Metatheory and the NIST report

[CHF]

Apollo,

given that we have no photos, witness testimony or live temperature readings from inside the WTC collapse zone, assumptions must be made based on other evidence.

What we know for sure:

- a plane hit the WTC
- a massive fire raged
- trusses were warping and columns were bending inwards along the facade at the exact area of collapse

Given these facts, is it plausible to assume that enough fireproofing would be dislodged by a jet impact to result in the fire's heat warping the trusses and columns? I'd say so.

Anyone opposing this theory had better be able to explain the known facts in their alternative explanation. Your theory may very well do that and I would really love to see you pursue it.

Contrary to what you believe, we don't all have blind faith in NIST, if in fact any of us do. All I ask for in an alternative theory is that it make sense and that its author stand behind his/her work via peer-review.

Truthers won't do this, but I trust that you will.

 

[GregoryUrich]

...
Again could you cite for 43.3mph?

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

NCSTAR1-6A appendix C introduction gives .4-.7 original impact velocity for debris approaching the core.

The core is full of partitions, ducts, mechanical equipment, elevator tracks and cables, electrical cables, water and sewer pipes, storage areas, restrooms and other stuff and is capable of absorbing alot of energy.

NCSTAR1-2 gives initial impact conditions starting on p. 151. Velocity = 433 mph for flight 11 (WTC1).

A graph of momentum transfer is shown as a function of time on p. 178. The diagrams above that show debris first exiting the core at 0.40 seconds. At 0.40 seconds the graph shows 10% of momentum remaining. Since the mass is constant (may need to be corrected based on Apollo's new theory) the average velocity is 10% of the original velocity = 43.3 mph. Actually due to temporal displacement a good portion of the debris exits the core after 0.40 seconds with even less energy.

 

[R.Mackey]

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.

Absolutely wrong!

The fact that the NIST theory was tested against others, by virtue of the existence of those tests, proves falsifiability. That is the end of the argument.

The NIST theory may well be the "best false theory," but to find that, we need to have a better theory. NIST doesn't have one. If it did, then it wouldn't have proposed what it did.

If you can't follow the argument above, then you are not ready for science.

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.

If I knew of a better theory I would present it. I can think of two valid competing theories -- one is the Ove Arup hypothesis, and the other is a NIST variation with chemical attack as suggested by Greening. If you have other ideas, you should articulate them, not us. I can't do your work for you. Nor, apparently, can I make you understand the scientific method.

 

[R.Mackey]

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:

[qimg]http://www.cool-places.0catch.com/docs/NCSTAR1SFRM2.jpg[/qimg]

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.

Wow, you are actually proposing your ridiculous modified ballistic trajectory model...

The NIST test points in NCSTAR1-6C were used to validate a theoretical model. Your claim that only the two sizes and speeds of projectiles (as tested real-world) are valid, while any other speed and size cannot apply, is totally wrong.

e^n's observation is correct. Momentum and kinetic energy are the relevant quantities. You fail to understand NIST's reasoning.

 

[GregoryUrich]

Absolutely wrong!

The fact that the NIST theory was tested against others, by virtue of the existence of those tests, proves falsifiability. That is the end of the argument.

The NIST theory may well be the "best false theory," but to find that, we need to have a better theory. NIST doesn't have one. If it did, then it wouldn't have proposed what it did.

If you can't follow the argument above, then you are not ready for science.

If I knew of a better theory I would present it. I can think of two valid competing theories -- one is the Ove Arup hypothesis, and the other is a NIST variation with chemical attack as suggested by Greening. If you have other ideas, you should articulate them, not us. I can't do your work for you. Nor, apparently, can I make you understand the scientific method.

Absolutely wrong. I would have thought you knew more about logic and science.

Example:

Theory 1 The World Trade Center had a masculine soul.

Theory 2 The World Trade Center had a soul named Irene.

Neither theory is falsifiable. Test one against the other and theory 1 is better because the chances of the World Trade Center having a masculine soul are 50/50 while the chances of the soul being named Irene are much less.

Regardless, the NIST theory can be shown to be false in absence of any alternative theory. Any theory can fail on its own premises due to mistakes (i.e. a wrong calculation, misapplication of rules of physics, etc.), incorrect logic or self-contradiction.

I hope this is the end of the argument.

 

[GregoryUrich]

Wow, you are actually proposing your ridiculous modified ballistic trajectory model...

The NIST test points in NCSTAR1-6C were used to validate a theoretical model. Your claim that only the two sizes and speeds of projectiles (as tested real-world) are valid, while any other speed and size cannot apply, is totally wrong.

e^n's observation is correct. Momentum and kinetic energy are the relevant quantities. You fail to understand NIST's reasoning.

Nope, see my later post.

 

[R.Mackey]

Absolutely wrong. I would have thought you knew more about logic and science.

Example:

Theory 1 The World Trade Center had a masculine soul.

Theory 2 The World Trade Center had a soul named Irene.

Neither theory is falsifiable. Test one against the other and theory 1 is better because the chances of the World Trade Center having a masculine soul are 50/50 while the chances of the soul being named Irene are much less.

Regardless, the NIST theory can be shown to be false in absence of any alternative theory. Any theory can fail on its own premises due to mistakes (i.e. a wrong calculation, misapplication of rules of physics, etc.), incorrect logic or self-contradiction.

I hope this is the end of the argument.

This is certainly the end of the argument, because I have no idea what you're talking about. Whatever it is, it isn't science.

If you're going to remain obstinate, clinging to your own woefully inadequate opinions as you did in your "analysis" of the Flight 93 impact crater, then I will simply ignore you. If, on the other hand, you actually assemble a coherent theory, I'll be glad to put it to the test. Your choice.

 

[beachnut]

Facts will not get in the way of his conclusions

Absolutely wrong. I would have thought you knew more about logic and science.

Example:

Theory 1 The World Trade Center had a masculine soul.

Theory 2 The World Trade Center had a soul named Irene.

Neither theory is falsifiable. Test one against the other and theory 1 is better because the chances of the World Trade Center having a masculine soul are 50/50 while the chances of the soul being named Irene are much less.

Regardless, the NIST theory can be shown to be false in absence of any alternative theory. Any theory can fail on its own premises due to mistakes (i.e. a wrong calculation, misapplication of rules of physics, etc.), incorrect logic or self-contradiction.

I hope this is the end of the argument.

Was this example from your software or music experience?

You have made conclusions and you will not let facts mess up your ideas!

observe that most of these apparent crimes, including but not limited to abetment of mass murder, criminal negligence, insider trading, and obstruction of justice fall well within the jurisdiction of New York's top law enforcement officials

Sounds like a conclusion not backed with facts or evidence. I thought you had no conclusion on 9/11. Your conclusions are clouding your ability to use facts, logic, and rational thinking to bring your software and music expertise to bear on this serious problem. Yes?

 

[defaultdotxbe]

Absolutely wrong. I would have thought you knew more about logic and science.

Example:

Theory 1 The World Trade Center had a masculine soul.

Theory 2 The World Trade Center had a soul named Irene.

Neither theory is falsifiable. Test one against the other and theory 1 is better because the chances of the World Trade Center having a masculine soul are 50/50 while the chances of the soul being named Irene are much less.

whether these theories are falsifiable or not depends on what a "soul" is, if its something grounded in science, that can be tested for (and its presence proven or disproven) then both theories are falsifiable

if you take a "supernatural" definition of a soul then it lies outside the realm of science and has no bearing on the discussion here

also, you theories are not mutually exclusive, while the name "Irene" implies feminine it doesnt necessitate it

Regardless, the NIST theory can be shown to be false in absence of any alternative theory. Any theory can fail on its own premises due to mistakes (i.e. a wrong calculation, misapplication of rules of physics, etc.), incorrect logic or self-contradiction.

im sure you will be applying this same criteria to alternative theories as well

 

[jay howard]

Hey, R.

I apologize for the irregular posting--for reasons you're aware of. I'm working on your other ones as well. But this hits to the core of the discussion--at least this part of it.

Several reasons.

The tests were not intended for that purpose at all. They were designed to see whether or not, as built, the floor truss assemblies would meet their intended fire rating.

Why then, don't they do controlled lab test of their theories instead of depending on simulation outcomes?

The results are not directly comparable to the actual fires in the WTC Towers because (a) the floor assemblies in the Towers did not have intact fireproofing, while the test articles did; (b) two of the controlled tests were stopped before diagonal members buckled, rather than being run to their full durations, whereas the WTC Towers ran until total failure; and (c) the WTC Towers included truss spans that were nearly double the size of the longest article tested.

A couple things:

1. Why didn't they run the tests to complete failure?
2. How does NIST know what to compare the tests to?
3. How can they verify the extent of fireproofing that was removed from the impact?
4. 35 ft assemblies were used in two of the tests--which conforms exactly to the shorter lengths of the actual WTC floor assemblies.

It's true that the tests were run with fireproofing on, but that just raises the question of why they didn't take the SFRM off for some of the tests. That just sounds like a poorly designed test.

It seems they have to assume temperatures based on the conclusion that the heat initiated the collapse--not the actual forensic evidence recovered.

That's part of my beef with the investigation. We are to take their word that the temperature assumptions are correct--even though the physical evidence they gathered doesn't comply.

 

[jay howard]

Conversely, proving the impact theory false would do the same thing.

There is a huge amount of evidence that supports both, though. It would be a daunting task to disprove either in an honest, scientific way.

It would be difficult and (in my opinion) fruitless to try to disprove the impact data because it is based largely on public evidence: photographs, calculations of speed based on video evidence, counting severed beams from photos/video, etc. I accept NIST's description of severed columns because it is not unreasonable based on flying chunks of metal.

The heat theory is much more tricky to substantiate because it depends on a lot of information that is either not publicly available or not readily understood.

I'm going to respond to R. Mackey specifically about this in more detail, but suffice it to say, the fire reconstruction of the NIST report that attempts to substantiate the collapse is a more appropriate target of criticism mainly because they had to make up a lot of data in order to make it work.

That, for everyone who's been wanting clarification on my position, is the thrust of my argument.

 

[jay howard]

As a falsification criterion that would be fully acceptable provided it was based on observation of the fire times and temperatures during the actual events. However, a line of reasoning that simply draws the conclusion that time and temperature would be unsufficient would not, in itself, falsify NIST,

Why not?

because it would itself be a falsifiable counter-theory that would then need to be compared with NISTs prior theory that time and temperature were sufficient to weaken the steel to the extent claimed.

Not sure why you are complicating this. The whole point of performing time/temperature tests on the steel floor assemblies is to find confirmation of the official theory. If those tests do not confirm structural failure, then there is either something wrong with the test or with NIST's theory of collapse.

...If you're aware of actual, direct measurements of the fire temperatures within the WTC towers and can verify their provenance, I would say you've got an earth-shatteringly important piece of evidence that has escaped NIST's attention. If you simply have a counter-theory, then you haven't.

Dave

My theory is that NIST is ignoring the results of their own tests and inserting data into the simulations that makes the towers collapse. This is not a very scientific way to conduct an investigation.

 

[jay howard]

This is an absurd bastardization of science. "More convincing"? To whom? The point of scientific inquiry- of the scientific method- is to eliminate as much bias as possible. To claim that one theory is "more convincing" (which we all know means that evidence is really just being ignored in favor of fantasies) is to be completely unscientific.

You are absolutely correct here. "More convincing" doesn't mean anything without some kind of operational definition that we can agree on.

This is exactly why I didn't come here saying "Just look at the video! Can't you SEE the explosions?" That crap doesn't cut the scientific muster.

 

[jay howard]

If I recall didn't NIST explicitly claim no evidence of blast or CD event?

If that's the case, wouldn't actual, verified physical evidence of explosives or numerous eye witnesses claiming they saw explosives being planted falsify it?

Fair question. Although eye-witness accounts are useful as a corroborative tool, they shouldn't be used as stand-alone evidence.

In other words, if some physical evidence were to surface for which only some kind of incendiary or explosive device could account, then any position countering the CD hypothesis would have to explain away both physical evidences and corroborating eye-witness accounts. But eye-witness accounts by themselves don't mean much.

 

[jay howard]

Actually, counter-theories are perfectly acceptable as falsification if they are more convincing than the NIST theory.

Greg,
You are completely missing the concept of "falsifiability".

Partly true. Counter-theories are subject to the same criteria for falsification as the NIST theory. Showing that a counter-theory agreed with the experimental data better than the NIST theory would require falsification of the NIST theory.

This too is a misunderstanding of the concept. Falsifiability is a quality of theories that is irrelevant to the existence of other theories. Falsifiability is a quality of a theory whereby is has the ability to be unequivocally demonstrated to be false (by some set of criteria).

For instance, if I claim a pen will fall to the ground if I let it go, it will be demonstrated to be false if it does anything other than fall to the ground.

The only way a counter-theory that gave an equally good explanation of observations as NIST could supersede the NIST theory would be if it was more parsimonious. If a counter-theory is equally good at explaining phenomena but less parsimonious, Ockham would have us retain NIST. "Convincing" is not really an appropriate word to use in this context.

Parsimony is a desirable quality of theories, but often, a more complicated theory turns out to be true. Parsimony is no guarantee of truth.

More important than parsimony is a theory's explanatory power. If theory A explains most of the evidence and is fairly parsimonious, but must ignore some evidence, then theory B, which ignores none of the evidence, but is less parsimonious, is a better theory by these criteria. It is much more important to be able to explain all the evidence regardless of how complicated a theory gets. Parsimony will come into play after all the evidence has been taken into account.

 

[Gravy]

Plan to read the NIST report at any point, Jay, which answers most of the questions you just asked?

Or are you just asking questions?

 

[R.Mackey]

Why then, don't they do controlled lab test of their theories instead of depending on simulation outcomes?

Because it's too complicated, and because it's unnecessary.

If you have read NIST NCSTAR1-6C, you will note that they had to travel to Canada to find a 35-foot furnace suitable for testing. Full-size fire tests simply aren't done. The tests are expensive and the facilities are rare. Another example, one I cite frequently, is the Cardington series of fire tests. You will note the extreme complexity and expense of such a test.

The test in NCSTAR1-6C, as I have already noted, was conducted to test the intact fire rating of the construction. It was not intended to test any specific case, nor could it, for reasons below.

A couple things:

1. Why didn't they run the tests to complete failure?
2. How does NIST know what to compare the tests to?
3. How can they verify the extent of fireproofing that was removed from the impact?
4. 35 ft assemblies were used in two of the tests--which conforms exactly to the shorter lengths of the actual WTC floor assemblies.

It's true that the tests were run with fireproofing on, but that just raises the question of why they didn't take the SFRM off for some of the tests. That just sounds like a poorly designed test.

That's not correct.

The tests were not run to failure because that would destroy the test cell. The furnaces are not designed to have multi-ton steel structures collapse upon them. Cleanup after such a test is hazardous. Remember, this is not a tiny benchtop experiment we're talking about -- each of the short-span full-scale truss tests involved roasting a structure bigger than my house.

There's no need to run the tests further, anyway. Elementary structural mechanics will tell you what will happen next to a high degree of accuracy. The difference between the stopping point in the UL furnace tests and what happened in the WTC Towers is whether or not the diagonal elements buckled. Up until that point, the NIST models can be verified against the truss tests in terms of displacement as a function of steel temperature, and they were, and the fit was excellent. But after that, there's no point. You're now talking about a dynamic structure, one with much larger uncertainties about condition, but the gross order behavior is completely predictable. Running this test, besides being dangerous, doesn't really tell us anything that we don't already know.

Regarding the scale of tests, the half-scale and full-scale short span tests revealed that contrary to their assumptions, they could not simply "scale up" the design and assume the same fire rating. For that reason, the difference between the short and large spans cannot be estimated without doing an experiment. However, this experiment can be done digitally, and was.

All of the computer models created were verified (that means "tested against known cases") against simple test cases, such as the NCSTAR1-6C tests. They were also tested for sensitivity and validated (that means "tested to show the correct behavior within a bounding envelope of conditions") independently, by varying each of the input conditions and verifying the effect of each, giving us a way to estimate the error for any given test case. The structural models, in total, are simply not all that sensitive to the kinds of errors you suppose. Minor variations in heating or even in displacement are not significant to the overall structure.

Regarding the fireproofing, that's a totally separate issue. It is difficult to be certain of the fireproofing damage. This is why NIST used conservative estimates of the damage, and also ran two fire cases for each tower, verifying the results against the many observations including extent of "hanging objects," appearance and progression of inward bowing at exterior walls, and measured lean of the tower superstructures. What the results show is that there is a minimum of fireproofing damage expected, but that within a wide envelope of performance, the fine details really make little difference.

It seems they have to assume temperatures based on the conclusion that the heat initiated the collapse--not the actual forensic evidence recovered.

That's part of my beef with the investigation. We are to take their word that the temperature assumptions are correct--even though the physical evidence they gathered doesn't comply.

The physical evidence they gathered does comply. You're wrong about that. Nobody is asking you to take anything as gospel.

So far, all of the difficulties you've had with the report stem from either not reading the report, or from fundamental confusions about the role of simulation in engineering. This is perfectly understandable if you do not come from a technical background. However, at this point you should at the very least give the NIST scientists the benefit of the doubt, trusting that perhaps it is you who has misinterpreted or misunderstood the process.

As always, feel free to ask questions.

 

[David Wong]

In other words, if some physical evidence were to surface for which only some kind of incendiary or explosive device could account...

Are you asserting, or are you going to assert, that such physical evidence exists?

 

[chipmunk stew]

Because it's too complicated, and because it's unnecessary.

To generalize for a moment: the more complicated the test, the less certain the results and conclusions. An ideal test would have only one variable. In the real world, it's often very difficult or impossible to design such a test, but still, good tests are ones are designed to answer a very narrow question or set of questions. These give much more meaningful results.

R.Mackey, you have a real gift for synthesizing technical information and communicating it to laymen. I suspect that you're a highly effective project leader.

 

[R.Mackey]

For what it's worth, model-based engineering is a big, big part of my job. Not structural engineering, mind you, but the hurdles are similar.

I'm trying to build models that will eventually have authority over what a spacecraft does. At a minimum this is risking, oh, say a $50M asset. At most, four astronauts' lives could depend on it.

As a result, the spacecraft hardware designers are very, very hard-nosed when it comes to the question of model validation.

Model validation and synthesizing simulation and real-world results are hard problems. Much too hard for a non-expert to casually glance at it and conclude that NIST has got it "all wrong." You have to read the report, really read it, and even then it's not going to be easy to assimilate without the right background. I learned quite a few things from it.