Use of Scale Model or Full Sized models for investigating 9/11 collapses

[Mick West]

This is not false equivalence, but let's leave that to one side. You appear to be saying that you understand something that is simple in principle yet too complex to represent experimentally, even in simplified form.

It's not too complex. It's just the specific examples are very complex, being very large buildings with lots of parts. There's just no perceived need to spend the money on making high resolution models of the towers, seeing as it's quite evident to most people that the tower would progressively collapse.

And I don't think @econ41 thinks it can't be represented in simplified form, but I'll let him clarify that.

 

[econ41]

And I don't think @econ41 thinks it can't be represented in simplified form, but I'll let him clarify that.

I cannot explain it any clearer whilst Cube Radio simply ignores my EXPLANATIONS and reverts to BARE ASSERTIONS. About 12 of them in that post - all the on-topic relevant ones I have already explained in detail. The personal comments add nothing to discussion. I'm tempted to take his post assertion by assertion and once again repost what I have now actually stated several times.

Try this - the SECOND such example in his post where he ignores my several detailed explanations and reverts to his original unsupported bare assertion:

You appear to be saying that you understand something that is simple in principle yet too complex to represent experimentally, even in simplified form**. This is laughable***.

** Yes that is (a) what I have said several times AND (b) what I have explained several times. Cube Radio does not address my explanations so I do not know if he is ignoring them OR simply doesn't comprehend. And - where I have been pedantically precise in defining what I am saying - he reverts to the writing style of vagueness and ambiguity including changing to words with different meanings.

*** "This is laughable" apart from the personal insult aspect - IF Cube Radio would tell me (or us) what he doesn't understand we could progress the explanation.

 

[benthamitemetric]

Please. You're not seriously attempting to pretend that modelling fire on the 96th floor is the same as demonstrating experimentally that the supposedly gravity-driven mechanic of the collapse of the towers actually exists on any day other than 9/11?

Where in any of my posts did I say that I was offering the paper I referenced to prove all of that? In fact, I stated exactly how I felt the paper was a useful contribution to the study of collapses. Notice how that explanation is nothing like your re-characterization. Hello, Mr. Strawman.

 

[Cube Radio]

It's not too complex. It's just the specific examples are very complex, being very large buildings with lots of parts. There's just no perceived need to spend the money on making high resolution models of the towers, seeing as it's quite evident to most people that the tower would progressively collapse.

My point is that you don't even have a model as low-resolution as psikey's to provide rudimentary experimental evidence for the existence of a phenomenon the cause of which you assert is "quite evident".

That is why you are reduced to using the appeal to popularity fallacy to support your assertion. What you think "most people" believe is irrelevant. What is relevant is that absolutely no people -- no people at all -- can demonstrate that the progressive, total collapse of a structure in any way representative of the Towers is experimentally reproducible.

It is notable that of all the people who lined up to slander psikey on this thread (mostly after he'd been banned from it) -- econ41, OneWhiteEye, jaydeehess -- not one was capable of making constructive criticism of his model. Everyone was keen to rubbish it but no-one could say how it might be practically improved to make it more representative of the phenomenon it was (at least according to its creator) designed to investigate.

That shows to me how little genuine interest these individuals have in the experimental validation of a phenomenon that has never been successfully reproduced in even the most simplified fashion by anyone, despite its significance and supposedly obvious cause.

 

[Mick West]

My point is that you don't even have a model as low-resolution as psikey's to provide rudimentary experimental evidence for the existence of a phenomenon the cause of which you assert is "quite evident".

Yes I do.

 

[Jeffrey Orling]

And one which more closely matches what happened to the the buildings. Well done Mick!

 

[Keith Beachy]

My point is that you don't even have a model as low-resolution as psikey's to provide rudimentary experimental evidence for the existence of a phenomenon the cause of which you assert is "quite evident".

That is why you are reduced to using the appeal to popularity fallacy to support your assertion. What you think "most people" believe is irrelevant. What is relevant is that absolutely no people -- no people at all -- can demonstrate that the progressive, total collapse of a structure in any way representative of the Towers is experimentally reproducible.

It is notable that of all the people who lined up to slander psikey on this thread (mostly after he'd been banned from it) -- econ41, OneWhiteEye, jaydeehess -- not one was capable of making constructive criticism of his model. Everyone was keen to rubbish it but no-one could say how it might be practically improved to make it more representative of the phenomenon it was (at least according to its creator) designed to investigate.

That shows to me how little genuine interest these individuals have in the experimental validation of a phenomenon that has never been successfully reproduced in even the most simplified fashion by anyone, despite its significance and supposedly obvious cause.

psikey model is not a valid model of the WTC; it did not act like the WTC did. We have the full up model on 911 destroyed by impacts and fire - his model did not match reality.
Mick's simple model is better. How does psikey's model the shell is lateral support for the core. Where is the sharing of gravity load by psikey's model? Where is the fact a floor in the WTC can only hold 11 more floors in psikey's model; when his washers total 12 or more on one washer, the washer has to fail.
Where is the model in the model of the system, core-floor-shell, the WTC is a system and the floors are the key to holding the WTC system together.

We already know why the WTC collapse as it did, a model is a waste of time; save education.

Once you understand the WTC is a system, shell-floors-core, you can understand why Leslie Robertson was not surprised how his structure failed on 911, he already knew why it collapsed as it did; he is what you might call the expert.
https://www.nae.edu/Publications/Br...ecurity/ReflectionsontheWorldTradeCenter.aspx
https://www.nae.edu/File.aspx?id=7345
Why can't AE911T, Gage and company, get Leslie Robertson on board for the conspiracy theory of CD.

 

[Cube Radio]

Yes I do.

Mick, your three-floor construction here doesn't represent three dimensions, still less support itself: it's a much lower-resolution model than psikey attempted.

I've asked the people on the thread what an acceptable level of simplification might be if a model of the phenomenal collapse of the Towers were to be attempted -- but for me a self-supporting three-dimensional structure would be an initial requirement.

We have the full up model on 911 destroyed by impacts and fire - his model did not match reality.

You have repeatedly attempted to argue that an event which has never been experimentally modelled is in itself an experimental model of itself and therefore experimentally modelling the event is unnecessary.

This argument really does rather typify the question-begging level of discussion here, and that's why I don't visit Metabunk much.

 

[Mick West]

Mick, your three-floor construction here doesn't represent three dimensions, still less support itself: it's a much lower-resolution model than psikey attempted.

It's one more dimension that psikey used, as his dowel is the exact equivalent of my board, except constraining movement in the full horizontal plane. And how are you measuring the "resolution"? How is a ring of paper and a washer per floor "higher resolution" than four jenga blocks, two horizontal supports, and taped "seats"?

 

[econ41]

It's one more dimension that psikey used, as his dowel is the exact equivalent of my board, except constraining movement in the full horizontal plane. And how are you measuring the "resolution"? How is a ring of paper and a washer per floor "higher resolution" than four jenga blocks, two horizontal supports, and taped "seats"?

The fault with psikey's model is even more fundamental than that. Psikey's model mimics the wrong mechanism.

Your model Mick correctly shows floors stripped out and unbuckled columns free to topple over but otherwise undamaged. EXACTLY what happened in the main driving mechanism of the three sub mechanisms involved.

psikey's model requires crushing of the columns - the vertical supports he models by the paper loops. EXACTLY what DID NOT happen. And a point that OneWhiteEye and I have explained to psikey in full detail on at least two other forums. All those explanations already posted on this forum for CubeRadio to consider..

Psikey's version of your jenga model would require that the vertical blocks be crushed end for end.

AND I note K Beachy's correct observation. We have records of the best model there is. TWO examples of the real thing. Unless there is a defined need to model some part of the overall process the prototype event is always better than scale modelling. The suggestion that somehow a scaled model is better than the real thing is not credible EXCEPT when there is a clearly defined and justified need to test or trial some aspect of the real event. There is no such defined need and in previous posts I have identified the range of criteria involved for such a justification.

 

[jaydeehess]

Well psikey's model does not represent anything that was occurring in the towers, most certainly not any mechanism that was identified as the probable driver of global collapse.

We've been through this before.

 

[econ41]

We've been through this before.

Yes - several times here for CubeRadio and many times econ41/ozeco41 and OWE/KD DIRECT interaction with psikeyhackr on other forums. Not sure the depth of your involvement but you are aware of those other interactions on at least one other forum we attend.

 

[jaydeehess]

Yes - several times here for CubeRadio and many times econ41/ozeco41 and OWE/KD DIRECT interaction with psikeyhackr on other forums. Not sure the depth of your involvement but you are aware of those other interactions on at least one other forum we attend.

https://www.metabunk.org/threads/us...-for-investigating-9-11-collapses.3828/page-3

round round we go

 

[econ41]

https://www.metabunk.org/threads/us...-for-investigating-9-11-collapses.3828/page-3

round round we go

Time for the "Earwiggo Song"


Earwiggo round the mulberry bush....

And we still have regressions to putting those columns back in line. They were not in line.

 

[Marcel Prout]

Mick, your three-floor construction here doesn't represent three dimensions, still less support itself: it's a much lower-resolution model than psikey attempted.

I've asked the people on the thread what an acceptable level of simplification might be if a model of the phenomenal collapse of the Towers were to be attempted -- but for me a self-supporting three-dimensional structure would be an initial requirement.

What kind of resolution would you need? If you want 3D, imagine Mick's model applied to the other columns and floors of the WTC. The principles represented in the model already make sense. Models are as good as models go, you can model a principle but not reality because you never know what will truly happen. Models exist solely to approximate reality, not replace it, if your model doesn't fit what happens in reality, then maybe it is your model that needs to be checked rather than reality.

Besides, you seem already pretty OK with psikey's model, what's the need to ask for another model if you're already sold on that one? The scientific method is not only modelling and reproducibility of experiments, but it is also always being open for critical thinking and consider arguments that don't fit in your way of thinking. Consider Mick's model and consider psikey's model, what are the differences? How come they don't get the same results?

 

[Cube Radio]

The suggestion that somehow a scaled model is better than the real thing is not credible

Please indicate exactly where this suggestion has been made on this thread, or consider yourself exposed in the act of creating a straw man.

 

[jaydeehess]

Please indicate exactly where this suggestion has been made on this thread, or consider yourself exposed in the act of creating a straw man.

You are probably correct in that.

Lets deal with something demonstratable, one can point out that on this page you asked something , again, that was addressed on page three of this same thread.
One wonders why, or am I also building a strawman.

 

[Cube Radio]

These videos represent something of what I would expect from a modelling effort that explains how the Towers collapsed so completely. Those on this thread who have insisted that the Towers were somehow themselves experimental models of themselves and therefore don't require modelling do make an accidental point with such nonsensical arguments: the fact that it happened twice, despite very different impacts, means it should be reproducible in a model with quite different inputs.

I say these videos represent something of what I would expect but I do not suggest that these models are sufficiently accurate -- or sufficiently verifiable -- to convince anyone on this forum: added to which, neither of them even vaguely support the official collapse theories everyone here (apart from me) clings to with such craven, desperate belief. So I'm sure people here will rush to criticise them (without being able to suggest how they might be made more accurate, of course).

These videos are basically made with games. However they represent the scale and detail of modelling that I think would be required to achieve a simplified but acceptable model that, if its input data was available, could be convincing.

If only there was a debunking website -- run by an ex-computer games programmer, perhaps -- and a free software physics engine for them to use to model the Towers collapsing -- without the need for explosives or accelerants, of course. They'd probably be able to debunk pretty much the entire 9/11 Truth movement's take on the Towers in a couple of weeks if they put their mind to it. Oh well.

 

[Mick West]

They'd probably be able to debunk pretty much the entire 9/11 Truth movement's take on the Towers in a couple of weeks if they put their mind to it. Oh well.

The problem here is that the 9/11 Truth movement's take on the towers has already been debunked multiple times. What's lacking is an effective way of convincing you that this is so. I find this a very interesting problem.

Suppose I were to take one of those models and tweak the constrains, sizes, and masses until it collapsed more like the WTC towers. Would that help? I don't think so.

Do you follow the argument here, that the mechanism of collapse is not one solid block crushing another, but is a falling mass of thousands of tons of rubble stripping away floors leaving columns unsupported so they fail at their connections largely without bending?

 

[Mick West]

This is a very interesting set of simulation I'd not seen before (that I remember):

 

[Keith Beachy]

These videos represent something of what I would expect from a modelling effort that explains how the Towers collapsed so completely. Those on this thread who have insisted that the Towers were somehow themselves experimental models of themselves and therefore don't require modelling do make an accidental point with such nonsensical arguments: the fact that it happened twice, despite very different impacts, means it should be reproducible in a model with quite different inputs. ...

Those models failed to model the fact a floor can only hold 29,000,000 pounds. Then it failed to model the fact without a floor, because the floors failed instantly when the mass above exceeded the floors capacity, the system, core-floor-shell was compromised leading to complete failure as long as enough mass was falling on floors below. Thus the momentum model, a simple math model reflects the movement of the WTC towers collapse.

As for full up models being models of what the WTC would do in fires like 911, they are. We, including engineers, do model to gain insight on what can happen, not what will happen, like a prediction. With exactly how two full up models acted on 911, we don't need to model the WTC collapse, we have it on video, and the result.

What people who believe in CD on 911 need is not a model, but evidence it was CD. There is no evidence, never will be because there was no blast damage on any steel, no thermite damage on any steel. How do we know, because engineers were picking out the most unique damage to steel on 911, and the trying to find steel at the impact zones. How do we know no CD, not a single blast from explosives, not a single gram of product from thermite. We also know exactly how aircraft impacts would damage the WTC, both by physics, and by photo evidence. We also know the WTC was built up to the codes that were required.

The one reason the WTC collapse continued, is due to a floor only holding 29,000,000 pounds; in the cartoons in the videos, the floors would fail when debris exceeded the capacity of a floor, but the model was not correct, it was not a model of the WTC towers.

How do you model the towers? The core of the towers can't stand without the floors and shell. And a floor can only hold 29,000,000 pounds. When you model the floors failing at 29,000,001 pounds, then your model will match 911; or you can use the models on 911, two full up models. As 911 truth has found, only 0.1 percent of all engineers fall for the conspiracy based on silent explosives and no product thermite. Steel fails in fire, fails quickly, this is why firefighters are killed in steel framed buildings due to collapse, and why we leave building of fire.

The massive strength of the WTC towers to stand in hurricane winds and hold up so much weight was based on a system of shell, floors, and core. The weak point is the fact a floor fails at 29,000,000 pounds. Model the floor failure and understand the collapse. In fact, what I just said is the model, and why we see what we see. I have modeled the WTC with one simple fact, the failure of a floor. There is no way the floor below the impact area can hold the mass of the top of the WTC as it fails due to fire, the floor fails, then the mass hits the floor below. At the same time the shell has no support, and the core has no support, each begins to fail due to the mass collapsing. We see the floors failing on 911, as ejections of subsonic air, not explosives, are seen.

You can do the momentum model to see how fast the WTC falls, and it will match the initial collapse speed of the WTC. It is simply floors failing as the WTC above falls on floors below. This is the model, mass falling, destroy floors, destroying the WTC system of shell-floor-core as it goes. I just modeled the collapse in my head, and it does not match the cartoon effort of people who are not capable engineers, and did not model the WTC. How can you show models which floors don't fail when the upper mass is greater than the capability of the floor?

 

[Oystein]

Pontifex and Blender are essentially games. The models presented have some design features in common with the WTC towers, but many not. In particular, I am missing floor joists; and there's little to no realistic pre-collapse fire-damage. I see no reason to assume that the specifics of the structures - individual strenths and loads to members and nodes - represent reality in any way approaching fairness.

So at best these models can show concepts. It's better when they show behaviour that was actually observed - that might improve our assessment of the plausibilty that such behaviour was "natural". Apply great caution! The reverse case - model not showing observed behaviour - however would not affect assessment of plausibility as long as the model differs in many obvious ways from reality. GIGO.

 

[Mick West]

Pontifex and Blender are essentially games. The models presented have some design features in common with the WTC towers, but many not. In particular, I am missing floor joists; and there's little to no realistic pre-collapse fire-damage. I see no reason to assume that the specifics of the structures - individual strenths and loads to members and nodes - represent reality in any way approaching fairness.

So at best these models can show concepts.

Indeed, and I was showing that firstly because it's a simply opposite of Cube's videos. But I think it's a little more interesting in that some attempt was made to model the actual situation, rather than just the visuals. I also found it interesting how the Pontifex software showed the transmission of forces through the structure - something that seems to be modeled more accurately here than in the simple emergence of the Blender models.

It is still a relatively simple model though. But what it does do is show something that is more like that actual mechanism of collapse. I would be interested to hear Cube's thought's on this model.

 

[Cube Radio]

In general Mick I am unimpressed by models that represent only a few floors of the collapse. My point is that no-one has ever been able to model the total collapse of the Towers. For the purposes of this thread I am happy to accept your mechanism of collapse if it can be modelled as a collapse wave completely destroying a structure representing the whole -- not a section -- of the buildings. This is because I would want to see the suggestion that the collapse wave would stop or decelerate debunked experimentally.

Oystein: I said these were games, so thanks for repeating that. What we are looking for is an acceptable degree of simplification. We can say with certainty that both Towers collapsed despite quite different impacts and fires (in terms of location and duration). This suggests that their structural vulnerabilities can be generalised to some degree in terms of reproducing the effect that destroyed them. If relatively simple models cannot be made to reproduce the collapse effect, then one move would be to increase their fidelity.

Keith Beachy: as far as I am concerned you are trolling the thread by repeatedly insisting that the Towers were "full up" models of themselves. We have video of weather, for example: this does not stop us from using computers to attempt to model its behaviour in an attempt to understand how and why it behaves in the way it does. The Towers were by many orders of magnitude simpler than the climate. I am not going to attempt to explain this painfully simple point to you again. The Towers were not models of the Towers. You are ignored.

 

[Efftup]

I think the reason MOST models only show a few floors is that for most people, it seems fairly intuitive that once one floor collapsed, the rest were going to go as well.
If floor 98's vertical beams give way, 12 floors are going to come crashing down onto floor 97. If this is enough to collapse floor 97, then 13 floors minus ejecta will come crashing down onto floor 96 and so on and so on.
for those who do not intuitively think it will continue to collapse, or for those who want a bit more than just intuition, an ACCURATE model of all 110 floors collapsing would be very nice.
But basically, unless MORE than a floor's weight is ejected in the space of falling one floor, then this chain reaction will continue.

IF you are using a model to try and prove a controlled demolition (that was unlike any normal controlled demolition) then you have a couple of problems.
1)IF you only use demolition to FORCE the collapse of the upper floors where the plane has hit (never mind knowing exactly where the plane would hit so as to plant charges on the correct floors) then the REST of the collapse, just like in any normal CD is GRAVITY DRIVEN. A normal CD will fire explosives ONCE and gravity does the rest.
In a scenario such as this, it makes NO DIFFERENCE whether the collapse of those supports has been caused by TNT, verinage, fire weakening the steel or Hollywood nanobots, the rest of the collapse will happen exactly the same either way, making the super accurate model completely pointless.

2) IF you are assuming that the collapse WOULD arrest if it was purely gravity driven, THEN you would have to have demolition devices on EVERY floor, with charges that go off when they feel the pressure of the floors above crashing down on them in order to ensure that the collapse would continue. This then requires a MUCH bigger, completely HUGE amount of special silent charges to blow each floor on the way down, and with that much involved, then surely there would have been some trace found.

This comes back to WHO the model is for, as has been mentioned many times.
If it's a pretty graphical video to show the layman the basic method of collapse, then the models we currently have are perfectly accurate enough.

If it's to try and show EXACTLY how the collapse happened which is a very complex event, involving far too many variables (If we can't know the wind speed and direction at every point in the building, we have no no way of knowing how part x would have fallen or rated with respect to part Y, so we have no way of knowing their exact interaction and whether that part would have ejected from the building, thus losing weight to contribute to the dynamic load.) then we have absolutely no way of actually modelling it accurately enough.
Even if we were able to build ANOTHER two WTC towers, AND destroy them to the exact same damage as per the 2 planes hitting ( an impossible task in itself), the ambient temperature and wind and distribution of people on each floor would still be different, so it would still not be exact.

 

[Mick West]

n general Mick I am unimpressed by models that represent only a few floors of the collapse. My point is that no-one has ever been able to model the total collapse of the Towers.

I think the reason MOST models only show a few floors is that for most people, it seems fairly intuitive that once one floor collapsed, the rest were going to go as well.

Yes it seems pretty obvious that this collapse is going to continue. The falling mass is increasing, and it's getting faster. How could it stop?

 

[Cube Radio]

"Most people" don't understand Newton's Third Law either, Efftup. What is significant to the topic of this thread is that not even the simplified physics engines of computer games support what Mick claims is "pretty obvious" about how and why the Towers collapsed in the way they did.

 

[Oystein]

"Most people" don't understand Newton's Third Law either, Efftup.

This includes David Chandler and everybody who parrots Chandlers invalid arguments when he invokes N3

What is significant to the topic of this thread is that not even the simplified physics engines of computer games support what Mick claims is "pretty obvious" about how and why the Towers collapsed in the way they did.

Hehe you MAY have this arse about: Perhaps it is BECAUSE those are "simplified physics engines of computer games" that they don't resemble reality faithfully

 

[Oystein]

Throwing in a suggestion for a "Full Size Model" test (or an appropriately scaled model; real world at any rate) that MIGHT please truthers and debunkers alike, if only AE911Truth would cough up the dough:

Remember that some truthers claim NIST ignored shear studs in their WTC7 fire response model; and that the girder between 44 and 79 could not have expanded the additional 3/4 "" that shows up in the errata.

I am currently reading Chapter 11.4.1 of NIST NCSTAR 1-9, which explains on page 526:

Review of the literature did not find much data that documented shear stud failure in composite floor assemblies subjected to fire. Fire tests of composite floor assemblies typically have the same, highly restrained boundary conditions for the floor slab and the steel floor beams. It is not likely that shear stud failures would be observed in Standard Fire Tests of floor assemblies since the beam is wedged tightly to the reaction frame and the concrete slab is cast against the frame, resulting in the condition where neither the beam nor slab can expand. Thus, there is no differential displacement between the beam and the slab, and no shear transfer.
If such tests had been conducted where the concrete slab was laterally restrained (representing the restraint of the surrounding slab) but the floor beams were allowed to elongate thermally with minimal restraint (representing the weak axis of the wide flange girder), the shear studs would likely have failed. The behaviour of composite floor assemblies when exposed to fire is strongly dependent on the boundary conditions and degree of thermal restraint imposed by the member connections and surrounding structure.

My bolding highlights the predicted result of a physical that has nit been conducted.

I suppose this would not require a full scale model, and could also be done with a smartly reduced assembly.

Showing the infamous girder-walk off might require a significantly larger and more comprehensive model, as this depends more critically on interaction with differentially heated elements on floors above and below and farther way from the immediate region of interest.

 

[Cube Radio]

Hehe you MAY have this arse about: Perhaps it is BECAUSE those are "simplified physics engines of computer games" that they don't resemble reality faithfully

No, it is you who have misunderstood. It seems to me that you have no interest in establishing what kind of reasonable simplifications could be made if the collapse of the Towers was to be modelled. You see: there are no models of the Towers -- or anything resembling their structure -- that can be made to collapse completely. This is despite the widely-held belief (which is to say, an item of faith that has no evidence to support it) exemplified by contributors here -- including yourself -- that the phenomenon that destroyed the Towers is essentially simple.

If there were a simplified model of the Towers that could be made to collapse completely I'm sure you would be satisfied with it. But there is not. If you think that the Blender physics engine is incapable of modelling reality in an acceptably simplified way I think you should explain what is wrong with it, and if you think the physics of the collapse of the Towers cannot be simplified I think you should explain why this supposedly easily-explained and well understood phenomenon cannot be modelled in simplified terms.

 

[Oystein]

No, it is you who have misunderstood. It seems to me that you have no interest in establishing what kind of reasonable simplifications could be made if the collapse of the Towers was to be modelled. You see: there are no models of the Towers -- or anything resembling their structure -- that can be made to collapse completely. This is despite the widely-held belief (which is to say, an item of faith that has no evidence to support it) exemplified by contributors here -- including yourself -- that the phenomenon that destroyed the Towers is essentially simple.

If there were a simplified model of the Towers that could be made to collapse completely I'm sure you would be satisfied with it. But there is not. If you think that the Blender physics engine is incapable of modelling reality in an acceptably simplified way I think you should explain what is wrong with it, and if you think the physics of the collapse of the Towers cannot be simplified I think you should explain why this supposedly easily-explained and well understood phenomenon cannot be modelled in simplified terms.

Still arse about.

I take the following two claims to be true:

1. You can design a tall model, or a tall real-world structure, that does not progressively collapse all the way to the ground
2. You can design a tall model, or a tall real-world structure, that does progressively collapse all the way to the ground

And you can do both with Blender, Pontifex, LS-DYNA or any other physics engine you like.

The challenge is to model a building that is sufficiently similar to any of the WTC towers and their accumulated structural damage just prior to main collapse sequence.

Then, a thousand models not exhibiting total collapse cannot prove it's impossible
But a single model exhibiting total collapse does prove it's possible.

Your challenge would be to show how the Blender sims you showed recreate fairly the WTC situation in significant ways. You can't of course, as both models are pbviously dissimilar to the towers in numerous ways. You have provided zero technical detail on typical nodes - what are the loads, and what are the capacities, at critical nodes in the model? Are those comparable to equivalent members/connections in the real towers?

One obvious way in which the Blender sim is unrealistic is: The columns and girders are way too brittle - none bend, but several fracture into several parts.

As beachy pointed out: The floors appear relatively much too strong - and of course they are subjected to impact from only 2-4 floors, instead of 15-30.

in short: There is no reason to believe the entire model and sim represent any realistic building at all. Please state and support your case with evidence if you think differently!

 

[Mick West]

"Most people" don't understand Newton's Third Law either, Efftup.

I think many people who claim to understand it in the context of WTC don't understand that it only applies to point masses. It's an abstraction. It can be only roughly applied to rigid bodies, which are themselves abstractions, as there are no true rigid bodies, and certainly not in a collapsing skyscraper.

What is significant to the topic of this thread is that not even the simplified physics engines of computer games support what Mick claims is "pretty obvious" about how and why the Towers collapsed in the way they did.

You are paraphrasing, what I just said was pretty obvious was that the collapse in the pontifex video was going to continue, and was in response to you saying there were not enough floors in the model.

And that model DID collapse. So why is that not significant?

 

[Keith Beachy]

No, it is you who have misunderstood. There are no models of the Towers -- or anything resembling their structure -- that can be made to collapse completely. This is despite the widely-held belief (which is to say, an item of faith that has no evidence to support it) exemplified by contributors here that the phenomenon that destroyed the Towers is essentially simple.

If there were a simplified model of the Towers that could be made to collapse completely I'm sure you would be satisfied with it. But there is not. If you think that the Blender physics engine is incapable of modelling reality in an acceptably simplified way I think you should explain why, and if you think the physics of the collapse of the Towers cannot be simplified I think you should explain why this supposedly easily-explained phenomenon cannot be modelled in simple terms.

Yes there are models which collapse completely, two full up models, and simple math models which match the collapse speed for the first part of the collapse. Knowing the floor to core to shell connections are the weak points, when a floor is overloaded to more than 29,000,000 pounds, as on 911, the WTC collapses. If we have more than 12 floors above the impact zone, as on 911, where fires are free to burn and destroy the strength of steel. We do not have to model the collapse after it starts, it will not stop. Simple logic based on what a floor can hold. The exterior fails as the accelerating increasing mass of debris busts up the shell structure. The core can't stand without the shell with floor connections. The shell is the lateral strength of the WTC.

There is no model of the WTC which will not collapse completely when you overload a floor as was done on 911. You can't build a model of the WTC which will not collapse completely when a floor is overloaded like 911. Finding fake models of the WTC on youtube and claiming no models collapse completely is no science, it is exposing people who are not engineers.

The simple model to prove WTC will collapse as seen is based on what a floor can hold and understanding the WTC is a system, as seen on construction. The WTC can't stand without a shell, a floor and core. Their is no stopping the collapse of the WTC due to the fact a floor can't hold a certain weight, and the collapsing mass of the WTC top is more than any floor can hold. To deny the WTC collapsed to the ground is implying a floor can hold more than 29,000,000 pounds.

I don't need to build a model, but I have, because the WTC floors fail when overloaded, and they do it instantly when the collapse begins. It is intellectual dishonesty to deny complete collapse once started with initial conditions seen on 911; after knowing how the WTC was built.

ROBERTSON: Yes, I do. I support the general conclusions of the NIST report. It was prepared, by the way, not just by NIST, but by a series of engineering firms around the country who provided advice and assistance to NIST in their investigations. It was reasonably thorough, amounting, as I recall, to about $16 million of effort. And our firm participated in a small way in providing information about the basic structure that was in fact constructed. It's a little more complicated than one might suppose, because there were a lot of modifications made to the structure as it was being built. That's rather normal – tenants have individual requirements – and so there was strengthening done for the most part here and there to achieve the needs of the individual tenants.

Here we have the big chance for the structural engineer of the WTC to support an inside job of CD; he can't, he knows fire did it, and he agrees in general.

Anyway, my model shows one of the WTC towers falling in 12.08 seconds. A simple model based on momentum and the fact floors fail instantly when overloaded. Anyone can do a model which will collapse like the WTC.

ROBERTSON: —This is a very robust floor system, rather different from that portrayed in the British press, but in any event—the other issue having to do with the failure mechanism, again, I've not performed an in-depth study on the matter, but I carried the event far enough along so that I became convinced that if you dropped the floors above onto the floors below, i.e., caused a collapse in the middle of the building some place, that without question, the collapse would continue, right down to the foundations. There's no way that the structure below would be able to carry, let us say 14 floors. Not possible, not even close to being possible. And it would not be a slow failure either; drop 14 floors on any one floor of that building and it would collapse instantly. Well, no, not "instantly"; that's a bad term. It would collapse ins—instantly as far as you or I would be able to perceive it.

The chief structural engineer for the WTC needs no model to understand the collapse of his building, he can model in his head with words, as can anyone who understands his structure.

The lower floors of the WTC do not hold up the upper floors of the WTC, the core and shell hold up the floors, all the floors. A floor does nothing but hold itself by connecting to the core and shell; the floors only hold the shell and core together.

Maybe 911 truth followers fail to realize a floor fails instantly and the only thing slowing down the collapse is the new mass added by lower structure which is at rest, slows the collapse based on momentum.

There is nothing stopping 911 truth from modeling the WTC collapse showing the towers will not stop collapsing. With over 2,000 engineers on board the truth CD inside job explosives and thermite train, the models should be flowing freely. (BS note which means nothing, I went to school and grad school to get my engineering degree and worked as an engineer, not one of the thousands I went to school with, or worked with believe in 911 truth claims of CD, explosives or thermite)

As an engineer since 1974, I find it ironic and self critiquing 911 truth ignores the real WTC towers, and can't properly model the collapse mentally, or otherwise. 13 years of nonsense from 911 truth, no competent models to support the inside job claims for a deed done by 19 terrorists with 4 aircraft.

http://www.nmsr.org/nmsr911a.htm

911 truth's best model,

is empty claims of explosives, thermite, and CD.

I don't think models are needed. Only an understanding of physics. As an engineer/soldier/citizen I would be the first to jump up and expose NIST, or other studies, or anyone who lied; it is 911 truth who has the lie of CD.
http://www.nmsr.org/nmsr911a.htm

Physics, math and logic are the only model we need to understand the WTC completely collapses given conditions of 911.

 

[Oystein]

...

ROBERTSON: Yes, I do. I support the general conclusions of the NIST report. It was prepared, by the way, not just by NIST, but by a series of engineering firms around the country who provided advice and assistance to NIST in their investigations. It was reasonably thorough, amounting, as I recall, to about $16 million of effort. And our firm participated in a small way in providing information about the basic structure that was in fact constructed. It's a little more complicated than one might suppose, because there were a lot of modifications made to the structure as it was being built. That's rather normal – tenants have individual requirements – and so there was strengthening done for the most part here and there to achieve the needs of the individual tenants.

Here we have the big chance for the structural engineer of the WTC to support an inside job of CD; he can't, he knows fire did it, and he agrees in general.
...

ROBERTSON: —This is a very robust floor system, rather different from that portrayed in the British press, but in any event—the other issue having to do with the failure mechanism, again, I've not performed an in-depth study on the matter, but I carried the event far enough along so that I became convinced that if you dropped the floors above onto the floors below, i.e., caused a collapse in the middle of the building some place, that without question, the collapse would continue, right down to the foundations. There's no way that the structure below would be able to carry, let us say 14 floors. Not possible, not even close to being possible. And it would not be a slow failure either; drop 14 floors on any one floor of that building and it would collapse instantly. Well, no, not "instantly"; that's a bad term. It would collapse ins—instantly as far as you or I would be able to perceive it.

The chief structural engineer for the WTC needs no model to understand the collapse of his building, he can model in his head with words, as can anyone who understands his structure.
...

And these quotes come from a thoroughly truthy source: The JoNES:
[Steven E.] Jones v. [Leslie] Robertson- A physicist and a structural engineer debate the controlled demolition of the World Trade Center
Annotated by Gregg Roberts, a ... business analyst.

 

[Cube Radio]

The challenge is to model a building that is sufficiently similar to any of the WTC towers and their accumulated structural damage

I think the challenge is to experimentally verify the theories of Bazant at al. As we know very different impacts and fires produced very similar collapses, one approach to modeling them would be to leave the precise details of the structural damage to one side, and simply "drop" the upper section of the model squarely onto the remainder. As I understand it this is pretty much what Bazant envisages.

Then the only question is how accurately the towers would have to be modelled if simplified versions fail to collapse, as people like you would always be able to pretend that the reason why they didn't collapse the way you think they should because they were too simple.

That would be nonsense because, as we have discussed, a collapse that has a mechanic you feel is simple must be capable of being simply modelled. However, to avoid people objecting that the model is too simple, I am trying to establish first what an acceptable degree of simplification might be.

When we've agreed that, I'll consider hiring Mick to build the model ;-)

 

[NoParty]

...I'll consider hiring Mick to build the model ;-)

That Mick has already taken the time to put together models...only to have certain people whine
that those models didn't do what they wanted...reinforces my belief that satisfying some folks'
endless questioning is a Sisyphean task: No model--no matter how redundant or expensive--will ever be enough...

 

[Oystein]

I think the challenge is to experimentally verify the theories of Bazant at al. As we know very different impacts and fires produced very similar collapses, one approach to modeling them would be to leave the precise details of the structural damage to one side, and simply "drop" the upper section of the model squarely onto the remainder. As I understand it this is pretty much what Bazant envisages.

Right.
With one qualification: I am not sure whether the aim is to "model Bazant". His first paper (Bazant & Zhou, 2002) was a VERY simplified 1D analytical model, a limiting case, done long before any detailed collapse initiation model was suggested. A Bazant&Zhou-like model would neither resemble the twins, nor would its collapse mechanics resemble the WTC collapse mechanics. Would that satisfy anyone who so far doubts the commonly accepted narrative for how the collapses progressed and make him accept it? Hardly.

But the approach seems reasonable: Model a reasonably reduced version of the WTC design.

E.g.: closely spaced perimeter columns with spandrels; joisted open office floors; core columns. A top part with hat truss weighing the equivalent of 15 floors; and several floors below collapse initiation level. Perhaps We don't need 240 perimeter columns, 80 might do. 15 instead of 47 core columns. But make sure relative load capacities and relative dimensions and distances of all sub-assemblies are true to scale. Then cut out one element after the next; this perhaps guided by observation of the real event, until a collapse ensues. Watch what happens.

Then the only question is how accurately the towers would have to be modelled if simplified versions fail to collapse, as people like you would always be able to pretend that the reason why they didn't collapse the way you think they should because they were too simple.

That would be nonsense because, as we have discussed, a collapse that has a mechanic you feel is simple must be capable of being simply modelled. However, to avoid people objecting that the model is too simple, I am trying to establish first what an acceptable degree of simplification might be.

I wasn't so much criticizing simplification as such - all modelling necessarily requires simplification. I primairly doubted that the Blender models were AT ALL true to scale and resembling actual high rise buildings, imn terms of propirtions, demand-to-capacity ratios, strength of subassemblies relative to each other, and material properties. Remember, Blender made some single columns shatter into several pieces, but never bend, as if they were made of glass and not of steel.

When we've agreed that, I'll consider hiring Mick to build the model ;-)

I totally lack the engineering skills to affirm that a model is "good enough" for the purpose stated, but I certainly can affirm for many models that those are NOT good enough - there are many ways of being very wrong, and relatively few of being right.

I don't recall - did Mick suggest a specific tool?

 

[Mick West]

I don't recall - did Mick suggest a specific tool?

I said:

Now I'm thinking I'll look into using Blender to build a model. While it's not engineering grade physics, it should suffice to demonstrate the principle of collapse, and how it varies with scale. It has scriptable constraints. But most of the existing models seem to be solid block type things.

The scriptable constraints thing is important because the collapse of the building seems more a failure of connections (splices, bolts, seats), not so much a failure of members (girders, columns).

 

[OneWhiteEye]

It is notable that of all the people who lined up to slander psikey on this thread (mostly after he'd been banned from it) -- econ41, OneWhiteEye, jaydeehess -- not one was capable of making constructive criticism of his model. Everyone was keen to rubbish it but no-one could say how it might be practically improved to make it more representative of the phenomenon it was (at least according to its creator) designed to investigate.

That shows to me how little genuine interest these individuals have in the experimental validation of a phenomenon that has never been successfully reproduced in even the most simplified fashion by anyone, despite its significance and supposedly obvious cause.

CubeRadio, as others have since pointed out to you, this wasn't the first barn dance with psikey we've had. econ41's interactions go back to 2007, mine to 2008/2009. These interactions involve many thousands of posts spanning multiple forums.

Contrary to what you claim, I've spent a great deal of effort analyzing psikey's experiment in depth, to the point where I could reproduce his model and results in software. See here and subsequent posts, from 2010:

[URL]http://www.rationalskepticism.org/post636274.html#p636274[/url]

After all that effort and explanation, what did psikey do? He ignored it entirely. See for yourself.

It pays to know of what you speak before you speak. You've made a number of incorrect assumptions about those arguing here with psikey and I'd like to know from you that you understand the nature of your error.

 

[jaydeehess]

In general Mick I am unimpressed by models that represent only a few floors of the collapse.

Quick, and serious, question.
Imagine a model of the lower 1/10th of a tall tree. The model then includes a notch on one side of the modeled section and then includes a cut through from the opposite side. The model predicts the tree tilts and wood fibres part. The model runs only until the tree has tilted a few degrees and stops. Do you take issue with a conclusion that the model predicts that theatres will completely fail and continue falling?