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

But I predict the even if it takes 50 years, there will still be no physicist or structural engineer who will have successfully modelled the fast, destructive collapse of a high-rise tower using a virtual model even approximately representing the twin towers by then.

Want to bet? I'll bet $100 there will be one in ten years.
 
Want to bet? I'll bet $100 there will be one in ten years.
I'd pay you $100 to build one today, provided that your approach to the build was fully open and transparent, the conditions of the build were agreed beforehand with @psikeyhackr and @aka, and the tower you made collapsed over 50+ levels at a speed comparable to that observed with the twins. I'm under that impression that @aka has been trying to persuade the well-known Blender creator Kai Kostack to do this for a while, but that's merely my impression from other discussions. Cash on delivery :)
 
Blender is here now of course. We also have games like Demolition that don't claim to be physically accurate. I think it'll be a fair few years yet before a game like that puts a really powerful physics engine in the hands of kids.

But I predict the even if it takes 50 years, there will still be no physicist or structural engineer who will have successfully modelled the fast, destructive collapse of a high-rise tower using a virtual model even approximately representing the twin towers by then.

Instead, people on forums like this one will still be insisting the effort would be meaningless and unnecessary.
But there is nothing. It's not a case of nothing being good enough for the likes of me -- fact is, when it comes to a virtual model of a tower that shows how the twins could possibly have fallen in the way they did, there's literally nothing that's ever been done that successfully demonstrates this. All efforts have failed.
.
Wait, Mick notes that you previously said that the modeling capability was not yet attainable, but now it is. So you absolve NIST from any error in not doing so a decade+ ago. Correct?

Once again then, is Blender capable of modeling the collapse beyond the first second or two after first downward movement?
It is an incredibly complex situation. You would have to make a lot of assumptions as to internal conditions. Tony Szamboti for instance would have this begin with upper section columns meeting their couterparts in the lower section. Econ41, myself and others, feel that would not be the case.
 
And yet not one of those millions of people -- including you, Mick -- has ever been able to build a virtual model of a tower that demonstrates how the twins could possibly fall with such speed and destructive power under the influence of gravity.

How odd -- perhaps there was more than gravity involved. Will we have to wait another 15 years before some physics student actually bothers to demonstrate their understanding of what you take to be so self-evident with a virtual model?

Quick, everyone here poo-poo the suggestion that experiments are important in demonstrating scientific understanding immediately.
Simple models based on math, help understand 9/11. But the real towers falling are solid proof of speed, and that it is possible. Full up, the real towers, did collapse as seen caused by fire - all backed by evidence.

I "built" a math model which shows how fast the building falls, it matches closely 9/11, the two full up models which already prove how fast WTC tower fall after failing in fire. All I used was physics, and excel. 12.08 seconds for one of the towers to collapse. It is easy to use a math model since a floor fails instantly when the mass is overwhelming. The destructive power is found quickly, E=mgh, >100 Tons of TNT in energy due to gravity.
A simple momentum model proves the speed as seen, already done by many independent engineers and laypeople who can do simple physics. Amazing how close the towers match the math model based on momentum.
 
fact is, when it comes to a virtual model of a tower that shows how the twins could possibly have fallen in the way they did, there's literally nothing that's ever been done that successfully demonstrates this.

--Especially by the accusing Truther community.

there will still be no physicist or structural engineer who will have successfully modelled the fast, destructive collapse of a high-rise tower using a virtual model even approximately representing the twin towers by then.
--and no Truthers who will model it either......

-Cube. If Blender is such a great free product, and you are so eager to have someone use it to make a model.... Might I suggest that YOU, yourself, use this program to make a model and see if it is impossible to replicate without explosives? Or would you rather just keep "asking questions" like most of the Truther community and keep demanding answers without any work on your own?

The fact of the matter is that NO Truther will ever be satisfied with a result that doesn't involve bombs, explosions, and govt. conspiracy. Without these, you have no purpose in life.

Someone could invest billions of dollars to make an exact replica of the Twin Towers, somehow age them 24 years, fly two identical planes as flight 175 and 11, with identical fuel loads and passenger loads, at exactly the same speed, fight the fires and destruction in exactly the same way, only to have the towers collapse exactly the same as they did, and the Truthers would still find something that screams "conspiracy".

It seems like that is what most Truthers live for and I doubt that anything is going to change that
 
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You really can't have it both ways. Either the principle is simple -- so simple in fact that it hasn't been worth modelling the complete collapse sequence in more than a decade and half -- in which case translating the mathematics into a reasonably representative three dimensional model should be a relatively trivial task.

Or it is extremely complex question, in which case the imperative to model the mechanic of the collapses and experimentally demonstrate that the extraordinarily violent nature of their destruction has been fully understood by the structural engineering community becomes overpowering. The question cannot be more complicated than the question of how they were constructed.

It is reasonable to expect that some middle way can be found. The principle of what caused the towers' destruction remains apparently simple, which is why both Mick and @psikeyhackr attach significance to their simplified models. The objections that Truthers make from Newton's Third Law and so forth are certainly simple. But the fact remains that absolutely nothing has been done in terms of 3D modelling to resolve this question -- or, to be more accurate, all efforts have failed or have been highly inconclusive because they have modelled very few "floors".

Thanks for mentioning @Tony Szamboti. If I am allowed to add him to my moderating team for Mick's potential build then I will be fully satisfied to commit $100 to the challenge. Mick has previously affirmed that the Blender physics engine is equal to the task at a reasonably representative level of abstraction. Of course every detail cannot and should not be modelled, but anything that may be taken to be highly significant can be discussed and added to the calculations through an open and inclusive group effort.
 
I'd pay you $100 to build one today...

Thanks for mentioning @Tony Szamboti. If I am allowed to add him to my moderating team for Mick's potential build...anything that may be taken to be highly significant can be discussed and added to the calculations through an open and inclusive group effort.
The fact remains that while the overwhelming majority are confident that the collapses on 9/11
--witnessed by millions watching via quality cameras on a clear day--
are what they appeared to be...a small, obstinate minority claims to be steadfastly unsatisfied.
You may (understandably) find it uncomfortable for it to be said, but the fact remains that these
people are heavily invested publicly (I have no idea or concern if they actually believe it privately)
in the idea that something radical, dramatic--and unsupported--happened that day,
rather than the relatively straightforward cause and effect.

There is little incentive for those people to ever admit that their conspiracy theories are empty,
so my $100 goes to a wager that they will claim dissatisfaction at any model that doesn't suggest a CT,
no matter how elaborate, detailed or credible. Perpetual complaint is the easiest, laziest course of action.
Thus, it isn't surprising. (note: I have no idea what your motives are...though your doggedness on this is interesting).
 
Very few people are publicly invested in the idea that something radical, dramatic and unsupported happened on that day, my friend. Otherwise why would I be forced to express my doubts in a godforsaken corner of the internet like this place?

Nevertheless, heavyweights of the "truther" movement such as @Tony Szamboti and @aka have been known to frequent these parts, and Mick has stated that he could build a Blender model in fairly short order.

I suggest that we can bridge the divide here on Metabunk through just such an experiment, and will pay Mick a token amount for his efforts. How about you?
 
I suggest that we can bridge the divide here on Metabunk through just such an experiment, and will pay Mick a token amount for his efforts. How about you?
My discretionary income--that part I apply to charity--goes entirely to
meaningful causes, mostly protecting wildlife and the environment.

I would no more divert hard-earned money away from such quality purposes for a redundant 9/11 model than I would pay to have someone "model" a spherical Earth
for those who petulantly insist it's flat.
 
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Very well.

I myself will gladly invest $100 in Mick's potential model. I have faith in his programming skills and @aka and @Tony Szamboti to hold his as-yet unbuilt model to a reasonable experimental standard.

This is because a vast amount of environmental destruction has been carried out in direct consequence of 9/11, and insofar as humanity can be called wildlife, a huge amount of destruction has happened in that sphere, too.

Copernicus proved his point experimentally, against the overwhelming consensus. All I am asking -- and offering to pay for -- is that an experiment is done.
 
Keep your ad hominems out of this forum please. I want you to contribute constructive criticism. You know nothing about me.
Sorry... "It seems like that is what most Truthers live for and I doubt that anything is going to change that" Might have been a better way to say it.
 
Blender is free, and the last time Mick said he could build in tower in less than a month (working part time) he insisted he'd do it for free when I suggested a fundraising effort.

But perhaps you didn't see that.

yes, I saw it.. but Im not talking about a snarky reply about a fundraising campaign Cube. YOU want it done.. YOU use YOUR money to make it happen.. Start your OWN fundraising campaign if you want.. but YOU need to take the steps to get YOUR model created. You wont accept anything less, so get off your butt and make it happen.
 
My discretionary income--that part I apply to charity--goes entirely to
meaningful causes, mostly protecting wildlife and the environment.

I would no more divert hard-earned money away from such quality purposes for a redundant 9/11 model than I would pay to have someone "model" a spherical Earth
for those who petulantly insist it's flat.
I agree (no need to waste money), there is no need to model what we saw on 9/11 caused by fire. I see nothing wrong with people learning why by doing their own models if they wish. It take minutes to do a math model, or seconds to see the energy released when the towers fell was equal to over 100 tons of TNT in each tower.

When NIST used a full size model of a floor subsystem to determine facts about the WTC, the results were misused by 9/11 truth. If there are models done which don't support the CD fantasy, 9/11 truth will make up nonsense about them, as they have failed to accept fire caused the collapse.

There is no model, no experiment which will change the fact fires caused the collapse of the WTC tower. There was and never will be evidence for anything but fire to be the cause. It is hard to ignore the Eight (10 oops) terrorists who took 2 planes and caused the damage which started the biggest office fires in history causing the collapse of the WTC towers. Never in history has 10,000 gallons, 66,000 pounds of flammable fuel been used to start office fires on this scale. (except in other large plane crashes in to other buildings https://en.wikipedia.org/wiki/El_Al_Flight_1862 )

I am an engineer, and I think it is great if people what to pay engineers to model anything. 100 percent employment is good.
 
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It is hard to ignore the Eight terrorists who took 2 planes and caused the damage which started the biggest office fires in history causing the collapse of the WTC towers.
I can't keep up with the engineers in here, re structural stuff...
(so I don't try)...but I'm good at history. It would be ten terrorists.
 
I'd pay you $100 to build one today, provided that your approach to the build was fully open and transparent, the conditions of the build were agreed beforehand with @psikeyhackr and @aka, and the tower you made collapsed over 50+ levels at a speed comparable to that observed with the twins.

But how would we go about agreeing upon the conditions of the build?

What I would do is first build a 2D version, essentially a virtual version of physical wooden model (with the magnetic connections). This would have the huge benefit over the physical model that you could very quickly try different things.

I would then (perhaps) attempt to extend that to 3D, if the 2D simulation is not a convincing enough demonstration.

Would it be acceptable to model essentially as Masses and Connections? i.e a collection of cuboid invincible masses representing the columns, girders, beams and floors - all tied together at points or planes of contact by virtual connectors?

I see the inevitable problem here that such a model is only going to be a demonstration of the principle that a building can rapidly collapse from the top down, and the objection will be raised that it is not an exact simulation of the building state. How can we possibly agree upon conditions beforehand? For example, how do we agree upon the values for the failure criteria for the connections. A specific example, how can we agree what the failure parameters are for the floor seats?

Now I designed my physical model so that the floor seats would take the sudden application of six times the weight of one floor. Would that be acceptable again? The model would include test demonstrations for such things. I'd also suggest it include a simulation of wind loading

What about collapse initiation?
 
I'd pay you $100 to build one today, provided that your approach to the build was fully open and transparent, the conditions of the build were agreed beforehand with @psikeyhackr and @aka, and the tower you made collapsed over 50+ levels at a speed comparable to that observed with the twins. I'm under that impression that @aka has been trying to persuade the well-known Blender creator Kai Kostack to do this for a while, but that's merely my impression from other discussions. Cash on delivery :)

Kai did do this in 2011:

Source: https://www.youtube.com/watch?v=4_J7ak_IZXk


Quite a lot of work, probably far more that I'm likely to do.
 
That is not accurate despite the floor trusses. He missed the fact that the floor trusses are framed into belt girders which are on small outlooker beams cantilevered from the perimeter core columns. Why not make it correct?
 
So what's your take on this model? In what way is it not acceptable to you?

Where did I suggest it's not acceptable? I shall be very interested to see it collapse when it's completed [hearsay, paraphrasing another member removed] But it hasn't been completed yet, as far as I'm aware.

I have no objections to Kostack's earlier model either -- except that it models the collapse of only a few levels, so it's inconclusive as a demonstration of how the collapse could progress so rapidly through multiple floors to the ground (so inconclusive in fact that I've seen it separately cited by both "truthers" and "debunkers" as evidence to support their respective positions on this).

If Kostack publishes his new model and it is a poor or partial representation of what happened I suppose this situation could persist, although I think it is unlikely -- either the collapse will progress rapidly and completely to the ground, or it won't.

I'm sure however that if Kostack uses his new model to claim he's discovered a "new phenomenon that can cause the collapse of buildings" and then uses a "public safety" argument to refuse to publish his input data for analysis by skilled individuals such as yourself, Mick, you'll laugh him out of court.
 
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What do you mean by completed? Using the full number of floors, or is some other factor missing?
It was my assumption that Kostack was building this tall tower to investigate how it could collapse -- in a similar manner to the way he used his previous, "low-rise" collapse model.

But perhaps I was wrong to make that assumption, and he's building the tower just to build it, with no intention of investigating its collapse dynamics.
 
It was my assumption that Kostack was building this tall tower to investigate how it could collapse -- in a similar manner to the way he used his previous, "low-rise" collapse model.

But perhaps I was wrong to make that assumption, and he's building the tower just to build it, with no intention of investigating its collapse dynamics.

The twin towers collapse was basically a wash, rinse and repeat... what happened below... once the "ROOSD" began did not matter how tall the building was... it could be 1000 stories and once it went ROOSD up top the building was a goner.

There are some issues with extremely tall buildings... as they get taller the structure below gets beefier and beefier because of the accumulated axial loads. Columns need to be stronger and this usually means larger cross section/column foot print and this means that the lower stories are all given to columns and no usable space. And of course the practical concerns of moving people up and down such vast distances is a limiting height factor.

[...] Collapsing floors of equal strength because they had the same dead and live loads... and equal strength connections to the axial load transfers (columns) collapsed when they became either over loaded... or their connections to the frame weakened... or the trusses that supported them failed... once begun the floor collapse was unstoppable and total right to the bottom. The strength or number of the columns could not prevent or slow the collapse.

The columns collapsed because they lost their bracing... which was the floor system. Without their bracing the columns were unstable... and weaker. There is a limit to how tall a steel column can be before it self collapses/buckles under its own weight. Other columns tipped when the vertical load moved outside of the column's neutral axis... became spindly and toppled over.

These models are a waste of time because all this is settled engineering and physics... nothing to investigate....except how the driving mass was freed from structural matrix....
 
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These models are a waste of time because all this is settled engineering and physics... nothing to investigate....

I don't really see the purpose of the models as "investigation" any more that I see the simulations of flat earth sun motion as such. The purpose is mostly demonstration.
 
all this is settled engineering and physics

Then a representative if simplified virtual model that demonstrates the engineering and physics principles involved in the towers' rapid, gravity-driven destruction must be possible, if only to demonstrate that the principles here are truly settled and understood.

What is curious is that no such model exists, even at a high degree of simplification or abstraction, of any kind of tall tower (50+ stories, for arguments' sake) collapsing in such a way. Of course some attempts have been made, but all have failed.

And we are talking about the worst structural failures in history -- the most catastrophic events to be initiated by human agency since the Second World War. So it is a reasonable question to ask. Can't anyone build a simple virtual model of a tall tower that falls down in such a way? How many decades will it take?

The initiation factors cannot be impossibly complex in modelling terms either. Essentially the same result was achieved in roughly the same amount of time after two quite different initiation points of impact/fire.
 
The models I saw.... do not deal with the fracturing and communition of the concrete intosand and dust....fro, billions of mechanical collisions. Towers are not simply stacks of jenga blocks.
 
The models I saw.... do not deal with the fracturing and communition of the concrete intosand and dust....fro, billions of mechanical collisions. Towers are not simply stacks of jenga blocks.
Which models are these that you saw? Can you link to them, or information relating to them, please?
 
Which models are these that you saw? Can you link to them, or information relating to them, please?

I don't know the "names" of the models... I have seen on the www including Mick's excellent one which was not a virtual but a "table top" type model. I don't believe models are necessary for the collapse phase because as stated previously.... the floor system... each identical except the slightly stronger mech floors were designed to carry X loads and fail when X+1 load presented on the floor system. This load information is exactly what the design engineer does... he selects/designs a floor system to meet and exceed the required design loading parameter... These design loads include a margin of safety as well. For floors and beams the criteria includes limits to deflection when loaded. In the case of the twin tower floors.... in the real event when we all observed... the top sections dropped. The did so because the elements of the top were disengaged from the axial load transfer system which supported the top load. If a table has 4 legs holding it up and you destroy 2 of them... the remaining two will likely buckle and fail as their limit of of axial capacity has been exceeded. You could also cause the top to drop by forcing a mis-alignment in the columns... freeing the top to drop unsupported.

Regardless.. the tops mass dropping on the uppermost intact floor system FAR exceeded it capacity... similar to dropping a bowling ball on a thin pane of glass. The glass immediately shatters and offers little resistance to the ball. The ball in the towers was the mass of floors and structure and contents of the floors which dropped... in 1wtc it was about 12-15 floors in the 2wtc is was about 30 floors. To shatter a typical wtc floor would require only a few drooping floor masses.

Nothing to model here.

The grid of columns could not and did not resist the collapsing floor mass. The floor connections to the columns were over come and failed... leaving the columns largely intact. They came down because they cannot stand without lateral bracing which the floor system provided. That too, is settled engineering. Nothing to model.

These models if anyone bothers to waste their time will collapse in 12-15 seconds as predicted.by physics/engineering. This is really trivial and like dropping apples to demonstrate gravity.... it's been done.
 
JSO, Econ41, myself and others, contributed to a generic description of the tower collapses on ISF.
http://www.internationalskeptics.com/forums/showpost.php?p=11224323&postcount=413
It says in part:
Generic Description of the Collapse Progression of the Two WTC Towers:

Video evidence demonstrates aircraft impact destroyed or bent a number of perimeter columns. A lesser amount of core column severance or damage is expected. Some floor spans also directly damaged.

Aircraft fuel spread through several vertically adjacent floors of the structure and ignited. This created a condition of very large area office contents fire on those floors with various levels of "rubblization" of the contents. This is a fire condition well beyond design expectations for fire spread. Office fires are expected to usually begin small, in a waste basket, or an electrical fault in a device or circuit, for instance.
.........
The capability of the structure to resist any collapse was being eroded. One very obvious indication of this is the inward bowing of part of the perimeter. Each tower also twisted and tilted noticeably up to collapse. These demonstrate that the structure was responding to further weakening due to the heat. Loads were continually changing and redistributing during this time. At some point a redistribution caused one or more columns to exceed its capacity. Column capacity in this case does not necessarily mean it original engineered load bearing ability. Loads were not necessarily on axis (due to impact or heat induced creep, or expanding floor beams) and many columns were subjected to significant heating, both of which would tend to lower any individual column's strength.

At one point a rapid progression of column failures occurs. A column or columns fail and in redistributing the load, cause other columns to exceed capacity, causing another rapid load shift. Column failures rapidly progressed to all columns over one or more levels

With all columns now having failed over one or more adjacent levels, a large section of the upper building is now falling, accelerating to next contacts. A combination of factors result in few, if any, buckled columns impacting on lower parts of themselves. Upper falling section column ends are, in many locations, the first contacts with lower structure. That contact would be proximate to the lower section columns and thus the greatest impact occurs near or directly on lower floor truss to column connecting components immediately failing the lateral support provided by those trusses. This is occurring both to long span truss to column connecting components, at perimeter and belt truss, as well as with the core's beams running between core columns.

As upper mass continues its lowest floor begins contacting floorspace below the initial failure level. This first contact is between floor systems that are already severely compromised. They are among those that have been affected by impact and heat and one has suffered loss of connections to columns as per last paragraph.

With columns largely being bypassed by the vast majority of falling upper section, they contribute very little in opposing collapse.
 
Like this?


Do you not see what the difference is?

In your clip the falling object falls a long distance to first impact, which is obviously sufficient to shatter the first pane. The distance to the next impact though is very much shorter. The falling object obviously cannot regain the velocity it had at first impact. It will retain some velocity after shattering first pane, it will gain a bit more in the short fall to next impact but will be slower than that first impact. If it does have enough velocity to break that second pane it will again fall through that short distance but will now have even less velocity than at second impact.

In the towers the initial fall was sufficient to break through the first impact floor.
AND the distance of subsequent fall is the same as the first fall.
In addition that first fall initial condition was a velocity of zero, but the second floor impact velocity included not only the gain in velocity in falling through the same distance as the first, but also remaining velocity after first impact.

You do not need to be a rocket surgeon to understand the differences.
 
What is curious is that no such model exists, even at a high degree of simplification or abstraction, of any kind of tall tower (50+ stories, for arguments' sake) collapsing in such a way. Of course some attempts have been made, but all have failed.

You mean just because they are not tall enough? What do you think would happen if my physical model were made taller?

What would be the advantage of making Kai's model taller? What do YOU think that would actually demonstrate?
 
However, since we've scaled it 200x, the actual weight loaded on the model needs to be 200x as much, or 7,500 kg.

So for our 1/200th scale model to work, we would have to cram 7,500 kg into about 7 cubic feet. That's about 16,500 pounds per cubic foot.

Solid gold weighs 1206 pounds per cubic foot. So the 1/200th scale model is non-starter.
very informative post, i now understand why a small scale model is not practical, just one small error,
'that's about 16,500 pounds per cubic foot', error being, 'per cubic foot'.
 
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very informative post, i now understand why a small scale model is not practical, just one small error,
'that's about 16,500 pounds per cubic foot', error being, 'per cubic foot'.

Thanks! fixed to:
So for our 1/200th scale model to work, we would have to cram 7,500 kg into about 7 cubic feet. That's about 16,500 pounds, or about 2,360 per cubic foot.

Solid gold weighs 1206 pounds per cubic foot. So the 1/200th scale model is non-starter.
 
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