Do we agree the towers were designed to withstand jetliner crash?

God ain't so great either ---- supernovae

Without novae & supernovae, elements heavier than (IIRC) lead don't exist.
Without radioactive heavy elements, earth becomes a cold, dead, lifeless planet.
Without novae & supernovae, 9/11 doesn't happen.

You realize what this means, of course...

... God is part of the conspiracy..!!
 
We frequently fail. Every engineering design is analogous to a scientific hypothesis. The realization of that design and its operation in the real world is the empirical test of that hypothesis. Just because a design exists does not mean it is known to work flawlessly, or even that it is intended to work flawlessly.



Indeed, the expectation of failure, and learning from it, is the central thesis of a book my engineer father read a long time ago:

To Engineer Is Human: The Role of Failure in Successful Design

http://www.amazon.com/Engineer-Human-Failure-Successful-Design/dp/0679734163


The moral of this book is that behind every great engineering success is a trail of often ignored (but frequently spectacular) engineering failures. Petroski covers many of the best known examples of well-intentioned but ultimately failed design in action -- the galloping Tacoma Narrows Bridge (which you've probably seen tossing cars willy-nilly in the famous black-and-white footage), the collapse of the Kansas City Hyatt Regency Hotel walkways -- and many lesser known but equally informative examples. The line of reasoning Petroski develops in this book were later formalized into his quasi-Darwinian model of technological evolution in The Evolution of Useful Things, but this book is arguably the more illuminating -- and defintely the more enjoyable -- of these two titles. Highly recommended.
 
Without novae & supernovae, elements heavier than (IIRC) lead don't exist.
Without radioactive heavy elements, earth becomes a cold, dead, lifeless planet.
Without novae & supernovae, 9/11 doesn't happen.

You realize what this means, of course...

... God is part of the conspiracy..!!

O M G !!
When you put it that way its so obvious!
:D
 
...
Engineers do not eliminate all risk. They try to eliminate all reasonable and forseen risk. And even at that, they sometimes fail.

...

We frequently fail. Every engineering design is analogous to a scientific hypothesis. The realization of that design and its operation in the real world is the empirical test of that hypothesis. Just because a design exists does not mean it is known to work flawlessly, or even that it is intended to work flawlessly.

We engineers do not purport to be able to foresee all risk. Hence the assurances in an engineering design are always in a specific form, showing the limits of what has been considered and addressed. The customers of engineering must understand that beyond that limit there be dragons. Most often unforeseen risk arises in the form of systemic complexity: two or (typically) more factors acting in a combined fashion that isn't implied by their individual behavior.

And amoral as it may seem, there is the notion of reasonable risk. Any risk we can foresee we will also attempt to quantify. How likely is that to happen? What are the consequences if it does? Then finally, what will it take to mitigate or eliminate this risk? Sometimes it's simply too costly to mitigate the risk, and that's usually okay because the human race inherently maintains the notion of an acceptable risk. Building the tallest building in the world doesn't mean it will also be the safest, especially in terms of being hit by flying things. But that risk is offset by the desire to be superlative. That desire is quantifiable. The risk required to attain it is also quantifiable. One of the risks of a very tall building is being stuck a thousand feet in the air with a fire underneath you.
...

There were many posts along the line of the above. As a retired electrical engineer, I wanted to add my concurrence to the basic idea: Nothing that an engineer does provides a guarantee that the thing he has designed will not fail. He can't even design something that can be guaranteed to not fail because of hazards he has anticipated. And, of course, hazards that the engineer didn't anticipate are probably a more likely cause of failure.

Engineers use various models that approximate reality to predict how their design will perform. A lot of the time they are wrong. Sometimes because their models do not approximate reality closely enough, sometimes because the engineer has failed to predict a problem from a particular hazard and sometimes the engineers just make mistakes.

The notion that has been put forth in this thread that analysis that may have been done by an engineer forty years ago about the resistance of the WTC to destruction as the result of an airplane crash is significant evidence that the WTC couldn't fail as the result of an airplane crash strikes this retired engineer as one of the silliest notions ever put forth.

Even with all the tools that a modern structural engineer has available and all the failure mechanisms that a modern structural engineer might consider there is still a probability that some buildings will fail. Maybe the engineers use a building technique that has a hidden flaw. Maybe a human error causes a big oversight. Maybe some unanticipated geologic problems under the building causes the foundation to fail. Maybe the unique forces of a particular storm set up an oscillation that wasn't properly accounted for in the design. Maybe a terrorist attack exploits a weakness that wasn't accounted for. etc. etc. If this kind of risk wasn't anticipated by the owners and lenders nobody would get insurance. They would just hire engineers and builders that could create failure proof structures. Since there is a widespread knowledge in the general public that engineers and builders that can create failure proof structures don't exist, people buy insurance.

In truther land though, at least in the version of truther land that has been put forth in this thread, engineers did create a building that could withstand a failure mechanism that could not possibly have been modeled accurately by the designers of the WTC and that was highly unlikely to have been anticipated in detail during the design of the WTC. And based on this completely silly notion, it is claimed that a completely loony tunes notion about how the WTC failed might be true.

The truther theories about the collapse of the WTC constitute some of the silliest conspiracy theories of all time. The particular aspect of the truther theories that has been discussed in this thread is my choice for the silliest notion in the pantheon of monumentally silly notions that truther theories consist of.
 
The notion that has been put forth in this thread that analysis that may have been done by an engineer forty years ago about the resistance of the WTC to destruction as the result of an airplane crash is significant evidence that the WTC couldn't fail as the result of an airplane crash strikes this retired engineer as one of the silliest notions ever put forth.

Actually, NB has refused to say what he's trying to prove. We all know he's trying to make the hypothetical old study "override" the more modern study, therefore the Towers couldn't have fallen, but he won't actually say so. He keeps going on about determining the "state of the science" back then, and ignores any comparison to modern studies, or the multiple people who have informed him of exactly what he claims to be asking for.
 
Even with all the tools that a modern structural engineer has available and all the failure mechanisms that a modern structural engineer might consider there is still a probability that some buildings will fail. Maybe the engineers use a building technique that has a hidden flaw. Maybe a human error causes a big oversight. Maybe some unanticipated geologic problems under the building causes the foundation to fail. Maybe the unique forces of a particular storm set up an oscillation that wasn't properly accounted for in the design. Maybe a terrorist attack exploits a weakness that wasn't accounted for. etc. etc. If this kind of risk wasn't anticipated by the owners and lenders nobody would get insurance. They would just hire engineers and builders that could create failure proof structures. Since there is a widespread knowledge in the general public that engineers and builders that can create failure proof structures don't exist, people buy insurance. .


So true. Many years ago, the was structural collapse of a beam at a local mall. The mall had been built about 30 years previously, and then one day, this particular beam fails and a portion of the roof collapsed about 2 hours before the mall was to open (fortunately) After months of investigation, it was determined that the beam, (about a 4 deep glulam) had by accident/poor oversight/etc had been manufactured with about 30% of the lams having a knot in alignment. It still took 30 years for that beam to fail.
 
it was determined that the beam, (about a 4 deep glulam) had by accident/poor oversight/etc had been manufactured with about 30% of the lams having a knot in alignment. It still took 30 years for that beam to fail.

Are you saying that for the first time in the history of the mall, the beam "failed"? Do you believe everything they tell you?

What a..."coincidence"...that..."noone"...was inside the..."mall". Hmm.
 
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No one has disputed the calculations that a 707 at cruising speed actually supplies more kinetic energy than a 767, so I am still waiting on that one. As for Beachnut, I don't know what to tell you. You keep insisting that I have come up with the 600 MPH figure. I am quoting John Skilling, so if you don't like it why don't you mention that you think he is an idiot instead of calling me one. I do not think Skilling felt he was restrained by speed limits when did calculations for a potential disaster. Also you and others continue to insist that flights 175 and 11 were going 600 MPH. Are you just going to ignore that MIT says 429 and 537 MPH?
As for Anti-sophist, I felt I addressed your question with this quote from my second post-"As for the fact that beyond the 1964 white paper there is no record of this work (according to the NIST investigation). In general when I quote a top expert in a field as having made a statement to research he has done, I am not accustomed to being asked to reproduce his results. If his results are missing it is noteworthy, but it does not give you licensee to dismiss his statements on the subject. We do not go discounting top experts with exemplary records just because someone lost their research. How does that work in favor of the official story? In my opinion it casts doubt the other way since so many of the pertinent documents and evidence involved in 9-11 are missing." I know I am not allowed to cast any suspicion on the fact that seemingly key documents about the trade center are missing, but what would you have me do. Is this supposed to imply that he didn't do any research? And while we are on the subject maybe some of you can assist me in understanding exactly what information is available to the public regarding the engineering and construction of the towers. I assume you all believe in making as much as possible available to the public right? There is a photocopy of the 1964 white paper at pilots for 9-11 truth. Also we had this from Gravy in case you missed it A three-page document from the Port Authority of New York and New Jersey (PANYNJ or Port Authority) Indicates that the impact of a Boeing 707 flying at 600 mph was analyzed during the design stage of the WTC towers in February/March 1964 (Letter with an attachment dated November 13, 2003 from John R. Dragonette(Retired Project Administrator, Physical Facilities Division, World Trade Department) to Saroj Bhol (Design and Engineering Department, PANYNJ).
NB - Note to Roger Harris here who claimed that Skilling performed tests after the design. Your position is contradicted by this information. Skilling was considering the airplane crash during the design phase.
No documents on the aircraft impact analysis are available to review the criteria and method used in the impact analysis of a Boeing 707 aircraft on the WTC tower and to verify the assertion in the three-page document that "...such collision would result in only local damage which could not cause collapse or substantial damage to the building and would not endanger the lives and safety of occupants not in the immediate area of impact." Without the original calculations of the aircraft impact analysis, any comment on the document would be a speculation. In March 1964, a calculation was made by the Port Authority to determine the period of vibration of the tower due to an aircraft impact at the 80th floor. Although no conclusion was stated on the calculation sheet, it clearly indicates that the Port Authority recognized during the design stage the possibility of an aircraft impact on the tower.
Has anyone asked NIST where they looked for the documents, or where they ought to be? There explanation to this point is inadequate, though I doubt this aspect of the story concerns you.
To those of you who claim Skillings efforts were to a varying degree ineffective or ill informed in trying to protect against a jetliner crash, we have several problems.
1- I assume most of you believe the towers came down from the jetliner crashes alone. Thus you are of the belief that Skilling was wrong, so it is easy to infer his calculations were faulty. I of course do not believe that to be the proven case, so we have a little break in our realities on this. It would seem to me in the interest of neutral observation for both sides to consider Skillings claims without conclusions on what happened on Sept 11. I am sure that will get some howls from some quarters, but from my perspective I am trying to meet to you all halfway.
2- It seems a little hypocritical to say that making calculations on what factors will make a building remain standing or collapse is so complex that no one can be sure of such multi factorial assessments, and at the same time claim that a hypothetical analysis on the WTC collapse done by NIST is absolute proof. You start with the premise that the planes and the fires brought down the towers and NIST has to just fill in the blanks.
3- The titanic thing is cute, but what is it that you really say with it. That all technology is fallible and not to be trusted ? If so that's fine, but lets not pick and choose the technologies we see as legitimate and put our trust in without evidence.

Are you kidding me?!? Your argument IS the definition of "cherry picking". I'm being honest and respectful when I say this.

You need to go do lots more reading before you cast yourself in with the CTers. Read contrary papers, and things beyond CT sites. Read the NIST and FEMA reports, so you KNOW what they really say. Read Andrew Burfield's scathing rebuttal of the NORAD standdown argument (available here on JREF, btw). Read Mackey's articles on anything 9/11-related.

Then you'll be ready to discuss this subject. The rest of us have already done this work, and having to spoonfeed you is tiring (and Google is your friend).

Hope that helps.
 
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DGM- It means the top expert did not believe they would? It must be a pretty paranoid world for you if you have no trust in experts simply because the titanic sank

So, despite the fact that I have no confidence that you will answer honestly, for the record, I'll ask anyway:

What mechanism(s) caused the collapses of the three WTC towers that fell?

Please show your work.
 
It is amazing how many Truthers seem to be unable to understand that there are options for someone to be wrong besides "actively lying". It's a really obvious straw man.

Actually, looking back, NB has a lot of straw men. Odd.
 
So true. Many years ago, the was structural collapse of a beam at a local mall. The mall had been built about 30 years previously, and then one day, this particular beam fails and a portion of the roof collapsed about 2 hours before the mall was to open (fortunately) After months of investigation, it was determined that the beam, (about a 4 deep glulam) had by accident/poor oversight/etc had been manufactured with about 30% of the lams having a knot in alignment. It still took 30 years for that beam to fail.

Probably the first thought the investigators had was nanothermite, I guess they were embarrassed when it turned out to be an alignment of knots.
 
NB, no one is disputing that the buildings could survive the impact forces , it is patently obvious that they did!!!

What is in dispute is what approach in such an analysis was emplyed or could be accomplished in the 1960s. When one reads for comprehension rather than to support a prejudiced opinion one sees answers to these questions.
They only managed to determine if the impact could immediatly transfer enough momentum to the structure to push it over immediatly , a calculation that can be accomplished relatively quickly by hand , in terms of man hours. What was not possible was the detailed analysis that a modern FEA can accomplish. Furthermore the 1960s work could only adress a general case whereas NIST knew where the plane hit, and could approximate the angles (left/right & up/down) , they could examine in detail the difference in outcome varying values of various parameters within the margins or error in measuring these parameters in videos.

What was not possible in 1964 was a detailed analysis of the effect of igniting large area office fires on several floors within seconds, beyond the obvious, that this would kill many people on these floors.
 
Originally Posted by Animal
it was determined that the beam, (about a 4 deep glulam) had by accident/poor oversight/etc had been manufactured with about 30% of the lams having a knot in alignment. It still took 30 years for that beam to fail.

Are you saying that for the first time in the history of the mall, the beam "failed"? Do you believe everything they tell you?

What a..."coincidence"...that..."noone"...was inside the..."mall". Hmm.

Obviously, the Vast Conspiracy staged this event just as it did so many others (Sight and Sound Theater, McCormick Place, Ronan Point) in preparation for 9-11 to "prove" that structural failure in modern buildings is possible! :rolleyes:
 
Actually, NB has refused to say what he's trying to prove. We all know he's trying to make the hypothetical old study "override" the more modern study, therefore the Towers couldn't have fallen, but he won't actually say so. He keeps going on about determining the "state of the science" back then, and ignores any comparison to modern studies, or the multiple people who have informed him of exactly what he claims to be asking for.

I would go further and point out that NB seems to have abandoned this discussion, not having posted anything in four days.

A de facto surrender?
 
I would go further and point out that NB seems to have abandoned this discussion, not having posted anything in four days.

A de facto surrender?

No.

Prediction: NB will be back in a few days, ignore everything that has been posted since the beginning of the month, and basically repeat the same faulty stuff, as if it hadn't been addressed.
 
No.

Prediction: NB will be back in a few days, ignore everything that has been posted since the beginning of the month, and basically repeat the same faulty stuff, as if it hadn't been addressed.

Fringe resets are such an interesting psychological phenomena. Do woo believers get recalled to somewhere when this happens? Do they go back to the guru on the mountaintop or something?
 

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