Does the exclusion of stiffness from Nordenson's falling girder calculations demonstrate anything?

[Gamolon]

FYI--I already wrote Nordenson this morning to ask (1) whether, given the suggestions to the contrary by certain conspiracy theorists, he could confirm that it is his opinion that fires could account for the observed collapse of wtc 7, and (2) whether he could provide his opinion on the discussion of the role of stiffness in this thread. If he replies back to me, I'll let everyone here know (unless he specifically requests otherwise, of course).

Does anyone know if there was any response or further dialog from Nordenson on this subject?

 

[Oystein]

Does anyone know if there was any response or further dialog from Nordenson on this subject?

Tony said - I think in the recent interview with AE's "Free Fall Radio" (host Andrew Steele) that he wrote to Nordenson twice, and got no response. Perhaps he can elaborate?

 

[econ41]

Four months later, I am still wishing someone would help me scrutinize Tony's FEA presented in Post #200, which he recently also presented in his AE911Truth webinar...

I doubt that Tony or any other FEA practitioner would make significant errors in applying FEA to the problem. The faults - if any - would in my experience almost certainly be in defining the problem - setting a valid context for the use of FEA. Multiple examples across the forums of both "sides" arguing the details when the starting scenario or linkages to the context were wrongly defined. And both "sides" heads down in the details of the numeric calculation (which is what FEA does - a sophisticated many factors calculator.)

And the sort of persons we meet on forums tend to be from that "details" school. So even if you got a "taker" to check the FEA s/he is unlikely to be one who would check the definition of problem. "Missing Jolt", "Axial Impact v Tilt" and this topic of WTC7 initiation have all suffered from "both sides" chasing the same wrongly defined problem. AKA "alligators v swamp drainage" syndrome.

Thanks Tony - makes sense, answers one question. There are more - especially questions that I don't know how to ask - to scrutinize your FEA.

Agreed and fully understood - both Tony's truisms and your comment. I can do it but only when motivated by interest in the topic. And the macro view here is still the top level false dichotomy - Proving that one or more specialists made errors of explanation does not prove that a "new investigation" is warranted. There are dozens of wrong explanations out there. For both the "Twins" and 7 WTC.

 

[Oystein]

Oz, "scrutinze Tony's FEA" was shorthand and would of course need to include the context and how it connects to that context.

Remember that this particular FEA has a limited purpose: To determine the effective stiffness of that part of the floor assembly which, in Nordenson's model, rotated about some hinges as defined by Nordenson, resulting in girder end impacting girder below.
This stiffness would then be input to the Nordenson model, which we improved by adding one term that we have already agreed is significant: That very floor assembly stiffness.

Since this thread is about the debunking, or upholding, Nordenson's conclusion that a failure of the c79-44 girder at c79 would start a cascade of floor failures, and since we have established that Nordenson ought to have included that stiffness - a number with a unit -, it follows that we need that number.

FEA apparantly is a tool that can give us that number.
Tony provides a number using FEA.
I want to check that number.
So the question is: Did Tony do the FEA right?
I see no argument suggesting he might have done something wrong.
So I tentatively accept Tony's number as "correct".
"Correct" as in "in the right ballpark".
That number points to "floor collapse would more probably arrest than not", to put it cautiously.
I don't have a feel for that "probably", as I don't feel competent to estimate the error bands in all of this.

If the dynamic force were at least an order of magnitude (i.e. factor 10) less than connection capacity, I'd be rather confident that Tony debunked Nordenson.
As I was confident that Nordenson was correct when his dynamic force was still more than an order of magnitude (i.e. factor 10) higher than capacity.
As it were, Tony's result is a factor of 3 - that's about half an order of magnitude (on a logarithmic scale), and thus my shaky confidence.


I never forget that, of course, the building did, in fact, collapse; that col 79 was almost certainly one of the first two columns to fail; that almost certainly the heat of fires was the ultimate cause of this failure of col 79; that almost certainly, col 79 could not have failed directly due to having been heated as it was too massive to reach critical temperature; that therefore it is almost certainly true that some lateral members - parts of floor assemblies, transfer truss, whatever - failed first and put col 79 (or 80) in a critically undersupported state. All this is almost certainly true regardless of how debunked any specific claims by NIST or the ARUP bunch might be.

 

[econ41]

Oz, "scrutinze Tony's FEA" was shorthand and would of course need to include the context and how it connects to that context.

Understood - but the differences in our scopes of interest and preferred approaches were once again evident.

Remember that this particular FEA has a limited purpose: To determine the effective stiffness of that part of the floor assembly which, in Nordenson's model, rotated about some hinges as defined by Nordenson, resulting in girder end impacting girder below.
This stiffness would then be input to the Nordenson model, which we improved by adding one term that we have already agreed is significant: That very floor assembly stiffness.

Since this thread is about the debunking, or upholding, Nordenson's conclusion that a failure of the c79-44 girder at c79 would start a cascade of floor failures, and since we have established that Nordenson ought to have included that stiffness - a number with a unit -, it follows that we need that number.

Also understood even tho debunking Nordenson has IMO little value to add to 9/11 discussion other than to once again show that even the ranking experts occasionally get something wrong. And we already know that. Plus - and I won't derail here - there is at least one other significant aspect of Nordenson's method that I am not persuaded is correct. (Note "not persuaded" - I'm not claiming "wrong" --- yet.) (I haven't raised it previously given that discussion has been within the scope of Nordenson's method/findings.)

FEA apparently is a tool that can give us that number.
Tony provides a number using FEA.
I want to check that number.
So the question is: Did Tony do the FEA right?
I see no argument suggesting he might have done something wrong.
So I tentatively accept Tony's number as "correct".
"Correct" as in "in the right ballpark".
That number points to "floor collapse would more probably arrest than not", to put it cautiously.
I don't have a feel for that "probably", as I don't feel competent to estimate the error bands in all of this.

There are three issues in that lot:
1) Burden of proof - I still prefer the hard line of it is "not proven" till it is "proved";
2) You give Tony benefit of doubt until disproven....Sure I would bend the BoP rules if the poponent had a record for honesty and accuracy in dealing with me. You, OWE and a few others I would rarely question on the maths and sums details;
3) My interactions with with Tony suggest that he is usually right on the number crunching BUT every previous example of Tony's I have analysed and/or discussed with Tony he has relied on false premises. (It's not one sided - I've pressed several debunkers on the same issues of false definition of problem/false context and two prominent debunkers currently have me on their list for dishonest tricks and personal attacks.)

If the dynamic force were at least an order of magnitude (i.e. factor 10) less than connection capacity, I'd be rather confident that Tony debunked Nordenson.
As I was confident that Nordenson was correct when his dynamic force was still more than an order of magnitude (i.e. factor 10) higher than capacity.
As it were, Tony's result is a factor of 3 - that's about half an order of magnitude (on a logarithmic scale), and thus my shaky confidence.

My recollection is that the first error took Nordenson out of "overwhelming" into "marginal". And Tony's shifting from "marginal"
to "3 times in the other direction" is far too significant for me to accept without proof. Especially given Tony's record of denying the issues of definition that I have correctly identified with his earlier work. AND that is presuming I will go along for the ride with the Nordenson limited context - not the full "real event".

Al those reasons aside I think you and I are more or less in the same position. There is a "case to answer" opposing Nordenson. It is not resolved with any clarity or assurance at this stage.

And the overall or "macro" situation is unaffected - as per this concluding paragraph of your post:

I never forget that, of course, the building did, in fact, collapse; that col 79 was almost certainly one of the first two columns to fail; that almost certainly the heat of fires was the ultimate cause of this failure of col 79; that almost certainly, col 79 could not have failed directly due to having been heated as it was too massive to reach critical temperature; that therefore it is almost certainly true that some lateral members - parts of floor assemblies, transfer truss, whatever - failed first and put col 79 (or 80) in a critically undersupported state. All this is almost certainly true regardless of how debunked any specific claims by NIST or the ARUP bunch might be.

 

[benthamitemetric]

Does anyone know if there was any response or further dialog from Nordenson on this subject?

Just to confirm--Nordenson never responded to my initial email and, out of courtesy, I chose not to email him again.

 

[econ41]

Just for the record I've never been persuaded that approaching Nordenson was appropriate. Several reasons.

The main one being that it puts him in the "between a rock and a hard place" situation.

If it had been a professionally published paper the avenue of open reubutal would have been available.

BUT it was prepared for anther scenario - legal processes - and never tested in that process.

And the current interest has arisen out of yet another scenario - false logic by supporters of a CT based on the false dichotomy "if this claim by Nordenson is wrong it means our claims are right" - or "...our claims have a bit more support" Neither of those positions valid. There are many wrong explanations of WTC collapses. The missing element for the CTers is lack of a definitive proof of their claims - not multiple faulty arguments against their claims. Reversed burden of DISproof framed in a false dichotomy.

 

[benthamitemetric]

Just for the record I've never been persuaded that approaching Nordenson was appropriate. Several reasons.

The main one being that it puts him in the "between a rock and a hard place" situation.

If it had been a professionally published paper the avenue of open reubutal would have been available.

BUT it was prepared for anther scenario - legal processes - and never tested in that process.

And the current interest has arisen out of yet another scenario - false logic by supporters of a CT based on the false dichotomy "if this claim by Nordenson is wrong it means our claims are right" - or "...our claims have a bit more support" Neither of those positions valid. There are many wrong explanations of WTC collapses. The missing element for the CTers is lack of a definitive proof of their claims - not multiple faulty arguments against their claims. Reversed burden of DISproof framed in a false dichotomy.

Right--I don't blame him for not responding to me. Sometimes I've had luck reaching out to experts and other people of importance re 9-11 issues, and sometimes they ignore me. In this case, the litigation aspect makes his choice to respond especially complicated, not the least of all because the fact that I am an attorney in NY would have been easily google-able to him. I'm not a litigator and, in any case, wouldn't have any stake or involvement in the issue at hand, but I could understand someone like Nordenson being especially reluctant to correspond with me over what could be considered partially a legal issue. Oh well, nothing I could do but try, anyway.

 

[econ41]

The approach would put him between the proverbial "rock and a hard place".

Given that it arose from CT discussions and CTers are notoriously "less than fully truthful" the chance was that his name would be dragged through the mud when the error if any had zero effect in the process it was intended for AND was never subjected to the option of falsification as presented by that process.

The best he would have access to if he had made any concessions would be "Shucks - I may have made a boo boo there BUT it was never tested by the opposition otherwise we could have worked something out better. Now we will never know."

And my comment deliberately avoids the legal process/practice aspects. I've never put my law degree into practice and the issues are procedural risk in practice NOT UNI Bachelors degree text book theory.