WTC 1 & 2. What happened after collapse initiation?

[rwguinn]

I'm not an engineer ... but I sleep with one.

Engineers don't talk in their sleep at all. At least, not in English...

 

[tanabear]

Depends on your definition of pulverized. Anywhere from 1% to 99% depending on how large a chunk you consider "pulverized." Stop hiding behind semantics.

That sounds like a careful way to avoid answering the question. So if someone stated that only 1% of the non-metallic portions of the towers were pulverized, that would be an accurate statement?

Your confusion is greater than that I would have imagined possible in a literate being. Let me try it again with really, really small words.

The upper block is on top of the debris. They fall together. They fall because there is nothing that can hold them up. They hit floors. They break floors loose. Broken floors add to the pile of debris. The part that is debris gets bigger. This falls on more floors. They break too. By the time all the floors break, there is no building left, just a big pile of debris, maybe with some of the upper block still on top. It falls until it hits the ground. Only the ground is strong enough to stop the pile of debris. The upper block slowly comes apart as it falls. It comes apart because it isn't designed to stand on a shifting pile of debris. If some of the the upper block is still there when the debris hits the ground, the upper block then crumbles too, because the debris stops when it hits the ground. When the debris stops the upper block feels more resistance. It can't handle this. It breaks too. Nothing left but debris.

So the upper block is merely riding this cushion of debris down the tower. If there is a separation between the lower block and the upper block, after a couple of floors, the material for this "cushion of debris" will primarily come from the lower block. So it is really the lower block consuming itself. That sounds similar to what happened to Pizza the Hut in the movie SpaceBalls. He was trapped in the back of his stretched limo and ate himself to death. Essentially falling debris would have to destroy the entire tower. But how is this possible? Can debris falling less than the speed of gravity pulverize building material, cut through steel, and eject it laterally?

There would have been lots of bombs. Bombs would shatter steel and make small pieces. They would shatter windows. They would break concrete and break furniture. Small pieces would fly very fast. Just like shrapnel. They would fly all over the place. They would be like bullets in all directions. Thousands of tons of bullets -- billions of bullets! Anyone close by would be killed. This didn't happen.

This is what happened to the towers and the people that were inside them. There were hundreds of bone fragments found on the top of the Deutsche Bank building.

"Many are in the size range of one-sixteenth of an inch," said Ellen Borakove, spokeswoman for the city medical examiner's office.

That certainly sounds like an effect of explosive charges, not falling debris.

Because the debris mass is not only falling but accelerating, the upper block does not press with its full weight on the debris mass. Instead of mg the force it exerts on the debris (and that the debris exerts on it, to damage it) is m(g - a) where a is the debris mass downward acceleration. That's one reason why the upper block stays intact longer, and there's no reason to expect it to penetrate the debris mass (which again, is not "loose" but rather is compressed and far denser than the intact structure). The upper structure remains on top of the debris mass for roughly the same reason you cannot shove your foot down through several feet of gravel -- especially when you and the gravel are on an elevator descending at 1/2 to 2/3 g.

Respectfully,
Myriad

So according to your theory the upper block and lower block are compacting this intermediate layer of debris. Let's assume the upper block fell away and there wasn't anything to compress this debris, would the collapse continue in the same manner? In other words, is your theory contingent on this existence of an upper and lower block?

How dense is this layer of debris? Is it more dense than say the concrete floors?

 

[Grizzly Bear]

This is what happened to the towers and the people that were inside them. There were hundreds of bone fragments found on the top of the Deutsche Bank building.

"Many are in the size range of one-sixteenth of an inch," said Ellen Borakove, spokeswoman for the city medical examiner's office.

That certainly sounds like an effect of explosive charges, not falling debris.

Ah naw,,, couldn't possibly be 100 floors of acre-sized concrete slabs and structural frame work violently collapsing. Couldn't possibly be!

[/sarc]

Tana, ignorance must be a past time for ya

 

[BenBurch]

Engineers don't talk in their sleep at all. At least, not in English...

I actually shout things in my sleep. Like "ALL HANDS ON DECK!" and "FIRE ONE!"

Seriously.

I have interesting dreams.

 

[R.Mackey]

Attention to tanabear

I'm really not sure I should continue this discussion with you. You're making repeated mistakes that are so baffling, so counter-intuitive, that I honestly don't think you're ever going to get it.

This happens sometimes. I'm reminded of a good friend who attempted Calculus five times, and failed it every time. Finally he came to terms with his limitations, changed his major to American Literature, and now does fine work as a rehab therapist and remedial educator for high school kids with disabilities. Sometimes banging your head against the same wall isn't the answer.

There are things we all can't grasp. I can't learn German, for whatever reason. You seem to have a problem with elementary physics. What I'm hoping to avoid is the perception of picking on you, by grinding to ever simpler and more obvious answers. You won't be the first -- I once had to explain to someone here why you can't add 125 feet and 575 MPH together. No kidding.

If you find yourself getting frustrated at your lack of progress, you should probably drop it, but you should also acknowledge that your opinions on this particular subject are worthless until you understand. On the other hand, if you can handle yet another failing grade, I can try to explain... again.

That sounds like a careful way to avoid answering the question. So if someone stated that only 1% of the non-metallic portions of the towers were pulverized, that would be an accurate statement?

As I said before, it depends on your definition of pulverized. Also, is that 1% by mass or by volume?

I would accept that statement, but I would also recognize that it is a bit vague. The estimate we worked out here was that 1% of the overall mass was pulverized into "dust," meaning roughly 50 micron particles or smaller. If you exclude metals, it would be more, perhaps closer to 2%. You might consider anything smaller than 1 cm as "pulverized," in which case it would be more; I don't know how much, perhaps 5%. If you consider anything under 10 cm to be "pulverized," then it would be higher still. Etc.

So the upper block is merely riding this cushion of debris down the tower.

That's right. Think of standing on top of pile of bricks that slides down a ramp. You won't sink into the bricks, not until they come to a halt, and perhaps not even then.

If there is a separation between the lower block and the upper block, after a couple of floors, the material for this "cushion of debris" will primarily come from the lower block.

There is no separation. Never.

The upper block HITS the lower block. When it does, a portion of the lower block (and a smaller portion of the upper block) is destroyed. This creates the debris layer. All of this is still moving downward.

Then the upper block, and the debris layer, hit what remains of the lower block. More lower block and a smaller portion of upper block are destroyed. The debris layer is bigger than it was before. And it's still moving downward.

This continues all the way down. Once the debris layer is comparable to the mass of the upper block, the upper block suffers virtually zero additional damage, until the whole thing is jolted to a halt at ground level.

At no time is the upper block/debris combination "separated" from the lower block. It would have to move upward to do so, and that isn't going to happen.

We think of the lower block failing one floor at a time, but in reality the collapse isn't quite even, because the upper block has some tilt to it. So the destruction is pretty much continuous.

The material in the debris layer does, indeed, mostly come from the lower block. This is because the lower block gets hit with the full weight of debris plus upper block, whereas the upper block only absorbs its own weight, and only a portion thereof (since it is accelerating downward in partial freefall), thus the lower block suffers much, much more damage.

So it is really the lower block consuming itself. That sounds similar to what happened to Pizza the Hut in the movie SpaceBalls. He was trapped in the back of his stretched limo and ate himself to death.

No. The weight of the upper block is also applied to the lower block at all times. The debris layer, again, is mostly from the lower block, but that doesn't mean the lower block is destroying or "consuming" itself. If you could magically cause the debris and upper block to vanish mid-collapse, whatever remained of the lower block would stay standing. It is the moving upper mass that crushes the lower floors, and this mass grows as the parts it crushes are added to its total.

Regarding the "Spaceballs" analogy, in a classroom situation you would probably be warned not to mock the teacher. There is no value to your comment whatsoever.

Essentially falling debris would have to destroy the entire tower. But how is this possible? Can debris falling less than the speed of gravity pulverize building material, cut through steel, and eject it laterally?

Yes, the falling debris destroys the entire tower.

This is not a surprise. The falling debris has the same weight as the original load on any given part of the Tower (minus a small fraction due to losses over the side), since it's the exact same material. Except instead of being a static load, it's moving. The lower block sees vastly higher stresses as it tries to overcome the momentum of the upper block before it fails, and it simply cannot do this. It isn't strong enough.

Your comment "Can debris falling less than the speed of gravity..." is gobbledygook. The "speed of gravity" is the speed of light. What I think you mean is the speed as compared to the speed of a freefalling object over the same time period, and the answer is, absolutely, yes. The BLBG paper considers pulverization and the energy to fail the structural steel, and shows a vast energy surplus. A much simpler and more approximate energy budget calculation can be performed using the energy actually expended in the structure, calculated from the time of collapse -- see Appendix B of my whitepaper for details. This figure compares favorably to the destruction energy of the load bearing structure and the energy required to pulverize materials and contents to the degree seen.

Regarding "ejecting material," the energy of ejection is actually extremely low. I cover this in my whitepaper as well on pp.96-97. The furthest ejection seen implies initial velocities no greater than 30 meters per second, which is slower than the debris is falling. So it's quite easy to see how it could simply bounce out of the collapse.

This is what happened to the towers and the people that were inside them. There were hundreds of bone fragments found on the top of the Deutsche Bank building.

"Many are in the size range of one-sixteenth of an inch," said Ellen Borakove, spokeswoman for the city medical examiner's office.

That certainly sounds like an effect of explosive charges, not falling debris.

There's nothing at all about that inconsistent with the collapses, or even the initial aircraft impacts. I suspect but am not going to bother proving that those pieces were there before the collapses. This is at best assuming the consequent.

So according to your theory the upper block and lower block are compacting this intermediate layer of debris. Let's assume the upper block fell away and there wasn't anything to compress this debris, would the collapse continue in the same manner? In other words, is your theory contingent on this existence of an upper and lower block?

No, not really. I don't think the intermediate layer gets compacted very much. Solids don't compress easily. Only intact structures compress, and the debris is, by definition, not an intact structure. There may be some packing as the collapse progresses, but it really makes no difference.

If the upper block fell away, the collapse would probably halt. It depends on how much falls away, and whether any remaining debris had sufficient mass to continue the collapse.

This question is academic, however. I also show that the top cannot fall away in my whitepaper (pp. 92, 104-105, 250 ff.). It's simply too big, and there are no forces available to push it aside; if there were, it's doubtful that the upper block would survive this force, rather than simply shattering and adding to the debris pile.

How dense is this layer of debris? Is it more dense than say the concrete floors?

The density is somewhere between that of furnishings and pure steel, since it includes all of those. It would have a specific gravity somewhere between 2 and 10 or so, comparable to concrete, depending on packing. It also depends on where you define the perimeter.

The density is also not particularly relevant. It is the total mass, and therefore the total momentum, that matters. Slightly less or more dense, provided the total mass doesn't change, won't have any effect on the collapse behavior.

----

So give that a shot. I really would like to see some progress before you ask the same questions again.

 

[tanabear]

If the upper block fell away, the collapse would probably halt. It depends on how much falls away, and whether any remaining debris had sufficient mass to continue the collapse.

Okay, if the upper block fell away then the collapse would probably halt. So point to the upper block and the cushion of debris that is destroying the towers in the following pictures.

South Tower:

North Tower:

 

[R.Mackey]

Okay, if the upper block fell away then the collapse would probably halt. So point to the upper block and the cushion of debris that is destroying the towers in the following pictures.

It's obscured by the dust, which is predominantly gypsum wallboard.

Have you ever worked with sheetrock? Ever sanded or cut it? Makes a whole lot of dust, doesn't it?

Now imagine several acres of it per floor being crushed by 30,000 tons of steel and concrete.

That's all we see. We can't see the details of the more massive elements.

You may as well ask me to point to the Statue of Liberty in those photographs. Like the bulk of materials, it's all obscured by other objects.

Be honest with me, just this once: You're not even trying to understand, are you?

 

[Jonnyclueless]

So what happened after the dust launching/catapulting initiation?

 

[pomeroo]

I'm beginning to think that Heiwa may have lost faith in his fantasy.

 

[A W Smith]

Know what else makes dust besides gypsum drywall?

The fragile cellulose ceiling tiles.
The sprayed on fire proofing.
lightweight pulverized concrete.
Dust that already exists that has gathered for thirty years in the ceiling plenum.
fractured and crushed ceramic tile
fluorescent tubes from light fixtures,
soot from combustibles

 

[tanabear]

That's all we see. We can't see the details of the more massive elements.

You may as well ask me to point to the Statue of Liberty in those photographs. Like the bulk of materials, it's all obscured by other objects.

Be honest with me, just this once: You're not even trying to understand, are you?

Your theory is based on the idea that there is an upper block and a lower block separated by a cushion of debris, and after a couple of floors, this cushion of debris is responsible for most of the crushing. The upper block is riding this cushion of debris down as the building is being destroyed. You stated that as the tower is being destroyed, this cushion of debris is getting larger. So point to the upper block and tell me where this cushion of debris is located. Or state the size of this cushion compared to the size of the dust clouds we see in the above pictures. If the upper block is riding on top of this cushion, shouldn't we be able to see it?

If you were going to argue your theory in a court of law what actual empirical evidence could you advance in it's favor? If the video record of the actual collapse doesn't match your theory then it is of limited use to your explanation. Maybe that is why Bazant stated that the video tape is only useful for the first couple of seconds(i.e. it is only useful for his theory)

The argument, "It is really there we just can't see it", seems to be special pleading. It is the same type of argument made by Bush apologists, "Saddam really was producing and stockpiling WMD in 2002 and 2003 we just couldn't find them."

 

[R.Mackey]

Your theory is based on the idea that there is an upper block and a lower block separated by a cushion of debris, and after a couple of floors, this cushion of debris is responsible for most of the crushing.

Correct so far.

The upper block is riding this cushion of debris down as the building is being destroyed. You stated that as the tower is being destroyed, this cushion of debris is getting larger.

Still looking good.

So point to the upper block and tell me where this cushion of debris is located.

Houston, we have a problem.

If I point to the upper block, I'm not pointing at the debris layer.

As the above explains, the debris layer is directly below the upper block. They are in contact. Should be really simple to figure out.

Or state the size of this cushion compared to the size of the dust clouds we see in the above pictures. If the upper block is riding on top of this cushion, shouldn't we be able to see it?

The debris field is, by definition, the width of the lower block -- about 64 meters square. Any debris outside this area falls away, with nothing to slow it down, and is no longer in contact with the upper or lower block.

Its height begins at a couple of meters but grows steadily as the collapse continues, until at the very end it is almost all of the structure, a pile about twelve stories in height.

We can't see it because we can't see through dust. Since the debris layer is created by destruction of floors, and destruction of floors creates large clouds of thick, opaque dust, we don't expect to be able to see it.

Can you see through dust? How much dust does it take for you not to be able to see through it? Not much, huh?

If you were going to argue your theory in a court of law what actual empirical evidence could you advance in it's favor? If the video record of the actual collapse doesn't match your theory then it is of limited use to your explanation. Maybe that is why Bazant stated that the video tape is only useful for the first couple of seconds(i.e. it is only useful for his theory)

The video record of the actual collapse does match our theory. The timing, in particular, is a very good fit to the BLGB paper. The seismic record, which doesn't need to see through dust, is also a good fit. In fact, there is nothing that isn't a good fit to that theory. Absolutely nothing.

The argument, "It is really there we just can't see it", seems to be special pleading. It is the same type of argument made by Bush apologists, "Saddam really was producing and stockpiling WMD in 2002 and 2003 we just couldn't find them."

It isn't special pleading, and you've made a nonsense analogy. Is it special pleading for me to say that I have a brain? Well, have you ever seen it? Have I? Nonetheless, it is there.

Rather than special pleading, you are engaging in sophistry, claiming that just because we can't see through a dust cloud, we must accept the possibility that the debris layer is doing something quite extraordinary, even though every other aspect of the collapse -- including the dust cloud itself -- matches our expectations without fail. This is absurd.

 

[phunk]

The argument, "It is really there we just can't see it", seems to be special pleading.

No, your argument that it's not there is the special case. The area where it should be is obscured by dust. It's seen falling into that area, and the effects of it crushing the building below it can be seen, so for you to declare that it's not inside that cloud of dust doesn't fit the facts. There isn't enough debris spilling over the sides to account for much of the upper block, and there's no where else for it to go except over the sides, so for it to not be where we claim, it would have to magically disapear. Do you believe David Copperfield was involved?

 

[tanabear]

The video record of the actual collapse does match our theory.

If the video record does not show this upper block or this cushion of debris, then how does it support your theory?

The debris field is, by definition, the width of the lower block -- about 64 meters square. Any debris outside this area falls away, with nothing to slow it down, and is no longer in contact with the upper or lower block.

Okay, that gives me the width, but what about the height of this cushion of debris? What is its height in the picture on the right? Since the upper block is riding on top of this cushion, most of the dust cloud must be coming from the lower block. As well, the debris falling outside the tower's perimeter is falling faster than the building is being crushed, so it shouldn't be hiding the upper block. The upper block is between 30-34 floors, so it seems like you should be able to see some of it.

There isn't enough debris spilling over the sides to account for much of the upper block, and there's no where else for it to go except over the sides, so for it to not be where we claim, it would have to magically disapear. Do you believe David Copperfield was involved?

About 95% of each tower consisted of air. So the huge dust cloud might not be able to account for all of the upper block, but it could certainly comprise a fair percentage. No, it would not have to magically disappear. It could have already been largely pulverized in the above pictures.

 

[R.Mackey]

If the video record does not show this upper block or this cushion of debris, then how does it support your theory?

I told you in the last post, in the part you removed from your quote. The timing information. Before the upper block disappears into the dust cloud, its acceleration can be measured. This fits the theory.

And, again, video is not the only evidence. We have the seismic record. And we also have the final distribution of debris. All consistent with the BLBG calculations.

Okay, that gives me the width, but what about the height of this cushion of debris? What is its height in the picture on the right? Since the upper block is riding on top of this cushion, most of the dust cloud must be coming from the lower block. As well, the debris falling outside the tower's perimeter is falling faster than the building is being crushed, so it shouldn't be hiding the upper block. The upper block is between 30-34 floors, so it seems like you should be able to see some of it.

The debris is falling faster than the upper block and the debris layer, but not the dust. Dust, due to its small size, floats. Surely you were aware of this.

Dust, in addition to floating, is opaque. We can't see through it. It is being generated continuously by the debris layer. Therefore, we cannot see the debris layer until long after it stops moving, and the debris clears.

Again, very, very simple. This isn't even physics you can't grasp, it's more like Home Economics.

About 95% of each tower consisted of air. So the huge dust cloud might not be able to account for all of the upper block, but it could certainly comprise a fair percentage. No, it would not have to magically disappear. It could have already been largely pulverized in the above pictures.

The fraction of each Tower that was open space has no bearing on the dust generated. The huge dust cloud, again, makes up a very small percentage of the total mass. And it is largely pulverized. That's why it's dust. If it wasn't pulverized, it wouldn't be dust.

I can no longer detect where you're going at all.

 

[rwguinn]

I told you in the last post, in the part you removed from your quote. The timing information. Before the upper block disappears into the dust cloud, its acceleration can be measured. This fits the theory.

And, again, video is not the only evidence. We have the seismic record. And we also have the final distribution of debris. All consistent with the BLBG calculations.



The debris is falling faster than the upper block and the debris layer, but not the dust. Dust, due to its small size, floats. Surely you were aware of this.

Dust, in addition to floating, is opaque. We can't see through it. It is being generated continuously by the debris layer. Therefore, we cannot see the debris layer until long after it stops moving, and the debris clears.

Again, very, very simple. This isn't even physics you can't grasp, it's more like Home Economics.



The fraction of each Tower that was open space has no bearing on the dust generated. The huge dust cloud, again, makes up a very small percentage of the total mass. And it is largely pulverized. That's why it's dust. If it wasn't pulverized, it wouldn't be dust.

I can no longer detect where you're going at all.

It is all quite simple. By putting fingers in the ears, one cannot hear what is said. If you cant hear it, nothing has been said.
By the same token, closing the eyes means you can't see it, and if you can't see it, it didn't happen.
Thus, obscured by dust=can't see=didn't happen.
Sabe's tu?

 

[Newtons Bit]

It is all quite simple. By putting fingers in the ears, one cannot hear what is said. If you cant hear it, nothing has been said.
By the same token, closing the eyes means you can't see it, and if you can't see it, it didn't happen.
Thus, obscured by dust=can't see=didn't happen.
Sabe's tu?

Can I do the same thing with therm*te?

 

[rwguinn]

Can I do the same thing with therm*te?

Only if you use it to pull higher brain functions

 

[Heiwa]

I'm beginning to think that Heiwa may have lost faith in his fantasy.

Actually all observations in my paper http://heiwaco.tripod.com/nist3.htm are still valid. No evidence of intact WTC upper blocks free falling anywhere on 911, of impacts, of crush downs during destruction or crush ups of the upper blocks at end of destructions have been presented ... except that they are hidden in the dust, débrise and rubble clouds, i.e. you have to believe they took place.
Actually an upper block, quite light structure, cannot destroy the lower, much stronger, structure according any law of physics. The lower structure will infact destroy the upper block if the latter actually drops down on the former ... and when the upper block is completely destroyed, the destruction would arrest.
But the upper block cannot even free fall drop down at all. All potential energy released is absorbed or consumed by local failures in the initiation zone, i.e. according laws of physics and simple energy calculations the upper block would always remain on top of the initiation zone, i.e. any collapse would be arrested at once.
However, it seems that members of a powerful sect believe differently ... and it is just typical sect mentality, i.e. a question of faith and pure fantasy. Has nothing to do with real physics.

 

[~enigma~]

Actually an upper block, quite light structure, cannot destroy the lower, much stronger, structure according any law of physics. The lower structure will infact destroy the upper block if the latter actually drops down on the former ... and when the upper block is completely destroyed, the destruction would arrest.

Heiwa, how about you do an experiment. Take a quarter ton (500 lb) vending machine, one that you can probably push across the floor by yourself and tip it forward onto the edge. Release it and jump away really fast because after it slips about 2 feet it is moving at a rate of 2 meters per second and exerting a force in excess of one ton. I would like you to find a human body that could stop more than 1 ton of crushing force. This was a 500 pound object. In the same vein, take the upper 15 story block of the WTC and after the first 0.5 second of slippage can you explain what force could have stopped it? Simple question and you will be the first and ONLY person in the history of the planet that could answer it. We are all ears...