Burden of Proof

[T.A.M.]

I dunno. I get the impression he is just an undecided, favoring Woo at this point, who got lumped in with the hardcore Wooers and is feeling ganged up on.

TAM

 

[Dave Rogers]

A few more thoughts on the futility of modelling the collapse

I know this is tangential to the OP's original point, but it does have bearing on how much burden of proof the USG can and should take on.

Firstly, it's been said that the intelligent engineer uses the simplest technology that will suit his purpose. In modelling terms, this means that there is no point in using a more complex model than is required to give the information needed. The simplest models of all are analytical models which can be solved mathematically, not requiring a computer model at all. What has been argued elsewhere in this thread is that simple mathematical modelling of the energy dynamics of the collapse makes it certain that virtually total collapse will occur, so there is no need for a more complex model that will add no useful data to that result.

Secondly, it's not necessary even to use much maths to demonstrate that complete collapse will occur. If the falling weight is enough to break the first set of floor supports, then for the collapse to be arrested requires that at some later point the kinetic energy of the falling mass be less than at the first impact. Since at every impact the weight of a floor is added to the falling mass, and at every impact the falling mass is not brought to a complete stop, for the collapse to stop at any subsequent point means that material be ejected from the collapse zone faster than it builds up within it; in other words, the impact of each floor throws out more than a whole floor's worth of material. To suggest that material is ejected sideways faster than it accumulates is patently absurd, so it follows that the collapse propagates all the way to the ground.

Finally, the only reason to carry out a full numerical simulation of the collapse would be to convince conspiracy theorists that such a collapse was possible. However, from the observed behaviour of conspiracy theorists, this would be completely futile. Any simulation that failed to predict minor details of the collapse - for example, if it were shown to eject columns far enough to strike WTC7 but the actual simulation used did not show specific columns actually striking the buildings - it would be attacked as an oversimplified model that failed to predict the results. Conversely, if a sufficient range of simulations were done, probably at astronomical cost, that yielded some results in which ejected columns struck WTC7, it would be argued that the choice of starting parameters was too narrowly constrained in order to fit the observed results, in other words the simulators cheated. (Response to strawman accusations: both these criticisms have been specifically addressed to the NIST model, which is therefore accused of being simultaneously over-simplified and over-constrained.) Even if the simulations showed that collapse was inevitable and that damage to WTC7 was a near certainty, the conspiracy theorists could still retreat to the position that proving the possibility of gravitational collapse does not disprove controlled demolition.

The last point, really, is the crux of the argument. Does the government have the burden of proof to a reasonable person, who is required to assess arguments without prejudicial bias? Or does it have the burden of proof to a person who is determined to reject any proof that is supplied? And how could it possibly meet the latter burden of proof?

 

[gumboot]

This is an excellent point. The WTC collapse isn't entirely a chaotic system, per se, but only in the sense that it can only evolve in one direction (downward) and thus doesn't have a well-defined attractor. It is an example of deterministic chaos in that its final state is not truly random, but involves so many interactions that it cannot be precisely predicted.

By definition a chaotic system is entirely deterministic and nothing in it is random. Actually the WTC collapse is a perfect example of Chaos Theory.

-Gumboot

 

[gumboot]

I know. We don't know much about them, not that I got a problem with that. Well, I do have a problem with that. But thats totally understandable and tolerable. The folks who should have done us the favor to provide more answers was the 9/11 Commission, and congress.

I appreciate your position, I just don't see that the US Government has a responsibility to reveal every aspect of a criminal investigation that is, need I remind you, still ongoing. One day when the perpetrators of 9/11 are all confirmed dead or locked up, we might get a definitive final account of the attacks. But until then, any criminal-related information is going to be nothing more than a stop-gap to keep the detractors quiet.

I know there's no stopping to the upper forces. What i doubt is a total collapse. Part of the intact building below could have resisted, since that debris didn't simply fall 90 degrees straight down. much was peeled away, and ejected away. So when the collapse wave is down to the 30th, 20th, there shouldn't be enough energy to keep demolishing the floors down. It's like there was no core columns at those points either. The collapse wave went straight down on both towers, no matter what the starting mass was.

I don't actually argue that the bottom of the towers was entirely "crushed" by the upper floors. You have to remember a building is a relatively fragile structure. I know the JENGA analogy is not a fantastic one, but when you pull out the blocks, and the entire thing collapses, it isn't because the bottom is crushed by the top. All of the blocks remain individually intact, and much of the upper area will fall "outside the footprint". But what happens is the shift in structural balance is catastrophic. The ENTIRE STRUCTURE becomes undermined, and fails as a result. It's Chaos Theory in action.

Thus is the WTC collapse. If we keep it simple and look only at the three basic structural componants - floor trusses, core columns, and exterior columns - each of these componants relies on the other two to maintain structural integrity.

Now, we saw the exterior columns peel away, so that explains their structural failure. As we saw, large sections of the exterior columns DID remain standing after the collapse - some collapsing later and some being torn down.

Now, the floors, structurally, are the weakest of the three componants. Light weight trusses, held by bolts. They also contain most of the live load in the building and have the largest horizontal surface area. As such, in a collapse, they're going to take the brunt of it. If the exterior columns fail, can you truely expect a floor truss to remain in place, one end bolted to the core whilst the other end hangs in space, and debris crashes on top of it?

Of course not. The trusses will fail. And they did. Indeed, if eyewitnesses are to be believed the truss failure accelerated and actually moved ahead of the exterior column failure. The structure became a giant chute, funnelling the debris downwards, ripping the lightweight trusses from their columns to add to the debris. The exterior columns, peeling from above and now without the rigidity supplied by the trusses, continue peeling outwards.

That leaves the core. The strongest of the three. Are we surprised that huge sections of the core (as much as over half the building) remained standing after the initial collapse? I'm not. But consider the enormous forces they were exposed to. Are those core columns actually designed to stand 200m straight up on their own? Of course not. There's no way a column that high will stand without support. So they fail as well. And then you have no building.

Ok. Gotta ask some New Zealand natives to help us out here. Our scientists from NIST could use their knowledge.

I'm sure the scientists at NIST are well aware of the nature of underground fires.

But that goes along with many other things that CTers, LIHOPers, LIHOIers doubt as well, you know. We may be discussing "why do I think they should have investigated the collapse" right now, but few here have brought up their opinion to why the 9/11 Commission Report also didn't talk about the warnings, the few NORAD drills as you know, the molten metal, any other foreknowledge issue known out there that I didn't mention before... like Mineta's testimony (which has just recently been further confirmed to be more reliable due to early white house evacuation), and that's been called by the commission itself! Why didn't the commission follow up that lead? Or the ISI lead? The money trail? list goes on of what they didn't investigate... I know other agencies did, which is how we might have got some answers over time, but case stands that the 9/11 Commission didn't follow up by itself.

For most of the things above the commission DID address them. They simply didn't address them to the Conspiracy Theorists' satisfaction. Which is another way of saying the conspiracy theorists rejected or ignored what they had to say because they are woo-woos who won't believe anything that contradicts their pet stupid little theory.

On other aspects, such as the molten steel, it's not important, and not worth studying. Indeed in many cases the ONLY reason CTers cling to things like molten steel is BECAUSE they weren't looked into (rather than because they're important).

In the example of the ISI/money connection there's a number of theories.

1) The operation cost so little in relation to access the terrorists had that it wasn't a vital componant of the investigation.
2) The money trail points to Pakistan and support from Pakistan is going to be essential in order to capture Al Qaeda in Afghanistan, so we don't want to piss them off.

I'm sure there's others.

Personally I think it's a bit of both.

If I change "government" to "9/11 commission that whole paragraph would make more sense. I would have done so had I reviewed it at all.. darn. But I get your point. It's all a matter of opinion whether you think they're being dishonest or ignorant up to this point. Simply because there's only a handful of direct evidence which directs to willful omission or distortion, if anything at all. And even those can be dismissed as ignorant mistakes. Literally everything they report can be brushed aside as misinformation or error in communication between second hand informants or whatever.
A funny saying about the government I heard before, goes something like "Working for the government means never having to say you're wrong". I forgot how it goes exactly.

I think it's "Censorship means never having to say you're sorry". At least that's the original version. No doubt people have adapted it.

I think Americans especially are often too quick to assume the worst of people. For example the 9/11 Commission concluded that NORAD intentionally lied to them in their initial report. They base this argument entirely on the assertion that there's "no way" NORAD commanders could still be ignorant of what the NORAD response to 9/11 was, several years later.

I personally dispute this finding. Firstly, it's entirely illogical for NORAD to lie about what they did, considering that they essentially made themselves look far worse than they actually were.

Secondly, I find it highly plausible - especially given what NORAD were doing after 9/11 - that NORAD staff never sat down and listened to the hours and hours of audio recordings from NEADS and tried to make sense of it.

I would imagine that NORAD were grossly understaffed post-9/11 and didn't have the opportunity to conduct a formal in-depth analysis of their response.

They do when they're properly requested to.

I think once the criminal investigations and NIST investigations etc. of 9/11 are concluded, the government would be able to release an official report detailing what happened. The problem is the relatives wanted a report NOW. Hence the 9/11 commission. It was really just to shut the relatives up and leave the government alone so they could get on with their investigations and vengeance.

-Gumboot

 

[Yurebiz]

So here is a question.

If the towers had collapsed in, lets say, 25-30 seconds, do you think the majority of truthers would be asking for the collapse itself, beyond initiation, to be investigated?

You see I do not buy the idea that most truthers feel the collapse itself needs investigation simply because it is something that a "thorough and complete" investigation should have addressed. The MAIN reason they whine about no study of the collapse itself is because they cannot get their heads around the "near freefall" collapse time...plain and simple.

TAM

Probably not. A 20 second collapse would be enough to shut most CTers advocating CD. Free fall speed is the most used argument as you know.
Yes that last paragraph sums it up. Agreed. Thought it's not only because of the speed but some other minor things like ejection, 'underground fires', explosions, etc. But yeah i'd say the speed supports about 75% of the CD theory.

Yurebiz sounds like he is just talk vs facts on 9/11. Could he be the David Ray Griffen of JREF; a free version? Anyone find any facts, evidence, or sign of intelligent thought in his posts? (As interrelated to 9/11)


Or is yureeebizzz a kind of random generator of posts based on nonsense responses to our inputs. Just a computer program. I use to have a program that talked to me just like this but it made more sense. That was in the 80s and 70s.

Added; I bet I will not be seeing any numbers or real answers to my questions. Just talk. Yure, you could get a physics teacher to help you.

I'm a name-mining bot, yo! I get your names, google em up, and put your personal information in a CTer black-list! I don't need no facts to lure you in my threads, mwahah.

I dunno. I get the impression he is just an undecided, favoring Woo at this point, who got lumped in with the hardcore Wooers and is feeling ganged up on.

TAM

I always get ganged from every side! Well not really. Only in my imagination. But still, it hurts! Damn voices.

I know this is tangential to the OP's original point, but it does have bearing on how much burden of proof the USG can and should take on.

Firstly, it's been said that the intelligent engineer uses the simplest technology that will suit his purpose. In modelling terms, this means that there is no point in using a more complex model than is required to give the information needed. The simplest models of all are analytical models which can be solved mathematically, not requiring a computer model at all. What has been argued elsewhere in this thread is that simple mathematical modelling of the energy dynamics of the collapse makes it certain that virtually total collapse will occur, so there is no need for a more complex model that will add no useful data to that result.

Secondly, it's not necessary even to use much maths to demonstrate that complete collapse will occur. If the falling weight is enough to break the first set of floor supports, then for the collapse to be arrested requires that at some later point the kinetic energy of the falling mass be less than at the first impact. Since at every impact the weight of a floor is added to the falling mass, and at every impact the falling mass is not brought to a complete stop, for the collapse to stop at any subsequent point means that material be ejected from the collapse zone faster than it builds up within it; in other words, the impact of each floor throws out more than a whole floor's worth of material. To suggest that material is ejected sideways faster than it accumulates is patently absurd, so it follows that the collapse propagates all the way to the ground.

Finally, the only reason to carry out a full numerical simulation of the collapse would be to convince conspiracy theorists that such a collapse was possible. However, from the observed behaviour of conspiracy theorists, this would be completely futile. Any simulation that failed to predict minor details of the collapse - for example, if it were shown to eject columns far enough to strike WTC7 but the actual simulation used did not show specific columns actually striking the buildings - it would be attacked as an oversimplified model that failed to predict the results. Conversely, if a sufficient range of simulations were done, probably at astronomical cost, that yielded some results in which ejected columns struck WTC7, it would be argued that the choice of starting parameters was too narrowly constrained in order to fit the observed results, in other words the simulators cheated. (Response to strawman accusations: both these criticisms have been specifically addressed to the NIST model, which is therefore accused of being simultaneously over-simplified and over-constrained.) Even if the simulations showed that collapse was inevitable and that damage to WTC7 was a near certainty, the conspiracy theorists could still retreat to the position that proving the possibility of gravitational collapse does not disprove controlled demolition.

The last point, really, is the crux of the argument. Does the government have the burden of proof to a reasonable person, who is required to assess arguments without prejudicial bias? Or does it have the burden of proof to a person who is determined to reject any proof that is supplied? And how could it possibly meet the latter burden of proof?

OK let me see if I understand.
-Model is unnecessary because simpler models can prove total collapse.
-Significant debris ejection before accumulation is absurd.
-3D models that ejected too much as to be able to hit WTC7 would have been arguably exploited
-3D models that don't eject too far or too much would be called irrelevant to the actual collapse witnessed. Especially if the'res no debris hitting WTC7

Before I make any attacks on ya I'd like to know if I got those points right from your opinion. Thanks for your input btw.

My opinion in 3D models is.. again..
If it's so simple to prove total collapse through analytical calculations, then why couldn't a 3D model confirm it's indeed possible? I can see the argument that it's not necessary, but not even possible? To anyone who wants to answer: Do you think it's impossible to emulate the collapses of the twin towers with 3D modeling, correlated with the available evidence of 300ft radius steel beam ejections, and 11 second complete collapse, given only the estimated (worst case scenario or not) of fire+crash damage by the NIST?

I appreciate your position, I just don't see that the US Government has a responsibility to reveal every aspect of a criminal investigation that is, need I remind you, still ongoing. One day when the perpetrators of 9/11 are all confirmed dead or locked up, we might get a definitive final account of the attacks. But until then, any criminal-related information is going to be nothing more than a stop-gap to keep the detractors quiet.

I hope so.

I don't actually argue that the bottom of the towers was entirely "crushed" by the upper floors. You have to remember a building is a relatively fragile structure. I know the JENGA analogy is not a fantastic one, but when you pull out the blocks, and the entire thing collapses, it isn't because the bottom is crushed by the top. All of the blocks remain individually intact, and much of the upper area will fall "outside the footprint". But what happens is the shift in structural balance is catastrophic. The ENTIRE STRUCTURE becomes undermined, and fails as a result. It's Chaos Theory in action.

Thus is the WTC collapse. If we keep it simple and look only at the three basic structural componants - floor trusses, core columns, and exterior columns - each of these componants relies on the other two to maintain structural integrity.

Now, we saw the exterior columns peel away, so that explains their structural failure. As we saw, large sections of the exterior columns DID remain standing after the collapse - some collapsing later and some being torn down.

Now, the floors, structurally, are the weakest of the three componants. Light weight trusses, held by bolts. They also contain most of the live load in the building and have the largest horizontal surface area. As such, in a collapse, they're going to take the brunt of it. If the exterior columns fail, can you truely expect a floor truss to remain in place, one end bolted to the core whilst the other end hangs in space, and debris crashes on top of it?

Of course not. The trusses will fail. And they did. Indeed, if eyewitnesses are to be believed the truss failure accelerated and actually moved ahead of the exterior column failure. The structure became a giant chute, funnelling the debris downwards, ripping the lightweight trusses from their columns to add to the debris. The exterior columns, peeling from above and now without the rigidity supplied by the trusses, continue peeling outwards.

That leaves the core. The strongest of the three. Are we surprised that huge sections of the core (as much as over half the building) remained standing after the initial collapse? I'm not. But consider the enormous forces they were exposed to. Are those core columns actually designed to stand 200m straight up on their own? Of course not. There's no way a column that high will stand without support. So they fail as well. And then you have no building.

I buy your words gumboot, but we have yet to see a model that includes all that it's said over and over again. For the toal collapse we seen, we need:

-Trusses breaking from most central core joints from around the 80 floor to the ground, as to leave some core columns standing after the collapse.
-Trusses pulling down the exterior columns, but also ejecting a few 300ft away, at random points.
-Trusses disconnecting from external columns near the last floors close to ground level as to leave some external columns. The floors keep going till the basement levels.
-Floors stack thanks to pancake? Well never mind that, we saw almost no pancake evidence, so yeah, there can't be pancaked floors. gotta be a mess at the bottom
-All under 11 seconds.
-Upper block leaning also. Don't forget about that!

Now that may be easy to convey mentally for you people, each sequence analyzed separately, but it's gotta take a lot of work to put all in the same 3D simulation.
I say if we were to model a fire+damage total collapse, it would be far more simple if we weren't bond to so much chaotic events.
I can't refute total collapse didn't happen, because it did, so sorry about that line. Whats in debate (it shouldn't be in debate in this thread but whatever lol) is whether fire+plane crash was the sole agent. NIST can't model their collapse hypothesis, because they weren't asked to. They just say what you say; I can't take your word for it either. I reckon it's a good one though. And it's the most likely, comparing it to CD or mini-nukes for example. I just feel it was too systematic to have happened within the chaotic mess we've watched times and times over.

I'm sure the scientists at NIST are well aware of the nature of underground fires.

http://video.google.com/videoplay?docid=-7180303712325092501&hl=en

I know you seen this before. I think.

For most of the things above the commission DID address them. They simply didn't address them to the Conspiracy Theorists' satisfaction. Which is another way of saying the conspiracy theorists rejected or ignored what they had to say because they are woo-woos who won't believe anything that contradicts their pet stupid little theory.

On other aspects, such as the molten steel, it's not important, and not worth studying. Indeed in many cases the ONLY reason CTers cling to things like molten steel is BECAUSE they weren't looked into (rather than because they're important).

In the example of the ISI/money connection there's a number of theories.

1) The operation cost so little in relation to access the terrorists had that it wasn't a vital componant of the investigation.
2) The money trail points to Pakistan and support from Pakistan is going to be essential in order to capture Al Qaeda in Afghanistan, so we don't want to piss them off.

I'm sure there's others.

Personally I think it's a bit of both.

Thank you for your opinion. Yes those are possible reasons why. I don't buy em though.

I think it's "Censorship means never having to say you're sorry". At least that's the original version. No doubt people have adapted it.

I think Americans especially are often too quick to assume the worst of people. For example the 9/11 Commission concluded that NORAD intentionally lied to them in their initial report. They base this argument entirely on the assertion that there's "no way" NORAD commanders could still be ignorant of what the NORAD response to 9/11 was, several years later.

I personally dispute this finding. Firstly, it's entirely illogical for NORAD to lie about what they did, considering that they essentially made themselves look far worse than they actually were.

Secondly, I find it highly plausible - especially given what NORAD were doing after 9/11 - that NORAD staff never sat down and listened to the hours and hours of audio recordings from NEADS and tried to make sense of it.

I would imagine that NORAD were grossly understaffed post-9/11 and didn't have the opportunity to conduct a formal in-depth analysis of their response.

Thanks, NORAD sure has motives to hide what they did (or did not do). What troubles me is why didn't the commission try to investigate whats going on in there. Maybe some agencies are on it, who knows. Point taken nonetheless.

I think once the criminal investigations and NIST investigations etc. of 9/11 are concluded, the government would be able to release an official report detailing what happened. The problem is the relatives wanted a report NOW. Hence the 9/11 commission. It was really just to shut the relatives up and leave the government alone so they could get on with their investigations and vengeance.

-Gumboot

Sure thats valid as well. Thanks.

 

[Dave Rogers]

OK let me see if I understand.
-Model is unnecessary because simpler models can prove total collapse.

Yes, I'd argue that this is the case.

-Significant debris ejection before accumulation is absurd.

No, that's not my point. The idea that each impact ejects more debris than it creates is absurd.

-3D models that ejected too much as to be able to hit WTC7 would have been arguably exploited
-3D models that don't eject too far or too much would be called irrelevant to the actual collapse witnessed. Especially if the'res no debris hitting WTC7

I hypothesised a couple of specific instances, but the main point is that whatever results were produced by NIST modelling the collapse would be rejected by conspiracy theorists, because (a) they come from NIST and (b) they don't support controlled demolition.

Before I make any attacks on ya I'd like to know if I got those points right from your opinion. Thanks for your input btw.

On the whole I'd rather you debated my opinions than attacked me personally, but I hope that clarifies my opinions. I should stress that they are no more than opinions, I'm not a structural engineer.

My opinion in 3D models is.. again..
If it's so simple to prove total collapse through analytical calculations, then why couldn't a 3D model confirm it's indeed possible? I can see the argument that it's not necessary, but not even possible? To anyone who wants to answer: Do you think it's impossible to emulate the collapses of the twin towers with 3D modeling, correlated with the available evidence of 300ft radius steel beam ejections, and 11 second complete collapse, given only the estimated (worst case scenario or not) of fire+crash damage by the NIST?

I'm sure a 3D model could confirm that total collapse is possible. However, note that NIST's simulation of the plane impacts, if I recall correctly, required about a month to run a single simulation on a high-end workstation. The level of complexity required for a model of the collapse that would be sufficiently detailed to be worth doing would be far greater, and the cost would be correspondingly greater too. It's a lot of money to spend in order to confirm a result that isn't in significant doubt within the structural engineering community as a whole. Still, I'm not American, so it's not my taxes that'll pay for it.

Dave

 

[Pardalis]

I'm only questioning how open investigations were carried out by congress. and if they fulfill our doubts. I take the instance of CD CTer as to ask how much did the NIST explain about the collapses, and if that was enough to settle the questions.

What questions?

You see, the CTists only ask questions but they don't want the answers. It's the same thing as the moon hoax CTists and the JFK CTists, these people want a conspiracy. They are not interested in the real answers, because they already have made up their minds about it. They are incredulous, and distrustful of any authority, so they'll never accept any answers that are given to them.

Most of them never even read the NIST report, and if they did, they don't even understand it. They are just anomaly hunting, they base their 'questions" on bad science and discrepencies that are easy to explain if you just stop a second to think about them logically and critically. Their entire doubts are based on misinterpretations of facts, quotes put out of their context, and sometimes flat-out lies. We've heard time and time again the same questions about Mineta, the "molten metal", the "free fall" idiocy. None of these questions have merit to begin with.

The question is, what exactly motivates your doubts?

Is it incredulity, hatred of Bush and CO, denial, fear or pride to admit you were wrong?

You see, none of these are critical thinking.