WTC 1 & 2. What happened after collapse initiation?

[Jonnyclueless]

Answering Heiwa's question.

Heiwa on his website asks the following question,

"How can serious authorities and scientists suggest that a global collapse or crush down of WTC 1 is driven only by gravity and an indestructible upper block when the latter - as a smoking gun - disappears before the collapse even starts as per fig. 8 and all videos?"

This question is answered by Bazant and others in some of their papers. In the paper, "Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions", by Bazant and Verdue, they write,

"Due to a shroud of dust and smoke, the videos of the World Trade Center are only of limited use."

"Because of the shroud of dust and smoke, these histories can be identified from the videos of the collapsing WTC towers only for the first few seconds of collapse, and so little can be learned in this regard from that collapse."

"Approximate information could be extracted from a regular video of collapse, but only for the first few seconds of collapse because later all of the moving part of the WTC towers became shrouded in a cloud of dust and smoke..."

In the paper, "What Did and Did not Cause Collapse of WTC Twin Towers in New York" by Bazant, Greening, Benson and Le, they write,

"Video records in which the motion of the tower top can be tracked are available for the first few seconds, until the tower top gets shrouded by a cloud of dust and smoke."

These are interesting statements to make. I like the first comment best, "the videos of the World Trade Center are only of limited use." Now why are the videos of limited use? The video tapes show what happened to the towers over the 15 or so seconds as they were being destroyed. The video tape record provides the best empirical evidence to explain what happened to the towers. So why is it only useful for the first couple of seconds?

What Bazant means is that the video evidence is only useful for his theory for the first couple of seconds, then the evidence begins to contradict his hypothesis. For those that follow Bazant's model, they treat the clouds of dust and smoke as some sort of exogenous factor. The building is collapsing then all of a sudden all these dust clouds obscure what is really happening.

Let's take another example. Assume a crime is getting ready to be committed. Three people have decided to rob a bank. Then right as they begin to rob the bank someone sets off a huge smoke bomb obscuring the view so the security camera can only catch the first few seconds of the crime being committed. In such a situation the video evidence might be of limited use.

This is how Bazant treats the huge dust clouds, something that hides what is really happening to the building. This is incorrect. The production of these massive dust clouds tells us what is happening to the towers, it doesn't hide what is happening. I, therefore, believe the video evidence is useful for the entire duration of the towers destruction.

Bazant has decided that his mathematical model provides a better illustration of what happened to the towers than the actual video tape evidence. If the world of reality does not agree with my mathematical model then so much worse for the world of reality.

So "how can serious authorities and scientists suggest that a global collapse or crush down of WTC 1 is driven only by gravity and an indestructible upper block...?"

By ignoring the evidence. Bad Science. Good Propaganda.

OMG!!!!! There are not enough laughing dogs in the world!!!

I nearly peed my pants laughing at this.

 

[R.Mackey]

What Bazant means is that the video evidence is only useful for his theory for the first couple of seconds, then the evidence begins to contradict his hypothesis. For those that follow Bazant's model, they treat the clouds of dust and smoke as some sort of exogenous factor. The building is collapsing then all of a sudden all these dust clouds obscure what is really happening.

Dr. Bazant in the BLBG paper treats the clouds of dust explicitly, as crumbling energy is a term in the model. Clouds of smoke are an exogenous factor, as they are created by the fires, not the collapses.

Heiwa, and yourself, are either liars or fools.

 

[beachnut]

So the answer is still; the towers collapsed in total devastation due to the release of gravitational potential energy, E=mgh. Easy to calculate and then you get the energy of over 200 2000 pound bombs acting on the WTC after collapse initiation. That more than 200 1993 basement bombing, or over 100 Tim Rat McVeigh murder bombs in OKC. Just because of mgh (mass, gravity, and height), simple physics is all that is needed to understand after collapse initiation. Got Physics?

The simple question of 9/11 truth. Like asking me what happen after your experienced falling initiation. I fell on the floor. 9/11 truth is too easy…
The same holds true for the WTC towers if you understand energy. After collapse initiation, the towers fell to the ground littering 19 acres around the WTC complex. With a release of over 100 TONS of TNT per tower, we see the results of the energy from the tower falling, total devastation. Over the energy of 200 2000 pound bombs. Clearly anyone can understand energy, or can they?

So after there was local failure with lots of mass above it, you have enough energy and weight to destroy floors below, and damage the core structure, and sheer away the exterior shell. The lower floors only needed 25,000,000 pounds of debris alone to cause failure. The unique structure of the WTC give you what you saw on 9/11. The massive amounts of wallboard, thousands of ceiling tiles covering 110 acres of floors, and the soft friable insulation under the floors give us the massive dust clouds see as massive amounts of energy were released as the building fell. even a floor in the WTC can only hold 25,000,000 pounds,

Answer is; they fell.

It is sad to note, 9/11 truth believes mass is gone if it not in it's original form. Like a building falling, if the top floors are all just a lump of steel and concrete with desks and rugs curtain etc, it can not destroy the lower section of the WTC. So when Mount St Helens blew up, after it was in tiny pieces of rock and dirt rushing down the hill, it could not damage the area like it did, someone had to plant thermite under all the trees to make it happen.

This is the thinking of 9/11 truth! They lack basic understanding of the physical world and prefer fantasy and CT thinking. Total failure.


Answer is; they fell. 9/11 truth can not figure it out, given the answer. Like when the teacher stomps her foot during review for final, 9/11 truth is not paying attention.

 

[e^n]

"The fact that the crush-up of entire stories cannot occur simultaneously with the crush-down is demonstrated by the condition of dynamic equilibrium of compacted layer B, along with an estimate of the inertia force of this layer due to vertical deceleration or acceleration...the hypothesis that the crush-down and crush-up cannot occur simultaneously is almost exact."
Bazant et al.

If you think this is at odds with what I said then you should re-read Bazant's paper. The reason that they do not occur simultaneously is that as the upper block resists more, the compacted layer of debris also resists more to the upper block. Unfortunately for the building, gravity only affects these sections in one direction and so the lower block will feel the majority of the force and the upper block will only be affected by the resistance of lower floors.

Perhaps you could explain very explicitly what you believe Bazant to be saying, and I will explain how my opinion differs.

 

[pomeroo]

We have engineers, physicists, chemists, and architects here, all of whom know this is all woo, and these guys without a lick of scientific training think they can prove us wrong? Well, if they could, it would only be because they would have learned the science for themselves, and they are either too lazy or too stupid to do it.

You make an important point. I constantly receive e-mails from deranged no-planers who insist that a "real" plane would have bounced off the building, or blown up outside, or whatever. Ryan Mackey was gracious enough to supply a clear and concise explanation of the physics involved. Now, of course, the loons are screaming that he doesn't know what he's talking about. Imagine--a NASA scientist being called ignorant by people who don't know a frikkin' thing about science!

But that prompts me to ask how they think they'll get their revolution off the ground. Suppose they manage to provoke a new investigation. A Senate committee holds hearings and "Heiwa" finds himself opposite some real engineers. He spouts his insane gibberish and is informed that his understanding is hopelessly deficient; everything he claims is wrong. So, we're right back to square one: EVERYONE,except the loons, is part of the Impossibly Vast Conspiracy and is lying.

 

[BenBurch]

... EVERYONE,except the loons, is part of the Impossibly Vast Conspiracy and is lying.

And those equations; THEY ARE TOOLS OF THE DEVIL!!!

 

[tanabear]

It is not far less dense. Destroyed or not destroyed, the upper block has the same specific gravity as the lower block. It's made of the same materials. Very little falls outside the footprint early on -- it can't. It hasn't hit enough stuff to impart enough momentum to move that material.

The top of the towers are mushrooming. How can the density be the same if it is occupying a larger volume? If the diameter of the dust clouds are increasing then in what way can the density remain the same?

It is not a meaningless phrase. I explained it to you two posts back. "Pancake initiation" means the collapse started because floors came loose from the columns, triggered other floor connection failures, and thereby destabilized the columns. Quite meaningful. And in WTC 1 and 2 it did not happen.

Right, that is sometimes referred to as truss failure. This did not happen according to NIST.

At initiation, there is no pancaking. Collapse is caused by buckling of columns with floors still attached. The attachment is central to the model.

Long after initiation, there is pancaking. We know this because a very large remnant of the core survived after the collapse had passed it, for a few seconds anyway. At this stage, floors are detaching at the connections, which should surprise no one.

The mistake you make, I'm beginning to suspect out of breathtaking idiocy, is to equivocate initiation and not initiation. Ergo, the one playing Humpty Dumpty is you.

Before you asked about initiation, and that's what I told you about. Your mistake was assuming the mechanism at initiation was the same as the mechanism all the way to the ground. Obviously, this is a bad assumption.

Keep reading the above until you understand.

You seem to believe in what I term the pile-driver pancake explanation for the collapse of the towers. Previously you stated,

"After a few floors collapse, the upper block is riding on a cushion of debris, and relatively smooth behavior is guaranteed...It will quickly become larger than the upper block, and it is responsible for most of the crushing..."

This is not a pancake collapse. Then at some point, this "cushion of debris" stops crushing the lower block and then a pancaking process begins. So how long after initiation does pancaking begin and why does it begin? Is it started by truss failure? If this "cushion of debris" is responsible for most of the crushing then what percentage is pancaking responsible for? Are there any videos or photographs that show this switch over?

Nevertheless, a pile-driver pancake sounds more like something that might be on the breakfast menu at Denny's, then a viable explanation for how the towers were destroyed.

Yes. Since when is the majority, holding the majority view, backed up by the majority of experts a 'cult'?

A cult is characterized by how its practitioners reason. It doesn't matter if it is numerical majority or minority.

Yes, one person can't seem to comprehend the most basic physics that everyone else has no trouble understanding. But it clearly is the fault of everyone else...

If NIST science, relating to how towers were destroyed, is well understood then it should be applicable to the real world. If you were assigned with the task of demolishing a steel-frame high-rise using NIST science, could you give me them your method using only impact damage and fire? If not, NIST science is nothing more than cartoon physics.

Did you even read my post?

Do you understand what I bolded?
The density does not matter (and it will be more dense, not less). The moving mass is what matters. And as has been pointed out, not much is falling outside the building. And what does fall away is more than made up for by the added mass from the floors of the lower section that are destroyed.

The towers were becoming more dense as they were destroyed? They were taking up a smaller area? The video and photographic record do not support that claim.

Actually, it does matter if the upper block was pulverized or not. Take the following example. Bazant and others assume the upper block falls onto the lower block from a height of 3.7 meters, roughly one floor. Let's assume that instead of an intact upper block, the non-metallic portions have already been pulverized down to a size between 1 and 100 microns. Then this pulverized mass is dropped onto the lower block, will the effect on the lower block be same as if the upper block was dropped intact?

Another example. Take a cardboard box and fill it full of sand. Then drop it on an aluminum can. Then perform the same experiment but instead of dropping the box as one unit, open the bottom and have the sand pour out as individual grains. Which experiment will have the best chance of crushing the aluminum can if dropped from the same height? The moving mass may be the same but not the force at which it impacts the lower block.

This is why Bazant et al. require the upper block to be intact as it plows its way through the lower block. This is also why they state the that video tape record of the collapse is only useful for the first couple of seconds. After the first couple of seconds, the upper block is pulverized.

 

[pomeroo]

The top of the towers are mushrooming. How can the density be the same if it is occupying a larger volume? If the diameter of the dust clouds are increasing then in what way can the density remain the same?



Right, that is sometimes referred to as truss failure. This did not happen according to NIST.



You seem to believe in what I term the pile-driver pancake explanation for the collapse of the towers. Previously you stated,

"After a few floors collapse, the upper block is riding on a cushion of debris, and relatively smooth behavior is guaranteed...It will quickly become larger than the upper block, and it is responsible for most of the crushing..."

This is not a pancake collapse. Then at some point, this "cushion of debris" stops crushing the lower block and then a pancaking process begins. So how long after initiation does pancaking begin and why does it begin? Is it started by truss failure? If this "cushion of debris" is responsible for most of the crushing then what percentage is pancaking responsible for? Are there any videos or photographs that show this switch over?

Nevertheless, a pile-driver pancake sounds more like something that might be on the breakfast menu at Denny's, then a viable explanation for how the towers were destroyed.



A cult is characterized by how its practitioners reason. It doesn't matter if it is numerical majority or minority.



If NIST science, relating to how towers were destroyed, is well understood then it should be applicable to the real world. If you were assigned with the task of demolishing a steel-frame high-rise using NIST science, could you give me them your method using only impact damage and fire? If not, NIST science is nothing more than cartoon physics.



The towers were becoming more dense as they were destroyed? They were taking up a smaller area? The video and photographic record do not support that claim.

Actually, it does matter if the upper block was pulverized or not. Take the following example. Bazant and others assume the upper block falls onto the lower block from a height of 3.7 meters, roughly one floor. Let's assume that instead of an intact upper block, the non-metallic portions have already been pulverized down to a size between 1 and 100 microns. Then this pulverized mass is dropped onto the lower block, will the effect on the lower block be same as if the upper block was dropped intact?

Another example. Take a cardboard box and fill it full of sand. Then drop it on an aluminum can. Then perform the same experiment but instead of dropping the box as one unit, open the bottom and have the sand pour out as individual grains. Which experiment will have the best chance of crushing the aluminum can if dropped from the same height? The moving mass may be the same but not the force at which it impacts the lower block.

This is why Bazant et al. require the upper block to be intact as it plows its way through the lower block. This is also why they state the that video tape record of the collapse is only useful for the first couple of seconds. After the first couple of seconds, the upper block is pulverized.

The comical fraud Heiwa had the good sense to flee the scene of his humiliation. You really don't understand a word that anyone writes, do you?

 

[beachnut]

As soon as the debris on one floor below exceeds 25,000,000 pounds, the floor fails and hits the next floor. You can hear this happening on 9/11.

Just weight. BTW, the towers collapse energy was greater than the energy of 100 2000 pound bombs. With no thermite or RDX added! Sorry, but a course in physics will cure your inability to understand energy and 9/11, mr. T.

 

[pomeroo]

As soon as the debris on one floor below exceeds 25,000,000 pounds, the floor fails and hits the next floor. You can hear this happening on 9/11.

Just weight. BTW, the towers collapse energy was greater than the energy of 100 2000 pound bombs. With no thermite or RDX added! Sorry, but a course in physics will cure your inability to understand energy and 9/11, mr. T.

Beachnut, you are too optimistic. He would have to pass the course.

 

[Cl1mh4224rd]

The top of the towers are mushrooming. How can the density be the same if it is occupying a larger volume? If the diameter of the dust clouds are increasing then in what way can the density remain the same?

You might want to read that part of his post again. You're arguing against something he never said...

 

[Grizzly Bear]

Another example. Take a cardboard box and fill it full of sand. Then drop it on an aluminum can. Then perform the same experiment but instead of dropping the box as one unit, open the bottom and have the sand pour out as individual grains. Which experiment will have the best chance of crushing the aluminum can if dropped from the same height? The moving mass may be the same but not the force at which it impacts the lower block.

I saw this and stared at it for over an hour trying to comprehend what the hell this was... You're not only making the box a completely solid object by adding the mass of 'sand' into it, but you're also trying to make a comparison with dropping it onto a aluminum can. I'm not sure an experiment can get much weirder than that... this even tops Gage's analogy... and then pouring only the 'sand' onto the can... Explain to me how this in any way compares to the towers...

 

[Jonnyclueless]

I just read Tanabears post.

If there was a fly in the room, it would have flow right in my mouth...

 

[Jwheelz]

I saw this and stared at it for over an hour trying to comprehend what the hell this was... You're not only making the box a completely solid object by adding the mass of 'sand' into it, but you're also trying to make a comparison with dropping it onto a aluminum can. I'm not sure an experiment can get much weirder than that... this even tops Gage's analogy... and then pouring only the 'sand' onto the can... Explain to me how this in any way compares to the towers...

When Marvin hit the tops of each tower with the "space modulator" everything above the impact zones was magically turned into super fine nano-thermite particles which then caused very loud silent explosions in the lower block with steel beams being shot out into neighboring buildings. It was the most perfect freefall collapse perfectly within it's own footprint ever seen by anyone. This allowed the debris to land perfectly on the flatbed trailers waiting to haul it away.

 

[R.Mackey]

The top of the towers are mushrooming. How can the density be the same if it is occupying a larger volume? If the diameter of the dust clouds are increasing then in what way can the density remain the same?

The dust clouds make up an estimated 1% of the total mass. They are insignificant.

Right, that is sometimes referred to as truss failure. This did not happen according to NIST.

Actually truss failure is yet a third mechanism -- the truss chords themselves failing under tension. This is different than either (a) trusses contributing to column failure, or (b) trusses breaking free of the columns at the connections. However, it is correct (if a total non sequitur) that NIST does not believe this happened, and for good reason.

You seem to believe in what I term the pile-driver pancake explanation for the collapse of the towers. Previously you stated,

"After a few floors collapse, the upper block is riding on a cushion of debris, and relatively smooth behavior is guaranteed...It will quickly become larger than the upper block, and it is responsible for most of the crushing..."

This is not a pancake collapse. Then at some point, this "cushion of debris" stops crushing the lower block and then a pancaking process begins. So how long after initiation does pancaking begin and why does it begin? Is it started by truss failure? If this "cushion of debris" is responsible for most of the crushing then what percentage is pancaking responsible for? Are there any videos or photographs that show this switch over?

One correction before I answer: At no point does the debris layer, between the upper block and what remains of the lower block, stop crushing the lower block. I have no idea where you got that from. It is massive, it is moving downward, therefore it crushes.

Now then, the transition from the initial progressive collapse to a pancaking effect is a complicated question. It's totally irrelevant from a building performance perspective, but we can investigate it anyway out of sheer curiosity.

During the collapse, floor by floor an enormous impulse is applied to each set of columns and floors. At some point, energetically the failure mode will favor the floors tearing free of their connections before the core columns buckle. The collapse has enough energy to induce both of these failure modes -- the question is merely which one happens first.

Which one happens first is a function of how fast the descending mass is falling. Since the falling mass is largely composed of debris, and the upper block is at an angle in any event, the impact will not be a sudden column-on-column impact. Instead, columns will experience a complex load, and the floors will see a sudden increase in load as well.

The question is, how great is the load on the floors? If the load is low enough, the connections -- which are far stronger than needed for ordinary use -- will survive for a fraction of a second, so rather than tear the floors loose, the floors stay intact while the columns buckle. Once the columns buckle the whole assembly falls, and the load is released until the next floor. However, once the upper mass gets large and fast enough, there simply isn't time for the connections to do this. As Dr. Bazant explained in his rebuttal of Dr. Jones et al., no structure can support a stress wave beyond its plastic limit, so once that upper mass gets moving fast enough, the floors shear before materially affecting the columns. After this point, the collapse transitions from the initial inward buckling failure to a "pancake" collapse.

I don't know precisely when this will happen, but it is after a few to a few tens of floors. We can also partially see this effect because, once it sets in, the core can now resist the collapse wave intact. Once the floors shear, the core structure is almost purely vertically loaded, with random side forces approximately cancelling out by virtue of being in the center of the collapse. So they can actually spear through the collapse in reasonably good shape. This does in fact happen for both Towers, leaving remnants several tens of floors high, for a few seconds.

As you should now be aware, all of your questions can be answered. It just may not be the answer you expect, or the one you like. But they're really fairly straightforward.

 

[NobbyNobbs]

[qimg]http://i203.photobucket.com/albums/aa213/j4m3zz/marvin.jpg[/qimg]

When Marvin hit the tops of each tower with the "space modulator" everything above the impact zones was magically turned into super fine nano-thermite particles which then caused very loud silent explosions in the lower block with steel beams being shot out into neighboring buildings. It was the most perfect freefall collapse perfectly within it's own footprint ever seen by anyone. This allowed the debris to land perfectly on the flatbed trailers waiting to haul it away.

But where's the "ka-boom"? There's supposed to be an earth-shattering "ka-boom"!

 

[X]

The towers were becoming more dense as they were destroyed? They were taking up a smaller area? The video and photographic record do not support that claim.

I've been thinking about how to reply to this all day.
I'm still not sure. It's almost as though you think the entire mass of the upper section was converted to dust, and expanded out into the surrounding air.
That is the only explanation I can think of that accounts for your statement.

I really shouldn't have to sat this, but it is wrong.

There was dust, this is true. But as has been pointed out already, the dust clouds consist of a very small amount of matter. And most of that was easily crushed stuff like sheetrock and office equipment.

The rest of the upper section (a amount so large as to render the mass of dust meaningless) came down. Hard. And as it built up a layer of collapsed structure, it increased in mass and density.

Density is defined as mass per unit volume. If you take the mass of, say, five floors, and collapse that into the volume of one floor (an arbitrary choice), then it has become denser. This is grade-school physics.

Actually, it does matter if the upper block was pulverized or not. Take the following example. Bazant and others assume the upper block falls onto the lower block from a height of 3.7 meters, roughly one floor. Let's assume that instead of an intact upper block, the non-metallic portions have already been pulverized down to a size between 1 and 100 microns. Then this pulverized mass is dropped onto the lower block, will the effect on the lower block be same as if the upper block was dropped intact?

Another example. Take a cardboard box and fill it full of sand. Then drop it on an aluminum can. Then perform the same experiment but instead of dropping the box as one unit, open the bottom and have the sand pour out as individual grains. Which experiment will have the best chance of crushing the aluminum can if dropped from the same height? The moving mass may be the same but not the force at which it impacts the lower block.

This is why Bazant et al. require the upper block to be intact as it plows its way through the lower block. This is also why they state the that video tape record of the collapse is only useful for the first couple of seconds. After the first couple of seconds, the upper block is pulverized.

Poor analogy. Extremely poor.
The reduced surface area of impact and the pouring of the sand as individual grains make the two scenarios not even remotely similar.

Tell you what: re-do the second experiment, with a sheet of particle board the same size as the box (bottom area) sitting atop the can.
Then, dump all the sand at once (don't pour it) onto the particle board.

Remember, the upper section had, for all intents and purposes, no support after it began collapsing. The "dust" you cling so desperately to would not obligingly pour down, one grain at a time. It would all come down at once.

BOOM!

Either way, a lot of mass impacting over a very short period of time.

Are familiar with the concept of "Impulse", Tanabear?

[latex]J = \int F dt

F = ma

J = \int ma dt = m\triangle v [/latex]

Note the "dt" term. With respect to time.
This is the area your analogy fails.
The same mass (sand in box, sand poured grain-by-grain) but over vastly different times.
And that is assuming the same amount of mass hits the can.




By the way: What does this have to do with the difference in appearance between the Twin Towers and a real controlled demolition involving explosives?

 

[Tartarus]

The dust clouds make up an estimated 1% of the total mass. They are insignificant.

What is your source for this statistic and how is it calculated? By dust cloud do you mean the percent of the mass that was ejected outside the perimeter of the tower during the collapse?

The question is, how great is the load on the floors? If the load is low enough, the connections -- which are far stronger than needed for ordinary use -- will survive for a fraction of a second, so rather than tear the floors loose, the floors stay intact while the columns buckle.

Are you speaking of the core columns, the perimeter columns or both? And by buckle, do you mean snap?

Once the columns buckle the whole assembly falls, and the load is released until the next floor. However, once the upper mass gets large and fast enough, there simply isn't time for the connections to do this. As Dr. Bazant explained in his rebuttal of Dr. Jones et al., no structure can support a stress wave beyond its plastic limit, so once that upper mass gets moving fast enough, the floors shear before materially affecting the columns. After this point, the collapse transitions from the initial inward buckling failure to a "pancake" collapse.

But is the debris that is doing the crushing moving faster than the floors are pancaking? And if the debris is still moving faster and doing most of the crushing, in what way does it make sense to refer to this "collapse" as a pancake?

I don't know precisely when this will happen, but it is after a few to a few tens of floors. We can also partially see this effect because, once it sets in, the core can now resist the collapse wave intact.

Why is the core now able to resist the collapse if the downward mass is getting larger and faster?

Once the floors shear, the core structure is almost purely vertically loaded, with random side forces approximately cancelling out by virtue of being in the center of the collapse. So they can actually spear through the collapse in reasonably good shape. This does in fact happen for both Towers, leaving remnants several tens of floors high, for a few seconds.

As you should now be aware, all of your questions can be answered. It just may not be the answer you expect, or the one you like. But they're really fairly straightforward.

Any question can be "answered," but this does not mean your answers are reasonable, accurate or scientifically demonstrable. Your "answer" is just a string of unprovable and random assertions.

Try this. Create a visual simulation of the collapse of one of the towers minus the dust cloud. That way we can actually "see" what you think is going on, and if it is scientifically plausible.

 

[Tartarus]

I saw this and stared at it for over an hour trying to comprehend what the hell this was... You're not only making the box a completely solid object by adding the mass of 'sand' into it, but you're also trying to make a comparison with dropping it onto a aluminum can. I'm not sure an experiment can get much weirder than that... this even tops Gage's analogy... and then pouring only the 'sand' onto the can... Explain to me how this in any way compares to the towers...

How about trying to answer the other example? In WTC1 the upper block -- the area above the impact zone -- fell 3.7 meters downward onto the lower block -- according to Bazant. However, if this upper block was first pulverized into dust and then dropped onto the lower block, would the results be the same?

 

[rwguinn]

What is your source for this statistic and how is it calculated? By dust cloud do you mean the percent of the mass that was ejected outside the perimeter of the tower during the collapse?



Are you speaking of the core columns, the perimeter columns or both? And by buckle, do you mean snap?

Buckling is a legitimate engineering term. Go look it up, and learn. Before criticizing, one should have at least a tiny bit of knowledge on the subject.

But is the debris that is doing the crushing moving faster than the floors are pancaking? And if the debris is still moving faster and doing most of the crushing, in what way does it make sense to refer to this "collapse" as a pancake?

If you's study a little, you'd know the debris gets there FIRST because that is its original position-lower down on the chunk

Why is the core now able to resist the collapse if the downward mass is getting larger and faster?

Read and comprehend the report, please.
Arguments from ignorance won't fly here

Any question can be "answered," but this does not mean your answers are reasonable, accurate or scientifically demonstrable. Your "answer" is just a string of unprovable and random assertions.

Try this. Create a visual simulation of the collapse of one of the towers minus the dust cloud. That way we can actually "see" what you think is going on, and if it is scientifically plausible.

Show us your simulation. You are making the claims.
We are not here to do your work for you.

How about trying to answer the other example? In WTC1 the upper block -- the area above the impact zone -- fell 3.7 meters downward onto the lower block -- according to Bazant. However, if this upper block was first pulverized into dust and then dropped onto the lower block, would the results be the same?

What if frogs had wings? What if 1+1=29831?
Hell, if we all had Randy Johnson's build and talent, the average MLB game would be a zero-zero no-hit tie...