Science fail 3: supporters of NIST physics still relying on faith, foggy notions, over logic

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Fidel

So it seems you're still wild about collapse down-up theory with inelastic collision,

[url=http://911blogger.com/node/19384]Anders Bjorkman: AE911Truth.org[/url] said:

Björkman Axiom wrote:
A smaller part of an isotropic or composite 3-D structure, when dropped on and impacting a greater part of same structure by gravity from above, cannot one-way crush down the greater part of the structure.

In other words, an isotropic(uniformity in all directions) structure A(lower blocks of floors) can not be destroyed by a part C(upper block according to Bazant and Greening's model) (C ≈= 1/10 A) by part C falling on A by gravity alone. Part C either bounces off A or is damaged upon impact with A or is stopped by A with A suffering damage. More simply, Part C will not annihilate part A.

The ridiculous one-way crush down-up theory proposed by Bazant and Greening assumes a rigid upper block. This is so whacky that I don't even think NIST dares to be associated with it. Or do they?

 

jas

jas wrote:

The video in this post (direct google vid link here) has some good close-ups of the I think it's the North Tower. It's also a really good video for showing the collapse time, because there's audio with it.

Here actually is the original video link posted by "Bob and Bri". The google vid seems to have been posted by someone else.

http://revver.com/video/59686/september-11-2001-what-we-saw/

jas

Pants-of-dog wrote:

Where does this "accreted material" come from? How does it come to rest on top of the intact block?

The accreted material is the pulverized material that gets crushed between the falling floors and the intact floors in the progressive collapse hypothesis. Accrete is another word for accumulate. I say that it "rests" on top of the intact block because if it doesn't get ejected out, where else would it go? Things tend to fall down rather than up--unless of course you want to dispute that, too.

Pants-of-dog wrote:
Please provide a link to this video. Thank you.

Pants-of-dog wrote:
By the way, the upper blocks never suffered fire damage.

Heh.

pants wrote:

It has 12 feet to build up that kinetic energy (not potential energy). Are you aware of the difference between potential energy and kinetic energy?

I may be misusing the term. I thought potential energy was energy available that has not yet been used. Would a block of floors that wanted to crush through a lower floor but haven't yet done so not possess potential energy?

Either way, 12 feet is not much height, considering the block has just crushed through 284 steel columns, concrete, and whatever other contents existed on those floors: stairwells, elevator shafts, the central supporting columns, furniture, that kind of thing. It's not 12 feet of air. It's not a drop from a height, it is (supposedly) a crushing through.


This photo shows that the fire spread to other upper floors in WTC1.

The video in this post (direct google vid link here) has some good close-ups of the I think it's the North Tower. It's also a really good video for showing the collapse time, because there's audio with it.

This photo (8/12) shows smoke issuing from all floors and a live source of smoke in one of the very top floors, left corner. These Toronto Sun pics also show an excellent view of the pyroclastic-like clouds that were created, as well as, in this pic, (4/12) the seeming dissolution of the building at the collapse wave, with no upper block visible whatsoever. It's as if the building is a fountain, spewing powder.

Again, I don't support the fire argument, so I don't care if you want to argue that fire didn't cause weakening below the impact zones. I agree that it didn't. But I think it's plausible to state that the fire did spread upwards beyond the impact zones--not that, again, it makes any difference to my argument. The main point I raise here, though, is that NIST does argue that fire weakened the floors below the impact zones, and the threads to which you have been contributing here are discussing the NIST theory, not the Pants-of-dog theory. So, again, if you don't have a basic understanding of the argument NIST puts forward, I would ask you to stay out of the thread or start your own thread outlining your own theory.

We're also not here to do your research for you. If you're going to argue against such basic things as the fires didn't reach the upper floors, or that you don't know what pancaking means in the context of WTC collapses, I would again ask you to read up on some of the older threads, as I will not keep going back to a definition of terms, or a re-argument of points that have already been discussed or are plainly obvious. OK?

Pants-of-dog

Fidel wrote:

So it seems you're still wild about collapse down-up theory with inelastic collision,

[url=http://911blogger.com/node/19384]Anders Bjorkman: AE911Truth.org[/url] said:

Björkman Axiom wrote:
A smaller part of an isotropic or composite 3-D structure, when dropped on and impacting a greater part of same structure by gravity from above, cannot one-way crush down the greater part of the structure.

Your "engineer" seems to be ignorant of what an [url=http://en.wikipedia.org/wiki/Axiom]axiom[/url] is, and is unaware that naval arhcitecture uses models that deal with stresses in all 3 dimensions, while civil engineers using static models only have to deal with stresses in one direction (i.e. due to gravity).

Fidel wrote:
In other words, an isotropic(uniformity in all directions) structure A(lower blocks of floors) can not be destroyed by a part C(upper block according to Bazant and Greening's model) (C ≈= 1/10 A) by part C falling on A by gravity alone. Part C either bounces off A or is damaged upon impact with A or is stopped by A with A suffering damage. More simply, Part C will not annihilate part A.

The ridiculous one-way crush down-up theory proposed by Bazant and Greening assumes a rigid upper block. This is so whacky that I don't even think NIST dares to be associated with it. Or do they?

The WTC buildings did not have a uniform structure in all directions. Therefore, even if the Bjorkman Axiom is correct (which I hesitate to believe) it is inapplicable to our discussion.

 

Fidel

Well some of us might smirk just a little concerning this part of Bjorkman's reply to Frank Greening: Laughing

 

Bjorkman wrote:
'Are you working for the perpetrators of the controlled demolitions of WTC 1,2,7 or some agents of those? Do you think you can convince anyone with your unscientific nonsense? Why do you do it? Why not simply shut up like most other poor bastards and don't say anything'

Pants-of-dog

jas wrote:
The accreted material is the pulverized material that gets crushed between the falling floors and the intact floors in the progressive collapse hypothesis. Accrete is another word for accumulate. I say that it "rests" on top of the intact block because if it doesn't get ejected out, where else would it go? Things tend to fall down rather than up--unless of course you want to dispute that, too.

So, you are actually agreeing with me to an extent. You are saying that the accreted matter is caused by the impact of the upper block and the lower block. This is what I said. You say it falls on the lower block. This is also what I said. But after that we apparently part ways. You seem to think that the matter falls down from the impact and lands on the lower floors, and then the upper block falls down from the same impact and lands on the accreted matter and the lower floor.

This is simply wrong. Remember the archetypal tale of Galileo on top of the Tower of Pisa, dropping two balls of different weights, and watching them both hit the ground at the same time? This story illustrates a principle of physics that you are apparently unaware of: all objects fall at the same rate (unless they encounter some resistance, obviously).

So, if the matter is dislodged during the impact with the upper floor, then the "accreting matter" and the upper floor will then fall towards the lower block at the exact same time. This is why the "accreted matter" gets added to the mass of the falling upper block: because it is falling with the upper block.

jas wrote:
Heh.

I may be misusing the term. I thought potential energy was energy available that has not yet been used. Would a block of floors that wanted to crush through a lower floor but haven't yet done so not possess potential energy?

The falling upper block has potential energy, yes. But it does not build up potential energy as it falls. The upper block translates potential energy into kinetic energy as it falls. So, as it falls, it loses potential energy.

jas wrote:
Either way, 12 feet is not much height, considering the block has just crushed through 284 steel columns, concrete, and whatever other contents existed on those floors: stairwells, elevator shafts, the central supporting columns, furniture, that kind of thing. It's not 12 feet of air. It's not a drop from a height, it is (supposedly) a crushing through.

You should be more consistent in your claims. Either it crushed the entire floor, as you claim here, or matter was also ejected, as you claim above. You don't get to make both claims as they contradict each other.

jas wrote:
This photo shows that the fire spread to other upper floors in WTC1.

No, it shows a fire on the upper floor. It does not show that the fire spread there. Considering the damage to the electrical, mechanical and fire protectin sytmes in the building, is it entirely possible for fires to also start elsewhere. However, for the purposes of arguing that the upper block may have been damaged by fire, you have provided evidence that there were fires in the upper block of one of the towers.

You have satisfied the burden of proof for that particular claim. Well done.

jas wrote:
The video in this post (direct google vid link here) has some good close-ups of the I think it's the North Tower. It's also a really good video for showing the collapse time, because there's audio with it.

That's nice. Is it supposed to also provide evidence for something?

jas wrote:
This photo (8/12) shows smoke issuing from all floors and a live source of smoke in one of the very top floors, left corner.

Yes, it certainly does look like another view of the same fire from your first picture.

jas wrote:
These Toronto Sun pics also show an excellent view of the pyroclastic-like clouds that were created, as well as, in this pic, (4/12) the seeming dissolution of the building at the collapse wave, with no upper block visible whatsoever. It's as if the building is a fountain, spewing powder.

Pyroclastic-like clouds? Is that like a geological term, but actually meaningless? It's a dust cloud, jas.

jas wrote:
Again, I don't support the fire argument, so I don't care if you want to argue that fire didn't cause weakening below the impact zones. I agree that it didn't. But I think it's plausible to state that the fire did spread upwards beyond the impact zones--not that, again, it makes any difference to my argument. The main point I raise here, though, is that NIST does argue that fire weakened the floors below the impact zones, and the threads to which you have been contributing here are discussing the NIST theory, not the Pants-of-dog theory. So, again, if you don't have a basic understanding of the argument NIST puts forward, I would ask you to stay out of the thread or start your own thread outlining your own theory.

Two things:

First of all, I would like a quote from an NIST report, plus a link to the actual report, confirming your bolded statement.

Secondly, even if fire did spread to the upper blocks, the structural steel of the upper block would still have intact fireproofing around it. therefore, even if the flammable contents (desks, paper, computer plastics, etc.) of the upper floors did burn, the structure itself would not have been appreciably weakened.

jas wrote:
We're also not here to do your research for you. If you're going to argue against such basic things as the fires didn't reach the upper floors, or that you don't know what pancaking means in the context of WTC collapses, I would again ask you to read up on some of the older threads, as I will not keep going back to a definition of terms, or a re-argument of points that have already been discussed or are plainly obvious. OK?

Please provide a link to one of the older threads where you provide a defintion of pancaking. Thank you.

By the way, I would like to congratulate you again on providing such clear evidence that there was a fire on one of the upper blocks. 

Pants-of-dog

Fidel wrote:

Well some of us might smirk just a little concerning this part of Bjorkman's reply to Frank Greening: Laughing

 

Bjorkman wrote:
'Are you working for the perpetrators of the controlled demolitions of WTC 1,2,7 or some agents of those? Do you think you can convince anyone with your unscientific nonsense? Why do you do it? Why not simply shut up like most other poor bastards and don't say anything'

Please note that Mr.Bjrokman's reply to Frank Greening shows no knowledge of physics or engineering, but does show more than a little rudeness.

jas

Pants-of-dog wrote:

You should be more consistent in your claims. Either it crushed the entire floor, as you claim here, or matter was also ejected, as you claim above. You don't get to make both claims as they contradict each other.

Actually, I'm not defending the progressive collapse theory - you are. But the video evidence shows us that much matter was ejected laterally, as well as reports of wrecked cars and steel pieces lodged in neighbouring buildings. Simple common sense would also tell us that matter can be ejected outwards when a floor is crushed between two other floors.

I believe it's you who needs to decide what it is you're arguing. It's still not clear from your numerous and wordy posts.

pants wrote:
That's nice. Is it supposed to also provide evidence for something?

Yes, it also shows that fire was present on numerous floors in the upper block of WTC1. A claim you denied several times. It would also be a really good video for you to watch as you seem to have a pretty foggy notion of how the buildings collapsed in reality.

pants wrote:

Pyroclastic-like clouds? Is that like a geological term, but actually meaningless? It's a dust cloud, jas.

Pyroclastic is a good term because it points out how similar to volcanic ash plumes the WTC dust plumes were - totally unlike any  natural building collapse or even controlled demolition.

pants wrote:
Secondly, even if fire did spread to the upper blocks, the structural steel of the upper block would still have intact fireproofing around it. therefore, even if the flammable contents (desks, paper, computer plastics, etc.) of the upper floors did burn, the structure itself would not have been appreciably weakened.

Just saving this one for posterity, as I'm pretty sure you'll be contradicting yourself on this one soon enough.

pants wrote:
Please provide a link to one of the older threads where you provide a defintion of pancaking.

Please stop asking others to do your research for you. If you don't know what pancaking means, look it up in the 9/11 literature, the FEMA report, or the debunked PBS Nova video whose collapse theory was later discarded by NIST.

pants wrote:
By the way, I would like to congratulate you again on providing such clear evidence that there was a fire on one of the upper blocks.

Yeah, I can tell that bugged you. You were so insistent on several occasions about this, as with a few other things. And now, of course, you're suggesting that fire wouldn't have done any significant damage to the upper blocks. Whatever. I don't need the upper blocks for my argument. You do, though.

Pants, is there going to be a point sometime soon to all this posting of yours? It's again not clear what you're arguing, as you've changed your argument and indeed have contradicted yourself a few times now--sometimes on points that appear, to you anyway, to be critical to your argument. Are you defending the progressive collapse theory or not?

Pants-of-dog

jas wrote:

Actually, I'm not defending the progressive collapse theory - you are. But the video evidence shows us that much matter was ejected laterally, as well as reports of wrecked cars and steel pieces lodged in neighbouring buildings. Simple common sense would also tell us that matter can be ejected outwards when a floor is crushed between two other floors.

I believe it's you who needs to decide what it is you're arguing. It's still not clear from your numerous and wordy posts.

You claimed that the official theory requires the upper block to crush all the columns. The official theory does not argue this. The official theory, as far as I can tell, accounts for the energy required to eject some debris.

I am arguing that "the official explanation offered by NIST and promoted in popular media for the collapse of the Twin Towers is that the upper floors of the towers, above where the planes crashed, crushed through the remaining intact building below the fire zones at a speed" slower than the rate of free fall, and that the evidence confirms this.

This is the second time I have answered this question. Link to my previous response:

http://rabble.ca/comment/1149618/jas-wrote-Thank-goodness

jas wrote:
Yes, it also shows that fire was present on numerous floors in the upper block of WTC1. A claim you denied several times. It would also be a really good video for you to watch as you seem to have a pretty foggy notion of how the buildings collapsed in reality.

I concede that I assumed that there was no fire in the upper portions of the buildings. And I have no problem admitting I was wrong, now that you have presented evidence.

But let us also be clear on what this part of the discussion is about. Your claim that there was fire in the upper block is part of another claim of yours that the upper block was already weakened by fire. Are you still claiming that?

jas wrote:
Pyroclastic is a good term because it points out how similar to volcanic ash plumes the WTC dust plumes were - totally unlike any  natural building collapse or even controlled demolition.

Dust plumes are meteorological phenomena (i.e they are clouds). Pyroclastic flows are geological phenomena (i.e. they are not clouds but rivers of hot air and debris). Volcanic ash plumes are like the former and not the latter. Therefore, volcanic ash plumes are completely different from pyroclastic flows.

Now, according to you, are the dust and debris clouds from the WTC collapse like pyroclastic flows, or like volcanic ash plumes?

jas wrote:
Just saving this one for posterity, as I'm pretty sure you'll be contradicting yourself on this one soon enough.

Feel free to point out any contradictions I have made.

jas wrote:
Please stop asking others to do your research for you. If you don't know what pancaking means, look it up in the 9/11 literature, the FEMA report, or the debunked PBS Nova video whose collapse theory was later discarded by NIST.

You should read what urban dictionary defined it as. Or perhaps not.

[url=http://www.helium.com/items/172508-firefighting-specialized-rescue-proce... website[/url] defines it thusly:

Quote:
A pancake collapse is characterized by both supporting walls failing or from the anchoring system failing and the supported roof or upper floor falling parallel to the floor below. Small voids where victims can be found are created by debris.

I asked for your definition because I wanted to be clear on what we were discussing so that there was no confusion. Having taken your suggestion, I have found a definition. However, I am still unsure as to whether or not this is what you mean by pancake collapse. Do you agree with this definition?

jas wrote:
Yeah, I can tell that bugged you. You were so insistent on several occasions about this, as with a few other things. And now, of course, you're suggesting that fire wouldn't have done any significant damage to the upper blocks. Whatever. I don't need the upper blocks for my argument. You do, though.

Oh, jas! You see right through my efforts at remaining calm!

jas wrote:
Pants, is there going to be a point sometime soon to all this posting of yours? It's again not clear what you're arguing, as you've changed your argument and indeed have contradicted yourself a few times now--sometimes on points that appear, to you anyway, to be critical to your argument. Are you defending the progressive collapse theory or not?

Please see my second paragraph in this very post. It should, once more, clarify my argument. And I would like to once again extend an invitation to finding one of my contradictions.

Fidel

And they say truthers are conspiracy theorists. I think it could be a case that very many non-truthers might never have gotten over being told there is no tooth fairy. It must have been traumatizing. Now they simply want to believe anything the guvmint sloughs on to them as the truth however flimsy.

jas

Pants-of-dog wrote:
 

You claimed that the official theory requires the upper block to crush all the columns. The official theory does not argue this. The official theory, as far as I can tell, accounts for the energy required to eject some debris.

What the fuck?

Like we've already pointed out, you don't understand the official theory.

pants wrote:
I am arguing that "the official explanation offered by NIST and promoted in popular media for the collapse of the Twin Towers is that the upper floors of the towers, above where the planes crashed, crushed through the remaining intact building below the fire zones at a speed" slower than the rate of free fall, and that the evidence confirms this.

This is the second time I have answered this question.

Indeed it is. And I should have just taken your word for it then, as I really have no argument with you over the free fall time, if that's the case, especially as it's clear you don't understand much of the rest of it.

I guess I thought you were going to try and claim that the buildings took 25 or 35 seconds or three minutes to collapse or some other kooky theory. Because you seemed to make such a big deal of the free-fall claim, as if it's critical to the truther argument. In fact, I believe you spent most of the last thread trying to get us to "admit" that the buildings did not collapse in technical free fall. As I've mentioned numerous times, including in the opening post of the thread in which you first appeared, I've always talked about "near free fall" and "within seconds of" free fall--a claim which you have now taken great pains to confirm. Thank you.

As for your belief that there were upper floors to crush through the rest of the building at a rate approaching free fall, I no longer care to convert you. I support your right to believe in whatever bullshit you wish. As long as you don't attempt to teach children or claim that it's true.

pants wrote:
But let us also be clear on what this part of the discussion is about. Your claim that there was fire in the upper block is part of another claim of yours that the upper block wats already weakened by fire. Are you still claiming that?

No, I think I believe now that the fires strengthened the upper block, perhaps by tempering the structural steel further, much more than the intact block which did not have the strengthening benefit of the fires.

pants wrote:
Now, according to you, are the dust and debris clouds from the WTC collapse like pyroclastic flows, or like volcanic ash plumes?

They're like pyroclastic clouds.

pants wrote:
Feel free to point out any contradictions I have made.

Well, for one, after you "wrenched" the "admission" about free fall from us, you then went on to say, in post 45 of this thread:

Pants-of-dog wrote:

Parts of the buildings definitely fell in free fall. Large portions of the buildings fell in free fall for a short while. Overall, the buildings collpased at slower than free fall speeds.

the point of which all is still a mystery. But hey, it's your mystery.

pants wrote:
You should read what urban dictionary defined it as. Or perhaps not.

I'm sorry that urban dictionary is the only source you have for this kind of information. It speaks to the quality of your research.

pants wrote:

Please see my second paragraph in this very post. It should, once more, clarify my argument. And I would like to once again extend an invitation to finding one of my contradictions.

Well, I'm glad we have this clarified, and I apologize for not simply aborting the discussion on this point much earlier. I can see we have no further issues to argue here. Hallelujah. More time for you to spend in bed. I hear your beloved calling you.

Pants-of-dog

jas wrote:
What the fuck?

Like we've already pointed out, you don't understand the official theory.

I think I have a fairly clear understanding of the official theory. I am a little confused about what you think the official theory is.

jas wrote:

Indeed it is. And I should have just taken your word for it then, as I really have no argument with you over the free fall time, if that's the case, especially as it's clear you don't understand much of the rest of it.

I guess I thought you were going to try and claim that the buildings took 25 or 35 seconds or three minutes to collapse or some other kooky theory. Because you seemed to make such a big deal of the free-fall claim, as if it's critical to the truther argument. In fact, I believe you spent most of the last thread trying to get us to "admit" that the buildings did not collapse in technical free fall. As I've mentioned numerous times, including in the opening post of the thread in which you first appeared, I've always talked about "near free fall" and "within seconds of" free fall--a claim which you have now taken great pains to confirm. Thank you.

As for your belief that there were upper floors to crush through the rest of the building at a rate approaching free fall, I no longer care to convert you. I support your right to believe in whatever bullshit you wish. As long as you don't attempt to teach children or claim that it's true.

This is why I asked you to give me a numerical value of the collapse time. The numbers you agreed with come from one of the people that supports the official theory. They can be (and have been) calculated based on the idea that the upper block crushed the lower floors with gravity alone. Therefore,by agreeing with those times, you implicitly agree that the collapse is plausible and that no other factors are required to remove any resistance in the lower block of storeys. Is this fair to say?

jas wrote:
No, I think I believe now that the fires strengthened the upper block, perhaps by tempering the structural steel further, much more than the intact block which did not have the strengthening benefit of the fires.

I see.

pants wrote:
They're like pyroclastic clouds.


Except for the difference in temperature, (i.e. pyroclastic flows are quite hot) and the lack of immediately lethal toxic elements (not necessarily present, but often so in volcanic eruptions), the dust and debris clouds do bear some resemblance to a slow moving pyroclastic flow.

jas wrote:
Well, for one, after you "wrenched" the "admission" about free fall from us, you then went on to say, in post 45 of this thread:

Pants-of-dog wrote:

Parts of the buildings definitely fell in free fall. Large portions of the buildings fell in free fall for a short while. Overall, the buildings collpased at slower than free fall speeds.

the point of which all is still a mystery. But hey, it's your mystery.

There is no contradiction there.

The matter ejected outwards definitely fell in free fall after it was ejected. The matter ejected outwards was made of parts of the building. Therefore, we can say with certainty that parts of the building fell in free fall. Please note that this claim is exactly like the first sentence in my "contradiction".

The upper block fell and collapsed onto the lower block at least once in free fall. This was once the fire damaged and impacted structure on the floors where the plane crashed gave way. And don't forget our disussion on "accreted matter". That accreted matter also fell in free fall onto the floor right below, did it not? So, these are two examples of when large portions of the buildings fell in free fall for a short while. Please note that this claim is exactly lke my second sentence, and that it contains no contradiction with my first sentence.

Now, since the ejected matter was not the entire mass of the building, or even a large portion of it, the velocity of the ejected parts of the building (i.e. free fall) will have little impact on the collpase time of the majority of the towers. And while th eupper block definitely fell in free fall for very short lengths of time, it also impacted many floors on the way down, and each of these impacts slowed the upper block. This meant that overall, the buildings collpased at slower than free fall speeds. Again, this is exactly what I claim in my third sentence, and you can see how it is consistent with the other two sentences in my "contradiction".

I hope this clarifies my position.

pants wrote:
 I'm sorry that urban dictionary is the only source you have for this kind of information. It speaks to the quality of your research.

If I hadn't also provided a clear definition of pancake collapse, and requested a confirmation from you that it matched your defintion, and even explaoned why, this would be amusing. As it is, I am merely baffled. Let me try again.

This website defines it thusly:

Quote:
A pancake collapse is characterized by both supporting walls failing or from the anchoring system failing and the supported roof or upper floor falling parallel to the floor below. Small voids where victims can be found are created by debris.

Do you agree with this definition?

jas wrote:

Well, I'm glad we have this clarified, and I apologize for not simply aborting the discussion on this point much earlier. I can see we have no further issues to argue here. Hallelujah. More time for you to spend in bed. I hear your beloved calling you.

Have a pleasant afternoon, jas.

jas

Pants-of-dog wrote:

Have a pleasant afternoon, jas.

Thanks!

Fidel

Pants-of-dog wrote:

Fidel wrote:

....Because after you claimed to fully understand Manuel Garcia's non-existent calculation for instantaneous time interval for duration of impact, we just don't trust you. Not really.

Here is where I specifically address the fact that Garcia does not mention how he came to that exact number:

http://www.rabble.ca/comment/1149152/Fidel-wrote-And-there-were

And so how does Dr. Griscom arrive at dt = 0.14 second? That's the $64,000 dollar question. I have no idea. In that respect, he is as uninformative as Dr. Garcia.

The only possible way I can see how tilting would change the duration of the impact would be if the upper block deformed as it hit the floor below.

Well if you think about it for just a moment, zero degrees tilting of a 63.4-meters-on-an-edge WTC floor would result in a duration time of 0 seconds(dt=0.0) for duration of impact after a 7.7m/s(Garcia) free fall descent. Iows, all points of the upper block available for impact would meet all surfaces of the lower block available at the time of impact. With any tilting of the upper block, there cannot be simultaneous impact at all points. Iows, the jolt was neither instantaneous nor simultaneous, and the magnitude of force applied downward on the lower block was not even 6.1 times the weight of the upper block loosely referred to by Garcia.  So in summarizing the idea expressed in this same paragraph and in just the previous sentence for the sake of a certain babbler's attention span, there is zero time delay for any part of the upper block impacting the lower. That's if there was zero degrees tilting of the upper block and maintaining a rigid state as per Bazant and Greening.

And we see from videos all over the internet that there was tilting with WTC1. Wikipedia's entry mentions tilting. And [url=http://heiwaco.tripod.com/nist3.htm]we see here by figure A2 [/url] that the upper block is rigid no longer and well before part A of the tower is destroyed according to the very whacky collapse down-up theory posed by Bazant and Greening in their unscientific dictum regarding 9/11 collapse-conspiracy theory.

 

Pants-of-dog wrote:
Since I addressed how he did not explain how he came up with that number, I hazarded two guesses. First I assumed that we were dealing with essentially rigid structures, and Bazant's work seems to confirm that, and secondly, I assumed that (s)he posited a relativley short impact time because impacts are, by defintion, very short

Guessing is not science, and in Garcia's case, it's bad science. Video evidence does not support Garcia's mysterious dt=0.01 second figure for duration of collapse pulled from a pyroclastic dust cloud of 9/11.

Pants-of-dog

Fidel wrote:

Well if you think about it for just a moment, zero degrees tilting of a 63.4-meters-on-an-edge WTC floor would result in a duration time of 0 seconds(dt=0.0) for duration of impact after a 7.7m/s(Garcia) free fall descent. Iows, all points of the upper block available for impact would meet all surfaces of the lower block available at the time of impact. With any tilting of the upper block, there cannot be simultaneous impact at all points. Iows, the jolt was neither instantaneous nor simultaneous, and the magnitude of force applied downward on the lower block was not even 6.1 times the weight of the upper block loosely referred to by Garcia.  So in summarizing the idea expressed in this same paragraph and in just the previous sentence for the sake of a certain babbler's attention span, there is zero time delay for any part of the upper block impacting the lower. That's if there was zero degrees tilting of the upper block and maintaining a rigid state as per Bazant and Greening.

And we see from videos all over the internet that there was tilting with WTC1. Wikipedia's entry mentions tilting.

Imagine you hit your thumb with a hammer. A nice, clean hit squarely on the thumb with the surface of the peen (that's the flat bit that is supposed to hit the nail) such that the hammer actually comes to rest on your thumb. Ouch!

Now,imagine you did the same thing, but hit yourself just with the edge of the peen. It still hits your thumb squarely (such that it ends up resting squarely on your thumb again. Ouch!

The only difference between the two examples is the angle of the hammer. The tilting, if you prefer.

Why would the impact time be any different in either of these scenarios? The impact area is different, but I see no reason why the time would be.

Fidel wrote:
And [url=http://heiwaco.tripod.com/nist3.htm]we see here by figure A2 [/url] that the upper block is rigid no longer and well before part A of the tower is destroyed according to the very whacky collapse down-up theory posed by Bazant and Greening in their unscientific dictum regarding 9/11 collapse-conspiracy theory.

Can you please decide if you are claiming that the upper block for WTC1 tilited or you are claiming that it was destroyed. You can't claim both.

Fidel wrote:
Guessing is not science, and in Garcia's case, it's bad science. Video evidence does not support Garcia's mysterious dt=0.01 second figure for duration of collapse pulled from a pyroclastic dust cloud of 9/11.

Yet when Griscom guesses some longer impact duration, you seem to be perfectly fine with that and accept it unquestioningly. You can not have one standard of scientific evidence for one side, and another standard for the other side. Science doesn't work that way.

Please explain how the dust and debris clouds from the collapse resembled pyroclastic flows.

Fidel

Pants-of-dog wrote:
Imagine you hit your thumb with a hammer. A nice, clean hit squarely on the thumb with the surface of the peen (that's the flat bit that is supposed to hit the nail) such that the hammer actually comes to rest on your thumb. Ouch!

Now,imagine you did the same thing, but hit yourself just with the edge of the peen. It still hits your thumb squarely (such that it ends up resting squarely on your thumb again. Ouch!

The only difference between the two examples is the angle of the hammer. The tilting, if you prefer.

Why would the impact time be any different in either of these scenarios? The impact area is different, but I see no reason why the time would be.

It wouldn't matter to your thumb because it's such a small area. However, duration of impact would change if we're talking about two large areas coming into contact that are roughly 12,000 metres square area.(That's a lot larger than your thumb, and a lot more area than a well aimed carpenter's hammer could possibly do real damage to). Iow's, the downward force begins to be absorbed sooner and ends later when the last of the upper block comes into contact with the lower due to the angle of tilting. In the case that there is no angle of floor tilt, the impact is more of a sudden jolt with total force applied instantaneously without delay.

Try diving off the high board at the local swimming pool at various angles to the water below. Do you feel more of the impact of hitting the surface of the water if you do the belly-flop at a zero angle of tilt, or when slicing into the water at some angle?

Pants-of-dog wrote:
Fidel wrote:
And [url=http://heiwaco.tripod.com/nist3.htm]we see here by figure A2 [/url] that the upper block is rigid no longer and well before part A of the tower is destroyed according to the very whacky collapse down-up theory posed by Bazant and Greening in their unscientific dictum regarding 9/11 collapse-conspiracy theory.

Can you please decide if you are claiming that the upper block for WTC1 tilited or you are claiming that it was destroyed. You can't claim both.

Yes, the upper block was tilting almost immediately during descent. As well, the upper block suffered severe loss of rigidity in the case of WTC1(not the large dust plumes ejected from the upper and lower blocks during collapse, and not to mention the first responders who became ill as a direct result of the myriad toxicants that filled the air that day) Bazant and Greening are full of baloney according to mainstream news and other video evidence that wasn't destroyed or carted away from the federal crime scene prematurely.

Pants-of-dog wrote:
Yet when Griscom guesses some longer impact duration, you seem to be perfectly fine with that and accept it unquestioningly. You can not have one standard of scientific evidence for one side, and another standard for the other side. Science doesn't work that way.

What Griscom merely says is that 0.01 second is crucial to Garcia's thesis. Garcia never mentions tilting of the upper block which was plainly the case. Tilting of a mere one degree increases duration of impact from 0.01 second all the way to 0.14 second, and so reduces Garcia's negative force figure of 6.1 times the weight of the upper block all the way down to 1.3 according to Griscom, a former DARPA project manager and research physicist. Perhaps your argument is with Griscom and Sir Isaac Newton and not me. I'm sure he can be reached for comment(David Griscom that is).

jas

I'm going to try again here, and summarize where we are with Pants' argument, so we can hopefully get back to a simpler, more focussed discussion.

Pants believes that an upper block of burnt floors crushed through the larger intact block of floors in both buildings (WTC1 and 2) at a rate that approaches free fall, in other words at 11.5 and 12.8? seconds or thereabouts. He says Bazant has made the calculations that verify that this is physically possible.

He also states that the 2.5 and 3.8 seconds of resistance provided by the 91 and 78 intact floors of the WTC represent normal resistance in this kind of scenario where a small upper block of floors is crushing through a larger lower block of floors that have not been weakened by anything.

Pants also states that the upper blocks fell in free fall through the damaged impact zone and then in near free fall through all the other floors.

Correct so far? Is there any other component of Pants' argument that I've missed? And is this representative of NIST's hypothesis? I think it's close enough for our purposes.

What I would be looking for here is an explanation as to how 2-4 seconds of resistance would be considered normal in a steel structure building that was almost half a kilometre high. NIST shys away from any such discussion and so far Pants has only provided someone else's mathematical calculations which don't actually explain in plain and common sense terms how this would be possible or believable.

The second thing I would be looking for here is some visual evidence that the alleged upper block of floors actually exists in both scenarios, as I have not seen any pictures or videos which show that these blocks are still present once the collapse begins, and through the collapse which they are supposedly piledriving. So far their existence is only hypothesized, and given that they're the main player in Bazant's picture, I think it's pretty important that we know that they exist.

Thirdly, I would wonder how many columns does NIST claim were damaged by the jet planes, and if many were remaining, how is it possible for the upper block to descend through these at a free fall speed through the impact zone, as Pants claims they did?

Also I would ask the believers why they think NIST did not go into any detail into the collapse progression after hypothesizing its initiation. Given that most scientific criticism centres on the unprecedented manner in which the buildings descended, why would NIST write a 10,000-page report, none of which actually explains the latter?

There are other questions that abound, of course, that have yet to be addressed by the believers, such as the numerous eyewitness reports of explosions occurring through the buildings including below the basements, workers in the basements being burned or thrown by these explosions, the numerous reports of the blown-out lobbies, which of course, are not explainable by the upper floor fire scenario, and NIST's curious omission of this testimony, but we can get to these once the first questions are answered.

Fidel

Yes, I believe it was Sir Fig Newton who once concluded that falling objects always take paths of most resistance at near free fall velocities. And we won't even mention WTC-7 which actually did fall at free fall for 2.5 seconds over 8 stories of steel frame building. As the Pointer Sisters once said, FIre! Burn me up with fire. 'Cause when we NISST Ooooh, fire

Pants-of-dog

Fidel wrote:

It wouldn't matter to your thumb because it's such a small area. However, duration of impact would change if we're talking about two large areas coming into contact that are roughly 12,000 metres square area.(That's a lot larger than your thumb, and a lot more area than a well aimed carpenter's hammer could possibly do real damage to). Iow's, the downward force begins to be absorbed sooner and ends later when the last of the upper block comes into contact with the lower due to the angle of tilting. In the case that there is no angle of floor tilt, the impact is more of a sudden jolt with total force applied instantaneously without delay.

Try diving off the high board at the local swimming pool at various angles to the water below. Do you feel more of the impact of hitting the surface of the water if you do the belly-flop at a zero angle of tilt, or when slicing into the water at some angle?

You are assuming that the force will not be completely transferred until the two surfaces come into full contact. This is not necessarily true. In fact, if the two objects colliding are rigid enough, the two surfaces will never come into complete contact with each other and the force will pass entirely through a relatively small impact area and during a very short time.

This is why your diving analogy doesn't work. Water is not rigid and deforms quite readily under load.

Fidel wrote:
Yes, the upper block was tilting almost immediately during descent. As well, the upper block suffered severe loss of rigidity in the case of WTC1(not the large dust plumes ejected from the upper and lower blocks during collapse, and not to mention the first responders who became ill as a direct result of the myriad toxicants that filled the air that day) Bazant and Greening are full of baloney according to mainstream news and other video evidence that wasn't destroyed or carted away from the federal crime scene prematurely.

So, did it tilt and then collapse? It must have because it could not have collpased and then tilted. So, then the question is when did it collapse? Because it obviously collapsed at some point or it would still be around right now. Now, it obviously began to collapse as soon as it started falling and impacting the lower floors. But did it lose so much rigidity that it was unable to destroy the lower floors? I don't think so.

Fidel wrote:
What Griscom merely says is that 0.01 second is crucial to Garcia's thesis. Garcia never mentions tilting of the upper block which was plainly the case. Tilting of a mere one degree increases duration of impact from 0.01 second all the way to 0.14 second, and so reduces Garcia's negative force figure of 6.1 times the weight of the upper block all the way down to 1.3 according to Griscom, a former DARPA project manager and research physicist. Perhaps your argument is with Griscom and Sir Isaac Newton and not me. I'm sure he can be reached for comment(David Griscom that is).

And let us look carefully at Griscom's calcualtions, shall we? After all, Garcia showed us how he came up with his numbers (as scientists are wont to do), so it seems that Griscom's criticisms should also be just as easy to follow:

Quote:
Well, to have such a small value of dt would require that the bottom of the falling “upper
block” meet the floor below without the slightest tilt. For example, accepting Dr. Garcia’s
free-fall speed calculation of 7.7 meters/second, tilting of a 63.4-meters-square WTC
floor by mere 1 degree would increase dt from his guesstimate of dt = 0.01 second all the
way to dt = 0.14 second, giving the instantaneous total force of the falling “upper block”
on the lower structure of just 1.3 times the static weight of the “upper block” instead of
the 6.1 times as estimated in his “example.”

Oh, wait. Griscom doesn't show any calculations at all. He does not describe, for example, how tiliting by a mere 1 degree would change the impact time.

I guess we're supposed to be so impressed by the number of accolades he gives himself at the beginning of his paper that we don't really need to see the math. Someone should tell Griscom that science doesn't work that way. Garcia understands why you have to show your work. Why doesn't Griscom?

Pants-of-dog

jas wrote:
...

What I would be looking for here is an explanation as to how 2-4 seconds of resistance would be considered normal in a steel structure building that was almost half a kilometre high. NIST shys away from any such discussion and so far Pants has only provided someone else's mathematical calculations which don't actually explain in plain and common sense terms how this would be possible or believable....

You may not be able to understand the language in which an idea is communicated, but that has nothing to do with whether or not the idea is true.

Quote:
The second thing I would be looking for here is some visual evidence that the alleged upper block of floors actually exists in both scenarios, as I have not seen any pictures or videos which show that these blocks are still present once the collapse begins, and through the collapse which they are supposedly piledriving.So far their existence is only hypothesized, and given that they're the main player in Bazant's picture, I think it's pretty important that we know that they exist.

Use google to look up images of the WTC collpase.

Here's one that shows a clear image of the alleged upper block:

[img]http://www.factsofisrael.com/en/images/articles/911/wtc-collapse-01.jpg[...

Quote:
Thirdly, I would wonder how many columns does NIST claim were damaged by the jet planes, and if many were remaining, how is it possible for the upper block to descend through these at a free fall speed through the impact zone, as Pants claims they did?

Any columns that were remaining would have been unable to appreciably slow the upper block because, by that time, any remaining columns had already been stressed to the failure point.

Quote:
Also I would ask the believers why they think NIST did not go into any detail into the collapse progression after hypothesizing its initiation. Given that most scientific criticism centres on the unprecedented manner in which the buildings descended, why would NIST write a 10,000-page report, none of which actually explains the latter?

From what I understand, and I may be incorrect about this, it was simply not part of their mandate. Once the building began to collpase, there was no stopping the process. The report seems to be focussing on those aspects where intervention could have saved lives, i.e. prior to collapse.

Quote:
There are other questions that abound, of course, that have yet to be addressed by the believers, such as the numerous eyewitness reports of explosions occurring through the buildings including below the basements, workers in the basements being burned or thrown by these explosions, the numerous reports of the blown-out lobbies, which of course, are not explainable by the upper floor fire scenario, and NIST's curious omission of this testimony, but we can get to these once the first questions are answered.

Not in this thread about collapse times, please.

I would like to apologise about my continued typo. I realise that it is spelt collapse and not collpase.

jas

Pants-of-dog wrote:

Not in this thread about collapse times, please.

This thread isn't about the collapse times. We established the collapse times a long time ago, long before you ever showed up. The mathematical calculations you provide, moeover, show no argument with the collapse times.

If you still dispute the collapse times that you yourself have confirmed, start your own thread. This thread isn't about that.

pants wrote:

You may not be able to understand the language in which an idea is communicated, but that has nothing to do with whether or not the idea is true.

No, it has to do with your inability to present your views with concision and clarity.

pants wrote:
Use google to look up images of the WTC collpase.

I have, actually. Still can't find any. However, I am willing to stand corrected on this issue.

pants wrote:
Here's one that shows a clear image of the alleged upper block:

[img]

">http://www.factsofisrael.com/en/images/articles/911/wtc-collapse-01.jpg[...

Yes, the one that twists and then mysteriously uprights itself then dissolves? I asked for visual evidence showing that these blocks exist once the collapse starts and through the collapse progression, since they are supposed to be piledriving this collapse.Burden of proof is on you, here. 

pants wrote:
Any columns that were remaining would have been unable to appreciably slow the upper block because, by that time, any remaining columns had already been stressed to the failure point.

Oh, now it's appreciably slow. Heh heh. I believe just a few posts ago, you were asserting that the upper block fell at free fall through the impact zone. You need that for your argument.

pants wrote:

From what I understand, and I may be incorrect about this, it was simply not part of their mandate. Once the building began to collpase, there was no stopping the process. The report seems to be focussing on those aspects where intervention could have saved lives, i.e. prior to collapse.

Repeating the mantra that "once it began, there was no stopping it" doesn't make it true. Once it began, if it began, normal resistance would easily and rapidly stop it.

I believe also that it was a specific part of their mandate, it being an unprecendented collapse which baffled many at the time. As would be investigation for explosives. I can look that up. But even if it wasn't, why wouldn't they have made it part of their mandate. The collapses were seen as highly unusual and difficult to explain, as the first FEMA report openly acknowledges.

Fidel

Pants-of-dog wrote:

Fidel wrote:

It wouldn't matter to your thumb because it's such a small area. However, duration of impact would change if we're talking about two large areas coming into contact that are roughly 12,000 metres square area.(That's a lot larger than your thumb, and a lot more area than a well aimed carpenter's hammer could possibly do real damage to). Iow's, the downward force begins to be absorbed sooner and ends later when the last of the upper block comes into contact with the lower due to the angle of tilting. In the case that there is no angle of floor tilt, the impact is more of a sudden jolt with total force applied instantaneously without delay.

Try diving off the high board at the local swimming pool at various angles to the water below. Do you feel more of the impact of hitting the surface of the water if you do the belly-flop at a zero angle of tilt, or when slicing into the water at some angle?

You are assuming that the force will not be completely transferred until the two surfaces come into full contact. This is not necessarily true. In fact, if the two objects colliding are rigid enough, the two surfaces will never come into complete contact with each other and the force will pass entirely through a relatively small impact area and during a very short time.

This is why your diving analogy doesn't work. Water is not rigid and deforms quite readily under load.

Uh, no. What Griscom is implying is that once a certain degree of tilt of the upper block comes into play, the total downward force, I believe, is no longer acting in a straight line. Forces are only additive when all are applied in the same straight line of motion.

But when total force is applied in different directions and with angulation introduced to the problem, vector math is required to calculate the resultant magnitude. This is when adding two or more numbers will not necessarily add up to the sum of their numerical totals. ie. With vectors, sometimes 5+5=8, or 5+5=4, or 5+5=2. And this is generally why Griscom says that one degree of tilt would reduce Garcia's figure of 6.1 all the way down to a magnitude of 1.3. I'm not sure what kind of math he used and would prolly be dazzled by it myself, but I do understand what he's talking about in general.

Pants-of-dog

jas wrote:

This thread isn't about the collapse times. We established the collapse times a long time ago, long before you ever showed up. The mathematical calculations you provide, moeover, show no argument with the collapse times.

If you still dispute the collapse times that you yourself have confirmed, start your own thread. This thread isn't about that.

So, do you agree that he collpase times show that the WTC towers collpased due to the impact of the plane and gravity?

 

jas wrote:
No, it has to do with your inability to present your views with concision and clarity.

Building collpase is not an easy thing to exaplin, especially when the people you are talking to have shown a certain ignorance concerning the physics of engineering. For example, you were unaware (and may still be unclear on) how loads are transferred through a structure, as shown by the dialogue we had about beams versus columns.

It is also not helped by the fact that when you and Fidel do use specific terms from the sciences (like pyroclastic), you do not use them correctly.

Consequently, it seems like it would be difficult to frame explanations using the jargon of building engineering. I am uncertain that you would understand a phrase like: the rivets fastening the tie joists and beams to the columns probably failed in shear when the dynamic live loads surpassed the designed limit and safety margin.

pants wrote:
I have, actually. Still can't find any. However, I am willing to stand corrected on this issue.

Yes, the one that twists and then mysteriously uprights itself then dissolves? I asked for visual evidence showing that these blocks exist once the collapse starts and through the collapse progression, since they are supposed to be piledriving this collapse.Burden of proof is on you, here.  

What is holding up that tilting block in the picture? Nothing. Therefore it must be collpasing onto the lower floors. Therefore it was exsiting after the collapse started.

pants wrote:
Oh, now it's appreciably slow. Heh heh. I believe just a few posts ago, you were asserting that the upper block fell at free fall through the impact zone. You need that for your argument.

No, I don't need it for my argument. If the upper block fell at 99% of the speed of free fall (i.e. slower but not appreciably slower), the buildings would still have collpased.

 

pants wrote:
Repeating the mantra that "once it began, there was no stopping it" doesn't make it true. Once it began, if it began, normal resistance would easily and rapidly stop it.

Please provide evidence for the bolded claim.

jas wrote:
I believe also that it was a specific part of their mandate, it being an unprecendented collapse which baffled many at the time. As would be investigation for explosives. I can look that up. But even if it wasn't, why wouldn't they have made it part of their mandate. The collapses were seen as highly unusual and difficult to explain, as the first FEMA report openly acknowledges.

To be honest, i find this irrelevant.

Pants-of-dog

Fidel wrote:

Uh, no. What Griscom is implying is that once a certain degree of tilt of the upper block comes into play, the total downward force, I believe, is no longer acting in a straight line. Forces are only additive when all are applied in the same straight line of motion.

You are incorrect about how force applies to a tilting object. The angle of the object does not dictate the angle of the applied forces. Gravity does not turn sideways because the falling object is sideways.

Fidel wrote:
But when total force is applied in different directions and with angulation introduced to the problem, vector math is required to calculate the resultant magnitude. This is when adding two or more numbers will not necessarily add up to the sum of their numerical totals. ie. With vectors, sometimes 5+5=8, or 5+5=4, or 5+5=2. And this is generally why Griscom says that one degree of tilt would reduce Garcia's figure of 6.1 all the way down to a magnitude of 1.3. I'm not sure what kind of math he used and would prolly be dazzled by it myself, but I do understand what he's talking about in general.

Angulation is not a word used outside of anatomy, where it is used to describe a bend in a bone or organ that is causing problems. I am aware of the differences between vectors and magnitudes (or scalar quantities if you prefer). There is no indication that force diagrams played a role in Griscom's work. He could have used simple trigonometry instead. We don't know because Griscom doesn't show his work, which is my complaint.

Fidel

Pants-of-dog wrote:

Fidel wrote:

Uh, no. What Griscom is implying is that once a certain degree of tilt of the upper block comes into play, the total downward force, I believe, is no longer acting in a straight line. Forces are only additive when all are applied in the same straight line of motion.

You are incorrect about how force applies to a tilting object. The angle of the object does not dictate the angle of the applied forces. Gravity does not turn sideways because the falling object is sideways.

Gravity normally works in one direction, straight down. But from video evidence of the collapses we see that several hundred thousand tons of concrete and steel did not all come down in the same direction gravity normally acts upon falling objects. (Galileo and Newton). In fact what we see is ejections of massive amounts of myriad materials sideways from the buildings and in horizontal and numerous other directions indicating forces other than gravity were at work. Iows, there were significant horizontal and other force vectors refusing to be swept under the rug by official conspiracy theorists and their unscientific groupees.

[url=http://www.pa.uky.edu/~phy211/Forces_discussion.html]interactive vector arithmetic tutorial[/url] (java applet)

To suggest that structural engineers study all that vector math and physics for nothing is absurd beyond belief.

Pants-of-dog wrote:
Angulation is not a word used outside of anatomy, where it is used to describe a bend in a bone or organ that is causing problems.

Angulation can simply mean the precise measure of angles, which is common to a number of scientific studies, trades and even pizza chefs paying some attention to angles when divvying up pizza pies. And least of, angles can sometimes be referred to by  babblers who refuse to swallow an ill -conceived 9/11 conspiracy theory dropped on the public like the dog's dinner that it is.

In his Handwaving the Physics of 9/11 essay:

 

David Griscom wrote:
So did the “upper blocks” of WTC1&2 fall without tilting? Well, according to NIST’s final report (Section 6.14.4, p. 146): “Failure of the south wall in WTC 1 and east wall in WTC2 caused the portion of the building above to tilt in the direction of the failed wall.” And in films, the "upper block" of WTC2 is seen to tilt as much as 23 degrees!

 [url=http://911research.wtc7.net/wtc/analysis/challenge.html]The Progressive Collapse Challenge[/url]

Anti-scientific NIST groupees everywhere can now prove to themselves beyond a doubt how the official conspiracy theory is a colossal pack of lies.

jas

Pants-of-dog wrote:

So, do you agree that he collpase times show that the WTC towers collpased due to the impact of the plane and gravity?

No, I am agreeing that the collapse times were somewhere within 10- 13 seconds, as do you. How many more times will we need to go over this point?

pants wrote:

Building collpase is not an easy thing to exaplin, especially when the people you are talking to have shown a certain ignorance concerning the physics of engineering. For example, you were unaware (and may still be unclear on) how loads are transferred through a structure, as shown by the dialogue we had about beams versus columns.

It is also not helped by the fact that when you and Fidel do use specific terms from the sciences (like pyroclastic), you do not use them correctly.

Consequently, it seems like it would be difficult to frame explanations using the jargon of building engineering. I am uncertain that you would understand a phrase like: the rivets fastening the tie joists and beams to the columns probably failed in shear when the dynamic live loads surpassed the designed limit and safety margin.

Having a basic model of how buildings collapse does not require advanced mathematics or physics, as shown by both the simple and detailed analyses provided by engineers and physicists. If it does, there's something a little suspect.

I would actually understand those terms much more than the vague examination of unnecessary detail that you've been providing. I have been asking in previous threads for people to bring the discussion into the concrete - no pun intended. Using plain language and common sense and accepted principles of physics. This not only helps everyone to understand, it also demonstrates that the person making these claims has, him or herself, an understanding of what it is they claim.

If you're just going to throw some math calculation up, then say "see?" it doesn't foster confidence that you actually know what you're talking about.

I also note that you have used a closed system analysis twice incorrectly to describe what is obviously an open system. As well you seem to be trying to argue that a mass that is tilted and applying pressure on one corner of the structure below will cause crushing or collapse around its perimeter. My sense is you do not have the knowledge of physics that you pretend to.

pants wrote:

What is holding up that tilting block in the picture? Nothing. Therefore it must be collpasing onto the lower floors. Therefore it was exsiting after the collapse started.

As questioned above, how does a mass that is applying pressure on one corner of  the floors below cause crushing around its perimeter, as is needed for your theory? How does it then right itself to complete its piledriving mission? These are pretty basic violations of physics. Do you understand?

pants wrote:
No, I don't need it for my argument. If the upper block fell at 99% of the speed of free fall (i.e. slower but not appreciably slower), the buildings would still have collpased.

Well, if half the columns remained, how would the upper block fall at 99% of free fall rate?

Quote:
jas wrote:
Once it began, if it began, normal resistance would easily and rapidly stop it.

Please provide evidence for the bolded claim.

Well, we have, but I'll be happy to repost this information for you. Do you understand that this is the crux of the argument?

Quote:
jas wrote:
I believe also that it was a specific part of their mandate, it being an unprecendented collapse which baffled many at the time. As would be investigation for explosives. I can look that up. But even if it wasn't, why wouldn't they have made it part of their mandate. The collapses were seen as highly unusual and difficult to explain, as the first FEMA report openly acknowledges.

To be honest, i find this irrelevant.

Interesting that you claim to defend their theory but find irrelevant their methods, mandate and the absence of an explanation of  the most important question: how the collapse progressed, since simple physics would tell us that it wouldn't. If it's such a common sense model, why wouldn't they be able to find a page or two in 10,000 pages to explain it to the science community? If the model itelf is violating basic principles of physics, then the model has to be declared incorrect, and some other explanation found. Then they don't need to waste time worrying for no reason about safety issues in a building collapse that can't naturally occur.

Pants-of-dog

Fidel wrote:

Gravity normally works in one direction, straight down. But from video evidence of the collapses we see that several hundred thousand tons of concrete and steel did not all come down in the same direction gravity normally acts upon falling objects. (Galileo and Newton). In fact what we see is ejections of massive amounts of myriad materials sideways from the buildings and in horizontal and numerous other directions indicating forces other than gravity were at work. Iows, there were significant horizontal and other force vectors refusing to be swept under the rug by official conspiracy theorists and their unscientific groupees.

[url=http://www.pa.uky.edu/~phy211/Forces_discussion.html]interactive vector arithmetic tutorial[/url] (java applet)

To suggest that structural engineers study all that vector math and physics for nothing is absurd beyond belief.

You are making a series of false assumptions here.

First, you are assuming, incorrectly I might add, that the engineers who have analysed the collapse ignored the fact that air pressure pushed material out of the building.

Secondly, you are assuming that I am ignoring it. It may seem that I did not address your concerns properly, but I will admit that I have some trouble understanding your arguments.

Third, you are assuming that I suggested that vector math does not apply to this problem. It obviously does and all the math I have done concerning this collpase, as well as the math that I have shown from other people, has been consistent with standard usage of vector math.

To address this specific concern about horizontal ejection of debris, it is simply the result of air pressure from the air being squeezed out from between the falling upper storey block and the lower one.

Scatter some confetti on a coffee table and then drop a phone book on it. You'll see the confetti fly out sideways from under the phone book.

Pants-of-dog wrote:
Angulation can simply mean the precise measure of angles, which is common to a number of scientific studies, trades and even pizza chefs paying some attention to angles when divvying up pizza pies. And least of, angles can sometimes be referred to by  babblers who refuse to swallow an ill -conceived 9/11 conspiracy theory dropped on the public like the dog's dinner that it is.

It sounds like a word that someone untrained in science would use in order to sound like what they think scientists sound like.

Fidel wrote:
In his Handwaving the Physics of 9/11 essay:

 

David Griscom wrote:
So did the “upper blocks” of WTC1&2 fall without tilting? Well, according to NIST’s final report (Section 6.14.4, p. 146): “Failure of the south wall in WTC 1 and east wall in WTC2 caused the portion of the building above to tilt in the direction of the failed wall.” And in films, the "upper block" of WTC2 is seen to tilt as much as 23 degrees!

 [url=http://911research.wtc7.net/wtc/analysis/challenge.html]The Progressive Collapse Challenge[/url]

Anti-scientific NIST groupees everywhere can now prove to themselves beyond a doubt how the official conspiracy theory is a colossal pack of lies.

Yes, the upper blocks tilted. Unfortunately, this doesn't prove anything. If Griscom showed us his math, it might prove that Garcia used one wrong number in one equation. This is very, very far from showing how "the official conspiracy theory is a colossal pack of lies."

Pants-of-dog

jas wrote:

No, I am agreeing that the collapse times were somewhere within 10- 13 seconds, as do you. How many more times will we need to go over this point?

I'm not going over that point again. I am asking you the next, related question. I will now ask you a third time: given that you have agreed with Greenings calculations concerning time of collpase, do you also agree with the rest of his conclusions (i.e. there was no controlled demolition)?

jas wrote:

Having a basic model of how buildings collapse does not require advanced mathematics or physics, as shown by both the simple and detailed analyses provided by engineers and physicists. If it does, there's something a little suspect.

I would actually understand those terms much more than the vague examination of unnecessary detail that you've been providing. I have been asking in previous threads for people to bring the discussion into the concrete - no pun intended. Using plain language and common sense and accepted principles of physics. This not only helps everyone to understand, it also demonstrates that the person making these claims has, him or herself, an understanding of what it is they claim. If you're just going to throw some math calculation up, then say "see?" it doesn't foster confidence that you actually know what you're talking about.

I also note that you have used a closed system analysis twice incorrectly to describe what is obviously an open system. As well you seem to be trying to argue that a mass that is tilted and applying pressure on one corner of the structure below will cause crushing or collapse around its perimeter. My sense is you do not have the knowledge of physics that you pretend to.

This is an intrigung meta discussion, but other than somehow blaming me for your lack of understanding, it doesn't move the conversation forward.

To me, it is quite simple. A plane impacts a building, knocking out a good portion of the structure and its fireproofing. The subsequent flames weaken the remaining structure, causing the upper block to collapse onto the lower block of storeys. The lower floor that is impacted, stressed in new ways that it was not designed to handle, collapses. This repeats at increasing velocities for the subsequent lower floors. The upper block falls apart somehwat as it falls, but mostly after it has impacted all the lower floors.

What is the problem?

pants wrote:
As questioned above, how does a mass that is applying pressure on one corner of  the floors below cause crushing around its perimeter, as is needed for your theory? How does it then right itself to complete its piledriving mission? These are pretty basic violations of physics. Do you understand?

You keep saying I need things for my theory as if you have some sort of diagram of my theory showing how all the calculations and data inter-relate. Can you scan it and post it please? It would help knowing what arguments I'm going to be making.

The upper block of storeys does not need to be upright to crash through the lower blocks. It only has to impact and collpase enough of each floor structure to make it impossible to hold up the upper block. It can do this in almost any direction.

pants wrote:
Well, if half the columns remained, how would the upper block fall at 99% of free fall rate?

You seem to be forgetting that the half of the columns that did remain had been subjected to fire (which weakens the steel) and incredible stresses far exceeding the designed load limit (which also weakens the steel). By the time the upper block fell, the remaining steel columns were severely weakened.

jas wrote:
Pants-of-dog wrote:
jas wrote:
Once it began, if it began, normal resistance would easily and rapidly stop it.

Please provide evidence for the bolded claim.

Well, we have, but I'll be happy to repost this information for you. Do you understand that this is the crux of the argument?

I understand that this is your argument. However, I must have missed the post where you provided supporting evidence for this claim. I would greatly appreciate it if you could post that evidence again or a link to your post.

Quote:

Interesting that you claim to defend their theory but find irrelevant their methods, mandate and the absence of an explanation of  the most important question: how the collapse progressed, since simple physics would tell us that it wouldn't. If it's such a common sense model, why wouldn't they be able to find a page or two in 10,000 pages to explain it to the science community? If the model itelf is violating basic principles of physics, then the model has to be declared incorrect, and some other explanation found. Then they don't need to waste time worrying for no reason about safety issues in a building collapse that can't naturally occur.

This may be an eye-opener for you, jas, but the NIST didn't write it for you and they don't particularly care what you think is important.

From what I can tell, the object of the report was to come up with guidlines that would help emergency responders in case something this horrible happens again. Once the building is collpasing, it's too late to save the people inside, so why spend millions of dollars analysing the physics?

Fidel

Pants-of-dog wrote:
You are making a series of false assumptions here.

First, you are assuming, incorrectly I might add, that the engineers who have analysed the collapse ignored the fact that air pressure pushed material out of the building.

Secondly, you are assuming that I am ignoring it. It may seem that I did not address your concerns properly, but I will admit that I have some trouble understanding your arguments.

Did you check out the vector tutorial? I don't think you did. Or is it a case that vector math simply doesn't apply in the fairy tale world of pro-crazy George Dubya conspiracy theories? A few of their guvmint scientists also aided them in denying climate science some time after Republicans lost the popular vote count in 2000.

Pants-of-dog wrote:
To address this specific concern about horizontal ejection of debris, it is simply the result of air pressure from the air being squeezed out from between the falling upper storey block and the lower one.

Scatter some confetti on a coffee table and then drop a phone book on it. You'll see the confetti fly out sideways from under the phone book.

But 500,000 tons of steel and concrete is not confetti. In fact, it was part of the building below which the 30 and 15 story upper floors of the two towers magically fell thriugh on the way to ground zero.

Quoting a retired [url=http://ming.tv/flemming2.php/__show_article/_a000010-001420.htm]physics and chemistry teacher[/url] on NIST's 9/11 collapse conspiracy theory:

Chuck Boldwyn wrote:
The Physics 'Normal' Force Vector upwards is the supporting force for the lower undamaged portion of the WTC. The upward supporting force vector for the South Tower is calculated to be 46 times greater that the downwards Gravitational Force Vector of the 30 stories of the upper portion. The upward supporting force vector for the North Tower is calculated to be 127 times greater than the downwards Gravitational Force Vector of the 15 stories of it's upper portion.  The case for Impossibility of Collapse rests there.

Pants-of-dog wrote:
It sounds like a word that someone untrained in science would use in order to sound like what they think scientists sound like.

I think you should contact Dr Griscom and ask him why your guy Garcia is full of baloney on duration of impact. He can provide you with the engineering equations and explanation of vector math as a proper cure for your disbelief. Or you could contact Garcia and ask him where his mysterious calculation for dt disappeared to. Either way you should be more knowledgeable about the issue than you appear to be now.

Pants-of-dog wrote:
Yes, the upper blocks tilted. Unfortunately, this doesn't prove anything. If Griscom showed us his math, it might prove that Garcia used one wrong number in one equation. This is very, very far from showing how "the official conspiracy theory is a colossal pack of lies."

 So you're just going to give up like this? I'm disappointed. It doesn't take a genie to figure out what they pulled on 9/11.

[IMG]http://img.photobucket.com/albums/v697/rabblerabble/cut3.jpg[/IMG]

First Responder wrote:
One piece [url=http://www.nytimes.com/2001/10/02/science/scarred-steel-holds-clues-and-.... Astaneh-Asl[/url] saw was a charred horizontal I-beam from 7 World Trade Center, a 47-story skyscraper that collapsed from fire eight hours after the attacks. The beam, so named because its cross-section looks like a capital I, had clearly endured searing temperatures. Parts of the flat top of the I, once five-eighths of an inch thick, had vaporized

jas

Pants-of-dog wrote:

I will now ask you a third time: given that you have agreed with Greenings calculations concerning time of collpase, do you also agree with the rest of his conclusions (i.e. there was no controlled demolition)?

You have never asked me this question, let alone three times. This is what I mean by your inability to communicate with concision and clarity.

I am not agreeing with the calculations, as they are derived working backwards from the facts, in order to fit the facts. Moreover you haven't explained these calculations, you simply posted them.

I am agreeing that the collapse time is probably within 10 - 13 seconds, a time frame that the calculations you provide confirm. Therefore, as I've stated several times already, we both agree that the collapse time of the towers was within 10 to 13 seconds. Therefore, we are not arguing about the collapse time.

If you still don't understand, you might want to try breaking those sentences down into smaller units for understanding.

Quote:
jas wrote:

I also note that you have used a closed system analysis twice incorrectly to describe what is obviously an open system. As well you seem to be trying to argue that a mass that is tilted and applying pressure on one corner of the structure below will cause crushing or collapse around its perimeter. My sense is you do not have the knowledge of physics that you pretend to.

This is an intrigung meta discussion, but other than somehow blaming me for your lack of understanding, it doesn't move the conversation forward.

To me, it is quite simple. A plane impacts a building, knocking out a good portion of the structure and its fireproofing. The subsequent flames weaken the remaining structure, causing the upper block to collapse onto the lower block of storeys. The lower floor that is impacted, stressed in new ways that it was not designed to handle, collapses. This repeats at increasing velocities for the subsequent lower floors. The upper block falls apart somehwat as it falls, but mostly after it has impacted all the lower floors.

What is the problem?

You say, "this repeats at increasing velocities" for the subsequent 90 and 77 floors. As you know, the problem is that the descent of the alleged upper block would slow, not increase. The pull of gravity does not overcome 91 and 78 floors presenting normal resistance. If you want to show us your calculations again and actually walk us through it, I'd be interested in seeing how those results are arrived at. We did this in another thread and found that the poster was unwilling to explain the math he posted.

A second problem is your wishy-washy statement that "the upper block falls apart somehwat as it falls, but mostly after it has impacted all the lower floors." Does NIST say this?? I don't think they do. Why do you say the upper block falls apart "somewhat"? If it's falling apart, how could it stay intact through the crushing and pulverizing of 90 and 77 intact floors? Why would it, only then, collapse itself?

A third problem of course is you still haven't provided evidence that this upper block of storeys is present through the collapse sequence in order to provide this piledriving of 90 and 77 intact floors - about one third of a kilometre, or higher, of steel and concrete highrise.

A fourth problem is the lack of acceptable physics that can explain how a block of storeys that begins tilting to the side could then crush the lower floor in a way that would then cause global, symmetrical collapse of the floors below it--and in the rapid fashion we saw. This defies both common sense and accepted physical principles. What also isn't explained from the picture you provide is how it is the collapse has already begun while the block is tilting--but on the opposite side of where it would be creating pressure.

pants wrote:
The upper block of storeys does not need to be upright to crash through the lower blocks. It only has to impact and collpase enough of each floor structure to make it impossible to hold up the upper block. It can do this in almost any direction.

Well, I'm sorry, but what you're describing would only produce partial collapse, if at all. And then the tilting block would fall over, in the direction it is tilting, because it has supposedly just crushed those portions of building below it, which then can no longer support it.

But I have a further question: What caused its tilting away from the impact zone in the first place, and why would it not have simply continued its momentum in that direction?

Quote:
jas wrote:
Well, if half the columns remained, how would the upper block fall at 99% of free fall rate?

You seem to be forgetting that the half of the columns that did remain had been subjected to fire (which weakens the steel) and incredible stresses far exceeding the designed load limit (which also weakens the steel). By the time the upper block fell, the remaining steel columns were severely weakened.

You ascribe a lot of power to the fireproofing, as well as to the hypothesis that the planes would have removed it, and only in the impact zone. Are you aware that there are pictures of people standing in the holes of the impact zones, and that these fires were largely smoking black? At the same time, you maintain that the fires in the upper blocks, which burned for 60 and 90 minutes respectively, did nothing to weaken the structural integrity of the upper block. Again, your hypothesis requires several leaps of faith.

So, now I will look for those calculations that show that gravity cannot overcome the normal resistance of 91 and 78 intact floors of the WTC and you will look for evidence that the upper blocks did in fact remain intact through the collapse sequence.

jas

double post again.

Fidel

And never mind that the areas where NIST claims FIRE! softened structural steel beams enough to cause floors to sag were situated far away from the plane impact zones. Unless they're positing a quantum non-locality theory for spooky fire action at a distance where steel heated in one part of the building causes steel in another area to fail, I don't really follow what it is NIST and their agents of spookiness are saying. It's as if their wacky theories are all g-ways like on purpose so that not even they can understand them. Pfff!

Pants-of-dog

Fidel wrote:
Did you check out the vector tutorial? I don't think you did. Or is it a case that vector math simply doesn't apply in the fairy tale world of pro-crazy George Dubya conspiracy theories? A few of their guvmint scientists also aided them in denying climate science some time after Republicans lost the popular vote count in 2000.

You seem to believe that I do not think vector math applies to this issue. This is incorrect.

Fidel wrote:
But 500,000 tons of steel and concrete is not confetti. In fact, it was part of the building below which the 30 and 15 story upper floors of the two towers magically fell thriugh on the way to ground zero.

The vast majority of the concrete that was ejected horizontally was in the form of small fragments. Larger chunks fell down vertically. As for the columns that fell outwards, it was simply the force of the two floors squuezing against thetop and bottom of the column that popped them out. Try holding a toothpick between your index finger and thumb, and then squeezing. The toothpick will fly out horizontally.

Fidel wrote:
Quoting a retired [url=http://ming.tv/flemming2.php/__show_article/_a000010-001420.htm]physics and chemistry teacher[/url] on NIST's 9/11 collapse conspiracy theory:

Chuck Boldwyn wrote:
The Physics 'Normal' Force Vector upwards is the supporting force for the lower undamaged portion of the WTC. The upward supporting force vector for the South Tower is calculated to be 46 times greater that the downwards Gravitational Force Vector of the 30 stories of the upper portion. The upward supporting force vector for the North Tower is calculated to be 127 times greater than the downwards Gravitational Force Vector of the 15 stories of it's upper portion.  The case for Impossibility of Collapse rests there.

The normal force has an upper maximum that is equal to the downward force. If the upward force was higher than the downward force, the WTC would have flown upwards.

Fidel wrote:
I think you should contact Dr Griscom and ask him why your guy Garcia is full of baloney on duration of impact. He can provide you with the engineering equations and explanation of vector math as a proper cure for your disbelief. Or you could contact Garcia and ask him where his mysterious calculation for dt disappeared to. Either way you should be more knowledgeable about the issue than you appear to be now.

No. If you wish to make claims about the physics of collpasing buildings, it is up to you to provide supporting evidence. It is not my responsibility to go out and find your evidence for you.

Fidel wrote:
So you're just going to give up like this? I'm disappointed. It doesn't take a genie to figure out what they pulled on 9/11.

I should have made myself clearer.

What I meant to say was: you haven't proven anything yet except the fact that the upper storeys tilted.

Fidel wrote:
[IMG]http://img.photobucket.com/albums/v697/rabblerabble/cut3.jpg[/IMG]

First Responder wrote:
One piece [url=http://www.nytimes.com/2001/10/02/science/scarred-steel-holds-clues-and-.... Astaneh-Asl[/url] saw was a charred horizontal I-beam from 7 World Trade Center, a 47-story skyscraper that collapsed from fire eight hours after the attacks. The beam, so named because its cross-section looks like a capital I, had clearly endured searing temperatures. Parts of the flat top of the I, once five-eighths of an inch thick, had vaporized

The image you chose is of a vertical HSS (hollow structural section) column, not a horizontal I-beam as described by Dr. Astaneh-Asl. Moreover, it i sunclear whther the claim of vaporisation cam efrom Dr. Astaneh-Asl or kenneth Chang, the journalist who wrote that article.

Pants-of-dog

jas wrote:

You have never asked me this question, let alone three times. This is what I mean by your inability to communicate with concision and clarity.

I am not agreeing with the calculations, as they are derived working backwards from the facts, in order to fit the facts. Moreover you haven't explained these calculations, you simply posted them.

I am agreeing that the collapse time is probably within 10 - 13 seconds, a time frame that the calculations you provide confirm. Therefore, as I've stated several times already, we both agree that the collapse time of the towers was within 10 to 13 seconds. Therefore, we are not arguing about the collapse time.

If you still don't understand, you might want to try breaking those sentences down into smaller units for understanding.

Science works by looking at the facts and then finding a theory to explain them. You have to work backwards from the facts, and your theory must fit the facts. Why are you stating that this approach is a problem?

 

jas wrote:
You say, "this repeats at increasing velocities" for the subsequent 90 and 77 floors. As you know, the problem is that the descent of the alleged upper block would slow, not increase. The pull of gravity does not overcome 91 and 78 floors presenting normal resistance. If you want to show us your calculations again and actually walk us through it, I'd be interested in seeing how those results are arrived at. We did this in another thread and found that the poster was unwilling to explain the math he posted.

We had calculated the Kinetic Energy (KE) for each upper block of storeys in this post:

http://www.rabble.ca/comment/1156932/Here-summary

Let us focus on one, WTC1, which is the smaller of the two upper blocks, and consequently the one with the least amount of kinetic energy. What this means is that if the WTC1 upper block had enough kinetic energy to overcome the resistance of the lower floors, the upper block of WTC2 which had more kinetic energy, would aslo have had enough kinetic energy to overcome the resistance of the lower floors.

So, right before it hit the lower block, KE (wtc1) = 14 x 1.67 x 10 to the 8 J = 23.4 x 10 to the 8 J

and the velocity was 8.5 m/s.

Now, it takes a certain amount of KE to demolish the structure of the floor. There have been several different estimates made of this number. I will use the highest one I found, from this study:

http://cat.inist.fr/?aModele=afficheN&cpsidt=14655835

Greening also uses this number in his energy calculations. I quote:

Quote:
Thus, based on T. Wierzbicki et al. calculation, we estimate a total of 6.29 x 10 to the 8 J of impact energy was
required to collapse one WTC floor, a value that is remarkably close to Bažant’s estimate
of 5.0 x 10 to the 8 J for the plastic energy dissipated by the collapse of one floor.

So, we will subtract that energy from the kinetic energy, as it has been expended.

23.4-6.29=17.1

So, we have 17.1 x 10 to the 8 J. for the left over kinetic energy at the time of impact.

 

Now the new mass is equal to the upper block of storeys plus the floor just impacted.

m for one floor = (510,000,000 / 110) kg, so the new mass is 15 times that amount (the 14 upper storeys plus the newly added single lower floor).

m=15*510,000,000/110=69,545,454kg

 

Using our equation for kinetic energy:

[img]http://upload.wikimedia.org/math/4/1/4/4140f53f66a68e92afec2389ba289e25....

we can calculate the new velocity by isolating the v variable, which stands for velocity.

v = sqrt of 2KE/m

v = sqrt of 2(17.1 x 10 to the 8)/69,545,454

v = 7m/s

 

Now, to determine the velocity of an object falling from rest in free fall, we use this equation:

[img]http://upload.wikimedia.org/math/1/a/6/1a6e5238d2ab226044c4f776d6ee7e97....

g=9.8 meters per second squared

d=3.7m

v = sqrt 2(9.8)(3.7)

v = 8.5m/s

 

But remember that this i sfor an object falling from rest, or an initial velocity of 0, but our upper storey was actually falling at 7m/s right after impact, so we have to add these 7m/s to our calculated velocity.

This means that the now slightly larger upper block was travelling at 15.5 m/s right before it impacted the second of the lower floors.

 

Let us now calculate KE for the upper block for the same instant:

KE = (1/2)(m)(v squared)

m=15*510,000,000/110=69,545,454kg

v = 15.5m/s

therefore,

KE=167.1 x 10 to the 8 J

 

Please note that the kinetic energy for the upper block and the velocity for the upper block were faster at the moment of impacting the second lower floor than they were when the upper block impacted the first lower floor.

This shows clearly that the upper block crashed through the lower floors at ever increasing speeds.

You asked for the math, jas. You got it.

 

jas wrote:
A second problem is your wishy-washy statement that "the upper block falls apart somehwat as it falls, but mostly after it has impacted all the lower floors." Does NIST say this?? I don't think they do. Why do you say the upper block falls apart "somewhat"? If it's falling apart, how could it stay intact through the crushing and pulverizing of 90 and 77 intact floors? Why would it, only then, collapse itself?

Do you remember your accreted matter? It ended up on the bottom of the upper block of storeys, cushioning the structure of the upper block of storeys from the impacts. Now, it didn't absorb all the energy, so some energy made it onto the upper block to cause some damage, but relatively little.

 

Quote:
A third problem of course is you still haven't provided evidence that this upper block of storeys is present through the collapse sequence in order to provide this piledriving of 90 and 77 intact floors - about one third of a kilometre, or higher, of steel and concrete highrise.

I provided a photo. You even comment on it in this very post that I am responding to.

 

Quote:
A fourth problem is the lack of acceptable physics that can explain how a block of storeys that begins tilting to the side could then crush the lower floor in a way that would then cause global, symmetrical collapse of the floors below it--and in the rapid fashion we saw. This defies both common sense and accepted physical principles. What also isn't explained from the picture you provide is how it is the collapse has already begun while the block is tilting--but on the opposite side of where it would be creating pressure.

I highly doubt it was perfectly symmetrical.

It may defy your common sense, but not mine.

It does not defy principles of physics, as I have mathematically demonstrated.

The collapse already begun because a plane crashed into the building, destroying structural elements and fireproofing and scattering burning jet fuel over most of the floor area on those floors where it impacted.

I have no idea how you can say that the picture is showing collpase on the opposite side of the tilt. There is a rather large debris cloud obscuring that area of the building.

 

jas wrote:
Well, I'm sorry, but what you're describing would only produce partial collapse, if at all. And then the tilting block would fall over, in the direction it is tilting, because it has supposedly just crushed those portions of building below it, which then can no longer support it.

But I have a further question: What caused its tilting away from the impact zone in the first place, and why would it not have simply continued its momentum in that direction?

Please provide evidence for the bolded statement.

As for the tilting question, it would depend on the magnitude and direction of whatever force is causing it to tilt. If it is caused by moment force couples (do you know what those are?), the tilting would only get worse if the structure providing the normal force does not collapse under the weight of the upper block. Since we can plainly see it did collapse, this would not be an issue.

 

jas wrote:
You ascribe a lot of power to the fireproofing, as well as to the hypothesis that the planes would have removed it, and only in the impact zone. Are you aware that there are pictures of people standing in the holes of the impact zones, and that these fires were largely smoking black? At the same time, you maintain that the fires in the upper blocks, which burned for 60 and 90 minutes respectively, did nothing to weaken the structural integrity of the upper block. Again, your hypothesis requires several leaps of faith.

From the [url=http://wtc.nist.gov/pubs/NISTNCSTAR1-1D.pdf]NIST report[/url] discussing building code regulations (see page 44/168) the fire resistance rating of the structural members for the WTC towers was 3 hours. This means that the fireproofing around the structure would have protected the steel from temperatures high enough to weaken it for 3 hours. Please note that this is considerably longer than the durations of the fires.

This is why I claim that the fire in the upper block did not weaken the structure.

Quote:
So, now I will look for those calculations that show that gravity cannot overcome the normal resistance of 91 and 78 intact floors of the WTC and you will look for evidence that the upper blocks did in fact remain intact through the collapse sequence.

I am eagerly awaiting your evidence.

Pants-of-dog

Fidel wrote:

And never mind that the areas where NIST claims FIRE! softened structural steel beams enough to cause floors to sag were situated far away from the plane impact zones. Unless they're positing a quantum non-locality theory for spooky fire action at a distance where steel heated in one part of the building causes steel in another area to fail, I don't really follow what it is NIST and their agents of spookiness are saying. It's as if their wacky theories are all g-ways like on purpose so that not even they can understand them. Pfff!

Please quote the relevant text of the NIST report and provide a link. Thank you.

Fidel

Pants-of-dog wrote:
You seem to believe that I do not think vector math applies to this issue. This is incorrect.

You're the one who said you don't understand Dr. Griscom where he states that degree of tilting changes Garcia's number for duration of impact and affecting force balance, and not me. That doesn't mean that David Griscom is wrong, and by some quirk of your own imagination, make you correct.

Pants-of-dog wrote:
The vast majority of the concrete that was ejected horizontally was in the form of small fragments. Larger chunks fell down vertically. As for the columns that fell outwards, it was simply the force of the two floors squuezing against thetop and bottom of the column that popped them out. Try holding a toothpick between your index finger and thumb, and then squeezing. The toothpick will fly out horizontally.

Anyone can see from video footage that large dust clouds and pieces of the building were ejected laterally from the building. They didn't fall, and some large percentage of the debris was deposited on the ground well outside WTC 1&2 collapse footprints. Concrete floors were pulverized, too. That takes energy, and according to Newtonian world physics, has to be subtracted from total kinetic energy alleged to be available for doing other things, like when non-truthers suggest that weaker and lighter upper block of floors crushed much larger and heavier lower sections of the two towers, incredible as it sounds.

Pants-of-dog wrote:
Fidel wrote:
Quoting a retired [url=http://ming.tv/flemming2.php/__show_article/_a000010-001420.htm]physics and chemistry teacher[/url] on NIST's 9/11 collapse conspiracy theory:

Chuck Boldwyn wrote:
The Physics 'Normal' Force Vector upwards is the supporting force for the lower undamaged portion of the WTC. The upward supporting force vector for the South Tower is calculated to be 46 times greater that the downwards Gravitational Force Vector of the 30 stories of the upper portion. The upward supporting force vector for the North Tower is calculated to be 127 times greater than the downwards Gravitational Force Vector of the 15 stories of it's upper portion. The case for Impossibility of Collapse rests there.

The normal force has an upper maximum that is equal to the downward force. If the upward force was higher than the downward force, the WTC would have flown upwards.

Ah! I see you've been reading a little physics. Bizarro Bizante's wacky theory relies on a crazy notion that the upper blocks fell on the lowers unimpeded, as in without experiencing deceleration as a result of any measurable resistance from 250 steel support columns, all of which he alleges to have failed simultaneously and instantly. One truther estimated the chances of that happening are about one in one-trillion. Do you believe in 9/11 fairy tales, Pants? I don't.

Pants-of-dog wrote:
You assume incorrectly that the towers collapsed at near free fall speeds.

Why not? Unimpeded free fall of the upper block onto the lower sections of WTC1&2 is basically what Bazant says happened. It's most crucial to his wacky theory. And you're disagreeing with him. Where do they recruit you people from? Anyway?

"The same folks that are bombing innocent people in Iraq were the ones who attacked us in America on September the 11th." -- Presinut Dubya, Prescott Bush's genetic baggage, Washington, D.C., July 12, 2007

Pants-of-dog

Fidel wrote:
You're the one who said you don't understand Dr. Griscom where he states that degree of tilting changes Garcia's number for duration of impact and affecting force balance, and not me. That doesn't mean that David Griscom is wrong, and by some quirk of your own imagination, make you correct.

I do not understand exactly how the degree of tilting affects the duration of the impact because Griscom has neglected to show how he comes up with his numbers. You are correct that it does not necessarily make him wrong, but since this is the exact same criticism you are levelling at Garcia, I would simply reply that the fact that Garcia does not show (s)he arrived at a much shorter duration of impact does not necessarily mean that Garcia is wrong.

Fidel wrote:
Anyone can see from video footage that large dust clouds and pieces of the building were ejected laterally from the building. They didn't fall, and some large percentage of the debris was deposited on the ground well outside WTC 1&2 collapse footprints. Concrete floors were pulverized, too. That takes energy, and according to Newtonian world physics, has to be subtracted from total kinetic energy alleged to be available for doing other things, like when non-truthers suggest that weaker and lighter upper block of floors crushed much larger and heavier lower sections of the two towers, incredible as it sounds.

http://www.rabble.ca/comment/1154860/Fidel-wrote-If-you-look

That link will take you to my first post discussing energy requirements in terms of concrete pulverisation.

Bazant gives a number of 12.63 × 10 to the 10 J.

Greening gives a higher number of 3.2 x 10 to the 11 J .

Mind you, Greening is calculating how much it takes to grind all the concrete in the WTC to a finer grade than Bazant's finest, while Bazant extrapolates from data found on site. In other words, Bazant is closer to the truth, while Greening is looking at a worst case scenario.

Either way, Greening's much higher number is still less than 36% of the total kinetic energy released by the collapse of the towers (8.95.x10 to the 11 J).

Fidel wrote:
Ah! I see you've been reading a little physics.

Fidel, please don't ever change.

Fidel wrote:
Bizarro Bizante's wacky theory relies on a crazy notion that the upper blocks fell on the lowers unimpeded, as in without experiencing deceleration as a result of any measurable resistance from 250 steel support columns, all of which he alleges to have failed simultaneously and instantly. One truther estimated the chances of that happening are about one in one-trillion. Do you believe in 9/11 fairy tales, Pants? I don't.

No, this is not what Bazant is arguing. If he actually is arguing this, please provide quotes of the relevant text from Bazant's work.

Here: http://www.crono911.net/docs/Bazant2007.pdf

Fidel wrote:
"The same folks that are bombing innocent people in Iraq were the ones who attacked us in America on September the 11th." -- Presinut Dubya, Prescott Bush's genetic baggage, Washington, D.C., July 12, 2007

I will say one thing about the politics of it and the theory of controlled demolition. Do you honestly believe they would not have pulled the same stunt (i.e using it as a pretext for invading iraq and Afghanistan) even if the building didn't collapse? As soon as those planes hit that building, the US military industrial complex already had justification enough for war. Collapse of the buildings themselves was not necessary at that point.

Fidel

Pants-of-dog wrote:
I do not understand exactly how the degree of tilting affects the duration of the impact because Griscom has neglected to show how he comes up with his numbers.

Obviously if one end of the upper block is delayed more than the other, then Bazant's sudden jolt doesn't occur instantaneously in order for 250 steel support columns to fail simultaneously over 1/100th of a second of impact.

Pants-of-dog wrote:
You are correct that it does not necessarily make him wrong, but since this is the exact same criticism you are levelling at Garcia, I would simply reply that the fact that Garcia does not show (s)he arrived at a much shorter duration of impact does not necessarily mean that Garcia is wrong.

If I remember correctly, you were the one saying everything about Garcia's calculations is correct as far as you are concerned. I was almost hoping you would defend Garcia in some way. It doesn't look like you will be doing so.

Pants-of-dog wrote:
Bazant gives a number of 12.63 × 10 to the 10 J.

Greening gives a higher number of 3.2 x 10 to the 11 J .

Mind you, Greening is calculating how much it takes to grind all the concrete in the WTC to a finer grade than Bazant's finest, while Bazant extrapolates from data found on site. In other words, Bazant is closer to the truth, while Greening is looking at a worst case scenario.

Either way, Greening's much higher number is still less than 36% of the total kinetic energy released by the collapse of the towers (8.95.x10 to the 11 J).

Gordon Ross wrote:
[url=http://www.journalof911studies.com/volume/200704/NISTandDrBazant-Simulta... is impossible(pdf0[/url] for all of the energy of the falling section to act on only the one topmost storey in the lower section, since the very act of transmission of the energy to that storey, dictates that all of the storeys in the upper section will come under load and consume energy(Gordon Ross, Mechanical Engineer, Dundee, Scotland).

And [url=http://journalof911studies.com/volume/2009/ChandlerResponseToGreening.pd... is Frank Greening(pdf)[/url] mixing up units of terms in his equations. It's clear that he either doesn't understand what he's talking about, or that he does understand and is deliberately trying to confuse non-technical people for some reason or another.

Pants-of-dog wrote:
I will say one thing about the politics of it and the theory of controlled demolition. Do you honestly believe they would not have pulled the same stunt (i.e using it as a pretext for invading iraq and Afghanistan) even if the building didn't collapse? As soon as those planes hit that building, the US military industrial complex already had justification enough for war. Collapse of the buildings themselves was not necessary at that point.

There are several theories why. The trade towers were money losing white elephants and that the port authority determined needed either extensive rennovations or demolishion by 2007.

There is the Pearl Harbor-like unifying event supportive of large increases to US military spending mentioned by the PNAC cabal and now plastered all over the internet by truthers.

And there needed to be a significant death toll in order to justify massive spending on "counter-terrorism" and costly taxpayer-funded wars in Iraq and Afghanistan still going on today. It's all part of the big lie and convincing millions of Americans that even though the red menace no longer exists(the former USSR), there are still reasons for maintaining an over-bloated military budget and creation of a huge homeland security bureaucracy as added justification for rolling back a wide range of civil liberties including the NSA-Telco spying on the lives of millions of Americans by warantless wiretaps and other electronic invasions of privacy.

[url=http://www.globalresearch.ca/index.php?context=va&aid=759]Ali Mohamed, a Green Beret and Al-Qa'eda leutenant[/url]

And there have been a number of blowers to the corruption and ongoing deep state events, like Sibel Edmonds. Edmonds says that the coverup includes concealing the existence of an entire organizational layer of Al-Qa'eda agents who have worked closely with the US Military and CIA during the CIA's glory years of anticommunist jihad in Central Asia and continuing right up to 9/11/01.

Pants-of-dog

Fidel wrote:
Obviously if one end of the upper block is delayed more than the other, then Bazant's sudden jolt doesn't occur instantaneously in order for 250 steel support columns to fail simultaneously over 1/100th of a second of impact.

Bazant does not say that 250 columns have to fail simultaneously. Or Garcia, for that matter.

I notice that you have not actually provided the quote I asked you for in terms of what Bazant is claiming. Also, you are confusing Garcia's work with Bazant's.

Fidel wrote:
If I remember correctly, you were the one saying everything about Garcia's calculations is correct as far as you are concerned. I was almost hoping you would defend Garcia in some way. It doesn't look like you will be doing so.

I was almost hoping Griscom would intelligently criticise Garcia in some way. He hasn't so far. It's hard to defend someone when the attack is so vague.

Fidel wrote:
Gordon Ross wrote:
[url=http://www.journalof911studies.com/volume/200704/NISTandDrBazant-Simulta... is impossible(pdf0[/url] for all of the energy of the falling section to act on only the one topmost storey in the lower section, since the very act of transmission of the energy to that storey, dictates that all of the storeys in the upper section will come under load and consume energy(Gordon Ross, Mechanical Engineer, Dundee, Scotland).

This quote from Ross is irrelevant to the statements of concrete pulverisation made by Bazant. Moreover, Ross's asumption about loads being transmitted to the remainder of the structure only holds if each structural member in the sequence of load transfer does not fail. If even one fails, the loads cannot be effectively transmitted through the columns, foundations, soil, etc. Basically, it is a problem of a chain being only as strong as its weakest link.

Fidel wrote:
And [url=http://journalof911studies.com/volume/2009/ChandlerResponseToGreening.pd... is Frank Greening(pdf)[/url] mixing up units of terms in his equations. It's clear that he either doesn't understand what he's talking about, or that he does understand and is deliberately trying to confuse non-technical people for some reason or another.

This is the second time we have visited this discussion on normal force. Please quote the relevant text from this PDF showing where Greening erred with his units.

Fidel wrote:

There are several theories why. The trade towers were money losing white elephants and that the port authority determined needed either extensive rennovations or demolishion by 2007.

There is the Pearl Harbor-like unifying event supportive of large increases to US military spending mentioned by the PNAC cabal and now plastered all over the internet by truthers.

And there needed to be a significant death toll in order to justify massive spending on "counter-terrorism" and costly taxpayer-funded wars in Iraq and Afghanistan still going on today. It's all part of the big lie and convincing millions of Americans that even though the red menace no longer exists(the former USSR), there are still reasons for maintaining an over-bloated military budget and creation of a huge homeland security bureaucracy as added justification for rolling back a wide range of civil liberties including the NSA-Telco spying on the lives of millions of Americans by warantless wiretaps and other electronic invasions of privacy.

[url=http://www.globalresearch.ca/index.php?context=va&aid=759]Ali Mohamed, a Green Beret and Al-Qa'eda leutenant[/url]

And there have been a number of blowers to the corruption and ongoing deep state events, like Sibel Edmonds. Edmonds says that the coverup includes concealing the existence of an entire organizational layer of Al-Qa'eda agents who have worked closely with the US Military and CIA during the CIA's glory years of anticommunist jihad in Central Asia and continuing right up to 9/11/01.

Like I said, this could all have been accomplished without demolishing the Towers.

Fidel

Pants-of-dog wrote:

Fidel wrote:
Obviously if one end of the upper block is delayed more than the other, then Bazant's sudden jolt doesn't occur instantaneously in order for 250 steel support columns to fail simultaneously over 1/100th of a second of impact.

Bazant does not say that 250 columns have to fail simultaneously. Or Garcia, for that matter.

1. Show us where Bazant says there was any deceleration of the upper block after impacting the lower block(s). He doesn't

2. Garcia's duration of impact is 0.01 second. His calculation is missing completely, and so Garcia himself simply says the force of the descending upper block was greater than the resistance of the lower block but never describes what the load capabilities are for the much heavier and massive lower blocks. But that shouldn't concern unscientific non-truthers as we already know.

Both of these frauds, Garcia and Bazant, are at odds with Newtonian physical laws. And you have illuminated nothing in regard to their pseudo-scientific theories. You're basically nodding your head up and down in rapid agreement with whatever they've said and no more.

Pants-ofdog wrote:
I notice that you have not actually provided the quote I asked you for in terms of what Bazant is claiming. Also, you are confusing Garcia's work with Bazant's.

Fidel wrote:
If I remember correctly, you were the one saying everything about Garcia's calculations is correct as far as you are concerned. I was almost hoping you would defend Garcia in some way. It doesn't look like you will be doing so.

I was almost hoping Griscom would intelligently criticise Garcia in some way. He hasn't so far. It's hard to defend someone when the attack is so vague.

Charade you are.

Pants-of-dog wrote:
Like I said, this could all have been accomplished without demolishing the Towers.

 And here's another question for you since you claim to know everything. [url=http://www.globalresearch.ca/index.php?context=va&aid=3422]Why would the FBI protect Al-Qa'eda's hijacking specialist?[/url]

Pants-of-dog

Fidel wrote:
1. Show us where Bazant says there was any deceleration of the upper block after impacting the lower block(s). He doesn't

Why should he? The upper block decelerates during the impact with the lower block, not after. After the impact with one of the floors on the lower block, it accelerates again due to the force of gravity before impacting again on the next floor down.

 

Fidel wrote:
2. Garcia's duration of impact is 0.01 second. His calculation is missing completely, and so Garcia himself simply says the force of the descending upper block was greater than the resistance of the lower block but never describes what the load capabilities are for the much heavier and massive lower blocks. But that shouldn't concern unscientific non-truthers as we already know.

Exactly. Your criticism, i.e. that Garcia does not reveal his calculations, is exactly the same criticism that you should have with Griscom. Neither reveal their calculations. Now, why does this make Garcia unscientific, but not Griscom?

 

Fidel wrote:
Both of these frauds, Garcia and Bazant, are at odds with Newtonian physical laws. And you have illuminated nothing in regard to their pseudo-scientific theories. You're basically nodding your head up and down in rapid agreement with whatever they've said and no more.

You and jas keep repeating the bolded claim. As of yet, you have provided absolutely no evidence to support this assertion.

 

Fidel wrote:
Charade you are.

Hmm.

 

Fidel wrote:
And here's another question for you since you claim to know everything. [url=http://www.globalresearch.ca/index.php?context=va&aid=3422]Why would the FBI protect Al-Qa'eda's hijacking specialist?[/url]

Feel free to start another thread about this topic, and I will be more than happy to answer your question in that thread.

Fidel

Pants-of-dog wrote:

Fidel wrote:
1. Show us where Bazant says there was any deceleration of the upper block after impacting the lower block(s). He doesn't

Why should he? The upper block decelerates during the impact with the lower block, not after. After the impact with one of the floors on the lower block, it accelerates again due to the force of gravity before impacting again on the next floor down.

Well no that's not what either Bazant or the video evidence says happened. Woohoo? Pay attention to what Bazant says here when tries to explain balance of energies immediately after collapse begins:

Quote:
[url=http://www.911-strike.com/BazantZhou.htm]" To arrest the fall,[/url] the kinetic energy of the upper part, which is equal to the potential energy release for a fall through the height of at least two floors, would have to be absorbed by the plastic hinge rotations of one buckle, i.e., Wg/Wp would have to be less than 1. Rather, Wg /Wp ?= 8.4 (3) if the energy dissipated by the columns of the critical heated floor is neglected."

And, do you imagine Bazant is talking about an empiricist's definition for "a fall" as in a fall with forces of gravity in play or some other wacky notion of fall, like "near free fall" or some unscientific dough-head's definition for free fall? I'm thinkin' he's meaning Newtonian type fall. So in case you missed it again, deceleration does not happen during "a fall" over "at least two floors" according to Bazant. You just said above that deceleration occurred during impact with the lower block. Most non-truthers are a mass of contradictions, and you're no exception.

Pants-of-dog wrote:
Exactly. Your criticism, i.e. that Garcia does not reveal his calculations, is exactly the same criticism that you should have with Griscom. Neither reveal their calculations. Now, why does this make Garcia unscientific, but not Griscom?

If dt=0.01 second as Garcia claims so unscientifically, and it repesents a slowing of descent in some feeble pseudo-scientific attempt to satisfy Newtonian laws of nature and a wacky conspiracy theory at the same time, do you think anyone would notice it? Of course not. Not in the realm of crazy George Dubya sponsored conspiracy theories.

Pants-of-dog wrote:
Fidel wrote:
And here's another question for you since you claim to know everything. [url=http://www.globalresearch.ca/index.php?context=va&aid=3422]Why would the FBI protect Al-Qa'eda's hijacking specialist?[/url]

Feel free to start another thread about this topic, and I will be more than happy to answer your question in that thread.

What if [url=http://www.globalresearch.ca/index.php?context=va&aid=7713]the CIA and Pakistani Army intelligence agencies created Al-CIA'duh?[/url] Boy it's like the questions just continue"piling" up. As the former Bill Christison said, 9/11 is now a matter for the World Court.

Pants-of-dog

Fidel wrote:
Well no that's not what either Bazant or the video evidence says happened. Woohoo? Pay attention to what Bazant says here when tries to explain balance of energies immediately after collapse begins:

Quote:
[url=http://www.911-strike.com/BazantZhou.htm]Link[/url]" To arrest the fall, the kinetic energy of the upper part, which is equal to the potential energy release for a fall through the height of at least two floors, would have to be absorbed by the plastic hinge rotations of one buckle, i.e., Wg/Wp would have to be less than 1. Rather, Wg /Wp ?= 8.4 (3) if the energy dissipated by the columns of the critical heated floor is neglected."

And, do you imagine Bazant is talking about an empiricist's definition for "a fall" as in a fall with forces of gravity in play or some other wacky notion of fall, like "near free fall" or some unscientific dough-head's definition for free fall? I'm thinkin' he's meaning Newtonian type fall.

Bazant is is no way disagreeing with my statement. The text you quote is comparing the kinetic energy of the falling upper block to the energy able to be absorbed by the bent columns below. Bazant is stating that there was not nearly enough energy to stop the fall ( I have no idea why you are so obsessed with this word), and it really has little connection to your previous claim concerning deceleration.

Fidel wrote:

Pants-of-dog wrote:
Exactly. Your criticism, i.e. that Garcia does not reveal his calculations, is exactly the same criticism that you should have with Griscom. Neither reveal their calculations. Now, why does this make Garcia unscientific, but not Griscom?

If dt=0.01 second as Garcia claims so unscientifically, and it repesents a slowing of descent in some feeble pseudo-scientific attempt to satisfy Newtonian laws of nature and a wacky conspiracy theory at the same time, do you think anyone would notice it? Of course not. Not in the realm of crazy George Dubya sponsored conspiracy theories.

Did you notice that you did not answer my question?

Fidel wrote:
What if [url=http://www.globalresearch.ca/index.php?context=va&aid=7713]the CIA and Pakistani Army intelligence agencies created Al-CIA'duh?[/url] Boy it's like the questions just continue"piling" up. As the former Bill Christison said, 9/11 is now a matter for the World Court.

Feel free to start another thread about this topic, and I will be more than happy to answer your question in that thread.

jas

Pants-of-dog wrote:

You asked for the math, jas. You got it.

I asked you to walk us through it, explain what the numbers are that you are using in the equations. But I will get back to this.

Pants-of-dog wrote:

Do you remember your accreted matter? It ended up on the bottom of the upper block of storeys, cushioning the structure of the upper block of storeys from the impacts. Now, it didn't absorb all the energy, so some energy made it onto the upper block to cause some damage, but relatively little.

Funny, I seem to remember you complaining about qualitative statements previously.  This is pure flake. You're not only making leaps of faith for the theory you're defending, but then you're adding personal guesstimates on top of it. This is a joke.

pants wrote:

I provided a photo. You even comment on it in this very post that I am responding to.

I asked for evidence showing that the upper blocks are present and maintain their integrity throughout the collapse progression. You have not provided this.

pants wrote:
jas wrote:
A fourth problem is the lack of acceptable physics that can explain how a block of storeys that begins tilting to the side could then crush the lower floor in a way that would then cause global, symmetrical collapse of the floors below it--and in the rapid fashion we saw. This defies both common sense and accepted physical principles. What also isn't explained from the picture you provide is how it is the collapse has already begun while the block is tilting--but on the opposite side of where it would be creating pressure.

 

I highly doubt it was perfectly symmetrical.

It may defy your common sense, but not mine.

It does not defy principles of physics, as I have mathematically demonstrated.

The collapse already begun because a plane crashed into the building, destroying structural elements and fireproofing and scattering burning jet fuel over most of the floor area on those floors where it impacted.

Please provide evidence for the bolded statement. All investigations conclude that the towers withstood the impact soundly and as expected. It was not the jet impact that caused the collapse.

Again, demonstration that you don't understand the theory you claim to defend, and you're making personal conjectures again.

pants wrote:

I have no idea how you can say that the picture is showing collpase on the opposite side of the tilt. There is a rather large debris cloud obscuring that area of the building.

Lol. Um, pants, what is causing the debris cloud?

pants wrote:

As for the tilting question, it would depend on the magnitude and direction of whatever force is causing it to tilt. If it is caused by moment force couples (do you know what those are?),

No, I don't. Why don't you explain it? And why are you making personal conjectures again? Why not just look up what NIST or Bazant claim caused the tilting?

Quote:
the tilting would only get worse if the structure providing the normal force does not collapse under the weight of the upper block. Since we can plainly see it did collapse, this would not be an issue.

You plainly have not answered my question. The photo shows the collapse beginning on the opposite side of where the tilting block is applying pressure. Your comments are nonsensical.

pants wrote:
I am eagerly awaiting your evidence.

Coming up. Was not on the internet this weekend. There are many people who have done independent calculations, but I will look for the David Chandler article and the guy who wrote "Muslims suspend laws of physics!", as I think they would be the easiest to understand.

Still await your evidence that the upper blocks were present through the collapse sequence.

Fidel

Pants-of-dog wrote:
Fidel wrote:
Well no that's not what either Bazant or the video evidence says happened. Woohoo? Pay attention to what Bazant says here when tries to explain balance of energies immediately after collapse begins:
Quote:
[url=http://www.911-strike.com/BazantZhou.htm]To arrest the fall[/url], the kinetic energy of the upper part, which is equal to the potential energy release for a fall through the height of at least two floors, would have to be absorbed by the plastic hinge rotations of one buckle, i.e., Wg/Wp would have to be less than 1. Rather, Wg /Wp ?= 8.4 (3) if the energy dissipated by the columns of the critical heated floor is neglected."
And, do you imagine Bazant is talking about an empiricist's definition for "a fall" as in a fall with forces of gravity in play or some other wacky notion of fall, like "near free fall" or some unscientific dough-head's definition for free fall? I'm thinkin' he's meaning Newtonian type fall.
Bazant is is no way disagreeing with my statement.
You mean this one?:
Pants-of-dog wrote:
"The upper block decelerates during the impact with the lower block."... The text you quote is comparing the kinetic energy...[summarizes Bazant more closely, for now]
If you didn't mean to use the word 'deceleration', and Bazant doesn't use it in favour of the empiricist words "fall through the height of at least two floors", then why did you carefully type the letters d-e-c-e-l-e-r-a-t-i-o-n with your little fingers above? Do you always contradict the people you nod up and down in rapid agreement with?
Pants-of-dog wrote:
Fidel wrote:
What if [url=http://www.globalresearch.ca/index.php?context=va&aid=7713]the CIA and Pakistani Army intelligence agencies created Al-CIA'duh?[/url] Boy it's like the questions just continue"piling" up. As the former Bill Christison said, 9/11 is now a matter for the World Court.
Feel free to start another thread about this topic, and I will be more than happy to answer your question in that thread.
[url=http://www.globalresearch.ca/index.php?context=va&aid=17961]A Guide to the 9/11 Whistleblowers[/url] Courageous insiders, gagged, hounded and ignored

Pants-of-dog

jas wrote:

I asked you to walk us through it, explain what the numbers are that you are using in the equations. But I will get back to this.

So, I am not allowed to use quantitative explanations without some sort of qualitative commentary. Okay.

 

Pants-of-dog wrote:

Do you remember your accreted matter? It ended up on the bottom of the upper block of storeys, cushioning the structure of the upper block of storeys from the impacts. Now, it didn't absorb all the energy, so some energy made it onto the upper block to cause some damage, but relatively little.

 Funny, I seem to remember you complaining about qualitative statements previously.  This is pure flake. You're not only making leaps of faith for the theory you're defending, but then you're adding personal guesstimates on top of it. This is a joke.

So, I am not allowed to use qualitative explanations without some sort of quantitative commentary. Okay.

Tell me, are you also going to operate under this same standard of evidence, or am I the only one who has to do so?

 

jas wrote:
I asked for evidence showing that the upper blocks are present and maintain their integrity throughout the collapse progression. You have not provided this.

Would you like the evidence in the form of a magical picture taken by my imaginary camera that can take pictures of objects through large debris and dust clouds?

Or would you prefer a quantitave dissection with the complete math involved, including a prose commentary in language accessible to an elementary school student who has apparently never taken a physics course?

Those seem to be your standards of evidence.

 

jas wrote:
Please provide evidence for the bolded statement. All investigations conclude that the towers withstood the impact soundly and as expected. It was not the jet impact that caused the collapse.

Again, demonstration that you don't understand the theory you claim to defend, and you're making personal conjectures again.

I can only assume that you are not deliberately misunderstanding me. The conditions that led to the collapse occurred when the planes impacted the buildings. Moreover, this does not relate to our discussion on the tilting of the upper blocks.

 

jas wrote:
Lol. Um, pants, what is causing the debris cloud?

The same thing that is causing debris clouds on the other sides of the building: collapse of the structure.

Just to remind you: you claimed that that the photo showed where collapse initiated. I have no idea why you claimed that, or where you thought that argument would lead, but your evidence is a photo of a debris cloud under an obvioulsy tilted upper block of storeys. Since the upper blocks could not begin tiliting until after collpase started, the photo could not have been taken at the beginning of collapse.

 

jas wrote:
No, I don't. Why don't you explain it?

Gravity pushes stuff downwards, right? Now, imagine a length of steel pipe falling. The pipe's centre of gravity is at the midpoint of the length of pipe. So, if it is a meter long, the centre of gravity is at the 50cm point. Now, on its way down, the pipe hits a ledge. It hits ten centimetres from the edge. At the exact instant of impact, there are two forces acting on the pipe: one is the force of gravity, while the other is the "normal" force of the ledge. Now, gravity points down, while the normal force pushes up. So the two forces are acting in opposite directions, but are separated by a distance (40cm in our example). This makes the pipe spin.

Try pushing a pencil along the top of your desk so that it rolls, now roll it so that one end of the pencil catches on something. The pencil will spin around a bit.

 

Quote:
And why are you making personal conjectures again? Why not just look up what NIST or Bazant claim caused the tilting?

Because I am fairly good at physics, and so I know that rotational movement is always caused by a pair of forces.

 

Quote:
You plainly have not answered my question. The photo shows the collapse beginning on the opposite side of where the tilting block is applying pressure. Your comments are nonsensical.

See above.

 

jas wrote:
Coming up. Was not on the internet this weekend. There are many people who have done independent calculations, but I will look for the David Chandler article and the guy who wrote "Muslims suspend laws of physics!", as I think they would be the easiest to understand.

I will patiently continue to remind you, do not worry.

 

jas wrote:
Still await your evidence that the upper blocks were present through the collapse sequence.

See above.

jas

From Kevin Ryan's "A New Standard for Deception" - summarized by Jim Hoffman here.

Quote:
3. Fireproofing widely dislodged?

The idea that fireproofing was removed from most of the structural steel surfaces of the impact zones is essential to NIST's theory. NIST sought to "prove" that the plane crashes could do this by shooting shotguns at surfaces coated with spray-on foam insulation. Contrary to the popular notion that the jolts of the plane crashes could knocked off large amounts of spray-on insulation from steel not directly in the line of fire, the tests showed that it took being sprayed with shotgun pellets to remove the insulation. In addition to the fact that there is no evidence that a crashing Boeing 757 could have been transformed into the equivalent of the thousands of shotgun blasts it would take to blast the 6,000 square meters of surface area of structural steel in the fire areas, Ryan makes another argument based on the available energy.

    40:00

        * NIST says 2500 MJ of kinetic energy from plane that hit WTC1
              o Calculations show that all this energy was consumed in crushing aircraft and breaking columns and floors *
              o Shotgun tests found that 1 MJ per sq meter was needed to dislodge fireproofing
              o For the areas in question, intact floors and columns had 6000 sq meters of surface area
          * Calculations by Tomasz Wierzbicki of MIT
 

jas
Pants-of-dog

Fidel wrote:

You mean this one?:

Pants-of-dog wrote:
"The upper block decelerates during the impact with the lower block."...

If you didn't mean to use the word 'deceleration', and Bazant doesn't use it in favour of the empiricist words "fall through the height of at least two floors", then why did you carefully type the letters d-e-c-e-l-e-r-a-t-i-o-n with your little fingers above? Do you always contradict the people you nod up and down in rapid agreement with?

The upper block falls through a height (of two floors, according to Bazant) and then impacts the lower block of floors. During that impact, it decelerates. This has nothing to do with its acceleration at other times, such as during the fall preceding, which Bazant is describing.

Is that clear? Bazant is describing the fall before impact. I am discussing the deceleration during impact.

Fidel wrote:
[url=http://www.globalresearch.ca/index.php?context=va&aid=17961]A Guide to the 9/11 Whistleblowers[/url] Courageous insiders, gagged, hounded and ignored

Feel free to start another thread about this topic, and I will be more than happy to reply in that thread.

jas

Pants-of-dog wrote:

So, I am not allowed to use qualitative explanations without some sort of quantitative commentary. Okay.

Tell me, are you also going to operate under this same standard of evidence, or am I the only one who has to do so?

I'm sorry, my friend. You were the one complaining about qualitative vs. quantitative, claiming that the statements we were quoting from the NIST FAQ were merely "qualitative", and did we know the difference between the two.

There is a difference between using a qualitative comment from a source that is providing a public explanation and a qualitative comment coming from some anonymous internet poster's personal conjecture. Do you understand the difference?

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