not known to essentially work both forwards and backwards from the middle to try to find realistic estimates of the proper input data that enable the model to produce results that match the observations?

Sure, I considered that. All I needed to do was to find anywhere in any of the reports where it said 5 lb/sq ft fuel load was substantiated by any evidence or reasoning whatsoever. What I found were accounts to the effect that increasing the fuel load above 4 lb/sq ft would contradict multiple data sets: photo/video observations, fire-spread rates, and timing in the simulations--not to mention the caveat that fuel load was "the most influential factor" in the simulations.

In other words, the experts at NIST provided various substantiations for the fuel load of 4 lb/sq ft as well as reasons NOT to increase it. Why they went ahead and increased it anyway is never made clear--other than to "create a more severe fire".

On the other hand, you have no reason to doubt their fuel load estimate AND no reason to accept a higher estimate. Further, you should WANT to know why they increased this estimate, but instead you tell me I should look harder for a reason to justify it. I've looked for a reason to justify it. If it's there, please point it out. You don't have one, yet you accuse me of not looking hard enough to find one. The fact is, neither one of us can find a good reason why they went against their own estimates in order to produce the collapse initiation, except that they needed to produce a collapse initiation.

Are you still convinced that the fires burned hot enough for long enough to produce the collapses? Of course you are.

Why? Do you have a reason that doesn't hinge on your faith in other people and their titles?

That it might be acceptable to increase the fuel load to compensate for other heat sources (e.g., Dr. Greening's PVC reactions, the heat from burning aircraft parts) that could not be input into the model?

Your people at NIST already thought about that:

“… it would have been possible to further refine or ‘tune’ the properties of the simulated workstations to better match the experiments, but this would have been a waste of time and resources since the workstations were merely convenient surrogates for a variety of other combustible furnishings found throughout the buildings. Indeed, sensitivity studies revealed that the total mass loading of combustibles was more important than its composition.”(NCSTAR 1-5F, 36)

Do you have any experience in numerical simulations that would enable you to answer these questions? Have you researched fire simulations or contacted any fire engineering experts? Have any experts complained about the way NIST handled the simulations?

It might be just my strange way of thinking, but if I were fudging input data into to produce a desired result, when I wrote the paper I would portray my fudged data as the best values for the input.

It looks like it was fudged well enough to convince the "skeptics" here at jref. Maybe instead of asking me to look harder for a reason why my criticisms aren't valid, you should try a little harder to look for a reason why the NIST report's conclusions make sense.

This is the whole point of falsifiability: if, after your theory fails to predict expected outcomes, and you still think it's a good explanation, you can still cling to your theory, but you do so by making it irrefutable.

What, in other words, would convince you that the NIST explanation is deficient? If you answer "nothing", then you are not participating in a scientific endeavor--you are acting on faith. Faith is for you and your family--not for data analysis and theory construction.

jay howard

9th September 2007, 12:16 PM

Once again, you have ignored what I said, kept clinging to the fuel load increase despite this, and have thrown in more snide and pointless comments. This of course, is why most posters don't bother with you anymore.

You're breaking my heart. I couldn't care less if you responded, yet you continue to carry on this conversation as if it had an effect on you. It's clear that despite a lack of directly corroborative forensic evidence and manipulated simulation data, you will not even consider the possibility that the NIST conclusions maybe just might be overstated.

I'm open to change my mind about the NIST conclusions if IF any substantive reason could be provided for the increased estimates used in the simulations. Yet, none have been pointed out. The piss poor attempts presented here don't come close to overcoming this fundamental problem. However, after being given reason after reason for why they SHOULD NOT HAVE changed their fuel load estimates, you still won't even consider the possibility that NIST's conclusions are flawed.

The temperatures produced by in the core were within the ranges that they found in the any experiments they did within the subproject.

What? "Temperatures produced by in the core" where? In the simulations? Where was the majority of the fuel located? In the cores? No. The majority of the fuel was located between the cores and the exteriors. They want to explore different damage estimates such that the soffits remained? Fine. That doesn't provide any grounds to increase the fuel load estimates by 25%.

To recreate a more severe case, using the FDS software, which has limitations, they decided to increase the fuel load. They are not claiming that an increased fuel load is needed for collapse,

In fact they are:

“The Investigation Team then defined three cases for each building by combining the middle, less severe, and more severe values of the influential variables. Upon a preliminary examination of the middle cases, it became clear that the towers would likely remain standing. The more severe case (which became Case B for WTC 1 and Case D for WTC 2) was used for the global analysis of each tower.”( NCSTAR 1, 144)

Just not explicitly. The fact remains that fuel load was determined to be the "most influential factor" in the simulations, and the middle cases "would likely remain standing". The fact is, the "more severe case" used for global analysis increased this fuel load without any apparent justification other than to "create more severe fires".

the load is only increased because that produced the sort of outputs the NIST wanted to examine, outputs which still remain within experimental uncertainty. So they have a simulation with reasonable data, albeit with limitations and uncertainties, which they are quite clear about.

How are you making the determination that these increased data parameters are "reasonable"? This is the part you are ignoring. You clearly have NO REASON to believe this, yet you believe it anyway for no other apparent reason than you want to believe it. That's called faith. You cannot argue from faith. And you cannot be convinced from faith either. If we were having a rational scientific discussion based on evidence and reason, you would have to admit that there is indeed no reason to assume higher fuel loads in the towers, yet the simulations use higher estimates to produce "collapse initiation".

cloudshipsrule

9th September 2007, 12:36 PM

Jay,

You are wasting your time typing your crap. It does NOT matter what you type. If you dislike NIST's report then please point us to a more thorough investigation with better simulations that you actually like.

Waiting..............

What? There isn't one?

Well then, we'll just have to look to the NIST simulations until the TWOOF movement does something better, huh?

I imagine we'll be waiting a looooooong time.

Here's the thing, Jay.

Planes hit the building. Damage occurred. Fires started. Fires weakened steel. The building was NOT designed to withstand the damage it sustained, and it fell just as Mother Nature intended. (You know, gravity and inertia and all.) It's really not rocket science. It's just basic science with complicated variables.

Give it up. You're wasting your time.

What are you trying to say anyaway?

Explosives were planted? ZERO EVIDENCE.
Accelerants were used? ZERO EVIDENCE.
What else could you possibly be hinting at?

All of the evidence points to exactly what the rational individuals on this forum believe.

Gravity is the root of collapse initiation. Oh yeah, fire and structural damage helped too.

cmcaulif

9th September 2007, 12:51 PM

Once again, drop the snide remarks and pointless comments on 'faith'. What is the point of that? I have stated what I think is potentially the best theory, so OBVIOUSLY I have considered that the NIST's conclusions are flawed.

What? "Temperatures produced by in the core" where? In the simulations? Where was the majority of the fuel located? In the cores? No. The majority of the fuel was located between the cores and the exteriors. They want to explore different damage estimates such that the soffits remained? Fine. That doesn't provide any grounds to increase the fuel load estimates by 25%.

And the disturbed combustibles were weighted towards the core, not evenly around the floor space, which is significant, AND the fuel load increase slowed the spread of the fire to concentrate it near the core to some degree. This was the case they wished to examine.

In fact they are:

...

Just not explicitly.

...

I realize the point you are making, but you are ignoring the my previous posts to make it. The simulation was very sensitive to the input of the fuel load. The temperatures produced by the simulation were within the limits of the laboratory experiments they performed. They increased the fuel load to produce the scenario they wanted to examine, but this is because a simulation can never perfectly capture real life, not because they thought an increased load was necessary.

How are you making the determination that these increased data parameters are "reasonable"?

1. Become familiar with FDS, its limitations, and what inputs the simulation is sensitive to.

2. Become familiar with the experiments performed in the subproject, the ones most relevant to this discussion are 1-5C and 1-5E.

3. Realize that there is a difference between 1, 2, and an uncontrolled environment such as the WTC.

4. Attempt to understand the uncertainties involved in all of the above, and make a judgment from there.

This is the part you are ignoring. You clearly have NO REASON to believe this, yet you believe it anyway for no other apparent reason than you want to believe it. That's called faith. You cannot argue from faith. And you cannot be convinced from faith either. If we were having a rational scientific discussion based on evidence and reason, you would have to admit that there is indeed no reason to assume higher fuel loads in the towers, yet the simulations use higher estimates to produce "collapse initiation".

If we were having a rational discussion you would drop these retarded accusations, and you might actually address my overall point, other that to say 'so ****** what?'. I have said that the justification for the fuel load increase is based on the sensitivity of the software, and does not translate to an explicit or implicit claim that there was a necessary increase in fuel load in reality. I don't know why you refuse to acknowledge that a software package may not be able to capture a given event perfectly. It responds to different inputs, and the outputs it produced were still within the experimental ranges. I expect your answer to be more of the same, so this will probably be the last post from me on the topic.

DGM

9th September 2007, 12:56 PM

jay howard

9th September 2007, 01:00 PM

I have stated what I think is potentially the best theory, so OBVIOUSLY I have considered that the NIST's conclusions are flawed.

Really? In what ways specifically, do you consider NIST's conclusions to be flawed?

I have said that the justification for the fuel load increase is based on the sensitivity of the software, and does not translate to an explicit or implicit claim that there was a necessary increase in fuel load in reality. I don't know why you refuse to acknowledge that a software package may not be able to capture a given event perfectly. It responds to different inputs, and the outputs it produced were still within the experimental ranges. I expect your answer to be more of the same, so this will probably be the last post from me on the topic.

If only this was your last response.

But again, in your words above, there is no clear justification for the fuel load increase.

I know perfectly well that the FDS software "may not be able to capture a given event perfectly." How does that answer the question of why NIST increased the fuel loads? It DOESN'T. period.

jay howard

9th September 2007, 01:08 PM

Jay:
I'd sure like to see your controlled demolition evidence that can pass the extreme scrutiny your putting this through. Can you post this for us? After all if it can pass your review it must be good. Thanks in advance.

I'd sure like to see where you gathered that I'm making such a claim.

Can you post that? No. Because it's not the point I'm making.

This is the typical strategy here: reduce all alternatives to some kind of absurdity, and HURRAY! You win!

That's why this thread is about the theoretical fortitude of the NIST Report. I've shown time and again here that NIST's conclusion do not follow from their own data. Yet no one here is willing to say "hey, jay, you've got a point. Maybe we should look for a theory that better fits the data."

That's how scientific deliberation happens.

If you have a reason to suspect the criticisms of the NIST report I've presented are flawed, I'll take them seriously and respond as rationally as possible. If you want to dismiss what I say because you don't think alternative theories hold water, you have not successfully overcome my criticisms.

If you still believe in the conclusions of the NIST report but you cannot overcome these criticisms, you are participating in an article of faith. There is no way around this.

DGM

9th September 2007, 01:22 PM

I'd sure like to see where you gathered that I'm making such a claim.

Can you post that? No. Because it's not the point I'm making.

This is the typical strategy here: reduce all alternatives to some kind of absurdity, and HURRAY! You win!

That's why this thread is about the theoretical fortitude of the NIST Report. I've shown time and again here that NIST's conclusion do not follow from their own data. Yet no one here is willing to say "hey, jay, you've got a point. Maybe we should look for a theory that better fits the data."

That's how scientific deliberation happens.

If you have a reason to suspect the criticisms of the NIST report I've presented are flawed, I'll take them seriously and respond as rationally as possible. If you want to dismiss what I say because you don't think alternative theories hold water, you have not successfully overcome my criticisms.

If you still believe in the conclusions of the NIST report but you cannot overcome these criticisms, you are participating in an article of faith. There is no way around this.
I'm not trying to win anything. It sounded to me that you had a better theory, that's all. I'll take your answer as a no.

cmcaulif

9th September 2007, 01:37 PM

Really? In what ways specifically, do you consider NIST's conclusions to be flawed?

I meant to say may be flawed, I would need to see more work on the Arup/Edinburgh hypothesis before I accept it fully, though I have corresponded with some people from Arup on this. To answer your question, I believe that it is highly likely that the effects of thermal expansion are under weighted in the NIST global models. The reason for this is because these effects are included for support columns, but not for floor trusses. Arup/Edinburgh show that these effects would be quite significant, and would result in collapse without structural damage and with lower fire temps, though, of course, there are limits to there models as well. In general, I would like to see more research into this and I am happy that Dr. Quintiere of Univ. Maryland has proposed a review of the NIST, in which some of these things migt be explored.

If only this was your last response.

this is what I have been saying from the start, the actual load increase some sinister deed as you seem to think.

But again, in your words above, there is no clear justification for the fuel load increase.

I know perfectly well that the FDS software "may not be able to capture a given event perfectly." How does that answer the question of why NIST increased the fuel loads? It DOESN'T. period.

I gave you a four step mini journey which you can take that could perhaps satisfy you. Hopefully at the end, you will, at the very least have calmed down, or maybe even figured out that they just produced a scenario within the boundaries of their experiments, using the inputs sensitive to the software.

chipmunk stew

9th September 2007, 04:34 PM

I'm speculating that the people who compiled the data and created the conclusions were smart enough to know that their data did not support their conclusions.
The 4 lb/sq ft figure is not a data point. It's a "reasonable estimate" based on data (which, given the size and complexity of the problem, is bound to be incomplete.) It gave them a starting point for building the model. The increase in fuel load was found to fit the observed data better than the 4 lb/sq ft estimate. This type of iterative model-building is typical in engineering analyses. R. Mackey illustrated this beautifully a number of pages back.

TellyKNeasuss

9th September 2007, 07:06 PM

But that's speculation on my part. I'm speculating that the people who compiled the data and created the conclusions were smart enough to know that their data did not support their conclusions.

But not smart enough to remember to not publish information that would show that they were fudging the results?

All I needed to do was to find anywhere in any of the reports where it said 5 lb/sq ft fuel load was substantiated by any evidence or reasoning whatsoever. What I found were accounts to the effect that increasing the fuel load above 4 lb/sq ft would contradict multiple data sets: photo/video observations, fire-spread rates, and timing in the simulations--not to mention the caveat that fuel load was "the most influential factor" in the simulations. Have you looked at the table on page 46 of NCSTAR1-5F? It lists the range of estimates for the combustible fuel load as 17 to 34 kg/m2 (3.5 to 7 lb/ft2) with a mid-range of 25 kg/m2 (5.1 lb/ft2).

In other words, the experts at NIST provided various substantiations for the fuel load of 4 lb/sq ft as well as reasons NOT to increase its well as reasons NOT to increase it. I only skimmed through the report, so I guess I missed all the reasons NOT to increase the fuel load. I personally never got the sense that NIST was claiming that 4 lb/ft2 was pretty certain to be the correct value. On page 51 of NCSTAR1-5F, they state "It was unclear what the combustible load was in the various core areas". But again, I only skimmed NCSTAR1-5F and haven't really touched any of the rest of the report (since my only goal was to throw out possible ideas, not to defend the NIST report to the death) and if I read it carefully I might draw a different conclusion.

Why they went ahead and increased it anyway is never made clear--other than to "create a more severe fire". I believe that page 78 of NICSTAR1-5F explains the reasoning. And yes, they were trying to create a more severe fire. They also explain why.

Are you still convinced that the fires burned hot enough for long enough to produce the collapses? Of course you are.Are you aware that they only tested the higher fuel load for WTC1? Does that mean only WTC1 was destroyed by a CD?

It looks like it was fudged well enough to convince the "skeptics" here at jref.Not to mention convincing essentially all the structural engineers and fire protection engineers in the world.

What, in other words, would convince you that the NIST explanation is deficient? If you answer "nothing", then you are not participating in a scientific endeavor--you are acting on faith. Faith is for you and your family--not for data analysis and theory construction.Drs. Greening and Quintiere have already pointed out possible deficiencies in the NIST report. Your statement is a false dichotomy. NIST was not the first to propose the airplane impact damage + fire damage -> building collapse theory, and it is not necessary to believe every word of the NIST to feel comfortable with the conclusion that a combination of impact damage and fire damage led to the collapses.

jay howard

10th September 2007, 04:00 PM

The 4 lb/sq ft figure is not a data point. It's a "reasonable estimate" based on data (which, given the size and complexity of the problem, is bound to be incomplete.)

What do you mean "incomplete"? If it is a reasonable estimate, why do they provide no clear justification for a 25% increase? There is no good answer to this. Saying it is not a "data point" and "incomplete" does not give anyone license to increase their reasonable estimate by this degree. If it does, they give no clear explanation why.

It gave them a starting point for building the model. The increase in fuel load was found to fit the observed data better than the 4 lb/sq ft estimate.

How can you say that when they explicitly contradict you?

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

Unless words mean whatever you want them to mean, then you are just plain wrong about this.

pomeroo

10th September 2007, 04:12 PM

TellyKNeasuss

10th September 2007, 04:18 PM

What do you mean "incomplete"? If it is a reasonable estimate, why do they provide no clear justification for a 25% increase? There is no good answer to this. Saying it is not a "data point" and "incomplete" does not give anyone license to increase their reasonable estimate by this degree. If it does, they give no clear explanation why.

I thought that the justification was pretty clear. Their first simulations were using conservative assumptions and then they tested a set of more liberal assumptions. In the case of WTC1, they stated that they didn't know what the fuel loading in the core area was. In case A, they assumed that the "tenant area" loading of 4 lb/ft2 was valid throughout the building and in case B they upped the average fuel loading to simulate the heat that would have been released if the fuel loading in the core was higher than the fuel loading in the "tenant area".

"The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

OK, now I'm totally confused. You've been complaining that NIST re-ran the simulation using what you claim is an arbitrary increase in the fuel load. But the simulation using the original 4 lb/ft2 produced the results that were the most likely to cause the WTC1 to collapse. So what exactly is your point?

jay howard

10th September 2007, 05:00 PM

But not smart enough to remember to not publish information that would show that they were fudging the results?

Smart enough to put all the data in the reports such that they cannot be accused of lying, but never explicitly saying "we had to increase the combustible load against our own estimations in order to get the fires hot enough to cause the steel to weaken to a critical point." But this statement is true.

Have you looked at the table on page 46 of NCSTAR1-5F? It lists the range of estimates for the combustible fuel load as 17 to 34 kg/m2 (3.5 to 7 lb/ft2) with a mid-range of 25 kg/m2 (5.1 lb/ft2).

Yes. So what? If your speedometer says 400mph does that mean your car can go 400mph? Changing the input parameters doesn't have an effect on their "reasonable estimates" of fuel load. If you think it does, I'd like to see why you believe that.

I only skimmed through the report, so I guess I missed all the reasons NOT to increase the fuel load. I personally never got the sense that NIST was claiming that 4 lb/ft2 was pretty certain to be the correct value. On page 51 of NCSTAR1-5F, they state "It was unclear what the combustible load was in the various core areas". But again, I only skimmed NCSTAR1-5F and haven't really touched any of the rest of the report (since my only goal was to throw out possible ideas, not to defend the NIST report to the death) and if I read it carefully I might draw a different conclusion.

“A number of preliminary simulations had been performed to gain insight into the factors having the most influence on the severity of the fires. The most influential was the mass of combustibles per unit of floor area (fuel load)….”(NCSTAR 1, 126)

“… it would have been possible to further refine or ‘tune’ the properties of the simulated workstations to better match the experiments, but this would have been a waste of time and resources since the workstations were merely convenient surrogates for a variety of other combustible furnishings found throughout the buildings. Indeed, sensitivity studies revealed that the total mass loading of combustibles was more important than its composition.”(NCSTAR 1-5F, 36)

“Simulations performed with doubled fuel loads slowed the fire spread well below the observed rates. Combined with the above results, this suggested that the estimated overall combustible load of 4 lb/ft2 was reasonable.”(NCSTAR 1, 129)

“NIST estimated the combustible fuel loading on these floors to have been about 4 lb/ft2 (20 kg/m2), or about 60 tons per floor. This was somewhat lower than found in prior surveys of office spaces. The small number of interior walls, and thus minimal amount of combustible interior finish, and the limited bookshelf space account for much of the differences.”(NCSTAR 1, 77)

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

“… the simulated fires encircled the building in roughly the same amount of time as the actual fires support the estimate of the overall combustible load, 20 kg/m2 (4 lb/ft2). The fires burned for roughly 20 min to 30 min in any one location, consistent with the visual evidence (NIST NCSTAR 1-5A) and the multiple workstation fire experiments performed at NIST (Chapter 4).”(NCSTAR 1-5F, 107)

I believe that page 78 of NICSTAR1-5F explains the reasoning. And yes, they were trying to create a more severe fire. They also explain why.

I've been over this before with cmcaulif. If you can find a "reason" that supports increasing the estimate, please show me. Please keep in mind what you would think if I was trying to [i]convince you of the opposite conclusion with this line of reasoning. The fact remains that there isn't really a good reason given. Just "we wanted to span the range of probable gas temperatures." But how are these "probable gas temperatures" if they had to ignore their estimates or the available evidence to get them?

Are you aware that they only tested the higher fuel load for WTC1? Does that mean only WTC1 was destroyed by a CD?

I'm sincerely glad to be having this conversation with you, but please read earlier posts. Yes. I'm fully aware. Are you aware that they had to return damaged office furniture to its undamaged state except in the direct path of the aircraft "in order to create a more severe fire"?

“In Case D, the furnishings were restored to their ‘undamaged’ state, except in the immediate vicinity of the airplane impact, to create a more severe fire.“(NCSTAR 1-5F, 87)

They also had to go against the visual evidence in order to get Case D.

“The heavy concentration of combustibles in the corner [Case C] produced a fire that lasted an entire hour in that location, consistent with visual evidence.”(NCSTAR 1-5F, 87)

and

“Because the airplane swept through a large expanse of the east side of the building, the fires were not as intense as would be expected along the east face, presumably because much of the furnishings were heavily damaged and a considerable mass was ‘plowed’ into the northeast corner, where the fires burned most intensely for the entire hour before collapse.”(NCSTAR 1-5F, 107)

So either NIST is producing good estimates and going against them, or they don't know what they're doing, in which case, none of their findings are useful. Either way, Cases B & D don't fit.

Which do you think it is?

Not to mention convincing essentially all the structural engineers and fire protection engineers in the world.

They obviously didn't convince them all--as you noticed, some very important ones like Quintiere have pointed out some major problems. Besides, experts are often wrong. If you can't find anything wrong with my interpretation of their data except that "all the experts haven't dissented" then maybe it's time to re-evaluate the reasons you put so much stock in the NIST report.

Your statement is a false dichotomy. NIST was not the first to propose the airplane impact damage + fire damage -> building collapse theory, and it is not necessary to believe every word of the NIST to feel comfortable with the conclusion that a combination of impact damage and fire damage led to the collapses.

What statement is a false dichotomy?

It certainly IS necessary to believe the simulations used good data in "re-creating" the collapses because that's the only place the heat-induced collapse theory is demonstrated. If the simulations used crap data, how can we rely on their results for an answer to why the towers collapsed? We can't.

jay howard

10th September 2007, 05:04 PM

You've been raving about the NIST Report for weeks. Why do I have the suspicion that you've never bothered to call the agency and ask Mike Newman for an explanation?

What's the purpose of writing a 10,000+ page report if you have to call people up for "clarification"?

Again, you don't have (or won't make) a specific criticism of my arguments, but would rather just assume that I must be mistaken. It couldn't possibly be that you've been fed dog food in a porcelain bowl, could it?

jay howard

10th September 2007, 05:10 PM

OK, now I'm totally confused. You've been complaining that NIST re-ran the simulation using what you claim is an arbitrary increase in the fuel load. But the simulation using the original 4 lb/ft2 produced the results that were the most likely to cause the WTC1 to collapse. So what exactly is your point?

Re-read that quote. They're saying when they increased the fuel load FROM 4 lb/sq ft TO the higher amounts, the simulation did not spread fast enough to get to the south side of WTC 1 in time to initiate a collapse.

TellyKNeasuss

10th September 2007, 05:21 PM

Re-read that quote. They're saying when they increased the fuel load FROM 4 lb/sq ft TO the higher amounts, the simulation did not spread fast enough to get to the south side of WTC 1 in time to initiate a collapse.

The important phrase is "resulted in slower fire spread rates". It's clear to me what they're saying even if it's not clear to you.

TellyKNeasuss

10th September 2007, 05:30 PM

What's the purpose of writing a 10,000+ page report if you have to call people up for "clarification"?

I believe that the purpose of the NIST study was to evaluate what roles various building techniques and materials contributed to the collapse. The intended audience was engineering and construction experts. It was written in the same style that engineering and scientific research papers are written. I agree that it would be useful for someone to produce a summary for laymen.

TellyKNeasuss

10th September 2007, 06:00 PM

Smart enough to put all the data in the reports such that they cannot be accused of lying, but never explicitly saying "we had to increase the combustible load against our own estimations in order to get the fires hot enough to cause the steel to weaken to a critical point." But this statement is true.

You figured it out, but you don't think that people knowlegeable about the subject also would?

I've been over this before with cmcaulif. If you can find a "reason" that supports increasing the estimate, please show me. Please keep in mind what you would think if I was trying to convince you of the opposite conclusion with this line of reasoning. The fact remains that there isn't really a good reason given. Just "we wanted to span the range of probable gas temperatures." But how are these "probable gas temperatures" if they had to ignore their estimates or the available evidence to get them? As I pointed out, they wanted to test what might happen if some of their assumptions were wrong. For example, in the case of WTC1 they wanted to test what would happen if the fuel load were higher in the core area, and given the limitations of their model the best way to do this was to increase the average fuel load over the entire area. If they had only run cases A and C, troothers would be complaining that NIST only tried one set of input data that was based on assumptions that might not be correct.

I'm sincerely glad to be having this conversation with you, but please read earlier posts. Yes. I'm fully aware. Are you aware that they had to return damaged office furniture to its undamaged state except in the direct path of the aircraft "in order to create a more severe fire"?

“In Case D, the furnishings were restored to their ‘undamaged’ state, except in the immediate vicinity of the airplane impact, to create a more severe fire.“(NCSTAR 1-5F, 87)You're just not getting it. They did NOT have completely accurate information about how much furniture was damaged, so they tried, in addition to what they thought was a good estimate, something close to the other end of the scale. You would have preferred that they not evaluate what changes making alternative estimates of the input data would have made? Would not someone then claim that NIST only tried one set of estimates of the input parameters because they only wanted to get a specific result and not show what might happen if their input parameters were wrong?

So either NIST is producing good estimates and going against them, or they don't know what they're doing, in which case, none of their findings are useful.The third alternative is that you don't understand the process.

They obviously didn't convince them all--as you noticed, some very important ones like Quintiere have pointed out some major problems. Besides, experts are often wrong. If you can't find anything wrong with my interpretation of their data except that "all the experts haven't dissented" then maybe it's time to re-evaluate the reasons you put so much stock in the NIST report.Quintiere's "problems" weren't all that major; he still agrees with the conclusion that aircraft impact damage + fire damage -> tower collapse theory.

How much stock have I put in the NIST report? I may or may not have ever cited it as evidence for something; I can't even remember.

What statement is a false dichotomy?SInce you brought up Quintiere, he is proof that it is possible to take issue with the NIST report but still come up with an evaluation that the aircraft impact damage + fire damage -> tower collapse theory is valid.

jay howard

10th September 2007, 07:58 PM

The important phrase is "resulted in slower fire spread rates". It's clear to me what they're saying even if it's not clear to you.

What do you think they are saying in the quote?

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

GlennB

11th September 2007, 02:55 AM

What do you think they are saying in the quote?

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

Keep reading the bullet points on pp183-184 ...

In the next bullet point on that page they also add that the aircraft added significant combustible material.

Later they point out that the Simulator is able to predict temperatures and heat release rates to 20% accuracy with exact input parameters of combustibles, ventilation and damage.

And yet you persist in claiming that NIST falls because the 4lb/ft2 average was exceeded in simulations?

You're insisting on a degreee of precision that is totally unavailable, and one that NIST does not claim. The exact average fuel loading can never be known. The exact degrees of damage, ventilation and combustible redistribution can never be known. Running the Simulator against a range of parameters is the only sensible way to approach the calculations. In any event, even NIST freely accept the FDS is only accurate to +/- 20%.

I put it to you that you're desperately seeking any reason to disbelieve NIST.

jay howard

11th September 2007, 07:59 AM

You're insisting on a degreee of precision that is totally unavailable, and one that NIST does not claim. The exact average fuel loading can never be known. The exact degrees of damage, ventilation and combustible redistribution can never be known. Running the Simulator against a range of parameters is the only sensible way to approach the calculations. In any event, even NIST freely accept the FDS is only accurate to +/- 20%.

I put it to you that you're desperately seeking any reason to disbelieve NIST.

Once again, you fall onto the horns of an uncomfortable dilemma:

either NIST had good information and ignored/went against their own estimations and evidence

or

A degree of precision was totally unavailable, and we cannot make a clear determination about the results.

But you can't have it both ways because you wouldn't apply those standards to the opposite side of the debate. If you can't use the same standards of evaluation for both sides of the debate, then you are not really having a debate.

So which is it?

chipmunk stew

11th September 2007, 08:12 AM

Once again, you fall onto the horns of an uncomfortable false dilemma:
(my edit)

jay howard

11th September 2007, 08:48 AM

(my edit)

If you think it's a false dichotomy, please show why.

I've shown why it's not. Where did I make a mistake of reasoning?

chipmunk stew

11th September 2007, 09:23 AM

If you think it's a false dichotomy, please show why.

I've shown why it's not. Where did I make a mistake of reasoning?
The theory doesn't hinge on knowing the precise fuel load. The theory hinges on whether the observed effects and theorized immediate causes can be replicated by introducing observed disruptions into the model. The disruptions are highly complex and can only be estimated, so they have to be carefully and iteratively tested over a range of parameter inputs within a reasonable envelope. Initial estimates are typically kept as conservative as possible. You start with an "at least" or "at most" and work away from it iteratively until the effects are successfully replicated, the model breaks down*, you get significant unobserved and unexpected results*, or your parameter stretches beyond the envelope of plausibility*.

This is the way engineers work.

edit: *all of which falsify your theory (if your model is proved valid)

A W Smith

11th September 2007, 09:29 AM

Once again, you fall onto the horns of an uncomfortable dilemma:

either NIST had good information and ignored/went against their own estimations and evidence

or

A degree of precision was totally unavailable, and we cannot make a clear determination about the results.

But you can't have it both ways because you wouldn't apply those standards to the opposite side of the debate. If you can't use the same standards of evaluation for both sides of the debate, then you are not really having a debate.

So which is it?

false choice fallacy (http://en.wikipedia.org/wiki/False_dilemma)noted
Where did I make a mistake of reasoning?

^Click the hyperlink^

GlennB

11th September 2007, 09:39 AM

..

But you can't have it both ways because you wouldn't apply those standards to the opposite side of the debate....

False.

If a 9/11 CT study produced a complex analysis/simulation such as this - whose parameters lie within reasonable boundaries - I would happily accept it.

Are you aware of any?

jay howard

11th September 2007, 10:14 AM

False.

If a 9/11 CT study produced a complex analysis/simulation such as this - whose parameters lie within reasonable boundaries - I would happily accept it.

Are you aware of any?

Why don't Cases A and C count? Because they didn't produce a collapse initiation?

jay howard

11th September 2007, 10:25 AM

false choice fallacy (http://en.wikipedia.org/wiki/False_dilemma)noted

^Click the hyperlink^

What choice am I leaving out?

Did NIST provide good data? Yes or no.

Horn 1.
If yes, and they admit (as pointed out several times) they must ignore this data and evidence to produce the collapse initiations in the simulations, then we cannot rely on their results, and by extension, their hypothesis.

Horn 2.
If no, then we cannot rely on their results, and by extension, their hypothesis.

You don't want option 2, so your best attack is against option 1. To do this, however, you've got to say that the NIST report doesn't mean what they say it means (when convenient). I.e.:

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

Unless NIST's data is simply no good, you've got to come to terms with the fact that increasing the fuel load DID NOT MATCH PATTERNS OBSERVED IN PHOTOGRAPHIC EVIDENCE.

It's not simply a matter of not having an exact fuel load estimate, it's about gaging estimates against observations. Increasing fuel load went against both the estimates and the observed data.

chipmunk stew

11th September 2007, 10:27 AM

Why don't Cases A and C count? Because they didn't produce a collapse initiation?
Because all the cases together are a set. They all used parameters within the same envelope. One of them produced a collapse initiation. That's all that's required to validate the plausibility of the theory.

chipmunk stew

11th September 2007, 10:34 AM

What choice am I leaving out?

Did NIST provide good data? Yes or no.
Yes. But good doesn't always mean precise. When you have imprecise data, you test iteratively over a range defined by the uncertainty of the data.

rwguinn

11th September 2007, 11:58 AM

Yes. But good doesn't always mean precise. When you have imprecise data, you test iteratively over a range defined by the uncertainty of the data.

Pointing out that precision and accuracy are not the same thing. You can be very precise, and not at all accurate-and vice-versa.
Precision: we put a 7.620 mm hole 1.02 mm from the exact center of the target.
Accuracy: We were aiming for the 6-ring.

jay howard

11th September 2007, 02:12 PM

Because all the cases together are a set. They all used parameters within the same envelope. One of them produced a collapse initiation. That's all that's required to validate the plausibility of the theory.

One set didn't produce collapse initiation. That set more closely resembled both the photographic evidence and the fire-spread rate.

The one that produced the collapse initiation not only did NOT match the photographic evidence, the NIST authors said this version didn't burn fast enough in WTC 1 to reach the south side in time to initiate the collapse.

But you can overlook that because "they're a set"? What kind of nonsense reason is that?

Why is it you dismiss the results of Cases A and C? Do you have a good reason to? They did not produce collapse initiation. You agree that the data NIST used to produce them was reasonable. They matched observations and fire-spread rates. But they did not produce a collapse. By what reasoning do you dismiss them?

If you want to take them as a "set" then you can't dismiss the ones that didn't give you the expected results. How do you reconcile the fact that when they input "reasonable" estimates that corroborated photos and fire-spread rates, the program demonstrated no collapse?

GlennB

11th September 2007, 02:51 PM

One set didn't produce collapse initiation. That set more closely resembled both the photographic evidence and the fire-spread rate.

The one that produced the collapse initiation not only did NOT match the photographic evidence, the NIST authors said this version didn't burn fast enough in WTC 1 to reach the south side in time to initiate the collapse.

But you can overlook that because "they're a set"? What kind of nonsense reason is that?

Why is it you dismiss the results of Cases A and C? Do you have a good reason to? They did not produce collapse initiation. You agree that the data NIST used to produce them was reasonable. They matched observations and fire-spread rates. But they did not produce a collapse. By what reasoning do you dismiss them?

If you want to take them as a "set" then you can't dismiss the ones that didn't give you the expected results. How do you reconcile the fact that when they input "reasonable" estimates that corroborated photos and fire-spread rates, the program demonstrated no collapse?

This is how science progresses, jay :

NIST's is the currently accepted, and widely respected, theory.

After countless posts where you nit-pick NIST's methodology and parameters, maybe it's time to propose your superior theory - accompanied by detailed evidence and analysis - with which to supplant NIST's.

Looking forward to hearing from you, although I must admit I'm not holding my breath. Personally I think you're full of hot air and self-important pseudo-science. But maybe you can surprise us by progressing beyond destructive argument and into productive argument?

jay howard

11th September 2007, 03:52 PM

Looking forward to hearing from you, although I must admit I'm not holding my breath. Personally I think you're full of hot air and self-important pseudo-science. But maybe you can surprise us by progressing beyond destructive argument and into productive argument?

You accuse me of "pseudo-science"? Yet, you cannot even admit the possibility that the "highly regarded" theory you've been all too eager to uncritically accept just might be incomplete, and might even be completely bunk.

Given well-reasoned argument, consistent explanations, and a failure of anyone to successfully defend pivotal flaws in the NIST report, your weak excuses to believe NIST's explanation come off like a child grasping at a safety blanket. And you want to accuse me of pseudo-science?

Gravy, time and again wants to call me a "denialist". Yet, in doing so, he ends up pointing his finger at himself along with all of you who claim you will only consider rational explanations when tossing out "conspiracy theories" one by one.

In a large way, this thread was test of whether you were willing to put your own theories to the same, agreed-upon standards of theoretical adequacy. If so, then it would become apparent that the official explanation was seriously lacking. If not, then those who still chose to support it would expose themselves as dogmatic and hypocritical--choosing to hold their own theory to a different set of standards than those of their interlocutors.

You can cling to the results of the NIST report--as you most certainly will--however, you cannot claim that the conclusion within it are "credible" or "scientific" no matter how many experts agree with, or refuse to disagree with them. By your own accounts, there is no clearly defined way the NIST conclusions could be refuted. They are definitively non-falsifiable.

Over 1000 posts and several weeks later, no one can produce specific, testable criteria with which to apply to the NIST theory. This is a fundamental failing.

Why have so many experts not spoken out? Many have. Unanimous dissent is a bit much to ask, but the report seems to have worked well enough to convince a swath of the public that the government did their job in looking into the collapses. Most people here--even the engineers--don't know falsifiability from their anus, so it's no surprise the general public couldn't express a specific criticism of the report. As a PR piece, the report was a success. As science, the final conclusions leak like a sieve.

pomeroo

11th September 2007, 04:14 PM

You accuse me of "pseudo-science"? Yet, you cannot even admit the possibility that the "highly regarded" theory you've been all too eager to uncritically accept just might be incomplete, and might even be completely bunk.

Given well-reasoned argument, consistent explanations, and a failure of anyone to successfully defend pivotal flaws in the NIST report, your weak excuses to believe NIST's explanation come off like a child grasping at a safety blanket. And you want to accuse me of pseudo-science?

Gravy, time and again wants to call me a "denialist". Yet, in doing so, he ends up pointing his finger at himself along with all of you who claim you will only consider rational explanations when tossing out "conspiracy theories" one by one.

In a large way, this thread was test of whether you were willing to put your own theories to the same, agreed-upon standards of theoretical adequacy. If so, then it would become apparent that the official explanation was seriously lacking. If not, then those who still chose to support it would expose themselves as dogmatic and hypocritical--choosing to hold their own theory to a different set of standards than those of their interlocutors.

You can cling to the results of the NIST report--as you most certainly will--however, you cannot claim that the conclusion within it are "credible" or "scientific" no matter how many experts agree with, or refuse to disagree with them. By your own accounts, there is no clearly defined way the NIST conclusions could be refuted. They are definitively non-falsifiable.

Over 1000 posts and several weeks later, no one can produce specific, testable criteria with which to apply to the NIST theory. This is a fundamental failing.

Why have so many experts not spoken out? Many have. Unanimous dissent is a bit much to ask, but the report seems to have worked well enough to convince a swath of the public that the government did their job in looking into the collapses. Most people here--even the engineers--don't know falsifiability from their anus, so it's no surprise the general public couldn't express a specific criticism of the report. As a PR piece, the report was a success. As science, the final conclusions leak like a sieve.

The reason you are widely regarded as a pompous fraud is that everyone here gets the idea that it would be necessary to rebuild the Twin Towers and fly commercial airliners into them to produce a model that might--might!--satisfy you. You are incapable or unwilling of making a phone call to NIST, but I didn't find it too difficult. Mike Newman commented on the extraordinary degree of exactitude that NIST's investigation was capable of achieving. The firm Marsh-McClennan provided data that showed exactly how much paper was present on each desk. You and your fellow fantasists pretend that real researchers function as you do--flying by the seat of your pants and fabricating whatever you require. Science doesn't work like that.

You started this thread on a bogus premise. The NIST Report is obviously falsifiable. You happen to believe that it is false, although you've failed miserably to show us why.

GlennB

11th September 2007, 04:34 PM

....
choosing to hold their own theory to a different set of standards than those of their interlocutors.
.....

Fine.

Then please present us with an "interlocutor's" theory for analysis. If we fail to analyse it to the same standard you will be justified in pointing out our failings.

Despite many requests you've refused to do so, so it's back to the point I made. Science advances where theory A is shown to be superior to theory B.

Time to stop dancing jay. What's your superior theory???

( Though, frankly, it might be more productive to ask my dog to take up chess ).

eta: damn - the dog has gone for the Petrov defence. I hate that, but he's doing better than you.

Myriad

11th September 2007, 04:45 PM

beachnut

11th September 2007, 04:51 PM

rwguinn

11th September 2007, 08:15 PM

chipmunk stew

12th September 2007, 03:42 AM

You accuse me of "pseudo-science"? Yet, you cannot even admit the possibility that the "highly regarded" theory you've been all too eager to uncritically accept just might be incomplete, and might even be completely bunk.

Given well-reasoned argument, consistent explanations, and a failure of anyone to successfully defend pivotal flaws in the NIST report, your weak excuses to believe NIST's explanation come off like a child grasping at a safety blanket. And you want to accuse me of pseudo-science?

Gravy, time and again wants to call me a "denialist". Yet, in doing so, he ends up pointing his finger at himself along with all of you who claim you will only consider rational explanations when tossing out "conspiracy theories" one by one.

In a large way, this thread was test of whether you were willing to put your own theories to the same, agreed-upon standards of theoretical adequacy. If so, then it would become apparent that the official explanation was seriously lacking. If not, then those who still chose to support it would expose themselves as dogmatic and hypocritical--choosing to hold their own theory to a different set of standards than those of their interlocutors.

You can cling to the results of the NIST report--as you most certainly will--however, you cannot claim that the conclusion within it are "credible" or "scientific" no matter how many experts agree with, or refuse to disagree with them. By your own accounts, there is no clearly defined way the NIST conclusions could be refuted. They are definitively non-falsifiable.

Over 1000 posts and several weeks later, no one can produce specific, testable criteria with which to apply to the NIST theory. This is a fundamental failing.

Why have so many experts not spoken out? Many have. Unanimous dissent is a bit much to ask, but the report seems to have worked well enough to convince a swath of the public that the government did their job in looking into the collapses. Most people here--even the engineers--don't know falsifiability from their anus, so it's no surprise the general public couldn't express a specific criticism of the report. As a PR piece, the report was a success. As science, the final conclusions leak like a sieve.
Here, from someone who read and understood the report, is a repetition of the first explanation (of several) given to you of why your fuel load misunderstanding is not a "pivotal flaw":
Actually, it's simpler than that.

The quote that "the Towers would likely remain standing" is based on the preliminary models -- and also doesn't mean "likely to remain standing forever." It actually means that, under those cases, the Towers would still have collapsed, but it would have taken longer than it did in reality.

As it turns out, the fuel loading is actually not that relevant. More relevant is the fuel placement, and how the fuel load determines the location -- not the intensity -- of the fires.

An increase in fuel load from 4 lb/ft2 to 5, i.e. 25%, is small compared to the increase that was tested during model sensitivity testing. That sensitivity testing, in which the fuel load was increased by 33%, found that the fuel load was relevant but only with respect to the duration of fires. See NCSTAR1-5F section 5.2 for the sensitivity analysis.

The overall effect of fuel load on the fires is described in Chapter 6 of NCSTAR1-5F:

In Case C and D, of course, there was no change in the combustible load at all:

Therefore, the complaint about increasing the fuel load in WTC 1 is groundless, and stems from lack of comprehension about the report.

It is similarly incorrect to state that the fuel loading or placement defined Cases A and C versus B and D. More importantly, B and D involved more impact damage, especially fireproofing damage. That makes a far greater difference than any change in the fuel load.

The reasons to prefer the higher impact damage estimates are given in NCSTAR1-2B. We've discussed them to death in this thread (http://forums.randi.org/showthread.php?postid=2542882#post2542882) (skipping most of the crap in that thread), and besides that cases B and D were seen to better simulate the leaning and floor behavior than cases A and C. This is why A and C were rejected:

For more information about this, please see Chapter 7 of NCSTAR1-6.

TellyKNeasuss

12th September 2007, 02:01 PM

jay howard

12th September 2007, 06:42 PM

The reason you are widely regarded as a pompous fraud is that everyone here gets the idea that it would be necessary to rebuild the Twin Towers and fly commercial airliners into them to produce a model that might--might!--satisfy you. You are incapable or unwilling of making a phone call to NIST, but I didn't find it too difficult. Mike Newman commented on the extraordinary degree of exactitude that NIST's investigation was capable of achieving. The firm Marsh-McClennan provided data that showed exactly how much paper was present on each desk. You and your fellow fantasists pretend that real researchers function as you do--flying by the seat of your pants and fabricating whatever you require. Science doesn't work like that.

You started this thread on a bogus premise. The NIST Report is obviously falsifiable. You happen to believe that it is false, although you've failed miserably to show us why.

You are just demonstrating my point that you don't understand what falsifiability is. If you are so convinced the conclusions are falsifiable, why are you unable to produce a single testable sentence from the report?

You cannot do it, yet you claim I'm the fanatic. Denial maybe?

What "bogus premise" did I start this thread on? That the NIST report is not a special case in which the principles of logic and reason do not or should not apply? What's bogus is that you think NIST's conclusions are irrefutable, yet you don't see that as a problem.

Think about it: if I told you that the towers were brought down by "mini nukes" in the basement, you'd show me tests that were done to check for levels of tritium that exceeded background levels. When no tritium was found exceeding background levels, you'd say "there could not have been any mini nukes because they would have increased tritium levels above background." If I still maintained the mini nukes position, it would no longer be based in science: I could say, "well, they used a new nuclear device that didn't create tritium". I have just made my position irrefutable, and hence, unscientific.

If you keep having to amend your position or redefine evidence so it doesn't count against your position, you may have already left the scientific field. This happens all the time in political discussions where people can get away with it more easily. In a scientific discussion, it's much more cut and dry: you either have a testable position or you don't. If you don't, you are not doing science.

You don't have to rebuild the towers to satisfy me. In fact, I'm of the opinion that the floor truss tests performed by UL do indeed satisfy the requirements of a good test. It's the people defending NIST that don't think that counts as a good test. But you are immune to reasons.

So again, can you show me a testable claim for the NIST collapse theory? This just needs to be one sentence to the effect of "floor trusses fail at x temp for t time under loading conditions and y impact damage without SFRM". Or something like that. I've looked in vain to find it. There are anecdotal versions all through it, but without time and temperature specifications.

How can a theory that cannot be shown to be false possibly be right?

jay howard

12th September 2007, 06:52 PM

Fine.

Then please present us with an "interlocutor's" theory for analysis. If we fail to analyse it to the same standard you will be justified in pointing out our failings.

Despite many requests you've refused to do so, so it's back to the point I made. Science advances where theory A is shown to be superior to theory B.

Time to stop dancing jay. What's your superior theory???

( Though, frankly, it might be more productive to ask my dog to take up chess ).

eta: damn - the dog has gone for the Petrov defence. I hate that, but he's doing better than you.

Why do you have such a hard on for "my theory" when my theory is that NIST's conclusions are not falsifiable?

I understand that it is uncomfortable to analyze your own theory, but before we move on to "my theory," there must be a reason to. Don't you agree? If the NIST position is completely adequate to answer the question of why the towers collapsed, then why waste time and energy looking into alternatives?

Do you believe NIST's conclusions are substantiated by all the available evidence? If so, there's no need for a new theory.

If you want to start a new thread about some alternative position, that's your business, but don't derail this conversation because you're not comfortable scrutinizing your beliefs.

jay howard

12th September 2007, 07:22 PM

To make this simple:

1. Both figures for fuel loading, 4 and 5 lbs, were well within the range of uncertainty for the parameter. They are equally likely to be closer to the real value that actually existed in the towers.

2. Results that matched the key observables were obtained with parameters that were all well within their respective ranges of uncertainty.

Then what did they mean by this:

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

Either they mean what they say here and the increased fuel load would not produce a collapse in the given time restraints, or none of their estimates are meaningful. Which is it?

These higher fuel loadings also "did not match the patterns observed in the photographic evidence." Either they meant what they said, or they didn't. If they did, you're plain wrong. If not, then how do we know if anything they said is useful or not?

3. If key observables in the results could not be replicated without using input parameters outside the range of uncertaintly, then the "impact damage and fire" theory of collapse initiation that was investigated by NIST would have been falsified.

Respectfully,
Myriad

YES!

Exactly. Only when they increased the fuel loads did they get collapse initiation, but at the expense of matching observable patterns of fire-spread rates. This is one of the reasons they give for substantiating their estimate of 4 lb/sq ft.

The question here is "why doesn't the incompatibility of increased fuel loads with the available evidence substantiate the middle case estimate of 4 lb/sq ft?" NIST seems to accept this as they mention above and elsewhere, however, it seems to have no effect on the defenders here. Why?

jay howard

12th September 2007, 07:24 PM

Jay, you are a failure .... You ... failure, but have fallen short. You failed .... Jones failed, you failed.... Failure; ...

(My edit, for brevity)

jay howard

12th September 2007, 07:36 PM

Every scientific theory is incomplete. That is the nature of the beast.
Newtonian physics is/was incomplete. Is it falsifiable? You betcha. Just one thing happening that violates it -- like a violation of conservation of momentum or energy in the wrong place.
Relativistic physics filled in some of the holes. and explained the anomolies while maintaining the basic concepts. E=m*C^2? That just puts a limit on the KE=1/2*M*v^2 Newtonian model. Now, through improved observation, even that is incomplete. Is it falsifiable? You betcha. Just one thing happening that violates it--some particle with mass that exceeds the C limit will do it.
Evolution has holes. We all know that. But it does explain what happende after life came to be. Just one dinosaur skeleton wrapped around a human skeleton would kill it, or at least require very major revisions.
Falsifiablilty requires just one thing that violates the theory. Steel that doesn't weaken with temperature, 3 pounds of negative entropy--any of thoise things will clobber the NIST, physical science, and engineering world's theories of how the towers came down.
These things ain't happened yet. No student of the scientific method expects them to.

Yes, you WANT your theory to be falsifiable. Astrology is non-falsifiable. The Bible Code is non-falsifiable. Many crappy theories exist.

And it's also true that falsifiability is no guarantee of truth. It is impossible to guarantee the truth of inductive arguments. That's the whole purpose of having metatheoretical criteria: they give us a basis from which to judge a "good" theory from the multitude of crappy ones in a world where "truth" has no capital "T".

However, if your theory isn't falsifiable, it can be immediately discarded as useless. Do you understand the importance of being able to show that the NIST theory is falsifiable?

jay howard

12th September 2007, 07:38 PM

Here, from someone who read and understood the report, is a repetition of the first explanation (of several) given to you of why your fuel load misunderstanding is not a "pivotal flaw":

Rather than repost arguments that I've already responded to, try rephrasing his words in such a way that you show why my response failed to answer them.

Otherwise, we're wasting bandwidth reposting exact duplicates from the same thread.

jay howard

12th September 2007, 07:44 PM

Having started reading the NIST report, I now see the context in which you were using this statement.

Good to hear it. What do you think?

Myriad

12th September 2007, 07:44 PM

Then what did they mean by this:

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

How much higher?

“Simulations performed with doubled fuel loads slowed the fire spread well below the observed rates. Combined with the above results, this suggested that the estimated overall combustible load of 4 lb/ft2 was reasonable.”(NCSTAR 1, 129)(emphasis added)

Either they mean what they say here and the increased fuel load would not produce a collapse in the given time restraints, or none of their estimates are meaningful. Which is it?

These higher fuel loadings also "did not match the patterns observed in the photographic evidence." Either they meant what they said, or they didn't. If they did, you're plain wrong. If not, then how do we know if anything they said is useful or not?

Double the fuel load would not produce a collapse in the given time frame or match the patterns observed in the photographic evidence.

Where is it stated that a 5 lbs/ft^2 fuel load did not produce a collapse in the given time frame or did not match the patterns observed in the photographic evidence?

Exactly. Only when they increased the fuel loads did they get collapse initiation, but at the expense of matching observable patterns of fire-spread rates. This is one of the reasons they give for substantiating their estimate of 4 lb/sq ft.

Where is it stated that a 5 lbs/ft^2 fuel load did not produce a collapse in the given time frame or did not match the patterns observed in the photographic evidence?

Respectfully,
Myriad

jay howard

12th September 2007, 07:56 PM

How much higher?

“Simulations performed with doubled fuel loads slowed the fire spread well below the observed rates. Combined with the above results, this suggested that the estimated overall combustible load of 4 lb/ft2 was reasonable.”(NCSTAR 1, 129)(emphasis added)

Double the fuel load would not produce a collapse in the given time frame or match the patterns observed in the photographic evidence.

Where is it stated that a 5 lbs/ft^2 fuel load did not produce a collapse in the given time frame or did not match the patterns observed in the photographic evidence?

Where is it stated that a 5 lbs/ft^2 fuel load did not produce a collapse in the given time frame or did not match the patterns observed in the photographic evidence?

Respectfully,
Myriad

Is 5 higher than 4?

Myriad

12th September 2007, 08:02 PM

Is 5 higher than 4?

Yes.

4.001 is also higher than 4.

Do you think that means that a fuel load of 4.001 lbs/ft^2 would have resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence?

Where is it stated that a 5 lbs/ft^2 fuel load did not produce a collapse in the given time frame or did not match the patterns observed in the photographic evidence?

Respectfully,
Myriad

jay howard

12th September 2007, 08:44 PM

Yes.

4.001 is also higher than 4.

Do you think that means that a fuel load of 4.001 lbs/ft^2 would have resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence?

Not likely. It's not an appreciable difference. The difference between 4 lbs/sq ft and 5 lbs/sq ft is the difference between 60 tons per floor to 75 tons per floor of combustible material. That, as far as I can ascertain from the reports, is the next "higher" amount of fuel used in the simulations as well as an appreciable difference.

Do you see some reason why their words regarding the failure of "higher fuel loads" to match observable patterns" does NOT mean 5 lbs/sq ft?

“The principal combustibles on the fire floor were workstations. The total combustible fuel load on the WTC floors was about 4 lb/ft2. Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

Higher than what? You seem to agree that they mean higher than 4 lbs/sq ft, but you somehow want to skip the 5 lbs/sq ft value because 4.001 lbs is greater than 4 lbs? You've got to take a ridiculous stance in order to make your position make sense. Either they mean what they say, or they do not. Which is it?

Where is it stated that a 5 lbs/ft^2 fuel load did not produce a collapse in the given time frame or did not match the patterns observed in the photographic evidence?

Respectfully,
Myriad

In the above quote. 5 lbs is higher than 4 lbs, and it is, as far as I can tell, the next higher value they used in the simulations. If they meant higher fuel loading than 5 lbs/sq ft did not produce the collapse, why didn't they say that? If they wanted to say 5 lbs/sq ft was a reasonable estimate of fuel load for the WTC towers, why did they say this:

“NIST estimated the combustible fuel loading on these floors to have been about 4 lb/ft2 (20 kg/m2), or about 60 tons per floor. This was somewhat lower than found in prior surveys of office spaces. The small number of interior walls, and thus minimal amount of combustible interior finish, and the limited bookshelf space account for much of the differences.”(NCSTAR 1, 77)

Complexity

12th September 2007, 08:47 PM

jay howard - What precisely do you mean by the term 'metatheory'?

Myriad

12th September 2007, 08:58 PM

Do you see some reason why their words regarding the failure of "higher fuel loads" to match observable patterns" does NOT mean 5 lbs/sq ft?

Yes, because they made a very similar comment specifically in refernce to double the fuel load earlier in the report. In discussing a parameter with a high range of uncertaintly, "higher" meaning "approximately double" can be quite reasonable.

But we don't have to guess about how much higher they meant by "higher" in the statement about higher fuel loads not matching the observable patterns. They did runs of the simulation at 5 lbs/ft^2, didn't they? (Of course they did, that's what you are complaining about!) So when they actually ran the simulation with that value, did the simulated fire behavior match the patterns observed in the photographic evidence, or not?

Respectfully,
Myriad

cmcaulif

12th September 2007, 09:12 PM

Do you see some reason why their words regarding the failure of "higher fuel loads" to match observable patterns" does NOT mean 5 lbs/sq ft?

because they essentially say it:

The fire simulation results for both Case A and Case B were similar, indicating only a modest sensitivity to the fuel load and the degree of the aircraft-generated damage. This was because, in general, the size and movement of the fires in WTC 1 were limited by the supply of air from the exterior windows. Since the window breakage pattern was not changed in Case B, the additional and re-distributed combustibles within the building did not contribute to a larger fire. The added fuel did slow the spread slightly because the fires were sustained longer in any given location.

So to summarize, a 100 percent increase in the fuel load slows the spread well below the observed rates, but a 25 percent increase is similar to the base case. These both remain within the experimentally determined gas temperatures as well.

"higher fuel load" does not mean automatic failure, as we see, the load needs to be increased by a great deal more than 25 percent for it to have an effect that would be critical to the collapses.

beachnut

12th September 2007, 09:34 PM

jay howard - What precisely do you mean by the term 'metatheory'?
It is a truther smoke screen, trying to show he can apply some physiological junk to discredit NIST while ignoring the facts that 9/11 happen with an impact, fire, and collapse of the WTC. He is a Jones thermite fan, who refuses to admit it, but lets it leak as he posts and shows his failure to apply his own methods properly.

question mark

12th September 2007, 09:39 PM

hello all, I was just wondering if anyone could tell me when the final NIST report will eventually be released?

The last I heard it would be in the spring of this year.

As far as I'm aware it still hasn't been released, is this the case?

Thanks in advance.

cmcaulif

12th September 2007, 10:05 PM

QM, if you are referring to the NIST report on building 7, it was pushed back, again, to the end of the year. Who knows if it will ever see the light of day;) . The final report on 1 and 2 was released in 05 though. here is the NIST website for all the announcements and documents on the WTC:

http://wtc.nist.gov/

question mark

12th September 2007, 10:15 PM

Pushed back again you say, oh well, thanks for your help.

jay howard

14th September 2007, 05:18 PM

So to summarize, a 100 percent increase in the fuel load slows the spread well below the observed rates, but a 25 percent increase is similar to the base case.

Where do you get the notion that a 25% increase over a baseline estimate is "similar to the base case"? Obviously, you're not trying to argue that 5 lb/sq ft is their estimate of fuel load. Given that they substantiate 60 tons per floor several times, why do you think the increase is warranted? If they said, "a reasonable fuel load was between 60-75 tons per floor", then your statement would follow, however, they do NOT say that.

Don't misunderstand me, I do believe they were warranted to adjust the simulation inputs, but to increase them 25% with no clear justification, and then to pin their entire theory on those increased results is very far from scientific. Increase them 10% or maybe 12%, but if the fuel load estimation seems well-founded, why increase it further? They give no reason why 4 lb/sq ft is not a reasonable estimate.

Can you find anywhere where they say "5 lbs/sq ft was a reasonable fuel load for the towers" or "4 lbs/sq ft is NOT reasonable"?

These both remain within the experimentally determined gas temperatures as well.

Temperature is not the issue. Like Eagar & Musso say, if you put another log on the fire, it doesn't burn hotter, just longer. Fire-spread rates are the issue on this one. And as i've pointed out several times, NIST makes clear that

"Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

Notice they don't say "double the fuel loadings..." here. If they meant to say that, they would have said that.

And they substantiate the slower fire-spread rates with higher-combustible loads:

"Since the window breakage pattern was not changed in Case B, the additional and re-distributed combustibles within the building did not contribute to a larger fire. The added fuel did slow the spread slightly because the fires were sustained longer in any given location."(NCSTAR 1, 129)

"higher fuel load" does not mean automatic failure, as we see, the load needs to be increased by a great deal more than 25 percent for it to have an effect that would be critical to the collapses.

Are you suggesting that NIST's theory is lacking? Where did this extra fuel you are implying come from? What do you mean "the load needs to be increased by a great deal more than 25 percent for it to have an effect that would be critical to the collapses"?

jay howard

14th September 2007, 05:24 PM

jay howard - What precisely do you mean by the term 'metatheory'?

Theory about how to sift the theoretical wheat from the chaff. See the first post for a more complete explanation.

jay howard

14th September 2007, 05:26 PM

Yes, because they made a very similar comment specifically in refernce to double the fuel load earlier in the report. In discussing a parameter with a high range of uncertaintly, "higher" meaning "approximately double" can be quite reasonable.

But we don't have to guess about how much higher they meant by "higher" in the statement about higher fuel loads not matching the observable patterns. They did runs of the simulation at 5 lbs/ft^2, didn't they? (Of course they did, that's what you are complaining about!) So when they actually ran the simulation with that value, did the simulated fire behavior match the patterns observed in the photographic evidence, or not?

Respectfully,
Myriad

If they ONLY meant "double", then why did they say "Higher combusted fuel loadings resulted in slower fire spread rates..." in the sentence from pg 183? If they ONLY meant "double" they would have said so in that spot. That was their opportunity to make that distinction.

But they chose to say "higher" and we know 5 is indeed higher than 4. Why do I actually have to explain this to you? Either they meant what they said or they didn't. Either words mean whatever is convenient or they are substantiated by their context. Which is it?

Again, did NIST produce good estimates and ignore them, or were their estimates poor from the start?

cmcaulif

14th September 2007, 05:51 PM

Where do you get the notion that a 25% increase over a baseline estimate is "similar to the base case"?

I realize you are fond of ignoring what others post, but reread the bit I quoted from the NIST, they say that exactly.

Obviously, you're not trying to argue that 5 lb/sq ft is their estimate of fuel load. Given that they substantiate 60 tons per floor several times, why do you think the increase is warranted? If they said, "a reasonable fuel load was between 60-75 tons per floor", then your statement would follow, however, they do NOT say that.

Don't misunderstand me, I do believe they were warranted to adjust the simulation inputs, but to increase them 25% with no clear justification, and then to pin their entire theory on those increased results is very far from scientific. Increase them 10% or maybe 12%, but if the fuel load estimation seems well-founded, why increase it further? They give no reason why 4 lb/sq ft is not a reasonable estimate.

Can you find anywhere where they say "5 lbs/sq ft was a reasonable fuel load for the towers" or "4 lbs/sq ft is NOT reasonable"?

I see, so you think an increase is justified, but you don't think a 25 percent increase is justified even though they explicitly say case a and b were similar, indicating a limited sensitivity to the fuel load increase. I get the feeling that your belief that the NIST report is junk science is unfalsifiable.

Temperature is not the issue.

snip

erm, I know, that is what I meant to point out.

Are you suggesting that NIST's theory is lacking? Where did this extra fuel you are implying come from? What do you mean "the load needs to be increased by a great deal more than 25 percent for it to have an effect that would be critical to the collapses"?

In order for it to produce a result that would be outside experimental uncertainty, as well as outside the observed rates of fire spread, with the range of experimental uncertainty associated with that, the fuel load would would have to be increased by a great deal more than 25 percent, since this produced results that were similar to case a.

jay howard

14th September 2007, 09:18 PM

I realize you are fond of ignoring what others post, but reread the bit I quoted from the NIST, they say that exactly.

Quote where they say

"a reasonable fuel load was between 60-75 tons per floor"?
or
"5 lbs/sq ft was a reasonable fuel load estimate for the towers"?
or
"4 lbs/sq ft was not a reasonable fuel load estimate"?

As has been pointed out ad nauseum for us both is that they explicitly justified the 4 lbs/sq ft estimate several times. In addition to this, they never give any explicit justification for increasing this estimate other than to "to create a more severe fire." They also state in no uncertain terms that in regard to WTC 1, when they increased the fuel load above 4 lbs/sq ft, the observations did not match the available evidence AND the fires did not reach the south side in time to initiate the collapse.

Did they mean to exclude 5 lbs/sq ft in that statement? Only if words do not mean what they normally mean.

If they had reason to believe they underestimated the fuel load by 25%, they give no indication. So, how 5 lbs/sq ft suddenly becomes implicit in a "probable range of gas temperatures" in the simulations is nothing more than an arbitrary assumption.

I see, so you think an increase is justified, but you don't think a 25 percent increase is justified even though they explicitly say case a and b were similar, indicating a limited sensitivity to the fuel load increase. I get the feeling that your belief that the NIST report is junk science is unfalsifiable.

I gave very clear statements of what would count as a counterexample to my interpretation. There are 3 unambiguous statements above. Is there some reason those would not count as tests of my theory?

In order for it to produce a result that would be outside experimental uncertainty, as well as outside the observed rates of fire spread, with the range of experimental uncertainty associated with that, the fuel load would would have to be increased by a great deal more than 25 percent, since this produced results that were similar to case a.

For the life of me, I do not understand what you are saying here. No sarcasm.

"In order for it [the simulation] to produce a result outside experimental uncertainty, [how do you get outside uncertainty and why do you want to get there?] as well as outside the observed rates of fire spread, [don't you want to be within observed rates of fire spread?], with the range of experimental uncertainty associated with that, the fuel load would have to be increased by a great deal more than 25 percent, [why?], since this [what? the increase outside the observed rates?] produced results that were similar to case a. [The whole point of differentiating 4 lbs/sq ft was that increasing the fuel load did not match observable fire spread rates.]

I may have slaughtered your meaning. If so, please clarify.

cmcaulif

14th September 2007, 09:55 PM

Quote where they say

"a reasonable fuel load was between 60-75 tons per floor"?
or
"5 lbs/sq ft was a reasonable fuel load estimate for the towers"?
or
"4 lbs/sq ft was not a reasonable fuel load estimate"?

As has been pointed out ad nauseum for us both is that they explicitly justified the 4 lbs/sq ft estimate several times. In addition to this, they never give any explicit justification for increasing this estimate other than to "to create a more severe fire." They also state in no uncertain terms that in regard to WTC 1, when they increased the fuel load above 4 lbs/sq ft, the observations did not match the available evidence AND the fires did not reach the south side in time to initiate the collapse.

you are just posting false information. They state case a and case b were similar, indicating limited sensitivity to the fuel load increase. Why do you keep ignoring that? And why do you keep ignoring that it was when the fuel load was doubled, it did not match observed evidence and did not reach the south side in time for collapse?

Yes they justify the 4 lbs/sq ft estimate, but it is an estimate, and numerous posters have given you various explanations for the fuel load increase, with your responses ranging from 'so what' to 'so ****** what,' while you still seem to believe that a statement that applied to a doubled fuel load applied to case B, which they explicitly state was similar to case a.

If they had reason to believe they underestimated the fuel load by 25%, they give no indication. So, how 5 lbs/sq ft suddenly becomes implicit in a "probable range of gas temperatures" in the simulations is nothing more than an arbitrary assumption.

The fuel load also affects the evolution of the fire, and the increase of fuel load increased the duration of the fires in the core area, as they say on page 78 of NCSTAR1-5F. This has been discussed as nauseam.

I gave very clear statements of what would count as a counterexample to my interpretation. There are 3 unambiguous statements above. Is there some reason those would not count as tests of my theory?

They could, but you of course know they can't be found. Numerous posters have explained the fuel load increase despite the fact that you insist on factual errors to be true, as have been pointed out above. You started a thread with no intention of listening to what others might say.

"In order for it [the simulation] to produce a result outside experimental uncertainty, [how do you get outside uncertainty and why do you want to get there?] as well as outside the observed rates of fire spread, [don't you want to be within observed rates of fire spread?], with the range of experimental uncertainty associated with that, the fuel load would have to be increased by a great deal more than 25 percent, [why?], since this [what? the increase outside the observed rates?] produced results that were similar to case a. [The whole point of differentiating 4 lbs/sq ft was that increasing the fuel load did not match observable fire spread rates.]

I may have slaughtered your meaning. If so, please clarify.

you are under the mistaken impression that the 25% increase in fuel load did not match the observed rates of spread, slowing the fire enough so that it would not reach the south side to cause bowing. This is clearly false because that statement applies to a doubling of the fuel load, and they state that case A and B were similar. As they note, this indicates a limited sensitivity to the load increase, rather than the large sensitivity that you mistakenly imply.

You seem to have no interest in correcting this error of fact, so I will just bow out of the conversation here, there are plenty of posts from a variety of posters for you to re ignore on the topic.

TellyKNeasuss

15th September 2007, 07:31 PM

You started a thread with no intention of listening to what others might say.

If jay howard doesn't consider our explanations satisfactory, he can always write to the engineering college at a local public university. Of course, that assumes that jay howard really does want to know if the manner in which NIST used the fire simulation results is acceptable in the engineering community.

jay howard

16th September 2007, 11:41 AM

you are under the mistaken impression that the 25% increase in fuel load did not match the observed rates of spread, slowing the fire enough so that it would not reach the south side to cause bowing. This is clearly false because that statement applies to a doubling of the fuel load, and they state that case A and B were similar. As they note, this indicates a limited sensitivity to the load increase, rather than the large sensitivity that you mistakenly imply.

You seem to have no interest in correcting this error of fact, so I will just bow out of the conversation here, there are plenty of posts from a variety of posters for you to re ignore on the topic.

Of course you will. However, it doesn't change the fact that if they meant to say that ONLY double fuel loads did not match fire-spread rates and observables, they would have said that.

The fact is they said "HIGHER", not just "double" to differentiate the fire-spread rates and inability to match observables. Higher than what?

Higher than 4 lbs/sq ft.

Is 5 lbs/sq ft higher than 4 lbs/sq ft?

“Simulations performed with doubled fuel loads slowed the fire spread well below the observed rates. Combined with the above results, this suggested that the estimated overall combustible load of 4 lb/ft2 was reasonable.”(NCSTAR 1, 129)

You can repeat this claim until the end of time, but it will still not be in contradiction to the claim that,

"...Higher combusted fuel loadings resulted in slower fire spread rates that did not match the patterns observed in the photographic evidence. Under these higher combusted fuel loadings, the fires likely would not have reached the south side of WTC 1 in the time needed to cause inward bowing and collapse initiation.”(NCSTAR 1, 183)

If it were true that only 8 lbs/sq ft did not match the photographic evidence as well as the fire-spread rates, they would have said so in the above quote. Instead they say "higher" twice. "Higher" is a relative term. In this context, the word is used against 4 lbs/sq ft. Since 5 lbs/sq ft is higher than 4, there can be no confusion (except that which we wish to posit) that 5 lbs/sq ft also did not match the photographic evidence and the fire-spread rates.

This is clear. Any other interpretations rely on a degree of speculation that is not substantiated by the report. Like I said before, if you can find a quote that says one of these things, you might be right:

"a reasonable fuel load was between 60-75 tons per floor"
or
"5 lbs/sq ft was a reasonable fuel load estimate for the towers"
or
"4 lbs/sq ft was not a reasonable fuel load estimate".

But you freely admit this verbiage is not to be found in the reports. So, you must pull an unsubstantiated interpretation out of your colon to avoid conceding the fact that 5 lbs/sq ft is not supported by any of the NIST literature as a reasonable fuel load estimate. Not only is 5 lbs/sq ft not supported, 4 lbs/sq ft is explicitly supported several times for several reasons.

The facts remain that 5 lbs/sq ft is not a reasonable estimate by their own words, AND they pin their entire theory on a simulation that uses 5 lbs/sq ft as the definitive amount to initiate collapse. Struggle as you might to weasel a coherent interpretation out of the NIST report, you cannot get around these facts.

Again, this is not an inconsequential issue. The entire NIST collapse theory rests on this assumption. Without substantiating 5 lbs/sq ft, you and everyone else who believes NIST is engaging in belief-without-reason, or "faith" as it is commonly called. I don't have to make anything up to get the interpretation I have. Nor do I have to stretch the meaning of any words or take any of their sentences out of context. All I had to do was read carefully and take their words to mean what they always mean.

You must stretch their meanings beyond reason in order for your interpretation of the information to congeal. Is this not exactly the problem you have with the "twoofer" movement?

Myriad

16th September 2007, 11:48 AM

NIST ran cases of the simulation with fuel loading of 5 lbs/ft^2.

Did the simulated fire behavior in those runs match the patterns observed in the photographic evidence, or not?

Respectfully,
Myriad

Myriad

16th September 2007, 11:57 AM

Like I said before, if you can find a quote that says one of these things, you might be right:

"a reasonable fuel load was between 60-75 tons per floor"

You mean like this?

Have you looked at the table on page 46 of NCSTAR1-5F? It lists the range of estimates for the combustible fuel load as 17 to 34 kg/m2 (3.5 to 7 lb/ft2) with a mid-range of 25 kg/m2 (5.1 lb/ft2).

Respectfully,
Myriad

jay howard

17th September 2007, 06:37 PM

You mean like this?

Respectfully,
Myriad

Did you read that page? If you did, you must have come across this:

"The intent of the exercise was not necessarily to determine the best values for each, but rather to assess the influence each [of the five parameters] had on the final result."(NCSTAR 1-5, 46)

They made a determination of the fuel load estimate several times in the report as 4 lbs/sq ft. This series of tests, according to NIST, was to assess the relative sensitivities of these parameters.

Will you ever admit that they did not ever give a real reason to increase the fuel load other than to "create a more severe fire"? You and a few others have been trying to justify the increase for several pages. Despite having equal access to all the same literature I have, you have produced no justification from the NIST report for the fuel load increase and several incoherent interpretations in the attempt.

This is what Gravy calls "denialism". Despite the fact that nothing can convince you that NIST's theory might be wrong, their entire case hinges on results that they admit are not substantiated by the evidence and indeed, contradict their own estimates.

Myriad

18th September 2007, 11:00 AM

Did you read that page? If you did, you must have come across this:

"The intent of the exercise was not necessarily to determine the best values for each, but rather to assess the influence each [of the five parameters] had on the final result."(NCSTAR 1-5, 46)

Yep. And if you read it, you must also have come across this, on the next page:

"Of the five parameters chosen for the study, two were seen to have the most significant effect on the results. Of these two, Combustible Load was the most important, followed by the damage to the core walls. The Combustible Load influenced the duration of the fires, more so than their intensity. In fact, simulations using the low (-) to mid-range (0) estimates of the Combustible Load produced results consistent with the visual evidence of the fire behavior in WTC 1 that was available at the time the study was done." (NCSTAR 1-5F, p. 47; emphasis added)

And, just to be clear here, the mid-range estimate they're referring to was 25 kg/m^2 = 5.1 psf.

So, there is the positive statement you were looking for (and yet managed to miss somehow) that 5 psf was consistent with the observed fire behavior. That makes it clear that the "higher values" of fuel loading described elsewhere as producing results inconsistent with the observed fire behavior, must refer to values higher than the midrange, that is, values higher than 5.1 psf.

Will you ever admit that they did not ever give a real reason to increase the fuel load other than to "create a more severe fire"?

Will you now admit that you have been misrepresenting NIST's rationale for using the 5 psf fuel load in some of their test cases, and that 5 psf is in fact a reasonable figure, consistent with all avaliable evidence, for the fuel load model input parameter?

Respectfully,
Myriad