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

[Cube Radio]

For what it's worth, I've head the scale model idea won't work because you can't scale gravity. Makes perfect sense to me, but I'm not a SE.

Mick is right, the square cube law has to be taken into account -- but that doesn't mean building scale models is impossible or would teach us nothing. Take a look at this video at 3.06 for an idea of what was built to understand structural disasters before computer models were available to structural engineers.


In the case of the Towers, a model like this has never been made, even in simplified form, although we are told the "gravity-driven collapse" of those structures was in principle quite simple. Needless to say there are several examples of physical "gravity-driven collapse" models that spectacularly fail to experimentally demonstrate what we are told was what happened on that day, and there are none that support the official collapse theory.

 

[Jeffrey Orling]

Mick is right, the square cube law has to be taken into account -- but that doesn't mean building scale models is impossible or would teach us nothing. Take a look at this video at 3.06 for an idea of what was built to understand structural disasters before computer models were available to structural engineers.


In the case of the Towers, a model like this has never been made, even in simplified form, although we are told the "gravity-driven collapse" of those structures was in principle quite simple. Needless to say there are several examples of physical "gravity-driven collapse" models that spectacularly fail to experimentally demonstrate what we are told was what happened on that day, and there are none that support the official collapse theory.

Pure rubbish... No columns were crushed as the towers came down... no evidence of this and so any model of crushing of columns is way off the mark.

There was a vertical avalanche of the floor mass racing down inside the cage of the perimeter... robbing both the perimeter and the core of needed lateral support. Both facade and core toppled from instability post floor collapse.

This is what the visual record shows and is perfectly consistent with basic physics.

Open your eyes and use your brain to process what you see.

 

[Cube Radio]

Pure rubbish... No columns were crushed as the towers came down... no evidence of this and so any model of crushing of columns is way off the mark.

You evidently did not watch the video I posted as that model has a single column, which is of course not crushed or even set up to be damaged.

the visual record... is perfectly consistent with basic physics.

Then it would be easy to set up a basic physical experiment that reproduces the effect of a simple tower structure being crushed totally to the ground by the dynamic momentum of a falling upper section of itself: shall we say, the top 20%.

As the experiment I have posted shows, this is not easy or basic at all: in fact, there are no examples comparable to the physical experiment above that successfully show how such a structure could crush itself in the way you believe is so self-evident; please post one if you can find one, or consider your belief that this is "basic physics" debunked.

 

[Cube Radio]

I'm not seeking to explain the collapse myself, I'm pointing out that a physical model that adequately demonstrates in principle the phenomenon you take to be so obvious cannot be constructed, and never has been.

If you can't use your "basic physics and engineering concept" to find such a model to post here, I suggest you build one to prove how easy it is -- and if you cannot, as I say: consider your expert opinion, which I am not surprised to see you hold to be superior than that of the scientists working for NIST, debunked.

 

[Jeffrey Orling]

I'm not seeking to explain the collapse myself, I'm pointing out that a physical model that adequately demonstrates in principle the phenomenon you take to be so obvious cannot be constructed, and never has been.

If you can't use your "basic physics and engineering concept" to find such a model to post here, I suggest you build one to prove how easy it is -- and if you cannot, as I say: consider your expert opinion, which I am not surprised to see you hold to be superior than that of the scientists working for NIST, debunked.

rubbish.... physical models are not the way to prove anything in this case.. the forces can't be scaled. PERIOD END OF STORY.

A floor system designed to support 75psf will fail with an applied dynamic load of 500psf PERIOD END OF STORY. These are piratical facts done in materials testing for years and used to engineer all structures.

Stupid little experiments prove nothing at all.

 

[Cube Radio]

Stupid little experiments prove nothing at all.

My point is that you don't even have stupid little experiments to support your position. You have nothing but bare assertion ("the forces can't be scaled"). Physical experiments are also conducted on this kind of scale, Jeffrey. If it's such a simple principle, I really think you should be able to show how it works in the real world.


I note that you really have no response to my point that NIST failed to even attempt to model the most interesting/significant part of the WTC 7 event.

Jason, I apologise: I've somewhat confused the thread by mentioning the Towers; my comments you're responding to above were referring to WTC 7.

 

[Mick West]

My point is that you don't even have stupid little experiments to support your position. You have nothing but bare assertion ("the forces can't be scaled"). Physical experiments are also conducted on this kind of scale, Jeffrey. If it's such a simple principle, I really think you should be able to show how it works in the real world.

That's a full size column, not a scale model. Are you suggesting someone build another WTC7?

Buckled columns offer very little resistance. You don't need a model to know that.

However, that's off topic, the AE911 letter only discusses a hypothetical initiating event.

 

[Cube Radio]

The point I'd choose to emphasise at this stage is indeed off-topic, Mick: there are no physical models representing at any kind of scale the experimental investigation of the phenomenon that is said to have destroyed the Towers. This phenomenon is frequently described as simple and basic by the likes of Jeffrey, but nobody taking his kind of a position on the question of how the Towers were totally destroyed can point to any credible physical experimental research to support their ideas. The experiment shown above represents how extensive physical investigation into structures can be. Here is another. If you want to make a new thread of this point, please do so.

 

[Mick West]

[Thread Split to here]

But that 30 story model is NOT a scale model. It's representation of the tower used to investigate something very specific. Notice they had to load each floor with a layer of iron ingots, equivalent to about a three feet thick iron floor.

How would you build a model of the towers (or a section of) to investigate the collapse mechanism?

 

[Keith Beachy]

... y, and there are none that support the official collapse theory.

The video is not science, and can't be used to make the claim, "none that support the official collapse theory". It is a joke. Where is the paper, in a journal? A simple model is what a floor can hold. A simple model we can do in our heads. A floor of the WTC can hold 11 more floors of debris, and the 12th floor of debris results in instant failure, then there are 12+i, and the mass grows. This simple momentum model gives a collapse time of 12.08 seconds. A model for collapse that matches close the initial collapse, based on momentum of what happened on 911. As an engineer, this is a simple model matches the collapse front exactly until you can't see due to dust. Anyone can take excel and model the WTC with momentum to get these results - and it matches the official collapse theory, NO, it matches what happened. In my story of 911 there is no official theory, I have the video which show the official reality, a gravity collapse due to fire. And we find that CD uses gravity as the primary energy source for collapse in CD, E=mgh is the majority source of energy used to destroy building in CD. Thus, CD looks like gravity collapse, Dan Rather was wrong. Does 911 truth forbid physics.

Have you tried a momentum model.

Simple models are possible, mathematically. The claim no models have been made is a lie. The the collapse, full up models collapsing. What 911 truth followers fail to realize, engineering models of such an event will not look like the collapse, which is why WTC 7 models only confuse followers of the CD fantasy, as the simple model of E=mc2​ would confuse them when they see a atomic test.

 

[Cube Radio]

That 30 story model is NOT a scale model. It's representation of the tower used to investigate something very specific.

Mick, I posted that video (and the previous video) to illustrate the general point that [large] scale physical experiments can be and are built to research structural behaviours. This has never been done in the case of the Towers, even though they were the most catastrophic structural failures in history, except by amateur researchers -- who of course have found that this apparently simple phenomenon cannot be reproduced. The experts, it seems, do not even have to try.

The claim no models have been made is a lie.

Please post what you consider the most persuasive example of the physical experiment you think best illustrates a structure like the Towers collapsing to the ground under the dynamic momentum of a falling upper section of itself.

 

[WeedWhacker]

Please post what you consider the most persuasive example of the physical experiment you think best illustrates a structure like the Towers collapsing to the ground under the dynamic momentum of a falling upper section of itself.

Now you are speciously requesting something that you previously admitted does not exist:

...who of course have found that this apparently simple phenomenon cannot be reproduced. The experts, it seems, do not even have to try.

No, the burden falls to you to explain what else besides a 'global' catastrophic and progressive collapse (initiated after severe structural damages were inflicted, and exacerbated by an out-of-control and very hot fire) led to the destruction of the Twins.

If the assertion is that the heat from the fires would not have "affected" the structural steel significantly enough to have caused them to fail under the stress of supporting the immense weight above the critical damaged areas, then one need only see a real-world example of some steel beams that failed while under much less vertical stress (mostly just their own weight) after being subjected to a fire....a fire fed primarily from just wood, doesn't include the significant amounts of other typical office building interior components, such as plastics, etc, that can make a fire even more hot:

http://www.reviewjournal.com/news/n...ch-ignites-bridge-fire-closes-i-15-california

http://ktla.com/2014/05/05/bridge-f...ions-of-15-freeway-in-hesperia/#axzz34e1Zzb5y

A bridge caught fire and completely collapsed...

More images.

 

[deirdre]

Please post what you consider the most persuasive example of the physical experiment you think best illustrates a structure like the Towers collapsing to the ground under the dynamic momentum of a falling upper section of itself

you do realize engineers don't use 'physical models' when building. They don't "build a bridge" to prove whether they can build a bridge.

They use mathematics and known physics stuff. And they can calculate collapses the same way.

 

[jaydeehess]

There's quite a difference between modeling a construction to see how it behaves as a corporeal structure, versus modeling a significantly damaged structure to see if it will fail by modeling further damage.

 

[Cube Radio]

you do realize engineers don't use 'physical models' when building. They don't "build a bridge" to prove whether they can build a bridge

You obviously haven't bothered to watch the video at the very top of this thread, and that is why you have completely missed the point. Watch from 3 minutes in.

 

[Cube Radio]

There's quite a difference between modeling a construction to see how it behaves as a corporeal structure, versus modeling a significantly damaged structure to see if it will fail by modeling further damage.

Yes, but the simplified principle is apparently basic physics, if Jeffery is to be believed. You just have to make a representation of the Twin Towers totally collapse, I guess.

 

[Mick West]

The BSB earthquake test is remarkable in its uniqueness. BSB make a big deal about how this is the only building that has undergone such a test. So why don't other skyscrapers get tested in the same way?

It's because such tests are not very useful. This BSB test is more of a publicity stunt than anything. The connections, assemblies, and welds used in the model are different to those used in the real construction - so you get no better than a rough idea of what might happen (and that assuming that they scaled everything else correctly.)

But lets say you want to create a similar 1/10 model of some of the WTC, to investigate if the "official story" was accurate? How much of it would you need to build?

 

[deirdre]

You obviously haven't bothered to watch the video at the very top of this thread, and that is why you have completely missed the point. Watch from 3 minutes in.

hhmm. well where I know what I'm trying to say, I'm having trouble providing links because I cant understand if the links are saying what I'm trying to say ; ) maybe this? http://www.di3.drexel.edu/DI3/Events/Presentation-Kitami.pdf

 

[jaydeehess]

The single greatest failure in Psikey's model is that he is modeling failure of the support system of his washer/paper loop set up. This is underlined by his doubling of the paper support further down.
That is simply not the manner by which the towers failed.

The towers failed due to , as Mackey states, when the dynamic loading on the floorspace caused the floors to fail thus destroying lateral support for column structural systems (perimeter and core).

The floors were all the same construction all the way from bottom to top(except for a few mech floors which had to carry extra mass). Thus the same ability to transfer a load to columns all the way down.

If Psikey wished to build a better representation using washers, cardboard and wooden dowels he could have.

Four dowels as columns. Cardboard floors taped to small pegs inserted into the columns. Load the floors with washers.
First test a floor to see what static load it can support before failure( tearing through pegs or buckling and tearing off the tape). Now load your tower floors with some percentage of max load say 1/10
Now drop mass equiv of ten floors onto the top floor.

I cannot envision a reason why the floors will not fail all the way down, leaving columns unsupported laterally and fall away.

 

[Redwood]

What is the point of "Cube Radio's" argument? Analytically, the collapses of the Twin Towers can be separated into two parts: (1) initiation caused by pulling in of the columns in the fire areas by the sagging floors (demonstrated by photographic evidence) and (2) continuation caused by failure of the floor-column connections under the dynamic load of the falling upper structure, verified by inspection of the columns. You're going to have a really tough time applying "square-cube" modeling for either part.

 

[Keith Beachy]

Please post what you consider the most persuasive example of the physical experiment you think best illustrates a structure like the Towers collapsing to the ground under the dynamic momentum of a falling upper section of itself.

I don't need a physical model to know how the WTC collapse goes. I have video. Already modeled and proved to fail in fire, and gravity.

29,000,000 pounds is what a WTC floor can hold. More than 11 floors dropping on the lower section will cause the floor below to fail, and this will go on to the ground, the model is weight a floor can hold.

The WTC is a system. Shell for lateral loads and up to 50 percent of the gravity load, the core for gravity loads, and the floors. The floors hold the shell to the core to provide the lateral support for the core and WTC. A hurricane can't topple the WTC. The WTC system can not stand without the core, shell, and floors. When the floors fail, the shell is compromised and so is the core. When the steel failed on 911, the lower floors can't hold the top floors and they fail, destroying the WTC system. A simple failure mode, as seen on 911, stored forever on video.

The chief structural engineer said the WTC collapsed as he expected. The Number 1 expert in the world knows it was an impact, fire, gravity collapse - I have found no engineers I went to school with, grad school with, or worked with that doubt it was fire and a gravity collapse. Plus, I know of no engineers who need a physics model to understand how the WTC collapsed. He needed on physical model, why do we need one? I did the momentum model to study why 911 truth failed so poorly with their claims.

Who need something past mathimatical, a few differential equations on a simple model to verify the possibility of what we saw. What we saw was from fire and gravity; no one found any blast damage, and zero damage from thermite.

I have two full up models collapsing from fires and gravity on 911, stored on video. It is a waste of time to do a model. The video you had was silly nonsense; hope he is not an engineer.

http://www.nist.gov/el/disasterstudies/wtc/faqs_wtctowers.cfm
The cool part here, is anyone can study the WTC and estimate the floor load, what a floor can hold and check NIST. Who needs NIST?

The weight a floor can hold along with understanding the WTC is a system of three parts, is enough for me to understand the collapse. I am an engineer, and can't find any engineers I went to school with (grad school and undergraduate school) or worked with who don't understand fire and gravity are the reason WTC collapsed. I am surprised 911 truth found any engineers until you do the stats, and see they have less than 0.1 percent of all engineers - and we know this due to the Internet - 50 years ago no one would know about 911 truth if it happened then. The Internet makes all the fringe few, known. We know who will not be doing engineering work for us, or flying us.

The physical model of the bridge did not model the bridge failure; ... it took 50 years to model it (or 30 years of study?); on computer, or math? Modeling the bridge is modeling the initiation of collapse, they did not model the collapse. ... why would you model the collapse?

Can you get the real story from from youtube videos? Maybe not, news sources are iffy
http://www.ketchum.org/billah/Billah-Scanlan.pdf
The simple math model got more credible - do we all get credit for this course in models, etc.

 

[Cube Radio]

I don't need a physical model to know how the WTC collapse goes. I have video. Already modeled and proved to fail in fire, and gravity.

What video is this you're referring to? You're surely not attempting to suggest that footage of the event itself is somehow in itself experimental evidence for its reproducibility. That would make a mockery of this forum, not to mention the scientific method, and would be a very silly thing to say.

 

[WeedWhacker]

You're surely not attempting to suggest that footage of the event itself is somehow in itself experimental evidence for its reproducibility.

Could you please explain this?

"Why" wouldn't the actual footage of the collapses be "evidence" of the (at least theoretical) mechanisms?

 

[Cube Radio]

Reproducibility is something you seek in the scientific method, Weedwhacker. That's one of the main points of building models: it's a way of testing hypotheses. If a hypothesis can be tested and reproduced, it gains credibility. You can't assume your hypothesis is true without testing it. Pretty basic point as I'm sure you'd agree but not something Keith seems to have grasped.

 

[Mick West]

Reproducibility is something you seek in the scientific method, Weedwhacker. That's one of the main points of building models: it's a way of testing hypotheses. If a hypothesis can be tested and reproduced, it gains credibility. You can't assume your hypothesis is true without testing it. Pretty basic point as I'm sure you'd agree but not something Keith seems to have grasped.

So, how big of a model would you have to build? To what scale? And how many times would you have to build it?

 

[Cube Radio]

To be honest Mick I don't think the technology to create models of the towers is quite there yet, although I think it will be fairly soon and when it is I predict a lot of models will be made. The important thing is that all necessary information about the structures must be available in the public domain for genuinely independent researchers to use. At the moment we have structures like this being made with 3D printing: when this kind of technology becomes a little more sophisticated, as well as more generally available and affordable, I think the question should be settled through multiple experiments conducted around the world.

 

[Mick West]

I think computer models are going to advance quicker than physical models. And they are already a lot more useful for large scale simulations.

3D printing is interesting, but it's only going to make a very small model, and it's not going to be made from the actual steel and concrete that's relevant to the discussion. And you won't be able to get the mass in there.

Going back to the BSB model. Even though it's not a very useful model in proving the integrity of the building, it's interesting to consider what they had to do in their attempt to make it as close as possible. Basically they build everything with linear dimensions (width, height, depth, any length) reduced to 1/10x. This reduces the cross sectional area (and hence the strength) of all the structural members to 1/100th. So (simplistically) the reduced structure should get able to support loads of 1/100th of the original (square). However the primary load is the weight of the structure itself, which is reduced to 1/1000th (cube).

So to get anything close to relevant results, they need to add 9x the weight of the reduced structure in a non-load-bearing manner. The do this by gluing iron ingots to each floor, the equivalent of about three feet thick.

Now, consider what you would have to do if you were to apply similar correction to a smaller model of the tower, one that someone might build at home on a 3d printer. Say you made a 1/200th scale mode, so you are building a model that's 1368/200 = 6.84 feet (with a base of about 1 foot square). Now ignore for the moment the issues of modeling the tiny connections, and girders flanges that are a thousandth of an inch thick. How much should it weight?

Well, if it's a perfect scale model, it would weigh 1/(200*200*200) = 1/8,000,000th of the original. Estimates vary, but let's take a common figure for the weight of a tower is 300,000,000 kg. So the weight of our model is 300/8 = 37.5 kg.

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, or about 2,360 per cubic foot.

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

 

[Pete Tar]

But what's so inexplicable about load-bearing steel losing it's structural integrity when heated that it requires modelling to prove?
What is it that the model is seeking to explain that isn't already clear and obvious? (eg, large heavy falling masses will obliterate anything in their path and fall straight down)

 

[Mick West]

But what's so inexplicable about load-bearing steel losing it's structural integrity when heated that it requires modelling to prove?
What is it that the model is seeking to explain that isn't already clear and obvious? (eg, large heavy falling masses will obliterate anything in their path and fall straight down)

Clearly the cause of collapse of the buildings is not so obvious to the truthers such as Cube, or AE911.

 

[WeedWhacker]

But what's so inexplicable about load-bearing steel losing it's structural integrity when heated...

That was the point I attempted to convey...perhaps it was lost in the verbiage. The designed load-bearing capacity weakened (altered) from the intense heat, combined with added (undesigned and lateral) stresses that were present due to the gaping damage.

It is significant to note the damage patterns RE: the two Twins, and the time element. I.E., the building hit second collapsed first. Simply because of the way it was damaged differed from the other.

 

[Mick West]

That was the point I attempted to convey...perhaps it was lost in the verbiage. The designed load-bearing capacity weakened (altered) from the intense heat, combined with added (undesigned and lateral) stresses that were present due to the gaping damage.

It is significant to note the damage patterns RE: the two Twins, and the time element. I.E., the building hit second collapsed first. Simply because of the way it was damaged differed from the other.

Yeah, but I think Cube is concerned about how fast it fell.

 

[WeedWhacker]

Yeah, but I think Cube is concerned about how fast it fell.

Ah, OK. Well, a careful viewing of any number of videos show that portions of debris that are "loose" and falling freely through the air are (as expected) accelerating downward due to the force of Earth's one-g were falling faster than the structures, as they collapsed.

(Accounting for the effects of wind resistance of course, though various objects encounter different "terminal velocities" as they fall. A skydiving Human, for example, spread-eagle and presenting a large surface area will "top out" at roughly 120 MPH).

 

[Cube Radio]

What is it that the model is seeking to explain that isn't already clear and obvious? (eg, large heavy falling masses will obliterate anything in their path and fall straight down)

It is precisely what you take to be "clear and obvious" that I am calling into question. Please post video evidence of what you take to be the best real-world example of why we should not be in the least bit curious about how structures like the towers could collapse in such a fast, progressive, pulverising and total manner.

If, for you, a controlled demolition technique like Verinage clearly and obviously explains how steel-framed high-rises like the Towers must clearly and obviously fall in the fast, progressive and total manner observed -- under the dynamic momentum of relatively small upper section of themselves -- please post a video of Verinage that you think most clearly and obviously corresponds to what happened to the Towers.

If you can think of a real-world model or event that explains why this falling top section of a structure like the Towers would clearly and obviously not itself be destroyed by the progressively stronger structure beneath it as it drops, before it reaches ground level -- or fall away from the perpendicular -- please post evidence of it.

If all this is so clear and obvious to you, real-world examples of why this is so clear and obvious must be clear and obvious to you, right?

 

[WeedWhacker]

If, for you, a controlled demolition technique like Verinage clearly and obviously explains how steel-framed high-rises like the Towers must clearly and obviously fall in the fast, progressive and total manner observed under the dynamic momentum of relatively small upper section of themselves, please post a video of Verinage that you think most clearly and obviously corresponds to what happened to the Towers.

I am sorry to "interrupt" here, but really.

As I have suggested, the collapse of the "Twins" is clear (on MANY videos).

I hope that the aspect of "Verinage" (which is a well-known technique) is not being suggested, here, as a "way" to collapse the Twin Towers?

This would...(apologies in advance) be beyond ridiculous.

(EDIT: I am hoping that a "gish-gallop" will not occur, here).

 

[Pete Tar]

under the dynamic momentum of relatively small upper section of themselves,

Small *relatviely* to the rest of the structure, but still a huge and significant force made up of at least ten floors.
So if you had a 20 story verinage demolition, do you think that collapsing it from the 10th floor would not be sufficient to crush the building?*
*(though to be honest the bottom ten floors being closer to solid ground may provide more resistance than would say, a 30 or 50 story building with it's top ten floors dropped on it, and which would more likely build enough momentum to plow all the way through to the ground.)

If you can think of a model that explains why this falling top section of the structure like the Towers would clearly and obviously not itself be crushed by the progressively stronger structure beneath it as it drops before it reaches ground level -- or fall away from the perpendicular -- please do so.

Maybe you can explain why you think it would behave that way, and what it not doing suggests*, because
I don't understand why that is suspicious? As for falling away from the perpindicular - why on earth would it do that, there is not enough rigidity in the structure that means it should somehow act as a lever and overcome the forces of gravity enough to topple over to the side.

*though first of course, please show that it remained intact.

 

[Cube Radio]

I don't understand why that is suspicious?

That is why you need to post examples that you believe effectively illustrate how structures like the Towers must clearly and obviously collapse in the way they collapsed. I can post several videos of high-rise structures that have caught fire and not suffered fast, total, pulverising collapse, and those videos have been posted elsewhere on this forum and are invoked ad nauseum in discussions of this nature.

However, you have, it seems, no real-world evidence that the Towers would "clear and obviously" collapse in the way they collapsed apart from the question-begging video evidence of the Towers themselves collapsing. Have you got any kind of comparative or experimental evidence to support your belief that this is clearly and obviously what must happen? Am I to take it that you believe a controlled demolition technique like Verinage does explain for you how a steel-framed high-rise structure like the Towers could collapse totally to the ground? If so, please post a video of what you think is the best, most comparative example.

 

[Pete Tar]

Am I to take it that you believe a controlled demolition technique like Verinage does explain for you how a steel-framed high-rise structure like the Towers could collapse totally to the ground?

In a limited sense it illustrates the concept that a moving weight will crush a structure underneath it - of course there is a critical point that must be crossed but once it is then yes its total collapse is pretty much ordained, and I'm satisfied that critical mass was provided by all the elements at hand.
This is a 110 storey structure though, and the largest demolition we've seen to date is 31 storeys.


(I'm not using that to illustrate anything other than the dearth of equivalent 110 storey building collapses from which we can decide what is 'normal' or expected)

Having the top 10-17 floors of a 110 storey building initiate a total collapse doesn't seem odd to me, no.

By your use of the phrase 'totally to the ground' you imply that there should have been a bit of it left standing? How much, and also why do think that? Isn't the falling weight of 100 floors enough to destroy the bottom 10, or however much you think should still be left?

 

[Pete Tar]

*(though to be honest the bottom ten floors being closer to solid ground may provide more resistance than would say, a 30 or 50 story building with it's top ten floors dropped on it, and which would more likely build enough momentum to plow all the way through to the ground.)

I feel I need to correct myself on this - 10 storeys is still very tall and is unlikely to offer 'resistance' in the way I'm picturing it here in this scenario if a further ten storeys were coming down on it.
I'm getting lost in scale by imagining 110 storey collapses compared to smaller ones.
But out of interest - at what floor would a 10 storey building be dropped to ensure total collapse in verinage? Would five floors be enough?

 

[Mick West]

This thread is about using models, please keep on topic.

If one really thinks about the weight and size of a scale model, the reason for the collapse becomes less and less surprising. The smaller the model, the more it would have to weigh.

 

[Cube Radio]

Having the top 10-17 floors of a 110 storey building initiate a total collapse doesn't seem odd to me, no.

However, it seems to me you must concede that you have precisely zero experimental evidence to support your belief that this was not "odd". You've posted a video of a controlled demolition of a concrete building being destroyed in the "traditional" manner with timed explosives at its base as if this bears a meaningful comparison with a steel-framed tower being (allegedly) destroyed by progressive collapse following the chaotic effect of fire and impact near its top. Why? You concede immediately afterward that it's a video that illustrates nothing under discussion here, so what point are you making? That there are no models or experiments of any kind to support your beliefs?

The collapse of the Towers is really a matter of common sense for you, isn't it, Pete. A bit like it's common sense to imagine the Sun goes around the Earth. No need to investigate, it's obvious

Isn't the falling weight of 100 floors enough to destroy the bottom 10, or however much you think should still be left?

To clarify, you are suggesting that the falling mass of the pulverised upper section of the towers, when the destruction wave reached the "bottom 10" floors, was still broadly representative of the total mass of 100 floors -- this despite the pulverisation of the building as the collapse proceeded, producing huge clouds of dust, and the vast sections that were seen to be violently ejected from the destruction wave and/or fall away from it?

If the answer to this question is "no", how much of the mass of the building do you think had been pulverised into dust or ejected away from the perpendicular by the time the collapse wave reached the last ten floors? 15%? 30%? 50%? This would be important in modelling the collapses, of course.