Metatheory and the NIST report

[CHF]

An analysis of the EXOTHERMIC REACTIONS involving these LOW MELTING POINT metallic species, as studied and reported in fires, especially in waste incinerators, shows these processes were very likely the dominant factors in bringing down the towers...

You could very well be on to something, Frank.

I'd love to see a paper on this.

 

[Dave Rogers]

I AM arguing that it is a self-fulfilling prophecy that the loss of thermal insulation was the primary cause of over-heating of the steel. This error is compounded by the fact that not all the heat sources in the impact zones of WTC 1 & 2 have been quantified by NIST. The loss of thermal insulation as THE main cause of the collapse of WTC 1 & 2 is an unfalsifiable hypothesis because it involves an unknown quantity - AS ADMITTED BY NIST! Occam's razor requires we rid our thinking of any unnecessary "storylines" to bolster our narrative.

FIRST we have to look at the most vulnerable materials that we know WERE present in the towers: the truss rods and seats, floor pans, welds, bolts, etc! These items wound up in a high temperature environment where direct metal wastage, stress corrosion cracking, liquid metal embrittlement, etc, were promoted by the presence of HCl, Cl2, H2, SO2 derived from many sources but especially PVC combustion, leading to the formation of FeCl2, FeCl3, ZnCl2, KCl, CaCl2, etc.

An analysis of the EXOTHERMIC REACTIONS involving these LOW MELTING POINT metallic species, as studied and reported in fires, especially in waste incinerators, shows these processes were very likely the dominant factors in bringing down the towers...

Frank, let me join with others in saying that I think this would be a very valuable line of enquiry, and I would urge you to pursue it and let us know what you find. My personal view of the NIST model is that it's necessarily incomplete to some extent because of the paucity of direct observation that was possible, that some of the use of language in describing its findings is poorly chosen from a point of view of clarity, and that, as you suggest, it may well have neglected significant sources of energy within the towers. However, at the moment it's better articulated and investigated than any other major theory of collapse initiation (I refer to the explosive demolition, thermite and space-based energy weapon theories, as I would consider your work to be a refinement/correction of the NIST theory rather than a competing theory), so for the moment it's the best we've got. It is in principle falsifiable - to take a hypothetical example, it's not totally impossible (though vanishingly unlikely) that someone escaping from one of the towers was able to photograph the state of the fireproofing in the affected areas and hasn't made the photographs public yet - however, by its very nature it must be diffucult to falsify, because it's been framed to account for all the known observations, and therefore there are unlikely to be any known observations that disagree because they'll already have been accounted for in the theory; I think this is the apparent lack of falsifiability that you are concerned about. However, I think it's the best theory we've got so far, which is as much as I can say for any theory anywhere in science. If you think you can improve it - and from your record, I strongly suspect that you can - then please do.

Dave

 

[Par]

I AM arguing that it is a self-fulfilling prophecy that the loss of thermal insulation was the primary cause of over-heating of the steel. This error is compounded by the fact that not all the heat sources in the impact zones of WTC 1 & 2 have been quantified by NIST. The loss of thermal insulation as THE main cause of the collapse of WTC 1 & 2 is an unfalsifiable hypothesis because it involves an unknown quantity - AS ADMITTED BY NIST! Occam's razor requires we rid our thinking of any unnecessary "storylines" to bolster our narrative.

Imagine standing on the sidewalk and seeing a bull walk into a china shop a few doors down. You then wince as you’re subjected to a cacophony of crashing, smashing and screaming. Now, in light of the fact that you’re unable to see what’s happened or to actually hold fragments of Royal Doulton in your hands, would the idea that the bull had caused at least some damage to crockery qualify as an “unnecessary storyline”?

 

[GregoryUrich]

In my last post, I described the two related classes of falsifying arguments that apply to NIST. They are the same as for any other hypothesis, about anything. This is just the standard tenets of the Scientific Method. If you're unsure about this, then please try to catch up on your own before posting further.

Mackey's classes of falsifying arguments

The falsifiability criterion for the NIST report is the same as for any other hypothesis:

1. If the NIST report can be found to be grossly inconsistent with one or more major observables, subject to consideration of the accuracy of those observables, or

2. The NIST report is found to be materially deficient compared to another, superior hypothesis in matching known observables, then
the NIST report is "falsified."

According to point 1 the NIST report can be falsified even in the absence of alternative theories. No misunderstanding on my part what-so-ever.

 

[GregoryUrich]

To begin, it is not the responsibility of NIST's proponents to derive specific means to falsify their own hypothesis, not unless they are comparing it against another specific hypothesis or set of observations. There is, so far, no other competing hypothesis in sight. Instead, it is the responsibility of those with the competing hypothesis, or any hypothesis coming later to the table, to come up with such falsifying criteria. This is for two reasons.

Imprimus, as a defender of NIST, I am likely to be biased. There is no reason why you should be restricted to my list, and no reason you should want to, either.

Secundus, those proposing the new hypothesis will be more versed in its detail. They will be inherently more capable of devising such criteria, as they have had the opportunity to study NIST, but not vice versa.

Furthermore, the NIST theory has already demonstrated that it is falsifiable because it was compared against alternate hypotheses as it was developed. I speak primarily of "The Pancake Theory," as proposed by Eagar and others, but also the similar yet not identical results of the Weidlinger Associates, MIT, and Exponent Inc. studies. NIST describes in its report the distinctions -- that is to say, the "falsifying criteria" -- between all of these options, and gives its reasoning for why its result is the best fit to the observed data. Therefore, there is no doubt at all that the NIST theory is falsifiable. It has already been exposed to, and survived, scientific comparison against at least four competing theories. Q E D.

Before we go overboard in our criticism of Gregory Urich and his misapprehensions of the basic tenets of science...

The issue of responsibility may be one of praxis here at JREF but it is not part of the basic tenets of science.

Furthermore, comparing the NIST theory to inferior theories in no way demonstrates falsifiability. It may be the best false theory.

The reason I want us to agree on the falsifiability criteria is that it will help us avoid going all the way through long arguments on a track deemed by NIST supporters to be insufficient to falsify the NIST theory.

NIST has not demonstrated falsifiability of it's theory and neither has anyone here. Every claim on which the NIST theory is dependent must be falsifiable. I have seen no proof of this anywhere, from NIST or it's supporters.

I propose sharing the responsibility for identifying these. If that doesn't suit you, fine no one can force you to contribute in that regard.

 

[twinstead]

Furthermore, comparing the NIST theory to inferior theories in no way demonstrates falsifiability. It may be the best false theory.

May be? Couldn't one cleverly declare ALL theories one doesn't agree with unfalsifiable this way?

 

[T.A.M.]

Apollo20:

Welcome back. You have been quiet as of late.

That said,

(1) What significance do the collapse times have? Any answer but "none" implies you believe there was some element of an "inside job".

(2) What is the signficance of "pulverization" of concrete with respect to the collapses. Noone has denied that some of it pulverized. Do you suggest they should look into it in order to come up with a "pulverization proof" concrete? If not, what other significance to "building safety" does this issue have?

(3) So the NIST report must be ALL INCLUSIVE, or EVERY ASPECT of the collapse, in your opinion, or else it is incomplete/inadequate as a scientific study of the collapses of the WTCs?

Did they cover the effect of the collapse on the copper plumbing in the WTCs? Did they cover the emotional impact on the crowds below, who witnessed the jumpers? Did they cover melting of the windows, and what impact this might have had? The list goes on and on, doesnt it?

What I see here is someone walking along the fence between Woo and Non-Woo, implying the Woo issues should have been investigated, by a group whose mandate had nothing to do with forensics, or "whodunnit".

See what bothers me, is that you, who tries to portray himself as an honorable scientist (and I am not saying you are not), spends so much time "bashing" NIST, when instead, IMO, the honorable thing to do would be to add to the knowledge it provides, rather than CRITICIZE it for what it lacks. Because in being critical, in the way you are, is IMPLYING at least, that you feel they either "purposely" or "incompetently" left things out. That said, I acknowledge, that you have contributed considerably to the scientific knowledge of the collapses...but why all the NIST bashing?

TAM

Edit: That said, if I am wrong, prove it to me.

APOLLO20:

Thought I would repost it, as you not only had nothing to say in reply, but you continue to bad mouth the report, rather than accept it for what it is, and simply add to it in a constructive manner.

TAM

 

[GregoryUrich]

...

Gregory's Model: Aircraft debris is treated as ballistic projectiles, affected only by gravity, but with a steeply decelerating horizontal velocity as predicted by NIST. These chunks of debris all follow uniform curves reminiscent of a parabola, caternary, or brachistochrone. There is no way for these curves to remove fireproofing in a wide area as predicted by NIST, as structure would interfere with the trajectories.

NIST Model: Aircraft debris is treated with a rigorous LS-DYNA simulation, accounting for aircraft size and impact geometry, inelastic and elastic impact, secondary impact, secondary debris, effects of material strength, fluid behavior and fluid erosion, at varying levels of fidelity (geometry being at high fidelity, fluid effects relatively low but still modeled). This model excludes deflagration effects and momentum from rotating machinery. The model shows that fireproofing that is screened or shielded from impact by structure can still be affected, according to the precise location and interior geometry.

Stacking these two models against each other reveals instantly which is superior. It is immediately clear, from photographs of the impact if not a basic understanding of impact and fracture mechanics, that Gregory's Model is far too simple to be credible.

If a simplification was desired, perhaps the best analogue would not be to ballistics, but instead to the behavior of a turbulent fluid jet. It is immediately clear that vorticity can lead to such a jet affecting regions in the structure that are not line-of-sight from the jet's point of origin. This turbulent effect is but one of many that would have been present in the jet impacts, which are perhaps best described as turbulent heterogenous density flows at an initial speed of about 0.8 Mach.

Comparing the two theories, Gregory's Model is therefore falsified. The NIST model remains the best known hypothesis.

Your weakest work yet Mr. Mackey.

I agree the gravity argument is the weaker of my claims but still a factor in reducing the amount of material that could possibly hit the floor trusses.

Nonetheless, assuming Mr. Macky's simplification:

The average velocity of debris is still 43.3 mph according to NIST. According to NCSTAR1-6A appendix C, the SFRM impact tests were done with projectile speeds of no less than 155 mph. One test misfired resulting in projectile speeds of around 70 mph. A few projectiles hit the sample but there was no visible damage to the SFRM such that the SFRM sample was reused for a second shot.

Thus there is no theoretical or evidential support for significant damage to fire proofing on the trusses (or the exterior wall for that matter) on the south side of WTC1.

Conclusion: One of NIST's most important claims is clearly not based on evidence, experiments or scientific theory.

 

[GregoryUrich]

May be? Couldn't one cleverly declare ALL theories one doesn't agree with unfalsifiable this way?

No.

 

[e^n]

Conclusion: One of NIST's most important claims is clearly not based on evidence, experiments or scientific theory.

You're joking right? I mean you do realise that p=mv right? Seriously what are you trying to claim here, that speed dictates impulse?

 

[GregoryUrich]

...
For the second example, Gregory provides us with an example of a logical error:

(Greg's reference to NCSTAR1)

This is, of course, incorrect. From NIST NCSTAR1-6A:

The rest of the report goes on to demonstrate, by way of experiment, precisely what type of impact -- what projectile weight and speed -- sets up such a vibration. The g-loading values are seen to be too low to be credibly shaken loose by the gross structural motion, but easily within the expected vibrations on individual structural members caused by impacts of minor primary and secondary debris.

Any hypothesis that makes such an easily demonstrated logical error, as Gregory's second hypothesis does, is also falsified. Such a theory might be salvageable if correction of the logical reasoning leads to similar conclusions, but until it is fixed, it deserves no additional attention.

The logical error appears to be either your's or NIST's. A more complete citation from NCSTAR1:

NIST did do the work you describe. However, it was not a basis for the conclusions and thus is outside the scope of our discussion.

 

[GregoryUrich]

You're joking right? I mean you do realise that p=mv right? Seriously what are you trying to claim here, that speed dictates impulse?

NIST designed the test to correspond to impact conditions. From NCSTAR1-6A appendix C:

This may have been incorrect, but this is what NIST bases its conclusions on. The results of the experiments are simply not applicable to the south side of WTC1.

 

[e^n]

NIST designed the test to correspond to impact conditions. From NCSTAR1-6A appendix C:

I've read the entirity of NCSTAR 1-6 and the subreports within. You are missing my point, the only criteria you use for fireproofing loss in your previous post is velocity. This is simply ludicrous as of course momentum is the conserved quantity, not velocity. By ignoring this you conveniantly slip from having energies in the same order of magnitude to energies seemedly far too low to cause damage.

 

[Anti-sophist]

How about a test that heats the floor truss systems for 2 hours under hotter conditions than for which any of the recovered steel got to, but didn't fail?

Why doesn't that test discount the NIST theory?

Do you hold the position that the NIST theory is unfalsifiable? For some reason I am under the impression that you were arguing that the NIST theory is not falsifiable. You seem to be implying the opposite, now. Maybe I've misinterpreted your argument.

First, and most importantly, the test you mention has never been performed. If you'd like to perform it, I'd be all ears. The test NIST performed that you are likely referring to did -not- test what you claim it did.

Also, I consider the maximum temperatures attained in the WTC to be a better temperature to perform this test as opposed to the maximum temperature of the steel recovered. They aren't the same and I suspect you know that which is why you've chosen the one that you believe will give you the results you want.

 

[GregoryUrich]

I've read the entirity of NCSTAR 1-6 and the subreports within. You are missing my point, the only criteria you use for fireproofing loss in your previous post is velocity. This is simply ludicrous as of course momentum is the conserved quantity, not velocity. By ignoring this you conveniantly slip from having energies in the same order of magnitude to energies seemedly far too low to cause damage.

You'll have to explain more thoroughly. To me it just sounds like you haven't thought all the way through this.

 

[e^n]

You'll have to explain more thoroughly. To me it just sounds like you haven't thought all the way through this.

I am no engineer, but I feel fairly confident you are being deliberately obtuse here. Still here we go.

R.Mackey has proposed an analogy of a turbulent fluid as opposed to discrete sections impacting the WTC. You have then taken the average velocity of debris after impact and then claimed as this velocity is much lower than the testing velocities NIST used that it can't possibly support their theory.

I don't know how I can explain how wrong this appears to me. Debris is not uniformly distributed nor does it have no velocity distribution, you cannot cherry pick numbers from a conserved quantity to try and support your beliefs. A chunk of aircraft weighing 1kg can be travelling 10x slower than a pellet weighing 100g yet retain the same amount of momentum. NISTs tests were done with light to very light debris who's kinetic energies were within an order of magnitude to the expected kinetic energies of the aircraft debris.

I apologise if this is a bad analogy but to my relatively untrained eye it appears you are picking simply the velocity of particles, ignoring the mass and claiming that this is somehow relevant, despite velocity not being a conserved quantity.

 

[Apollo20]

TAM:

I have said it before, and I will say it again: some sections of the NIST Report are EXCELLENT and I have nothing but respect for the scientists who wrote those sections...

But we are here to dissect the NIST Report, as in a peer review, and see if it is SCIENTIFICALLY SOUND, so some CRITICISM of NIST is bound to develop. For me this is especially true of the "thermal insulation loss theory". Even NIST admit that the condition of the thermal insulation inside the impact zone is essentially UNKNOWN. NIST try to deal with this lack of observational data with the ad hoc hypothesis that insulation was lost "if the room furnishings were damaged". And, by the way, the PLAUSIBILITY of such an hypothesis is never addressed. In any case, NIST "invent" a correlation between furniture damage and insulation loss. What NIST ignores is that, within this limited cause and effect space, an additional correlation is also required, namely that insulation must be lost in areas that were subsequently subject to sufficient heating to weaken the steel. This is made very uncertain by the fact that the WTC fires were chaotic and moved through the buildings in a random, sporadic manner. So we actually have to simultaneously satisfy THREE criteria, all of which have a fairly low probability of occurrence! However, we KNOW that it is quite possible that insulation was lost WITHOUT damage to furniture and conversely that insulation was potentially NOT lost at a location where the furniture was nonetheless damaged. So let's say that a sample of steel from the impact zones was recovered and was found to have lost its thermal insulation AND had been subject to high temperatures, we still have no way of ascertaining the condition of the furniture in the proximity of the recovered steel. Clearly we have an unfalsifiable hypothesis! Thus the proposed furniture damage - insulation loss hypothesis has got to go as UNSCIENTIFIC since other criteria could be invented that would lead to the same result!

 

[T.A.M.]

In my opinion, from what I have read here, and from what I know through reading the NIST exec summaries, the paper is falsifiable. You may contend different, but you have not proven so.

wrt to criticism of the NIST report, I have no objection to picking it apart and analyzing what they have done...in the end I suspect it is the tone, and the insinuation I detect within comments you and others have made, that any omissions within it were intentional, or from incompetence, yet no evidence is provided to indicate it was due to either. This is why I call it bad mouthing...

TAM

 

[GregoryUrich]

I am no engineer, but I feel fairly confident you are being deliberately obtuse here. Still here we go.

R.Mackey has proposed an analogy of a turbulent fluid as opposed to discrete sections impacting the WTC. You have then taken the average velocity of debris after impact and then claimed as this velocity is much lower than the testing velocities NIST used that it can't possibly support their theory.

I don't know how I can explain how wrong this appears to me. Debris is not uniformly distributed nor does it have no velocity distribution, you cannot cherry pick numbers from a conserved quantity to try and support your beliefs. A chunk of aircraft weighing 1kg can be travelling 10x slower than a pellet weighing 100g yet retain the same amount of momentum. NISTs tests were done with light to very light debris who's kinetic energies were within an order of magnitude to the expected kinetic energies of the aircraft debris.

I apologise if this is a bad analogy but to my relatively untrained eye it appears you are picking simply the velocity of particles, ignoring the mass and claiming that this is somehow relevant, despite velocity not being a conserved quantity.

I see what you are saying, but would appreciate if you would stay away from accusations of cherry-picking and obtuseness until you are quite sure about them. I'm here to learn and I'm not interested in fooling anyone. I am an engineer, but I don't expect you to take my word on anything that doesn't make sense to you.

Yes there is velocity and temporal variation in the debris field. The KEs that NIST is using based on debris approaching the core (.4 - .7 of the original impact speed). The highest speed being 303 mph and the lowest being 173 mph.

My argument is based on debris leaving the core. I haven't seen a velocity distribution but if we use a distribution based on the average of 43.3 mph, we would get something like 30-60 mph. Since the energy is proportional to the square of the speed, the energies are only roughly 3% of the NIST experimental case.

This by itself should indicate that the experiment is not applicable to the south side of WTC1.

 

[e^n]

I see what you are saying, but would appreciate if you would stay away from accusations of cherry-picking and obtuseness until you are quite sure about them. I'm here to learn and I'm not interested in fooling anyone. I am an engineer, but I don't expect you to take my word on anything that doesn't make sense to you.

To be fair I have trivially read through several threads involving you and have not been impressed but I will refrain from any accusations in future unless I have something to prove.

Yes there is velocity and temporal variation in the debris field. The KEs that NIST is using based on debris approaching the core (.4 - .7 of the original impact speed). The highest speed being 303 mph and the lowest being 173 mph.

I am not in a position to immediately check this so could you cite please?

My argument is based on debris leaving the core. I haven't seen a velocity distribution but if we use a distribution based on the average of 43.3 mph, we would get something like 30-60 mph. Since the energy is proportional to the square of the speed, the energies are only roughly 3% of the NIST experimental case.

Again could you cite for 43.3mph?

This by itself should indicate that the experiment is not applicable to the south side of WTC1.

Well no offence but I have a hard time believing the core slowed debris from 173-303mph to 30-60mph. That's a gigantic amount of KE (97% as you said) being expended into the core. I'm more than happy to read the references though, I wish I could remember the specifics myself but I am running on 0 hours of sleep at the moment and am stuck at work