The 9/11 Collapse Theory discussion thread

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Tue, 2010-07-13 15:08

PB66

I thought I'd let those heavily involved with this debate know how it looks to the casual reader:

1) jas and Fidel claim that it is immediately obvious that there is no way the towers could have fallen as fast as they did without something more than just collapse and that there is no way the fire could have weakened the building enough to trigger the collapse.

2) Pants-of-dog cites that the temperature of the fire (700-900 C) is sufficient to greatly reduce the strength of the metal supports, and then cites that the kinetic energy gained by the top part of the tower when it falls the height of a floor is sufficient to destroy the next lower floor, leading to a collapse in, roughly, the time seen.

3) A ton of posts back and forth on minor points.

4) Fidel claims that the only way anyone would disagree with him is if they are corrupt, but seems unable to rebut the claim that he believes Newton's third law can be applied to a falling object (without, at the same time, applying it to some other object which is, um, very much bigger than either tower).

Does NIST have a description of the collapse of the towers that is basically correct? I don't know, but I expect so. Are there some minor gaps in their description that could be covered better? Maybe, but it's not clear what they are. However, what jas and Fidel sometimes claim is that the flaws in the NIST description are complete obvious to casual inspection. In my view, Pants-of-dog has prettily clearly rebuted this claim - the description of the collapse in (2) is not completely unreasonable.

Maybe that description is incorrect, but if there's something wrong with it, then the innacuracy is somewhat subtle. If you object to their description, you need to be clear about your objections.

Also, it proves nothing to cite a petition of 1200+ experts, who think the NIST investigation is insufficient. To my consternation, when I google my name, I find that one of the first hits is a message I sent to NIST complaining that their investigation of WTC7 was inadequate in a certain, specific way. That doesn't mean that I dispute the general conclusion that rubble from WTC1/2 hit WTC7, that that started a fire in WTC7, and that the fire caused the building to collapse. I just think they need to investigate some of the details more thoroughly.The majority of the 1200+ signatories may feel similarly.

(PS: To avoid unfairly putting words in other people's mouths here, I should say that the description in (2) is my summary of the many thoughtful posts by Pants-of-dog, and not his.)

Tue, 2010-07-13 15:15

#53

jas

Pants-of-dog wrote:

jas wrote:
No you weren't. Read your post again.

Do not tell me what I was really thinking.

I am not telling you what you were thinking. I am telling you what you wrote. If, as I suspect, the problem is you cannot communicate what you are thinking through what you are writing, this would definitely explain the confusion of a lot of your posts. Please, in this case, own up to the problem instead of pretending that it's others who "don't understand" you.

Tue, 2010-07-13 15:21

#54

jas

PB66 wrote:

I thought I'd let those heavily involved with this debate know how it looks to the casual reader:...

...

Does NIST have a description of the collapse of the towers that is basically correct? I don't know, but I expect so. Are there some minor gaps in their description that could be covered better? Maybe, but it's not clear what they are. However, what jas and Fidel sometimes claim is that the flaws in the NIST description are complete obvious to casual inspection. In my view, Pants-of-dog has prettily clearly rebuted this claim - the description of the collapse in (2) is not completely unreasonable.

Thanks for your feedback, PB. It is genuinely helpful to hear what others are gleaning from this discussion. I summarize the main points we are down to with the NIST/Bazant hypothesis that Pants is defending here:

jas wrote:

The criticisms we have of Bazant's calculations still stand, and you don't need math knowledge to understand them: Bazant's hypothesis relies on a piledriver theory in which the upper block crushes through storey after storey of concrete and structural steel in a few seconds more than it would take to fall through air, AND it accumulates mass (i.e., layers of rubble that somehow serve to crush the lower floors) as it goes - two premises the visual evidence does not support, and also that violate not only real principles of physics but also common sense, everday understandings of how matter moves and interacts in our everyday world.

It seems pretty clear to me what the problems are with this model. What parts don't you understand or agree with?

Tue, 2010-07-13 15:28

#55

jas

Pants-of-dog wrote:

Please do not call me a liar. The animated gif obviously shows the first few moments after collapse initiation. This is obvious from the fact that the dust cloud does not appear in the first image of the animated gif, and is quite small in the second one. The only time when the dust cloud is this size is at the very begining of collpase. Thus, the storeys that collapse in the animated gif can only be the very first storeys collapsed: the storeys where the plane impacted.

The animated gif in posts #15 and #35 shows a floor immediately above where the red line is drawn that has blackened windows with smoke issuing from them. Since you yourself have insisted that fires did not occur below the impact zone, we can consider this floor to be part of the impact zone. Even if it isn't, it shows clearly that the upper block is crushing itself before it hits the intact floors below the drawn red line, floors which you have claimed it crushes.

Tue, 2010-07-13 15:31

#56

PB66

Fidel wrote:

WTC1 upper block clearly begins disintegrating here as per Newton's third law, from DrJudyWood.com

[IMG]http://img.photobucket.com/albums/v697/rabblerabble/WTC1_redLines.gif[/IMG]

1) Newton's third law does not describe disintegration.

2) The video doesn't show anything disintegrating. The first image shows the tower before collapse begins. In the second, as the collapse starts, a cloud of dust or smoke is blown out from the area destroyed by the plane impact (just above the lower redline). Of the part of the building above the red line, the lower part is obscured by the cloud, so the video provides no evidence that there is disintegration. We can see that the corner of the building -a grey line down the middle of both pictures- remains roughly intact. The upper left part of the upper part of the building, i.e. the part on the left, just beneath the upper red line is also clearly visible and also not disintegrating.

Tue, 2010-07-13 15:35

#57

jas

Pants-of-dog wrote:

jas wrote:
Gordon Ross and David Chandler already have. And they don't talk about tripods losing legs.

And I have shown how Ross's assumptions concerning collapse are not consistent with observed data; i.e. Ross assumes the load would be transferred to the columns as they were designed to, despite the fact that the loads being applied are not being applied in the places they were designed to.

I think the animated gif in posts #15 and #35 show that Ross' assumptions are correct. We can clearly see the intact portion of the building holding up below where the upper block begins disintegrating into itself. Thus, any stresses being transferred down from the upper block are not, or not yet causing failure below the impact zone.

pants wrote:
Chandler, once again, is misapplying Newton's 3rd law. I have explained how using conservation of momentum (which is a more universal rephrasing of Newton's 3rd law) makes more sense, and how there is no contradiction between Bazant and Greening's models and teh law of conservation of momentum. Thus, Chandler is wrong.

I'm not convinced you have the knowledge or qualifications to make this judgment. And the only works you continue to cite are those of Bazant and Greening, whose model does not accord with the visual evidence. Are you using some other model in your dismissal of Chandler's?

Tue, 2010-07-13 15:38

#58

jas

Pants-of-dog wrote:

jas wrote:
Would you agree that this video shows that much more mass is leaving the system than you account for in your calculations? Which, by the way, is zero.

You are correct that I have not looked at it mathematically, but I have clearly mentioned the mass ejecting laterally, as well as pointing out that neither of us have any evidence as to how much mass was ejected.

"Mentioning" the mass doesn't account for it, especially when your mathematical model depends on that mass accumulating. If you want your model to accord with reality, wouldn't you make some kind of effort to estimate the amount of mass exiting the collapse at each level?

Tue, 2010-07-13 15:54

#59

jas

But yes, I see you leave it to Bazant for that. Unfortunately, his whole explanation is based on his "crush-down" then "crush-up" phases. Phases which do not seem to describe what we see.

I also notice that he references the seismic records heavily, whereas NIST found the seismic records "unreliable" due to all the other "commotion". Another interesting inconsistency.

Tue, 2010-07-13 16:01

#60

jas

PB66 wrote:

Fidel wrote:

WTC1 upper block clearly begins disintegrating here as per Newton's third law, from DrJudyWood.com

[IMG]http://img.photobucket.com/albums/v697/rabblerabble/WTC1_redLines.gif[/IMG]

1) Newton's third law does not describe disintegration.

2) The video doesn't show anything disintegrating. The first image shows the tower before collapse begins. In the second, as the collapse starts, a cloud of dust or smoke is blown out from the area destroyed by the plane impact (just above the lower redline). Of the part of the building above the red line, the lower part is obscured by the cloud, so the video provides no evidence that there is disintegration. We can see that the corner of the building -a grey line down the middle of both pictures- remains roughly intact. The upper left part of the upper part of the building, i.e. the part on the left, just beneath the upper red line is also clearly visible and also not disintegrating.

Newton's third law describes why the building can easily hold up under the gravitational force of the descending upper block. The video indeed shows that the burnt upper block begins disintegration as the stress from the impact of collapse that would communicate downward into the intact building is transferred back up into the upper block, if it can be put that way.

Tue, 2010-07-13 16:03

#61

Pants-of-dog

jas wrote:

....

Thanks for your feedback, PB. It is genuinely helpful to hear what others are gleaning from this discussion. I summarize the main points we are down to with the NIST/Bazant hypothesis that Pants is defending here:

jas wrote:

The criticisms we have of Bazant's calculations still stand, and you don't need math knowledge to understand them: Bazant's hypothesis relies on a piledriver theory in which the upper block crushes through storey after storey of concrete and structural steel in a few seconds more than it would take to fall through air, AND it accumulates mass (i.e., layers of rubble that somehow serve to crush the lower floors) as it goes - two premises the visual evidence does not support, and also that violate not only real principles of physics but also common sense, everday understandings of how matter moves and interacts in our everyday world.

It seems pretty clear to me what the problems are with this model. What parts don't you understand or agree with?

I would like to point out that the visual evidence does not contradict Bazant and Greening's models either. Nor have you shown which principles of physics are violated.

jas wrote:
I think the animated gif in posts #15 and #35 show that Ross' assumptions are correct. We can clearly see the intact portion of the building holding up below where the upper block begins disintegrating into itself. Thus, any stresses being transferred down from the upper block are not, or not yet causing failure below the impact zone.

I refer you to PB66's observations concerning the gif in post 55, who states it as eloquently as I could.

jas wrote:
I'm not convinced you have the knowledge or qualifications to make this judgment. And the only works you continue to cite are those of Bazant and Greening, whose model does not accord with the visual evidence. Are you using some other model in your dismissal of Chandler's?

It doesn't matter if I have the knowledge or qualifications. I already showed you the wiki article that shows that newton's third law is derived from the law of conservation of momentum, and then I did the conservation of momentum math for you. My argument is completely independent from my qualifications, or possible lack thereof.

jas wrote:
"Mentioning" the mass doesn't account for it, especially when your mathematical model depends on that mass accumulating. If you want your model to accord with reality, wouldn't you make some kind of effort to estimate the amount of mass exiting the collapse at each level?

Please see my post 47. Thank you.

Tue, 2010-07-13 16:07

#62

Pants-of-dog

jas wrote:

But yes, I see you leave it to Bazant for that. Unfortunately, his whole explanation is based on his "crush-down" then "crush-up" phases. Phases which do not seem to describe what we see.

I also notice that he references the seismic records heavily, whereas NIST found the seismic records "unreliable" due to all the other "commotion". Another interesting inconsistency.

Please explain, using evidence, how Bazant's model is inconsistent with the observed data.

Thank you.

jas wrote:

....

Newton's third law describes why the building can easily hold up under the gravitational force of the descending upper block. The video indeed shows that the burnt upper block begins disintegration as the stress from the impact of collapse that would communicate downward into the intact building is transferred back up into the upper block, if it can be put that way.

Please explain how the bolded statement is true, and provide evidence. Thank you.

Tue, 2010-07-13 16:09

#63

jas

Pants-of-dog wrote:

I refer you to PB66's observations concerning the gif in post 55, who states it as eloquently as I could.

Pants, I see a floor immediately above the drawn red line that has a row of blackened windows and smoke issuing from them in the first frame. In the second frame, we actually see fire coming out of those windows. Do you deny this?

Tue, 2010-07-13 16:09

#64

jas

Tue, 2010-07-13 16:12

#65

jas

Pants-of-dog wrote:

Please explain how the bolded statement is true, and provide evidence. Thank you.

I will describe it in the way I understand it, but can we first agree on the question I ask in post #63?

Tue, 2010-07-13 16:17

#66

Pants-of-dog

jas wrote:

Pants, I see a floor immediately above the drawn red line that has a row of blackened windows and smoke issuing from them in the first frame. In the second frame, we actually see fire coming out of those windows. Do you deny this?

No, and it is consistent with my understanding of the collapse. The impact zone would have had fires still burning and smoldering near the windows, where the oxygen content was higher. During the beginning of the collpase, the air in the impact zone would have been pushed out by the pressure of the descending upper block. This would have resulted in movement of air out of the broken windows. This movement of air would have fanned any flames as well as pushed the flames out of the windows. If you have ever tried to light a cigarette in the wind, you would know that flames are easily blown around by wind.

Tue, 2010-07-13 16:37

#67

jas

Pants-of-dog wrote:

No, and it is consistent with my understanding of the collapse. The impact zone would have had fires still burning and smoldering near the windows, where the oxygen content was higher. During the beginning of the collpase, the air in the impact zone would have been pushed out by the pressure of the descending upper block. This would have resulted in movement of air out of the broken windows. This movement of air would have fanned any flames as well as pushed the flames out of the windows. If you have ever tried to light a cigarette in the wind, you would know that flames are easily blown around by wind.

I see what you are arguing. We would need to see more of this video to see whether the upper block continues to disintegrate or whether collapse onto the intact portion begins next. However, I think you are missing the main point. The first collapse, if that's what we're seeing is already occurring, and the intact portion of the building is still standing. It is already transferring stress from the collapse back up into the collapsing upper block, and showing no signs of crumbling at the upper edge. If it wasn't transferring this stress, it would be starting to fall with the upper block. You have said there was no time for the intact building to absorb that load.

Tue, 2010-07-13 17:28

#68

Fidel

Pants-of-dog wrote:
That post of his is actually another post from a forum:

http://the911forum.freeforums.org/post2095.html#p2095

We have already discussed why posts on forums are not good sources. Even if they were, there is still the ongoing problem that Szamboti gives no indication at all how he comes up with these numbers. His numbers for the energy requirements for destroying two floors of the WTC towers are far higher than other people have calculated.

[size=12]Sure, if Bazant is your 9/11 god, then I suppose you can ignore the opinions of 900 other engineers saying it's unscientific nonsense. You know what they say about putting all your eggs in an official government conspiracy theory basket.[/size]

Fidel wrote:
Yes? When you(Bazant and Greening) try to tell us that a "rigid upper block" fell through a lower block nearly six times its own mass, and finally disintegrating after doing all that work, you're talking US Gov.-sponsored conspiracy theory. Where's the video evidence to support these wild claims? You have none.

You keep referring to some kind of proof, but I haven't seen it.

Pants-of-dog wrote:
Fidel wrote:
Do you see a rigid body from video evidence? Because we don't. Not from Judy Woods' video. It looks a lot like the upper block is crumpling from the very beginning as per Newtonian physics.

You are correct that we are not dealing with solely rigid bodies, which is why it makes no sense at all that you keep insisting on discussing it in terms of rigid body mechanics. That is what Newton's thrid law is about: how rigid bodies interact.

No Bazant is the one talking about "the little upper block that could" which remained rigid and all powerful all the way to the bottom where it collapsed nealty into itself as its reward for annihilating Newton's third law of motion. And I'm still not sure what it is that you're saying.

Pants-of-dog wrote:
No, you don't understand.

Garcia is discussing the duration of the impact, which is a specific quantity that can be calculated using momentum and impact force. Or as Garcia puts it, the time interval dt during which the momentum of the upper block is reduced (in magnitude) from m*v(initial) to m*v(final).

[size=12]No, if you read Garcia's essay, [url=http://impactglassman.blogspot.com/2007/01/hand-waving-physics-of-911.ht... from Griscom's blog here[/url], he's talking about the impulse momentum form of Newton's 2nd law:[/size]

Manuel Garcia wrote:
The balance of forces on the upper block as it impacts the lower structure is presented here as the impulse momentum form of Newton's 2nd Law:

The time rate of change of momentum = The sum of the forces,

[m*v(final) - m*v(initial)]/dt = F - m*g.

[size=12]They must be using the integral , ∫F.dt , which would be an equation used to calculate vertical impulse in this case. And it should be a vector quantity measure of the effect of a force during a certain time interval. On an x-y graph, it's the area under force vs time curve.[/size]

Pants-of-dog wrote:
You are discussing the time it takes for the upper block to collapse the lower floor if it is lying at a certain angle. Since there is no reason to believe that v(final) occurs at the bottom point of your Pythagorean triangle, you are comparing two unlike things.

[size=12]I'm talking about no such thing. On his blog, Dr. Griscom describes the same duration of impact I am referring to, and the same time interval Garcia refers to:[/size]

éminence grise wrote:
"Good question, Ross. The force that the falling block instantaneously delivers to the floor below depends on how fast the impulse is delivered. If the upper block has rotated only one degree,[color=red] it delivers an instantaneous force only to the line of contact[/color], which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side. Tell the truth, I don't know if the videos show the upper block contacting the lower one in less than a second. If they DO show that, it can only have happened if all the columns were cut simultaneously..."

[size=12]No one in that exchange is talking about time "for the upper block to collapse the lower floor" as you put it. And the only person talking about time "for the upper block to collapse the lower floor" here in this thread is you. Not me, you.

Inserting the example dt=0.14s(from my right-angle triangle calculation, and Griscom who doesn't show his work) into Garcia's equation for force magnitude of reaction:

F/(m*g) = 1 + dv/(g*dt) = 1 + 0.5/(9.81*0.14) = 1.3, a load of 1.3 times, (not 6.1) the static+dynamic weight of the upper block. Watch out for Pythagoras, Pants[/size]

Tue, 2010-07-13 20:20

#69

Pants-of-dog

The refutation of Chandler's work is in two phases. The first phase involves pointing out that Newton's 3rd law is derived from the more general law of the conservation of momentum.

http://en.wikipedia.org/wiki/Momentum#Conservation_of_linear_momentum

Quote:
Newton's third law of motion, the law of reciprocal actions, which dictates that the forces acting between systems are equal in magnitude, but opposite in sign, is due to the conservation of momentum.

So, if it can be shown that Bazant's (or Greening's) model does not violate the law of conservation of momentum, we can safely say that the model does not violate Newton's 3rd law.

The second phase, of course, is showing how the model is consistent with conservation of momentum.

Here I begin to use the conservation of momentum equations to analyse the collapse of the first floor.

I conclude it here.

I show that there is more than enough kinetic energy to collapse each floor on the way down, as Bazant and Greening have done. Since I used conservation of momentum equations, it cannot be inconsistent with the law of conservation of momentum.

Therefore any claim that the progressive collapse theory is inconsistent with Newton's 3rd law is wrong.

Tue, 2010-07-13 20:43

#70

Pants-of-dog

Fidel wrote:
Sure, if Bazant is your 9/11 god, then I suppose you can ignore the opinions of 900 other engineers saying it's unscientific nonsense. You know what they say about putting all your eggs in an official government conspiracy theory basket.

What does this have to do with Szamboti's lack of calculations?

Fidel wrote:
You keep referring to some kind of proof, but I haven't seen it.

http://rabble.ca/comment/1162713/refutation-Chandlers

Fidel wrote:
No Bazant is the one talking about "the little upper block that could" which remained rigid and all powerful all the way to the bottom where it collapsed nealty into itself as its reward for annihilating Newton's third law of motion. And I'm still not sure what it is that you're saying.

Was the lower body deforming or rigid? It was deforming. Which is why it makes more sense to talk about conservation of momentum rather than force reactions.

Fidel wrote:
Pants-of-dog wrote:
No, you don't understand.

Garcia is discussing the duration of the impact, which is a specific quantity that can be calculated using momentum and impact force. Or as Garcia puts it, the time interval dt during which the momentum of the upper block is reduced (in magnitude) from m*v(initial) to m*v(final).

No, if you read Garcia's essay, [url=http://impactglassman.blogspot.com/2007/01/hand-waving-physics-of-911.ht... from Griscom's blog here[/url], he's talking about the impulse momentum form of Newton's 2nd law:

Manuel Garcia wrote:
The balance of forces on the upper block as it impacts the lower structure is presented here as the impulse momentum form of Newton's 2nd Law:

The time rate of change of momentum = The sum of the forces,

[m*v(final) - m*v(initial)]/dt = F - m*g.

Please note that my bolded statement above is a direct quote from Garcia's counterpunch article.

Fidel wrote:
They must be using the integral , ∫F.dt , which would be an equation used to calculate vertical impulse in this case. And it should be a vector quantity measure of the effect of a force during a certain time interval. On an x-y graph, it's the area under force vs time curve.

This does not logically follow from Garcia's statements.

Fidel wrote:

I'm talking about no such thing. On his blog, Dr. Griscom describes the same duration of impact I am referring to, and the same time interval Garcia refers to:

éminence grise wrote:
"Good question, Ross. The force that the falling block instantaneously delivers to the floor below depends on how fast the impulse is delivered. If the upper block has rotated only one degree, it delivers an instantaneous force only to the line of contact, which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side. Tell the truth, I don't know if the videos show the upper block contacting the lower one in less than a second. If they DO show that, it can only have happened if all the columns were cut simultaneously..."

No one in that exchange is talking about time "for the upper block to collapse the lower floor" as you put it. And the only person talking about time "for the upper block to collapse the lower floor" here in this thread is you. Not me, you.

Inserting the example dt=0.14s(from my right-angle triangle calculation, and Griscom who doesn't show his work) into Garcia's equation for force magnitude of reaction:

F/(m*g) = 1 + dv/(g*dt) = 1 + 0.5/(9.81*0.14) = 1.3, a load of 1.3 times, (not 6.1) the static+dynamic weight of the upper block. Watch out for Pythagoras, Pants

Please explain exactly what your right angle triangle calculation is showing, and how it comes to 0.14s.

Tue, 2010-07-13 21:42

#71

Pants-of-dog

jas wrote:
I see what you are arguing. We would need to see more of this video to see whether the upper block continues to disintegrate...

It is not disintegrating, as far as I can tell.

jas wrote:
...or whether collapse onto the intact portion begins next. However, I think you are missing the main point. The first collapse, if that's what we're seeing is already occurring, and the intact portion of the building is still standing. It is already transferring stress from the collapse back up into the collapsing upper block, and showing no signs of crumbling at the upper edge. If it wasn't transferring this stress, it would be starting to fall with the upper block. You have said there was no time for the intact building to absorb that load.

The bolded statement is wrong. The lower block will not be stressed to the point of collpase until the upper block falls thorugh the impact zone and lands on the lower floor.

Tue, 2010-07-13 23:51

#72

Fidel

Pants-of-dog wrote:
Please explain exactly what your right angle triangle calculation is showing, and how it comes to 0.14s.

Dave Griscom wrote:
If the upper block has rotated only one degree, it delivers an instantaneous force only to the line of contact, which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side.

This is tedium.

[url=http://www.carbidedepot.com/formulas-trigright.asp]Rt-Angle triangle calculator here[/url]

Using the right angle triangle calculator on that page,

1. Use 63.4 for side "c", which is the length of the floor in metres
2. Use 1° for angle "A" and click calculate. It should give you 1.106 or 1.11 for side "a", or the distance in metres which the high end of the tilted floor has yet to fall after the lower end makes initial contact with the top floor of the lower block.

3. Divide that result for side "a" by Garcia's rate of descent, 7.7m/s, and that's the new duration of impact, or as Griscom said to the poster Ross, which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side

4. Plug dt=0.14s into Garcia's eq'n for total reaction force, and you get 1.3 times the weight of the upper block.

But again, Garcia is assuming very, very small delays in transit time after the first impact and every successive one after that. And the associated small reduction in velocity is just as ridiculous. The duration of impacts and subsequent failures of 250 support columns at each floor, and from which Garcia derives delta-t from thin air, would be much faster than the blink of an eye, about 30 to 40 times speedier in duration. And then he goes on to apologize for the fact that NIST rejected Bazant's first progressive collapse theory as their own evidence indicated Bazant's pancaking theory was just as ridiculous as Garcia's CounterPunch essay and attempt at proof by intimidation. I only posted Garcia's handwaving physics article as an example of the pro-NIST baloney out there. I didn't think anyone would actually try to defend Garcia's unscientific nonsense. I was wrong.

Tue, 2010-07-13 23:53

#73

Unionist

http://www.coolissues.com/mathematics/Fermat/fermat.htm

Wed, 2010-07-14 01:04

#74

Fidel

From Unionist's link, is it Pythagoras or Pythagora? Jeez, now I'm really confused. Unionist knows Latin, which can only be a degree or two of variation from Greek. So what's the deal, U?

Wed, 2010-07-14 01:22

#75

jas

Pants-of-dog wrote:

It is not disintegrating, as far as I can tell.

It is losing some floors. Dis-integrate, if I can be literal.

pants wrote:
The bolded statement is wrong. The lower block will not be stressed to the point of collpase until the upper block falls thorugh the impact zone and lands on the lower floor.

Which it is doing. But yes, it would be helpful to see another second of two of this video.

Wed, 2010-07-14 01:37

#76

jas

Pants-of-dog wrote:

The refutation of Chandler's work is in two phases. The first phase involves pointing out that Newton's 3rd law is derived from the more general law of the conservation of momentum.

http://en.wikipedia.org/wiki/Momentum#Conservation_of_linear_momentum

Quote:
Newton's third law of motion, the law of reciprocal actions, which dictates that the forces acting between systems are equal in magnitude, but opposite in sign, is due to the conservation of momentum.

So, if it can be shown that Bazant's (or Greening's) model does not violate the law of conservation of momentum, we can safely say that the model does not violate Newton's 3rd law.

The second phase, of course, is showing how the model is consistent with conservation of momentum.

Here I begin to use the conservation of momentum equations to analyse the collapse of the first floor.

I conclude it here.

I show that there is more than enough kinetic energy to collapse each floor on the way down, as Bazant and Greening have done. Since I used conservation of momentum equations, it cannot be inconsistent with the law of conservation of momentum.

Therefore any claim that the progressive collapse theory is inconsistent with Newton's 3rd law is wrong.

You've said this before, but without actually explaining the connection or relevance of Newton's Third Law to the law of Conservation of Momentum, or why it matters to your argument, or Chandler's. You simply state the one is derived from the other, citing the same Wikipedia reference, and then say "therefore..." and jump to your conclusion. I'm sure I'm not the only one who needs the fill-in explanation here.

And as we've said before, Bazant's calculations are designed to explain a collapse that can't naturally occur, not to explain what should have happened. So, of course they explain the impossible collapse times--they are designed to--but they falsely ascribe it to gravitation. Ross and Chandler show what should have happened given what we know about the building structure and what we know about gravity. Theirs are the correct estimates. Bazant's had a pre-fab conclusion.

Wed, 2010-07-14 02:41

#77

Fidel

PB66 wrote:
1) Newton's third law does not describe disintegration.

2) The video doesn't show anything disintegrating. The first image shows the tower before collapse begins. In the second, as the collapse starts, a cloud of dust or smoke is blown out from the area destroyed by the plane impact (just above the lower redline). Of the part of the building above the red line, the lower part is obscured by the cloud, so the video provides no evidence that there is disintegration. We can see that the corner of the building -a grey line down the middle of both pictures- remains roughly intact. The upper left part of the upper part of the building, i.e. the part on the left, just beneath the upper red line is also clearly visible and also not disintegrating.

1) There isn't enough total potential energy in the building for 0.15 of itself to crush the remainder. More than one engineer and scientist have provided the rationale as to why not. The pile driver theory is pure fiction, as in they are lying to you

2) The alleged pile driver is also not seen to be whole and is also hidden by the massive dust cloud, which indicates that something is not nearly as much as it once was by a whole lot. Sir Isaac Newton says the pile driver will not remain rigid. Two guys named Bazant and Greening are trying to tell you otherwise. So it's a leap of faith really. And so it's really a matter of which way you decide to leap? Use the force, PB66. Use your gut instinct, like they do over at the JREF forum. And then imagine that all those guys are a bunch of pseudo-scientific wackos who tend to posit their own theories on the nature of reality and depending on what dip angle magnetic lines of flux surround the earth in their vicinity.

Wed, 2010-07-14 05:39

#78

Cueball

Fidel wrote:

[IMG]http://img.photobucket.com/albums/v697/rabblerabble/WTC1_redLines.gif[/IMG]

Wed, 2010-07-14 06:40

#79

Unionist

Fidel wrote:

From Unionist's link, is it Pythagoras or Pythagora? Jeez, now I'm really confused. Unionist knows Latin, which can only be a degree or two of variation from Greek. So what's the deal, U?

Good catch, Fidel - they did get the spelling wrong once! I can't believe you read the whole thing. My hat is off and staying off! PS: Have you found any flaws in the proof yet?

Wed, 2010-07-14 09:51

#80

Pants-of-dog

Fidel wrote:
Dave Griscom wrote:
If the upper block has rotated only one degree, it delivers an instantaneous force only to the line of contact, which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side.

This is tedium.

[url=http://www.carbidedepot.com/formulas-trigright.asp]Rt-Angle triangle calculator here[/url]

Using the right angle triangle calculator on that page,

1. Use 63.4 for side "c", which is the length of the floor in metres
2. Use 1° for angle "A" and click calculate. It should give you 1.106 or 1.11 for side "a", or the distance in metres which the high end of the tilted floor has yet to fall after the lower end makes initial contact with the top floor of the lower block.

So, 1.11m is the vertical distance of the tilting floor. Okay.

Fidel wrote:
3. Divide that result for side "a" by Garcia's rate of descent, 7.7m/s, and that's the new duration of impact, or as Griscom said to the poster Ross, which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side

And then you divide by the velocity right before impact to get the time it takes for the upper block to travel through that vertical distance.

This has nothing to do with the momentum.

Garcia's dt is, according to Garcia (not Griscom or Ross or anyone else), dt is a label for "delta t", a very brief time interval during which the impact occurs and the momentum changes from m*v(initial) to m*v(final);. Please note that this definition for dt is quoted directly from Garcia's article.

Garcia's dt is about the duration for the change in velocity associated with momentum transfer.

Your dt is about the time it takes for the upper block to travel a certain distance.

Apples and oranges.

jas wrote:
It is losing some floors. Dis-integrate, if I can be literal.

I don't see it losing any floors.

jas wrote:
Which it is doing. But yes, it would be helpful to see another second of two of this video.

I don't think the upper block has even impacted the first lower floor by the time that animated gif is done.

jas wrote:
You've said this before, but without actually explaining the connection or relevance of Newton's Third Law to the law of Conservation of Momentum, or why it matters to your argument, or Chandler's. You simply state the one is derived from the other, citing the same Wikipedia reference, and then say "therefore..." and jump to your conclusion. I'm sure I'm not the only one who needs the fill-in explanation here.

http://www.physicsclassroom.com/class/momentum/U4L2b.cfm

There is a short tutorial outlining how they are describing the same phenomenon.

jas wrote:
And as we've said before, Bazant's calculations are designed to explain a collapse that can't naturally occur, not to explain what should have happened. So, of course they explain the impossible collapse times--they are designed to--but they falsely ascribe it to gravitation. Ross and Chandler show what should have happened given what we know about the building structure and what we know about gravity. Theirs are the correct estimates. Bazant's had a pre-fab conclusion.

You keep repeating this. It would help if you provided some sort of evidence to support your claim.

Wed, 2010-07-14 15:00

#81

Fidel

Pants-of-dog wrote:

Fidel wrote:
Dave Griscom wrote:
If the upper block has rotated only one degree, it delivers an instantaneous force only to the line of contact, which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side.

This is tedium.

[url=http://www.carbidedepot.com/formulas-trigright.asp]Rt-Angle triangle calculator here[/url]

Using the right angle triangle calculator on that page,

1. Use 63.4 for side "c", which is the length of the floor in metres
2. Use 1° for angle "A" and click calculate. It should give you 1.106 or 1.11 for side "a", or the distance in metres which the high end of the tilted floor has yet to fall after the lower end makes initial contact with the top floor of the lower block.

So, 1.11m is the vertical distance of the tilting floor. Okay.

It's the high end of the tilted floor at the exact moment when the other end, the lowest end, makes contact with the lower block after an unimpeded 3 metre free fall that takes 0.78 seconds according to Garcia. What we're talking about is the very bottom part of the upper block, or "part C" according to Bazant's terminology.

Fidel wrote:
3. Divide that result for side "a" by Garcia's rate of descent, 7.7m/s, and that's the new duration of impact, or as Griscom said to the poster Ross, which at a rotation angle of 1 degree would take 0.14 seconds to march from the initially contacted side of the lower floor all the way across to the far side

And then you divide by the velocity right before impact to get the time it takes for the upper block to travel through that vertical distance.

Pants-of-dog wrote:
This has nothing to do with the momentum.

Garcia's dt is, according to Garcia (not Griscom or Ross or anyone else), dt is a label for "delta t", a very brief time interval during which the impact occurs and the momentum changes from m*v(initial) to m*v(final);. Please note that this definition for dt is quoted directly from Garcia's article.

Griscom is talking about the exact same "delta t" Garcia arbitrarily assumes a value for. Δt is merely a variable term in Garcia's force balance equation. It's a time value for the duration of impact. Even your hammer and dinner plate example will have a duration of impact. ie. dt will be shorter when hammer face makes perfect face-to-face contact with the dinner plate and longer time duration when hammer face meets dinner plate any angle and . It's a force vector, and yes it has momentum. In the graph below, linear impulse is represented by the integral, ∫F.dt. Delta-t is represented by the area under the force vs time curve. I don't know how else to explain this to you without making a fuckin' video tutorial.

[IMG]http://img.photobucket.com/albums/v697/rabblerabble/Capture-39.gif[/IMG]

Pants-of-dog wrote:
Garcia's dt is about the duration for the change in velocity associated with momentum transfer.

Your dt is about the time it takes for the upper block to travel a certain distance.

Apples and oranges.

My Δt and Garcia's Δt and Griscom's Δt are all the same mathematical expression, and you're the oddball orange. How do you like those apples?

And if you ever run into the babbler who goes by [url=http://rabble.ca/babble/humanities-science/nist-911-sussudio-science-tru..., maybe you can explain it to him. Because he was hung up on the exact same detail regarding Garcia's proof by intimidation Counterpunch essay.

Wed, 2010-07-14 15:11

#82

jas

Pants-of-dog wrote:

jas wrote:
And as we've said before, Bazant's calculations are designed to explain a collapse that can't naturally occur, not to explain what should have happened. So, of course they explain the impossible collapse times--they are designed to--but they falsely ascribe it to gravitation. Ross and Chandler show what should have happened given what we know about the building structure and what we know about gravity. Theirs are the correct estimates. Bazant's had a pre-fab conclusion.

You keep repeating this. It would help if you provided some sort of evidence to support your claim.

The only evidence I might have of this is Bazant's own admission as to what it was he was trying to explain. When he saw the buildings collapse, and he wrote his first paper two days later, was he asking himself, "what could possibly have allowed the buildings to descend at that speed?" or did he ask himself, "how can gravitation explain this speed and manner of collapse?". Since he entertains no other theories (at least not until others raise them) we can assume that it was something more like the second question that motivated him. Therefore, he finds a calculation that fits the collapse time.

I only wish I understood the math enough to see how he explains how his upper blocks crush through 80 - 90 storeys of concrete and structural steel at a speed that is 1- 4 seconds faster than free fall--oh, wait a minute. He doesn't, does he? He only provides the equation for the collapse initiation--but I do trust the work that other members of the science community have provided to evaluate that.

Wed, 2010-07-14 15:13

#83

jas

Pants-of-dog wrote:

jas wrote:
It is losing some floors. Dis-integrate, if I can be literal.

I don't see it losing any floors.

Do you see it shortening? Do you see it losing height? If what we are seeing is the upper block crushing into the impact zone, as you state above, then it is, by definition, losing floors.

pants wrote:

jas wrote:
Which it is doing. But yes, it would be helpful to see another second of two of this video.

I don't think the upper block has even impacted the first lower floor by the time that animated gif is done.

You've already stated that. It is hitting the floor above the drawn red line that has the blackened windows, the smoke issuing out of it, and, in the second frame, has flames shooting out of them, probably, as you say, from the compression action from above.

What it does show, however, if this is the beginning of the collapse, and this is the upper block descending into the damage zone where the planes made holes, that fire and other damage occurred below this impact zone, contrary to what you were trying to claim in an earlier thread. Doesn't really matter. I'm not sure why you needed to make that claim in the first place. But it's another claim about the buildings you made that is wrong.

What it also shows is that for the start of the collapse, as the upper block is descending onto the damaged floor above the intact building, i.e., above the drawn red line, the intact portion is indeed still intact. It has not started to fall. It has been intact long enough to begin absorbing the load from above and referring it through its frame.

Wed, 2010-07-14 16:24

#84

Pants-of-dog

jas wrote:
Do you see it shortening? Do you see it losing height? If what we are seeing is the upper block crushing into the impact zone, as you state above, then it is, by definition, losing floors.

I see an overall shortening of height caused by the failure of the last few columns in the impact zone. th eupper block itself does not seem to be losing any appreciable amount of mass or integrity.

jas wrote:

You've already stated that. It is hitting the floor above the drawn red line that has the blackened windows, the smoke issuing out of it, and, in the second frame, has flames shooting out of them, probably, as you say, from the compression action from above.

What it does show, however, if this is the beginning of the collapse, and this is the upper block descending into the damage zone where the planes made holes, that fire and other damage occurred below this impact zone, contrary to what you were trying to claim in an earlier thread. Doesn't really matter. I'm not sure why you needed to make that claim in the first place. But it's another claim about the buildings you made that is wrong.

What it also shows is that for the start of the collapse, as the upper block is descending onto the damaged floor above the intact building, i.e., above the drawn red line, the intact portion is indeed still intact. It has not started to fall. It has been intact long enough to begin absorbing the load from above and referring it through its frame.

The upper block in the animated gif is not hitting anytjing. In the first frame, it is still suspended by the last remaing columns. In the second frame, these columns have failed and the upper block is falling but has not yet impacted the first floor down. The smoke and the fire and being pushed out by the air dispalced during the fall of the upper block.

Since it does not show anything below the impact zone, and the fires shown are in the impact zone, this is not evidence that there was fire below the impact zone.

Since the upper block began to fall as a result of the failure of the remaining structure, there would have been no structural member that was still capable of transmitting stress to the upper block, or from the upper block to the lower block. This is actually one of the few instances during the entire collapse where there is no load or stress being transfrerred between the upper and lower blocks.

Wed, 2010-07-14 16:30

#85

jas

Here is another video of WTC1

http://www.plaguepuppy.net/public_html/video%20archive/Shaking%20before%...

that shows more clearly that it is the upper block disintegrating before the lower block begins to fall. I hold my cursor icon at the last level of damaged floor (see the tiny line of windows dotted with orange fire that we also see in our above gif) so I have a steady point from which to gauge the shortening of the upper block before it is obscured by the dust clouds. We see that dotted line of orange fire stay in place and turn into large bursts of flame as the collapse progresses.

We also see the antenna tilt over, suggesting complete disintegration.

Wed, 2010-07-14 16:45

#86

jas

Pants-of-dog wrote:

The upper block in the animated gif is not hitting anytjing.

It's elementary that it is. It is crushing itself on the intact building below. If there was no intact building below, if there was no force pushing up, we would see the upper block fall intact, through air, as it were.

Quote:
In the first frame, it is still suspended by the last remaing columns. In the second frame, these columns have failed and the upper block is falling but has not yet impacted the first floor down. The smoke and the fire and being pushed out by the air dispalced during the fall of the upper block.

The columns "failing" is from the crushing of the floors above the impact zone is it not? The impact zone is within the upper block, as is shown in the photo.

pants wrote:
Since it does not show anything below the impact zone, and the fires shown are in the impact zone, this is not evidence that there was fire below the impact zone.

That's fine. So now you are saying that everything above the red line is the impact zone. That confirms my point that the stress caused by the descent of the upper block is being resisted by the intact building below.

pants wrote:
Since the upper block began to fall as a result of the failure of the remaining structure,

Um, no... it is already falling into the impact zone first.

Quote:
... there would have been no structural member that was still capable of transmitting stress to the upper block, or from the upper block to the lower block.

It is clear from the picture and from the video I post above that the intact building below is absorbing the impact of the descending upper block.

Wed, 2010-07-14 17:13

#87

jas

This one nails it.

http://www.plaguepuppy.net/public_html/collapse%20update/close-up_north_...

Wed, 2010-07-14 17:36

#88

jas

Oh, Pannntsy....? Pants-on-fire...!

Golly, where did he go ??

Wed, 2010-07-14 18:39

#89

Yiwah

Oh golly, you mean s/he might have a life beyond breathlessly waiting for you to once more ask him/her to break down the too-difficult physics for you?

How DARE s/he!

Frankly, I think Pants deserves some sort of award for putting up with this nonsense for as long as s/he has.

Wed, 2010-07-14 19:01

#90

jas

says the "Burden of Proof" lady...

Wed, 2010-07-14 19:16

#91

Yiwah

A burden you have yet to discharge in any one of these threads.

Don't worry, no need to deny it, there are plenty of people watching and noticing.

Wed, 2010-07-14 19:46

#92

PB66

Fidel wrote:

Pants-of-dog wrote:
Garcia's dt is about the duration for the change in velocity associated with momentum transfer.

Your dt is about the time it takes for the upper block to travel a certain distance.

Apples and oranges.

My Δt and Garcia's Δt and Griscom's Δt are all the same mathematical expression, and you're the oddball orange. How do you like those apples?

And if you ever run into the babbler who goes by [url=http://rabble.ca/babble/humanities-science/nist-911-sussudio-science-tru..., maybe you can explain it to him. Because he was hung up on the exact same detail regarding Garcia's proof by intimidation Counterpunch essay.

My votes with Pants-of-dog and salsa on this one.

If I drive a 1m wide object at a speed of 1m/s through a sheet of glass which is .8cm thick and which has a slope of 3/4 relative to the front of my object, then, according to our friend Pythagoras, each point on the object will need to break through 1cm of glass. On the other hand, since the object is 1m wide, again by the Pythagorean theorem, one side of my object will need to travel 75cm further than the other to reach the sheet of glass.

How long is the impact? If you mean "how long does it take for each point on my object to pass through the glass", that's only 0.01s. If you mean "how long does it take from when one side of the object reaches the glass to when the other side reaches the glass", then it is 0.75s. Both could reasonably called \Delta t.

The quantity you calculated as dt=0.14s was the second. The quantity needed for momentum transfer is the first.

Wed, 2010-07-14 19:56

#93

writer

Yay, salsa!

Edited to add: Or did you mean Salsa? Oops, my bad!

Wed, 2010-07-14 23:22

#94

jas

Yiwah wrote:

A burden you have yet to discharge in any one of these threads.

Don't worry, no need to deny it, there are plenty of people watching and noticing.

Yiwah, if you were really watching and noticing--indeed, if you had even the remotest clue what we're talking about-- you would already know that the last video I posted buries the Bazant piledriver theory once and for all. Which buries the NIST theory. Which proves wrong the assertions that Pants-of-dog was making. Not that this wasn't already buried long ago, but apparently many Babblers weren't convinced. A fact which should be embarassing enough here.

There's just enough room left in the thread for apologies from you and Michael Nenonen and anyone else who believed in and defended such silly nonsense, and who whined on and on in these and other threads about the 9/11 threads. You can be the first.

Thu, 2010-07-15 00:07

#95

jas

And Fidel, I raise a wee glass in toast to you across our great, central Canadian skies. Cheers, my friend.

Thu, 2010-07-15 01:38

#96

Fidel

Cheers Jas. You're doing a-okay just fine. [url=http://www.lon-capa.org/~mmp/kap4/cd082.htm]This is[/url] an interesting interactive java applet demonstrating net sum of just three different force vectors.

Thu, 2010-07-15 03:04

#97

siamdave

RESPONSE TO post 48:

1. POD quote: "Am I being dishonest, shifty, and vehement? .. I was trying to be as clear and as calm as possible."

-- bordering on a dishonest representation of the exchange - as the context made clear, I was referring to the average OCT supporter in their interactions with those of us trying to let others know the OCT has a lot of problems - you seem to avoid the vehement denunciations, which is certainly a step forward, but your tendency to be dishonest / shifty etc in your arguments seems pretty consistent - examples following.

2. You say: "..I am not sure how this is a response to my discussion concerning the evidence for a continued fire in the impact zone of the planes..."

-- It was a response to your attempt to pretend my questions were irrelevant, not a response to your 'discussion' - which again is a dishonest representation of the exchange itself, and a rhetorical device indicative of a focus on 'winning' a debate on points or something rather than actually sharing information to inform opinion and get closer to the truth of something - which kind of in a nutshell describes the OCTers vs the 'truthers', and is certainly what I was talking about in the first point in general. Your 'discussion', with 'evidence' is a good example, as it appears to be this: "..Your questions about fire are easily answered. Any video of the planes impacts will show the large fireball that accompanied the impact. The continued presence of black smoke from the time of impact to the time of collpase show clearly that the fire continued to burn throughout this time. The fireproofing around the structure must surely have been dislodged when the planes impacted, and the weakening of steel under temperatures such as those present in normal fires is well documented..."

-- Many problems with this highly simplistic, evidence-free 'summary', generally misleading to the point of dishonesty. There were large fireballs certainly, which would certainly impress the tv-generation used to Hollywood FX but less familiar with reality. First, we might note that these fireballs must have consumed much at least, if not most (I have yet to see any reliable estimations of this) of the jet fuel the planes were carrying - certainly the explosions would have started fires, but then since most of the jet fuel was consumed in the fireball, the fires would be dependent on office furniture etc to keep burning, and there is a great lacking of evidence to 'prove' that such wood and paper fires could ever get to a temperature high enough to weaken steel, or maintain that temperature for the time required to start to have that weakening effect, especially when you consider that the fire was diffuse and not concentrated in any way, whilst the steel was part of a huge matrix which would tend to quickly dissipate whatever heat was applied anywhere, thus greatly reducing the chances that any single section of steel got anywhere near hot enough to start to weaken. There has been no 'informed speculation' that I have seen, let alone any kind of scientific analysis, that would try to explain how any of these relatively small, short-term fires (see the pics from my last post - the WTC fires were small - the Oriental and Madrid fires were big - please explain any disagreement with this assertion ..) first got concentrated enough in any particular area to start to weaken any steel, and second how the tendency of steel to dissipate that heat would have allowed the steel to get to any kind of temperature that might have resulted in weakening it. Smoke indicates fire, certainly - but there is no proof that the fires were hot enough to do any damage to the steel in the few minutes it burned before either building collapsed, and this proof would certainly be required before a skeptic wanted to hear much more of your theory.

3. Thanks for the reference to the MIT - the kind of analysis that needs to be done. Unfortunately, the authors don't do a very good job of it, but the paper is nonetheless useful in the same sense any experiment that has a negative result is useful - pointing out flaws in whatever. These guys first do exactly as all 'official' OCTers do - they start with the assumption that the plane impact and fires brought the towers down, and go looking for ways to explain this exceedingly odd phenomenon (i.e. http://911research.wtc7.net/sept11/analysis/anomalies.html#collapses ). In one limited sense this can be called 'scientific investigation', stating a hypothesis and trying to prove it - but in a much more important and broader sense it is anything but scientific, starting with a pre-formed conclusion that ignores at least one very obvious possibility, if not probability (controlled demolition). Real science, when trying to explain some new phenomenon, must consider everything - most of the 'official' investigations have not even used the term CD let alone try to explain the various things that CD most obviously and easily explains - and it is this failure that so many of us are fighting, as the prima facie case for CD is very strong (evidence? Have you heard of a guy named David Ray Griffin? He makes a case for CD far, far stronger than any of the official OCT people for plane crash - fire - fall down go boom!!).

You say: "..As we can see, the core columns received far more damage than could reasonably be described as minimal.." - very dishonest, really - nobody, including you, can 'see' anything beyond a hypothetical scenario offered by some guys at a major US government institution - people who admit from the start they are looking for ways to explain a conclusion they have already reached. Guys who also from the getgo manage, accidentally or otherwise, to be dishonest themselves - "..As the total number of core columns that existed was 44.." - no, I'm afraid I have to tell you there were 47 core columns ( http://wtcmodel.wikidot.com/nist-core-column-data ). When you see this kind of blatant misrepresentation of something this important, you cannot help but wonder if the writers are just careless with their work, or are intentionally trying to mislead to improve their results - either way, the confidence level gets some ***s. When mistakes are made on such basic easily verifiable facts, any conclusions must also be considered as less reliable also. I might also note this paper is quite notable for its many grammatical and spelling mistakes - that's not a problem of course on a discussion board like this where people write in a hurry with no time for various proofreadings etc, but in an important published paper from a major US university, it causes raised eyebrows, to say the least. If you pick up a scienctific or academic book in a bookstore and find this kind of thing, I at least am inclined to view the whole thing as perhaps less rigorous than I prefer in published scientific / academic works. If a scientist or academic is sloppy in his proofreading of a MS, there's not reason to suppose he's not just as sloppy in his other work.

4. You say "..The corner columns of any steel structure are always the weakest ones. This is because they only have to carry one quarter of the floor area that an internal column carries and only half the load of a perimeter column..."

-- again dishonest and an apparent attempt to give a flippant answer to a serious problem being pointed out with your theory - we have three solid corners still anchoring the support of this building - do you want some "proof" that in a 4-cornered structure, 1 corner can be removed and the 3 other corners will continue to support it? And in the WTCs 1-2, there was most of that inner matrix still intact as well, so the idea that the damage done by that corner being lost is enough to lead to global collapse after a few small fires burning for less than an hour is simply a non-starter - and all of the desperate theorizing trying to make this conclusion is just that, deserate speculations that are more than countered by the facts and rebuttals offered, here and elsewhere (for an alternative scenario to the effect the plane crashes etc would have had on the building that makes a great deal more sense to the impartial skeptic than your MIT paper, the curious reader could try this - http://911research.wtc7.net/mirrors/guardian2/wtc/WTC_ch2.htm . )

5. You say "..Assuming that someone is wrong simply because of who they are is a logical fallacy..." - I'm not going to debate you on the tactic of entering advertising brochures into a semi-serious discussion as 'proof' of anything, but I'm glad to hear you're not one of those who dismisses the work of David Ray Griffin because he's 'only a theologian' (you aren't, are you?}

6. YOu say: "..So, no evidence for your assertions except a photo of the building under construction.."

-- I'm sure the police forces of the world will be interested to learn that photos have no evidentiary value. Again your dishonesty comes to the fore - again for very understandable reasons, as like every OCT supporter before you, you dodge around the really diffucult questions. My 'evidence' here was more in the nature of rebuttal - you and your OCT compatriots would have us believe that the 'fires' (of which the only 'evidence' is in the pictures, yes?) that 'raged' that day brought down these buildings - I offer a detailed view of the inside of these buildings, and look for some comments on how some small fires (as noted in the last, big hot fires have big smoke, if we see very little smoke, then it would be up to you to prove that in spite of only a little smoke there are 'raging infernos' in the buildings, hot and concentrated enough to compromise that massive steel core, and the outer columns - and I might remind you that 'speculation' or comments the nature of 'must have' are not really 'proof'. So it would seem to me that in terms of it being clear who is failing in the offering of 'proof', the trophy must go to your side, in this case.

7. You say "Please see the PDF to which I have already linked for the evidence you require.' - as noted, I have already read it. The basic analytic technique is acceptable, and the direct conclusions concerning inner core damage at least appear to be in the ballpark, but at the end they get into some seriously bizarre speculation as they try to explain the 'global collapse' in terms of this limited damage, and once the reader sees their objective is political (supporting the OCT) at least as much as scientific, everything becomes questionable. As you have not mentioned this part of their paper, I won't get into it - but it does tend to cast more than a little doubt on their overall reliability as investigators of any sort, along with what I mentioned earlier.

8. You say "Now that I have provided evidence for my claims, I would like you to provide evidence for the bolded claim..."

-- well, as noted already, your idea of 'evidence' seems somewhat at variance with mine - speculation is not evidence. But photographs certainly can be, and it is not, I would suggest, up to me to prove why a very strong building with small fires is not falling - it is up to you and your comrades to prove why it does - which you have not come near to doing, in my opinion and that of many others. In those photos of the south tower with the corner hit, there is no bulging or any other signs of imminent failure - and your comment is simply 'so you have no evidence beyond pictures?' and say you do not need to respond - quite obviously, from my perspective, there is no response you can make that will sound even remotely reasonable to the skeptical observer - "Oh, sure, there's really big and hot fires inside, eh, but you just can't see em, eh?' might do well in a schoolyard full of not too bright children, but it's not flying here. It is fundamentally dishonest to present a speculative paper that is easily disputable, and then shrug off further questions by saying you have already provided evidence - but again, dishonesty such as this is the heart of the OCT - you really have nothing solid upon which to base your defence.

9. More dishonesty - you say "..The reason those buildings didn't fall is because they were not impacted by planes, did not have their fireproofing dislodged, suffered no large asymmetrical destructions of structure, did not have their fire safety systems like sprinklers overwhelmed or knocked out immediately, and had their loads distributed in the way they were designed to be distributed. In those respects, they were unlike the WTC towers..."

- certainly those differences between the Madrid and Oriental fires are true, but they are not persuasive, and as such are just another example of ducking and dodging with clever answers, then racing off as if you have answered a question which you have not. I could respond to each of those things, but this response is very long already. The key thing you avoid is magnitude - your theory says that the very small (compared to the Madrid etc) fires in the two WTC buildings (my 'evidence' for 'small' is the pictures I offered - if you have "evidence" that contradicts those pictures other than speculation, I'd be interested in hearing it .. referring specifically to the corner-hit south tower ...) weakened the steel to the point it could no longer bear the load above - so what I need to know is, if those relatively small fires, burning for a relatively short time in a non-concentrated fashion, could weaken the steel in those huge WTC core columns to the point of collapse, how in god's name do the huge fires consuming those buildings in the pics I showed, burning for many hours, not have the same weakening effect on the steel? There is no answer for this, aside from the very obvious one - the WTC steel 'failed' only because it was destroyed by explosives (of which there is indeed much evidence - i.e. http://www.serendipity.li/wtc5.htm )

10. You say "..No. I never said that "the columns would have become overstressed, causing them all to fail at once". That bolded bit is you putting words into my mouth..." - I was not putting words into your mouth, simply expanding a bit - it was my understanding that your whole 'piledriver' theory was based on the upper sections of these buildings falling as a block onto the lower section, thus creating 'ireesistable force' etc - - if they just sort of buckled over slowly, pivoting around the unbroken core and perimeter columns in some way, this 'piledriver' force would not be created, and there would be even less excuse for the collapse than you have now. In Post 39 of the last 'thread' you say, for instance "..mass of one floor and the velocity that this floor would have after dropping from rest (v=0) for a distance of 3.7m..." "dropping from rest for 3.7 meters" would be hard to do if everything did not just give way at once .. - if I have misunderstood this, I am sure others would be interested in hearing, as well as I, how you believe the upper section created a piledriver effect if it did not indeed fall as a unit onto the lower section ...

11. You say: "..There are several assumptions you make in your collapse model that I am not sure are accurate... You assume that the rest of the exterior walls are all perfectly sound..."

- it's somewhat more than an assumption - which is why I included the pictures earlier. Noting espectially the south tower (corner hit) - just look at the other walls - they ARE sound, to all intents and appearances. If you want to make the case they are melting from the inside, you need to do somewhat more, in the face of the obvious pictorial evidence to the contrary, than say 'they are all being stressed' - where's your evidence for this, beyond largely unsubstantiated speculation? A bit of smoke indicates fires, sure - but says nothing about intensity, location (in terms of being close enough to steel to even begin to weaken it) or duration ...

12. - and again - "...Again, you seem to be ignoring the effects of fire and overstressing due to loads being shifted onto the remaining structure. Now, the structure can hold up even if it overstressed, but not for long.."

-- either dishonesty or a failure to understand the construction of highrise buildings, including the WTC, which the authors of the paper you reference also make - if a building is expected to weigh 10 tons, then the builders do not build a steel structure that will hold ten tons, they build it to hold 20 or 30 or more, to allow for various things including stress because other parts have failed. The WTC included - I do not have a direct reference for this, but if you want to deny it out loud feel free. Your credibility is already pretty questionable, given everything else I have pointed out above. So when a column fails and its burden is shifted elsewhere, that does NOT immediately mean overstressing - if the column is designed to bear 10 tons but is only bearing 5 tons, then adding a couple of tons is not overstressing - this is something few of you OCTers seem to deal with, if any.

13: you say "..I agree with your hinge bit, by the way, except I do not believe the lower structure could successfully assume the weight of the upper block. This is due to the fact that the upper block is resting its weight on the weakest part of the floor structure: the composite deck and truss system that spanned the distance between the core and the perimeter..."

-- but so what? Where hard steel impacts the floor, the floor will give - but some parts somewhere of that steel frame will meet steel from the lower area, and an equilibrium will be found - or maybe the whole thing will topple to the ground. What is NOT going to happen is the collapse we see, the disintegration of that huge core in a way that steel has never collapsed before (without explosive assistance) and, I would predict quite confidently, never will again (without explosive assistance a la controlled demolition).

For any who are following this lengthy interchange, another interesting examination of the collapse of the WTC buildings here - http://themurkynews.blogspot.com/2008/04/chapter-three-closer-look-at-91... - as is usually the case with 'truther' stuff, considerably more credible than most of the 'scientific' reports about the WTC which start with the premise that 'This was not controlled demolition so we don't have to consider any evidence that indicates that, we'll just twist and bend whatever 'facts' we can find so they fit our 'fall down go boom!! WOW!! theory' - junk 'science' of the first order.

Thu, 2010-07-15 03:14

#98

Jacob Two-Two

I can't say who's right or wrong here but I just want to say to jas and Fidel that pants has clearly shown a lot more respect for you than you've shown for him. If people think he's demolishing your logic, it might be because you respond with mockery at least as much as you do with arguments. It doesn't help your cause.

I also want to comment on the impression that the suspicions of 1200+ professionals are irrelevent since there are so many more who haven't signed the document. This is very faulty logic in my opinion, akin to assuming that the huge numbers of non-voters are all closet anarchists. If any engineer, physicist, etc, hasn't put their name behind any version of events, then you have no way of knowing what they might be thinking. They could just as likely be disbelievers of the official Nist explanation as defenders of it, and even more likely have no opinion one way or the other. The bottom line is that if 1200+ doctors signed something saying that a medicine that the government approved wasn't safe, I wouldn't be taking it, despite the great mass of doctors who weren't involved. You don't put your reputation on the line like that for nothing, and it's always easier to maintain the staus quo than struggle against it.

Thu, 2010-07-15 04:36

#99

Jacob Two-Two

Just read through siamdave's link above and would encourage all others to do so. It's pretty damning stuff. I have always been of the opinion that something is seriously wrong with the official explanation of the events of that day and that a real investigation is badly needed to get some reliable information.

That said, I was never a big adherent of the controlled demolition theory. My reasoning was that it was just too elaborate. Even if the attack was intentionally allowed to happen (which seems very likely) why go to the trouble of destroying the buildings and possibly being caught doing so? Wouldn't the planes by themselves justify the PNAC agenda? What changed my mind was the discovery of the nanothermite in the WTC dust. This has caused me to revisit the possibility of a deliberate demolition and hence, follow this thread with great interest. I hope a credible and civil conversation of this can continue, as it is important to me what the facts actually show. What has impressed me so far is how, once again, we see the limits of human knowledge such that even something as straightforward as a collapsing building has so many variables that our math and science has trouble accounting for it in any unassailable way, leaving us with many versions of events posited by many educated people who are all utterly convinced that any other version but theirs is nonsense. We're not nearly as smart as we think we are.

Thu, 2010-07-15 05:06

#100

PB66

I watched the video you posted, and I don't see anything that contradicts the standard explanation.

1) The heat from the fire on the floors near where the plane hit causes the supports in those floors to lose their strength, so they can no longer support the weight of the floors above them.

2) The floors above begin to fall. (A huge cloud of dust and smoke is ejected obscuring what happens on the floor that first fails. If you watch tthe first two seconds of the building very slowly, you will see that the part of the building above the cloud is falling without being deformed.) The floor immediately beneath the first floor to fail receives the impact of the floors falling from above one by one. Initially, the each falling floor is simply crushed by its own impact.

3) At some point, the impact of the falling floors overwhelms the strength of the floor immediately above the one that first failed. (This is all behind the cloud of smoke.)

4) From then on, the impact of the falling floors (what has been called the pile driver on this board) is sufficient to destroy each of the successive floors, and the entire building collapses starting from the floor just beneath the initial failure, and then going down floor by floor.

jas, in what way does the video that you linked to contradict this?

Thu, 2010-07-15 05:52

#101

siamdave

PB66 wrote:

I watched the video you posted, and I don't see anything that contradicts the standard explanation.

1) The heat from the fire on the floors near where the plane hit causes the supports in those floors to lose their strength, so they can no longer support the weight of the floors above them.

...

4) From then on, the impact of the falling floors (what has been called the pile driver on this board) is sufficient to destroy each of the successive floors, and the entire building collapses starting from the floor just beneath the initial failure, and then going down floor by floor.

Your scenario involves something like a stack of dinner plates, separated by a few thimbles or suchlike, and as one dinnerplate drops, the next gets overwhelmed, etc.

Think of it more correctly like this - a huge, 1000-ft center core of 47 steel columns, surrounded by an outer perimeter of ~250 steel columns. The floors that stretch between the center core and outer column are something of a human convenience, but they do not represent any of the strength of the huge tube within a tube - some bracing and support, but all of the actual strength is in those two tubes. So - in the first place, if you smash something into that tube-within-tube structure, you will destroy some of the outer columns, and maybe some of the inner - but the matrix itself is still strong, and unless the destruction is catastrophic, both tubes will remain standing. But assume that you do destroy enough columns, inner and outer, that the section above the destruction will no longer be able to be supported by the lower - what will happen? The outer upper columns will be dropping toward the outer lower columns structure, and the upper core columns will be dropping toward the lower core structure - nothing remotely like a stack of dinner plates dropping one onto another. And in the tube-within-tube dropping scenario, that upper section will drop onto the lower, and just stop there and wobble around a bit until it finds some new equilibrium, or perhaps topple to one side if that is where the equlibrium takes it - but that lower section is NOT going to break up into70- or 80 floor-size sections to match the dinner plate scenario, because the dinner plate scenario is simply not what the actual arrangement of the structure is.

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