OOS Collapse Propagation Model

[pgimeno]

Apologies.. auto correct and I don't proof... and I am probably dyslexic and suffering from dementia... If you manage to read through my unproofed gibberish I am grateful. Can't edit anyway after the clock runs down.

I have to say, for a non-native speaker like me who hasn't learned spoken English, improperly spelled English or phonetically-alike English gets quite difficult to read.

That said...

We all seem to be way too invested in our egos to make progress in these discussions. We all lose in the end.

... kudos for using the word "lose" correctly. That's becoming increasingly rare nowadays.

 

[ozeco41]

But he is wrong... the core could stand alone without the OOS flooring or the facade...

This certainly isn't what I believed I had learned over the years. My understanding is that wind shear would have brought it down.

My understanding also - instabilty and not limited to wind forces - "slenderness" alone suggests it to my "engineers gut feeling" without even doing the sums/FEA.

BUT Benson in that series of exchanges with Major_Tom was wrong on so many aspects - there is no need to derail onto a misunderstanding of "core stability".

I'm tempted to review the whole sequence BUT:
1) I don't agree with cross forum posting per se; AND
2) From the bits we have seen Major_Tom has made the point that Benson is not correct; WHEN
3) It would be more appropriate IMO if M_T made the actual point as an assertion relevant to this thread on this forum.

Make the point as a positive assertion rather than the back handed way by asserting someone on another forum was wrong - by an attack on Benson's credibility - Benson has not posted here for years and NEVER in this thread.
.

 

[BasqueArch]

.....
I don't know what Tom's motive is. .....

Major Tom has claimed that explosives demolition was used in the three towers as a pretext for our barbaric society to steal the resources of others. He has collected large amounts of photos and videos, looking for evidence of CD. Over time the blatant claims of CD have been modified to professing that alleged errors in the “official story” are “anomalies” better explained by demolition instead. This change of clothes has deceived some.
His hypothesis that a “core failure mechanism” along one column line buckled the perimeter WTC1,2 columns instead of the sagging trusses has been proven wrong , but still remains on his web site.
Tom’s motive is to attempt to prove the inside job of CD of the core columns of WTC1,2.

 

[beachnut]

Direct measurements extracted from the visual record of the collapses grossly contradict history as it is generally presented. A record of measurements and documented observables of all 3 collapsed buildings on a level far more intricate than that which previously existed has been presented. The record is verifiably superior to and grossly contradicted by the record provided by U.S. Government agencies.

In reality there is no scientific approach and, therefore, no technical history of the collapses at all. This is a verifiable statement.

What a load of BS. Everyone is wrong except the gravity collapse is an illusion guy, which is part of the record never explained.

Who said the core can stand without the shell and floors.

 

[Crazy Chainsaw]

My understanding also - instabilty and not limited to wind forces - "slenderness" alone suggests it to my "engineers gut feeling" without even doing the sums/FEA.

BUT Benson in that series of exchanges with Major_Tom was wrong on so many aspects - there is no need to derail onto a misunderstanding of "core stability".

I'm tempted to review the whole sequence BUT:
1) I don't agree with cross forum posting per se; AND
2) From the bits we have seen Major_Tom has made the point that Benson is not correct; WHEN
3) It would be more appropriate IMO if M_T made the actual point as an assertion relevant to this thread on this forum.

Make the point as a positive assertion rather than the back handed way by asserting someone on another forum was wrong - by an attack on Benson's credibility - Benson has not posted here for years and NEVER in this thread.
.

That would be great, but I don't intend holding my breath for it.

 

[Myriad]

Which "CD people"? Apart from some personalising of the arguments the discussion is about the "OOS Collapse Propagation Model" which is emphatically not CD and some discussion about the limits of Bazant's models which have been misapplied by "debunker" side posting members.

Since you seem to understand Major_Tom's objections to my statements about Bazant's papers, or at least feel that those objections have some measure of substance, maybe you can explain them to me. His own explanation is limited to quoting each of my requests for clarification as evidence that I am being deceptive.

In what way have I, or anyone else, "misapplied" any of Bazant's findings?

I have stated that as far as I can tell, Bazant's calculations do correctly describe the behavior of Bazant's own model, including the fact that in that model crush-down comes to predominate over crush-up early in the process, which was merely taken as an assumption in BZ and then shown to be internally predicted by the model itself in BV. Does Major_Tom disagree with that, and if so, what are those math errors?

I have also stated that as far as I can tell, the model in BV continues to embody the same key simplifying and limiting-case assumptions as in BZ -- namely, that all impact force acts directly upon the columns below and that all columns buckle. I know Major_Tom disagrees with that, but he will not cite any part of BV in which those assumptions established in BZ are retracted or contradicted, so I see no reason to change my views to conform to his. Maybe you can tell me what I'm missing?

Finally, I am not aware of having misapplied -- or even applied at all -- Bazant's models to any real-world event. BZ's conclusions do agree with my own independently derived conclusions about collapse sustaining rather than arresting even in idealized (favorable to arrest) conditions, as it also agrees with Major_Tom's. Beyond that highly limited sense of "applied" (cited as an independent confirming view), I have not applied let alone misapplied Bazant's models at all, because I have never needed to.

For example, I have never stated or implied that the actual WTC tower collapses underwent clean separate crush-down then crush-up, nor does anything I believe or have stated about the events of 9/11 depend on separate crush-down crush-up being part of the scenario. Nor, to my knowledge, have the other members who have posted analysis of any depth. A large number of members post here so I can't say that no one has ever claimed something like "the upper block stayed intact all the way to the ground because Bazant said so" but it's certainly not a claim generally held by the rationalist (sorry, I mean "bee-dunker") side.

So as far as I can tell, Major_Tom's assertions that some members, and I specifically, have misconstrued and misapplied the limits of Bazant's models, is merely a lie.

He will not say where I misapply Bazant's models. Instead, he points to posts like this one where I have attempted to address his objections and says, "see, he's still doing it." He repeats the lie.

Since you claim to understand his position, maybe you can explain why he is lying and repeating the lie. Is he lying for a reason, or just for fun? And if there is a reason, does he understand that lying to me about my own position is not likely to be successful in deceiving me, and in fact is instead rather foolish?

Respectfully,
Myriad

Posted originally on page 34 of this thread, about four and a half years ago.

Still sufficient response to all of Major_Tom's accusations.

 

[Myriad]

Oh, then there was this follow-up:

You mix the collapse progression model in BV, BL and BLGB with the term " assumptions most favorable to collapse arrest", a term from the BZ argument.

Sorry, that is incomprehensible. I mixed a model with a term? How does one do that?

I did assert that the BV model incorporates the assumptions of all impacts being onto lower columns, and all columns buckling, from BZ. You have not shown that is wrong, by any reference to any portion of BV stating or suggesting otherwise. I've concluded that you are unable to.

I also asserted that those are indeed assumptions favorable to collapse arrest, as they maximize the energy absorbed in column deformation. You have not shown that is wrong, by any coherent form of analysis (e.g. by showing that those assumptions do not maximize the energy absorbed). I've concluding that you are unable to.

I told you that very clearly in May. 2010. You ignored me and kept doing it until the present.

I did not ignore you. I examined your claim that I was mistaken about the assumptions in BV, found no evidence to support it, and when you did not offer any such evidence to support it when requested, I rejected it. It is false. You are wrong.

You and Dave Rogers, R Mackey, and Newton's Bit made minced-meat of these papers and you still spread the same misunderstandings today.

It is either intentional or unintentional, but it is a deceptive mess all the same.

And there's the lie again.

One great example:

This is indeed an example of something I've written. I wouldn't go so far as to call it a great example, but it's reasonably concise and informative.

It is not an example of any error, because you have not pointed out any erroneous claim in it, and I've concluded that you are unable to. It does include information from two different papers, which you seem to have some kind of objection to, but that is not my problem as there is nothing objectionable about doing so.

Why do I consider the 4 of you to blame? Because the little sheep follow the big sheep. The 4 of you pose as big sheep, leading the flock astray.

If you didn't keep repeating the same mistakes, the others probably wouldn't either.

Exactly wrong. If you got rid of me, a dozen others would rise up to take my place.

(Seriously -- pose as a big sheep? Can you give me one example of any credential or advanced expertise I have claimed regarding the issues under discussion? Based on past experience I'm going to conclude in advance that you are unable to.)

Respectfully,
Myriad

 

[ozeco41]

Posted originally on page 34 of this thread, about four and a half years ago.

Still sufficient response to all of Major_Tom's accusations.

I will respond to the issues in Post #2806 - Not Post #2807 at this stage. We have a lot of material to cover.

My interest in this topic is part of my goal since mid 2007 to understand the WTC collapses so that I can explain them to other interested persons.

For this topic there are two areas of contention and I have sought to rigorously separate them. Please check my posting history if you have any doubt. Those two areas are:
1) The technical issues involved in this topic - what the mechanism of "Twin Towers" really was ; how it relates to the work of Prof Bazant and the extensive range of confusions which have arisen - despite many denials that there was confusion.

2) Issues arising out of the discourteous and offensive posting habits adopted by Major_Tom and many of those opposing him.

My primary interest is in those technical issues which M_T understands correctly, where many debunkers do not understand them correctly. I seek to avoid the aggressive two way bickering which takes place between M_T and his detractors.

However, if I am to assist you, we need to understand - either agree or agree to disagree on the technical issues. Independent of what Major_Tom may or may not say. And definitely clear of the offensive aspects of his style.

So Stage #1 lets see where I agree and where I disagree with your position. This is your 2011 post which you assert is "Still sufficient response to all of Major_Tom's accusations". I'll address the technical issues and set aside - take a rain check on - whether or not it rebuts Major_Toms "accusations" - for this post:

Since you seem to understand Major_Tom's objections to my statements about Bazant's papers, << 1 Probably true but only for those bits where M_T is correct - I am not commenting on either his style or anything technical that he may get wrong. or at least feel that those objections have some measure of substance << 2 They do have "some measure of substance" , maybe you can explain them to me << 3 I will try.. His own explanation is limited to quoting each of my requests for clarification as evidence that I am being deceptive. << 4 His characteristic style including JAQing - and reluctance to explain/reason/argue - rain check on this. It is not "technical"

In what way have I, or anyone else, "misapplied" any of Bazant's findings? << 5 Many times over the years but we will need to deal with them specifically and one at a time. IF we need to go there.

I have stated that as far as I can tell, Bazant's calculations do correctly describe the behavior of Bazant's own model, << 6 Maybe - depends on which calculations are referred to, We will need to be specific. including the fact that in that model crush-down comes to predominate over crush-up early in the process, << 7 That is one of the key areas of confusion. Put bluntly as an assertion which I can rigorously defend "crush down/crush up" is NOT relevant - does NOT apply to the actual WTC Twin Towers collapses. which was merely taken as an assumption in BZ << 8 Doesn't matter BUT I suggest that is wrong. and then shown to be internally predicted by the model itself in BV. << 9 There are lots of problems with BV applied to WTC as if it was the real event. It does not apply and that is another key area of confusion Does Major_Tom disagree with that, << 10 Yes he does. I agree with him. He is right. Another point of confusion needing further explanation. and if so, what are those math errors? << 11 The errors are more fundamental than maths. The mechanism and application of it to WTC are wrong - so the maths are irrelevant.

I have also stated that as far as I can tell, the model in BV continues to embody the same key simplifying and limiting-case assumptions as in BZ -- namely, that all impact force acts directly upon the columns below and that all columns buckle. << 12 There is the central error underpining most of these debunker confusions. The need to separate the fantasy "Limit Case" model from the real event. I've actually explained it several times. Many times since 2010 AND quite a few debunkers have asserted the same points. The "fun" (or "funny") issue is that SOME debunkers assert most of the true points but disagree when either I state them clearly OR M_T states them in his own unique way by JAQing "you do the reading - I won't explain" . We will need to discuss this matter more explicitly and detail. BV is wrong to apply crush down/crush up to the WTC Twins collapse as if it actually happened..it didn't and that is one of the main points of debunker misunderstanding, failure of reading comprehension or worse. And CD/CU is merely the extension of the limit case reasoning - NOT the reasoned explanation of the real event.
I know Major_Tom disagrees with that, but he will not cite any part of BV in which those assumptions established in BZ are retracted or contradicted, so I see no reason to change my views to conform to his. << 13 You shouldn't rely on M_T - or anyone - to get your thinking clear. People can help but bottom line is that we each have to understand for ourselves. Maybe you can tell me what I'm missing? << 14 Sure can - provided you will discuss it rationally with me - bit by bit - step by step - AND set aside the Major_Tom personal angst stuff until we understand the technical stuff.

Finally, I am not aware of having misapplied -- or even applied at all -- Bazant's models to any real-world event. BZ's conclusions do agree with my own independently derived conclusions about collapse sustaining rather than arresting even in idealized (favorable to arrest) conditions, as it also agrees with Major_Tom's. << 15 Not clear is there is any contention in that bit Beyond that highly limited sense of "applied" (cited as an independent confirming view), I have not applied let alone misapplied Bazant's models at all, because I have never needed to. << 16 Not that you are aware of. Some of the technical points we need to discuss could well change the basis of your confidence.

For example, I have never stated or implied that the actual WTC tower collapses underwent clean separate crush-down then crush-up, nor does anything I believe or have stated about the events of 9/11 depend on separate crush-down crush-up being part of the scenario. << 17 Great. That is positive -BUT the confusions come before CD/CU Nor, to my knowledge, have the other members who have posted analysis of any depth. << 18 I'm not aware of any valid analysis in depth - if we share understanding of the technical truths we may not - should not - need to do the archaeological heresy hunt into past sins A large number of members post here so I can't say that no one has ever claimed something like "the upper block stayed intact all the way to the ground because Bazant said so" but it's certainly not a claim generally held by the rationalist (sorry, I mean "bee-dunker") side << 19 Agreed - global assertions are always risky - it only take a single exception to falsify..

So as far as I can tell, Major_Tom's assertions that some members, and I specifically, have misconstrued and misapplied the limits of Bazant's models, is merely a lie. << 20 Take care asserting "lie" especially where your own understanding is doubtful and even if you can prove untruth you cannot prove the intent which is essential to prove "lie".

He will not say where I misapply Bazant's models. << 21 I know from extended experience - read the sad tale of my 5 years history of pressing him on style and illogic. Instead, he points to posts like this one where I have attempted to address his objections and says, "see, he's still doing it." << 22 Irritating isn't it? He repeats the lie. << 23 Presumption of "lie" when he is actually correct. You are "still doing it". The error of his claim is that he should be explaining. He is actually setting up "gotchas" I could give you the links to the times he has tried to play that trick on me. BUT remember we are not discussing M_T's sins in this post.

Since you claim to understand his position, maybe you can explain why he is lying and repeating the lie. Is he lying for a reason, or just for fun? << 23 Your presumption of lying when you do not understand either what he claims or the true position is - choose your own word "bold"? "Presumptuous" Still it is later stage rain check materiel. Lets get the technical stuff clear first. And if there is a reason, does he understand that lying to me about my own position is not likely to be successful in deceiving me, and in fact is instead rather foolish? << 24 Too confused and not "technical". rain check for now.

Respectfully,
Myriad

OK I've deliberately numbered those 24 points for easy reference.

Remember I'm trying to stay away from the Major_Tom stuff until we share understanding of the technicals.

Of necessity I've responded to your post in the order of how you expressed it. I would prefer to explain the technical issues in a sequence which follows the logic of my arguments/explanations. I have already posted most of the B&Z stage material in the last few days. So I recommend read the sequence of my recent posts and related comments by others.

THEN - If it will help - I can summarise the issues with BV, BLe and later stuff.

 

[JSanderO]

Nothing will change... pride, hubris...inability to see or accept one's fallibility.

Nice try Ozzie!

 

[Oystein]

oz, I will quote part of your reply twice:

1.) Highlighting what Myriad is talking about:

I have stated that as far as I can tell, Bazant's calculations do correctly describe the behavior of Bazant's own model, << 6 Maybe - depends on which calculations are referred to, We will need to be specific. including the fact that
in that model crush-down comes to predominate over crush-up early in the process, << 7 That is one of the key areas of confusion. Put bluntly as an assertion which I can rigorously defend "crush down/crush up" is NOT relevant - does NOT apply to the actual WTC Twin Towers collapses. which was merely taken as an assumption in BZ << 8 Doesn't matter BUT I suggest that is wrong. and then shown to be internally predicted by the model itself in BV. << 9 There are lots of problems with BV applied to WTC as if it was the real event. It does not apply and that is another key area of confusion Does Major_Tom disagree with that, << 10 Yes he does. I agree with him. He is right. Another point of confusion needing further explanation. and if so, what are those math errors? << 11 The errors are more fundamental than maths. The mechanism and application of it to WTC are wrong - so the maths are irrelevant.

I have also stated that as far as I can tell, the model in BV continues to embody the same key simplifying and limiting-case assumptions as in BZ -- namely, that all impact force acts directly upon the columns below and that all columns buckle. << 12 There is the central error underpining most of these debunker confusions. The need to separate the fantasy "Limit Case" model from the real event. I've actually explained it several times.

2. Highlighting what ozeco41 is talking about:

I have stated that as far as I can tell, Bazant's calculations do correctly describe the behavior of Bazant's own model, << 6 Maybe - depends on which calculations are referred to, We will need to be specific. including the fact that in that model crush-down comes to predominate over crush-up early in the process, << 7 That is one of the key areas of confusion. Put bluntly as an assertion which I can rigorously defend "crush down/crush up" is NOT relevant - does NOT apply to the actual WTC Twin Towers collapses. which was merely taken as an assumption in BZ << 8 Doesn't matter BUT I suggest that is wrong. and then shown to be internally predicted by the model itself in BV. << 9 There are lots of problems with BV applied to WTC as if it was the real event. It does not apply and that is another key area of confusion Does Major_Tom disagree with that, << 10 Yes he does. I agree with him. He is right. Another point of confusion needing further explanation. and if so, what are those math errors? << 11 The errors are more fundamental than maths. The mechanism and application of it to WTC are wrong - so the maths are irrelevant.

I have also stated that as far as I can tell, the model in BV continues to embody the same key simplifying and limiting-case assumptions as in BZ -- namely, that all impact force acts directly upon the columns below and that all columns buckle. << 12 There is the central error underpining most of these debunker confusions. The need to separate the fantasy "Limit Case" model from the real event. I've actually explained it several times.

Myriad makes it clear again and again and again and again that he is talking STRICTLY about the models and their math in BZ and BV. At no point is Myriad talking about the real event, or even conflating the models with the real event.

So why do you drag in that conflation again and again and again and again? That is YOUR fundamental error. It is an item of deep faith that you believe Myriad (or, for that matter, RMackey, N_B...) is conflating BZ/BV/BGBV/BXYZ with the real event, when he informs you directly an in no uncertain terms that he never ever applies BXYZ to anything, let alone the real event!



It would really help if you spotted that huge beam in your eye and tried to remove it!

 

[JSanderO]

oz, I will quote part of your reply twice:

1.) Highlighting what Myriad is talking about:


2. Highlighting what ozeco41 is talking about:



Myriad makes it clear again and again and again and again that he is talking STRICTLY about the models and their math in BZ and BV. At no point is Myriad talking about the real event, or even conflating the models with the real event.

So why do you drag in that conflation again and again and again and again? That is YOUR fundamental error. It is an item of deep faith that you believe Myriad (or, for that matter, RMackey, N_B...) is conflating BZ/BV/BGBV/BXYZ with the real event, when he informs you directly an in no uncertain terms that he never ever applies BXYZ to anything, let alone the real event!



It would really help if you spotted that huge beam in your eye and tried to remove it!

Oy..

And the point of discussing the non real event and writing papers about it is exactly what?

When you look at Mr B's diagrams... they sure look like 1WTC... don't they? And we've heard all this "stuff" about "limit case". Frankly no gives a hoot about "limit cases" they belong in acedemia.

NIST and the whole discussion was to figure out what happened... REAL WORLD... IS this REAL world or an (academic) exercise?


YOU tell us.

 

[Oystein]

Oy..

And the point of discussing the non real event and writing papers about it is exactly what?

Don't ask me. Ask M_T and oz, and yourself, who keep riding this dead horse.

When you look at Mr B's diagrams... they sure look like 1WTC... don't they?

That's what models do: In some way deemed interesting by their creators, most models look LIKE the real thing.
But they are not the real thing.
I put a but of emphasize on the key word.

So far I was under the impression that truthers do not understand similes.

And we've heard all this "stuff" about "limit case". Frankly no gives a hoot about "limit cases" they belong in acedemia.

Which is precisely where Myriad was determined to leave it and discuss it.
It is M_T and oz who keep dragging the academia stuff into conflation with the real thing and then point fingers at, for example, Myriad, who expressedly avoided doing that.

NIST and the whole discussion was to figure out what happened... REAL WORLD... IS this REAL world or an (academic) exercise?
YOU tell us.

No, you, the bashers of Bazant and the "alleged Bazantophiles" tell us.

You think this academia stuff does not belong in a subforum about 9/11 theories because it does not cover the real WTC? Well fine, let's move this to the more acadamia-prone "Science&Technology" subforum, ok?

Oh wait - this was done 4 or 5 years ago already and was met with loud cries by M_T!

 

[Bravin Neff]

And the point of discussing the non real event and writing papers about it is exactly what?

Don't mean to answer for Oystein, but B&V make quite clear their purpose: a generalized model applicable to demolitions and other progressive collapses.

When you look at Mr B's diagrams... they sure look like 1WTC... don't they?

They do, for reasons they make clear.

And we've heard all this "stuff" about "limit case". Frankly no gives a hoot about "limit cases" they belong in acedemia.

Last time I checked, this was the 9/11 conspiracy theories subsection. Back when the 9/11 truth movement existed, people cared very much about limit cases - they played a key role in the argument against the plausibility of CD. That might not serve a purpose germane to your goals, but they certainly serve a purpose in the conversation known as "9/11 conspiracy theories."

 

[GlennB]

What I most like about this place is the hivethink. It's almost like the resident debunkers are NWO clones, or something

 

[Myriad]

Oy..

And the point of discussing the non real event and writing papers about it is exactly what?

The point is addressing claims that collapse should have "arrested" itself in the absence of demolition charges or other false flag sabotage. A limiting case model such as Bazant's is a valid argument for doing so. Obviously.

(If you're instead asking why Bazant bothered to publish papers, you'll have to ask him. Why should I care?)

Those claims were prevalent at the time the quotes you and Major_Tom keeps reposting were originally posted. If you don't find the issue relevant now, then you're free at any time to stop parroting Major_Tom's mythical "debunkers criminally misrepresent Bazant's models as reality" narrative, or your own "debunkers caused terrible confusion by mistaking Bazant's models for reality" variation, at every opportunity.

 

[Dave Rogers]

Oy..

And the point of discussing the non real event and writing papers about it is exactly what?

Limit case.

The way I see it, there are four energy terms here. Let's call them E1, E2, E3 and E4.

E1 is the energy available to sustain collapse to ground level.
E2 is the energy required to sustain collapse in the most optimistic scenario.
E3 is the energy required to sustain collapse in the actual event.
E4 is the energy to sustain collapse in the ROOSD scenario.

Bazant and Zhou states that E1>E2. By definition E2>=E3, therefore E1>E3. Bazant seems to have fallen a little in love with his own model and over-applied it in later work, but that central conclusion of B&Z is the one that 9/11 truthers find most irksome. The main argument has therefore been whether E1>E2 is a true statement, because truthers can't seem to figure out that, even if it were true, E1<E2 does not imply E1<E3; Tony Szamboti among others is a master of this fallacy. However, Bazant is defending the claim that E1>E2, because if that is established then no further analysis is necessary to prove that the collapse was self-sustaining. And that, in a nutshell, is the limit case.

Major Tom, meanwhile, is up in arms because Bazant has not addressed the question of whether E4=E3, and claims that this demonstrates intellectual dishonesty on the part of Bazant. Since the very existence of the term E4 is never more than vaguely implied in Bazant's work and is not necessary to its most important conclusion, this seems an untenable claim by MT.

(Menawhile, CC is implying that E3>E4 from the collapse time, which is a most interesting result if valid; it strongly suggests some other mechanism than ROOSD.)

Dave

 

[JSanderO]

The point is addressing claims that collapse should have "arrested" itself in the absence of demolition charges or other false flag sabotage. A limiting case model such as Bazant's is a valid argument for doing so. Obviously.

(If you're instead asking why Bazant bothered to publish papers, you'll have to ask him. Why should I care?)

Those claims were prevalent at the time the quotes you and Major_Tom keeps reposting were originally posted. If you don't find the issue relevant now, then you're free at any time to stop parroting Major_Tom's mythical "debunkers criminally misrepresent Bazant's models as reality" narrative, or your own "debunkers caused terrible confusion by mistaking Bazant's models for reality" variation, at every opportunity.

Frankly it's pretty self evident that a floor collapse would not arrest. No need for a "limit case". Whatever the design load of the floor system.. 60 psf, 70 psf, 100psf It's settled engineering that that a super imposed load on a floor which exceeds its yield strength will FAIL... and this is precisely why the code has PSF limits for various uses.

It's trivial... pile up X number of floors on a typical floor and you have a "runaway" progressive and quite rapid collapse of the entire floor system BELOW. Any freshman who took statics knows this.

Perhaps to many the collapse of the columns was more incomprehensible and counter intuitive. But this again is SETTLED engineering about stability of structures with high aspect or slenderness ratios. Too tall and too thin are unstable as shown by Euler...

Again trivial And the "spire demise is the "proof" as in the proof of the pudding is in the tasting.

Mr. B et al's math was essentially a distraction with respect to the twin towers... because it did not address the issue... WHAT made the towers collapse... ie the mechanisms of the period post strike and mech damage to naked eye collapse. There was no need to show the collapse was not arrestable... because we are not dealing with either blocks or homogeneous masses... but building with beams, bolts, slabs and forth.

Whether you call it the inaccurate pancake collapse... as so many "smarties" did... or ROOSD... it was a trivial case of over loading of the stone cold floors below the plane strike zones.

ROOSD goes to show that as a CONSEQUENCE of the collapse of the floors... the axial supports lose their stability and topple. Right there for any person with 2 eyes to see. Why? Euler explained it.

This so called "debate" is hysterical to observe...

 

[ozeco41]

Don't ask me. Ask M_T and oz, and yourself, who keep riding this dead horse.

Oystein you were the last person I would expect to descend to this depth of dishonest debunker denialism. This is now the second time in recent days that you have resorted to near personal abuse rather than respond to my presentation of reasoned arguments.

I will not descend to that level OR return the trick. I do not attack your integrity in the areas of your interests. Nor do I post disruptive bits of false arguments on topics which are your areas of expertise.

I think you may have muddied the waters sufficiently to ensure that discussion with Myriad cannot progress. So I face two possibilities of ways forward with you rather than with Myriad.

As you know I prefer to lay out coherent reasoned argument starting from sound premises and progressing through logical steps.

So I would prefer our discusion to "start from the very beginning" BUT the current sticking point is a bit down the track. Put simply it goes to the assertion I have made many times:

"The later papers by Bazant et al are wrong where they apply 1D simplification models to the WTC real event".

I stand by that assertion and am prepared to support it in reasoned argument.

The objections to that assertion come in two forms (a) outright denial OR (b) claims that 1D can be a sufficiently valid approximation. I am prepared to consider (b) "sufficiently valid approximation" if it is ever supported by reasoned argument. I know of no such argument.

Now there is a missing link in Myriad's assertions and your understanding of them as expressed by these quotes:

Which is precisely where Myriad was determined to leave it and discuss it.
It is M_T and oz who keep dragging the academia stuff into conflation with the real thing and then point fingers at, for example, Myriad, who expressedly avoided doing that.

and the earlier version

Myriad makes it clear again and again and again and again that he is talking STRICTLY about the models and their math in BZ and BV. At no point is Myriad talking about the real event, or even conflating the models with the real event...

Those assertions are true. Most importantly you confirm that Myriad rested on BV (specifically BV at this stage) I agree that also. It is HALF of my key point. The other HALF is that BV itself applies the 1D approximations to WTC real event. I didn't create the conflation - it is in BV. A point of argument for which I was preparing the ground in my response to Myriad before your "pre-emptive strike". Myriad by "calling up" BV also calls up the 1D applied to real event conflation. Not me - I simply identify it.

Now that is NOT "fully reasoned argument" merely an outline of the claim I would make.

If we are to progress discussion on a reasoned basis I would prefer to do it in two stages - Stage 1 discuss and reach agreement on the limits of validity of B&Z and any issues arising from that THEN Stage 2 address the later papers BV, BLe etc.

I have outlined the basis of my position several times recently. The most relevant was directed at Major_Tom in this post

If I simply extract the facts from that post theyare:

Fact #1a Bazant identified that the real collapse mechanism was complicated and chose a simpler model which was valid for a "limit case argument";

Fact #1b Bazant clearly distinguished the two different mechanisms - the more complicated real event and the simpler version supporting a "limit case" argument;

Fact #1c Bazant's "limit case" argument was conceptually valid, it has not been successfully challenged and he did not confuse the two mechanisms.

Fact #2 Discussion of WTC collapses should not use or rely on confusion of any issues of fact including the facts derived from Bazant's work.

Fact #3 - The progression collapse stage for WTC1 and WTC2 was dominated by a mechanism in which material falling down the office space tube stripped floors leaving perimeter columns to fall away.

Fact #4 The real event collapse described by Major_Tom in the link from the OP AND restated as Fact #3 is a different mechanism to the column crushing model of the limit case argument.

Fact #5 Reaffirms that the two mechanisms are different - and that M_T and ozeco agree - not directly relevant here.

Fact #6 Arguments should not be confused over the two mechanisms and any relationship they may have.

And an "incidental issue" - which goes to the use of the label "ROOSD".

Please not that I am trying to start from a clean sheet. I am not commenting either way on past history.

Are you prepared to enter reasoned discussion in the two stages I propose?

If so do you agree that each of the facts is true fact? 1a, 1b, 1c, 2, 3, 4 and 6?
(AKA a valid premise for debate if you prefer to not call them "facts")

If not can you state your objections or ask for further clarification point by point?

If we can progress to agreement on those facts plus any you think I have missed at that foundation level we can then go to Stage2. Which should address the problems with BV - possibly BLe.


Finally let me take a "rain check" on the other issues you raise.

 

[ozeco41]

Limit case.

The way I see it, there are four energy terms here. Let's call them E1, E2, E3 and E4.

E1 is the energy available to sustain collapse to ground level.
E2 is the energy required to sustain collapse in the most optimistic scenario.
E3 is the energy required to sustain collapse in the actual event.
E4 is the energy to sustain collapse in the ROOSD scenario.

Bazant and Zhou states that E1>E2. By definition E2>=E3, therefore E1>E3. Bazant seems to have fallen a little in love with his own model and over-applied it in later work, but that central conclusion of B&Z is the one that 9/11 truthers find most irksome. The main argument has therefore been whether E1>E2 is a true statement, because truthers can't seem to figure out that, even if it were true, E1<E2 does not imply E1<E3; Tony Szamboti among others is a master of this fallacy. However, Bazant is defending the claim that E1>E2, because if that is established then no further analysis is necessary to prove that the collapse was self-sustaining. And that, in a nutshell, is the limit case.

Major Tom, meanwhile, is up in arms because Bazant has not addressed the question of whether E4=E3, and claims that this demonstrates intellectual dishonesty on the part of Bazant. Since the very existence of the term E4 is never more than vaguely implied in Bazant's work and is not necessary to its most important conclusion, this seems an untenable claim by MT.

(Menawhile, CC is implying that E3>E4 from the collapse time, which is a most interesting result if valid; it strongly suggests some other mechanism than ROOSD.)

Dave

Neat summary Dave - covers my "Stage 1" - and ventures into some of the "heresies arising" esp T Sz.

There is a tenable core in M_T's claim but his vagueness is where he and I part company. I wont back the untenable bit(s) as you know. Nor have I ever accepted his global assertions about dishonesty - that is one of the reasons I keep repeating explicitly that I only support those of his core technical assertions that are correct. The rest of his style and dubious global logic I abhor. And I don't see his behavioural psychology as a profitable area for discussion.

And - yes - CC's potential side track is interesting BUT he still has to make it fit the observables. To do that he needs to flesh out a complete and coherent hypothesis. Best of luck to him with that.

 

[JSanderO]

Ozzie,
It seems like some fellas can't seem to see that Mr B et al's work re the twin towers though "scientifically sound" explains nothing that anyone needs to know. It's a diversion and a derail from what ACTUALLY happened. You see it, I do, Tom and perhaps others do. But the "usuals" can't let go with their limit case "excuse" as its relevancy.

You have give NIST some back door credit.. they use the term something like... global collapse was inevitable or ensued.... which goes to the issue of settled engineering... you over load slabs in a high rise and they fail, fall crush, fracture and a high rise with slabs on the loose is not going to stand. This likely will destroy bracing and make columns unstable... They should have identified and explained... but used "global" which did not help.

CC's ideas are not terribly different in type that Greening's latest... lots of assumptions... little to no data. Not sure of how the fuel air blasts are destroying the building... because it appears to be a progress downward moving gravity driven... wave of destruction.