Open Letter to Dave Thomas

[Myriad]

I guess it's impossible for a tension load to break a piece of string, because for that to happen every one of thousands of separate fibers would have to break within a small fraction of a second. Can't happen, right?

Respectfully,
Myriad

 

[Dave Rogers]

Yes you're right I did ignore the possibility that a single eight story buckle occurred, with the top hinge eight stories above the bottom hinge occurring simultaneously at the same points on all 58 perimeter columns. Mainly because it is so absurd and because there is no photographic evidence whatsoever that would suggest that happened.

Firstly, the buckles don't all have to occur over the same length; a distribution of lengths of which most are in excess of eight storeys would give the observed near-freefall drop. Secondly, a longer buckle actually makes much more sense than a series of single-storey buckles, because an unbraced length due to collapse of the floor diaphragms, as Newtons Bit has pointed out, would be sufficiently slender to buckle elastically even under normal loadings. Thirdly, it was only the north face that was observed to fall at near-freefall acceleration; we know from videos and from the distribution of rubble that the building tilted southwards as it fell, and we also know from videos that there was a kink in the north face, so it's not necessary that all 58 perimeter columns failed simultaneously; on the contrary, we know with absolute certainty that the failures of the north face columns were not simultaneous. And finally, if hypotheses are to be rejected sue to lack of photographic evidence, then since there are no extant photographs or videos of the collapse of the lower storeys of WTC7 then it follows that we must reject all hypotheses as to what happened to those storeys.

A distribution of different length multi-storey buckles of perimeter columns with an unbraced length far in excess of their design, due to collapse of the floor diaphragms, that progressed rapidly and laterally from near the mid-point of the north face to the corners, seems to me an eminently reasonable explanation for the near-freefall period of drop, for the reasons given above. I'd need to see a better counter-argument than "because it is so absurd and because there is no photographic evidence whatsoever".

Dave

 

[Horatius]

I'd need to see a better counter-argument than "because it is so absurd and because there is no photographic evidence whatsoever".

Dave

Come now Dave, have you forgotten Bill's argument that "of course" the collapse progression would take long enough to be noticeable?

 

[Newtons Bit]

Come now Dave, have you forgotten Bill's argument that "of course" the collapse progression would take long enough to be noticeable?

But it did! Look at the penthouse collapse!

 

[cmatrix]

It's not even a fraction of a second. Many columns had "failed" when the penthouse collapsed. It was several seconds after that before the general collapse.

I know of no evidence that any perimeter columns "failed" prior to the main collapse. The penthouse was supported by core columns which "failed" causing the considerate crimp that allowed the building to collapse in on itself so as minimize damage to adjacent buildings.

 

[DGM]

I know of no evidence that any perimeter columns "failed" prior to the main collapse. The penthouse was supported by core columns which "failed" causing the considerate crimp that allowed the building to collapse in on itself so as minimize damage to adjacent buildings.

How do you define the "main collapse"?

 

[Newtons Bit]

I know of no evidence that any perimeter columns "failed" prior to the main collapse. The penthouse was supported by core columns which "failed" causing the considerate crimp that allowed the building to collapse in on itself so as minimize damage to adjacent buildings.

Core columns fail. They are temporarily supported by catenary action of the floor framing. This pulls inward and adds extra stress to already damaged perimeter columns. Those perimeter columns fail due to this and loss of bracing from the floors.

How is this difficult to understand? It even is a discrete "non-simultaneous" event which you "truthers" are looking for. If you could get some pictures from up close, you would probably see large deformations in the walls prior to collapse.

 

[cmatrix]

So, no substantive discussion of anything anyone has said in the last day or so, then? For someone who claims to want a serious discussion of how WTC7 might have fallen, you do seem to studiously avoid talking to those who actually address this issue.

Oh did someone explain how eight stories of structure were completely removed by all 58 perimeter columns buckling simultaneously at the same locations? I must have missed it.

 

[Horatius]

But it did! Look at the penthouse collapse!

Well, sure, if you want to go looking at all the evidence, you "scientist".

Oh did someone explain how eight stories of structure were completely removed by all 58 perimeter columns buckling simultaneously at the same locations? I must have missed it.

So, you demand that we attempt to address your objections in a rational and scientific manner, and yet, you refuse to allow us to follow the normal procedures of science. That is, when trying to analyse the behaviour of a complex system, we start by trying to understand the behaviour of smaller discrete elements of the system. Until we have a good understanding of how one column can be expected to collapse, it's ridiculous to try to discuss how 58 of them might collapse.

That you refuse to understand this is just more evidence that you have no real desire to have your "challenge" met. It's not a challenge, it's just a game of "gotcha!", in which you set rules so that no real scientist will ever win, because your rules have nothing to do with how science actually works.

 

[Dave Rogers]

Oh did someone explain how eight stories of structure were completely removed by all 58 perimeter columns buckling simultaneously at the same locations?

No, your strawman argument remains as implausible as it did the day it was framed. Since it bears no similarity to the actual collapse of WTC7, as various posters have pointed out, that's hardly surprising.

Dave

 

[DGM]

So, you demand that we attempt to address your objections in a rational and scientific manner, and yet, you refuse to allow us to follow the normal procedures of science. That is, when trying to analyse the behaviour of a complex system, we start by trying to understand the behaviour of smaller discrete elements of the system. Until we have a good understanding of how one column can be expected to collapse, it's ridiculous to try to discuss how 58 of them might collapse.
.

Your just trying to confuse things. Intuition is the ONLY way to go!!!!!!!!

 

[T.A.M.]

delete

TAM

 

[bill smith]

Core columns fail. They are temporarily supported by catenary action of the floor framing. This pulls inward and adds extra stress to already damaged perimeter columns. Those perimeter columns fail due to this and loss of bracing from the floors.

How is this difficult to understand? It even is a discrete "non-simultaneous" event which you "truthers" are looking for. If you could get some pictures from up close, you would probably see large deformations in the walls prior to collapse.

Can you be more specific about which perimeter columns were damaged with a view to anticipating the area of failure. ?

 

[Newtons Bit]

Can you be more specific about which perimeter columns were damaged with a view to anticipating the area of failure. ?

Start with this.

Then go to this.

No one is going to hold your hand anymore, BS.

 

[bill smith]

Start with this.

Then go to this.

No one is going to hold your hand anymore, BS.

Local failure of a small number of perimeter columns means local failure . Local damage does not cause GLOBAL simultaneous collapse. At least not without a worderfully inventive debunker unliklihood.

 

[9/11 Chewy Defense]

Local failure of a small number of perimeter columns means local failure . Local damage does not cause GLOBAL simultaneous collapse. At least not without a worderfully inventive debunker unliklihood.

Really, then why hasn't anyone come forward with evidence that explosives brought down the Towers?

It's been 9 years & still nothing!

 

[T.A.M.]

Local failure of a small number of perimeter columns means local failure . Local damage does not cause GLOBAL simultaneous collapse. At least not without a worderfully inventive debunker unliklihood.

Oh bill...ever build a house of cards???

TAM

 

[Newtons Bit]

Local failure of a small number of perimeter columns means local failure . Local damage does not cause GLOBAL simultaneous collapse. At least not without a worderfully inventive debunker unliklihood.

Do you have anything to back up that statement? Do you have any education, training or experience that would allow you to justify making a prima facie statement like that?

My education, training and experience tells me that a column failure in a skyscraper is exceptionally dangerous and may lead to a global collapse. The NIST report proves it with an engineering analysis.

You, on the other hand, have nothing. No experience, no training, no education. And you certainly don't have any evidence based on engineering analysis. So why should anyone believe you?

 

[cmatrix]

Firstly, the buckles don't all have to occur over the same length; a distribution of lengths of which most are in excess of eight storeys would give the observed near-freefall drop. Secondly, a longer buckle actually makes much more sense than a series of single-storey buckles, because an unbraced length due to collapse of the floor diaphragms, as Newtons Bit has pointed out, would be sufficiently slender to buckle elastically even under normal loadings. Thirdly, it was only the north face that was observed to fall at near-freefall acceleration; we know from videos and from the distribution of rubble that the building tilted southwards as it fell, and we also know from videos that there was a kink in the north face, so it's not necessary that all 58 perimeter columns failed simultaneously; on the contrary, we know with absolute certainty that the failures of the north face columns were not simultaneous. And finally, if hypotheses are to be rejected sue to lack of photographic evidence, then since there are no extant photographs or videos of the collapse of the lower storeys of WTC7 then it follows that we must reject all hypotheses as to what happened to those storeys.

A distribution of different length multi-storey buckles of perimeter columns with an unbraced length far in excess of their design, due to collapse of the floor diaphragms, that progressed rapidly and laterally from near the mid-point of the north face to the corners, seems to me an eminently reasonable explanation for the near-freefall period of drop, for the reasons given above. I'd need to see a better counter-argument than "because it is so absurd and because there is no photographic evidence whatsoever".

Dave

All this talk of buckling is completely irrelevant unfortunately. The three stage model of NIST is a fraud. WTC 7 was in free fall immediately when the northwest corner began descending. The first stage results from NIST setting an artificial start time as David Chandler eloquently explains:

http://www.youtube.com/watch?v=Ii49BaRDp_A

Free fall means 8 stories of structure were removed completely by something other than gravity or fire. Since NIST says the building came down due to the effects of gravity and fire their theory violates the laws of physics and is therefore a steaming pile of pseudo-science crap.

 

[bill smith]

Do you have anything to back up that statement? Do you have any education, training or experience that would allow you to justify making a prima facie statement like that?

My education, training and experience tells me that a column failure in a skyscraper is exceptionally dangerous and may lead to a global collapse. The NIST report proves it with an engineering analysis.

You, on the other hand, have nothing. No experience, no training, no education. And you certainly don't have any evidence based on engineering analysis. So why should anyone believe you?

Unless you can show me another example of a single-column failure of a steel-framed skyscraper causing global collapse other than WTC7 then I am strongly of the opinion that noth NIST and your good self have the same agenda .

Fortunately both of you are equally unconvincing.