9/11 Structural Engineer's poll 19

[WARose]

A former colleague of mine who is a structural engineer (now retired and with apparently too much time on his hands ) discusses various conspiracy theories on the net. One of them is the 9/11 theory that holds that the buildings that fell on that day did so due to a controlled demolition. (A theory he feels is “nonsense”.)

You've probably heard followers of this theory called “Truthers” (or worse). In any case, aside from telling my friend that he is/was apparently a member of the CIA (and trying to say he wasn't even a structural engineer), apparently another angle of argument is to say that the profession is somehow afraid to talk about it (noting a lack of support in journals, etc) or that my friend somehow doesn't know what the profession talks about. That got me wondering how much this is discussed beyond my (and his) experience. So the question I have as sort of a poll for structural engineers:

Is the controlled demo theory something that is a regular topic of conversation with your colleagues?

AND (if the answer to the above question is “yes”) Do you feel compelled to view it one way or the other?

Speaking for myself, I cannot think of a single time it has come up (except in conversations with my retired friend mentioned earlier). I've certainly discussed the failures on that day with other structural engineers as an example of progressive collapse. But not much beyond that.

However, public awareness on the topic (I would call it misinformation) seems to have done nothing but grow over the years......and will likely grow more in the years to come.....so I thought I'd ask fellow structural engineers for their thoughts and ideas as to be better equipped to answer the public’s concerns in the future.

 

[MacGruber22]

I've run some numbers for the collapse and I frankly don't see what the argument is.

Interesting that you felt compelled to attempt this. How many hours did you dedicate?

"It is imperative Cunth doesn't get his hands on those codes."

 

[JNieman]

Reminds me of another thread that was here or in the Pub about Flat Earth theories.

I'm back in manufacturing now, but when I was working in a purely civil/struc eng firm, it'd get brought up from time to time. Usually, someone will have seen something on Facebook or Youtube about a truther, or have run into someone they couldn't believe was a 'truther'. Then we'd start discussing how insane their arguments were, tearing them apart and going over exactly how possible it was that the buildings' structure WOULD fail, after looking up some data points.

The idea that "people are scared to discuss it" because you don't see it in trade journals is like Glenn Beck's tired sensational strategy. He would make up some insane accusation, and then repeat "Why hasn't <person> denied this accusations or at least come out saying they aren't true?!" and make it sound like his accusations have merit /because/ they haven't specifically been denied. Truth is that the accusations are fringe-lunatic fabrications. They don't deserve the respect of being refuted in official channels that require the expense of time, effort, and someone on a payroll. The absence of refutation is not evidence of truth.

I remember when Bill Nye debated Ken Ham regarding evolution. Many people who understand evolution were irritated that Bill Nye would debate Ken Ham because it simply gave him a level of respect that his opinions (Creationism, specifically Young Earth) did not deserve, which may 'legitimize' Ham's opinions beyond their merit.

Same with 9/11 conspiracy theories. Professionals don't directly refute it in official channels because... there are much better ways to spend their/our time.

 

[JohnRBaker]

And not going out of the way to refute the false claims is of course what has led to the so-called "fake-news" phenomenon. There's a large number of people out there who actually believe: "If I read it on the internet then is has to be true. After all, people are not allowed to post false claims or made-up stories as that's not how the internet works."

And while I had no intention of making this a political statement (however, Glenn Beck has already been mentioned so...), we can't ignore the political consequences of this sort of behavior where outrageous statements and/or claims are made and no one takes the proper time to refute them and set the record straight. If you don't believe that, you need to look no further than what happened in November. Case in point: The WSJ has just announced that they will no longer label the 'lies' being told by Donald Trump as 'lies', since that would be making a moral judgement and they claim that that's not the responsibly of journalists. A journalist's job, they claim, is to simply report what was said and let the reader decide whether it's true or not. When asked about the very high rate (some figures put it as high as 93%) of the times that statements made by Trump or his campaign were proven to be incorrect, or at best, grossly inaccurate, the editor of the WSJ stated that in the future they will simply consider these situations as having been a simple mistake with no intent to deceive or mislead unless it can be clearly demonstrated that that was the original intent.

Here's a link to the article discussing the new editorial policy at the WSJ:

http://www.huffingtonpost.com/entry...lies-donald-trump_us_586934b8e4b0eb586489df43

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[JNieman]

I'm ok with WSJ's stance, and think they made the correct 'journalism-centric' decision. Fact-checking is a separate item from journalism. In interviews, it's often normal to challenge statements and claims if demonstrably false, or ask for clarification. When reporting incidents, it becomes too much of an editorial if the journalist chooses to constantly pepper in additive assessments.

Then again, there's the old adage about politicians and salesmen. How can you tell when they're lying? Their lips are moving! (or they're tweeting, to bring it current, I suppose)

NPR has a fantastic journalism ethics handbook available for anyone to read, and they amend/update it as required. It can be as minor as the correct pronoun to use for a person or as extreme as whether or not to address someone by an unjustified title and when it's unjustifiable. (

http://ethics.npr.org/

) and I'm sure the WSJ has similar. That doesn't mean NPR won't occasionally post articles about "Truth-metering" someone's speech, but it'd be separate from the report of the speech itself.

It's the difference between an editorial and a news article. Especially when truth is neither black nor white, and the grey can never truly be 100% neutral when one considers what is left UNSAID or UNMENTIONED can sway things as much as how you phrase what IS said or mentioned.

 

[WARose]

[blue](MacGruber22)[/blue]

How many hours did you dedicate?

Not many. Just a few. It was a slow day at work anyway.

 

[IRstuff]

Oddly, in the last paragraph of the HP article, the WP editor tries to compare HRC's falsehoods with Trump's, but seems to forget there's a matter of massively different numbers. Of course, WP is a conservative bastion, isn't it?

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[JohnRBaker]

He was an editor for the WSJ (Wall Street Journal) which is part of Rupert Murdoch's media group. And yes, there is also the problem of "false equivalency" which is always used to justify the Right's defense of anything, including their support of Trump.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[IRstuff]

my bad, WP was on my radar for some reason' I'm pretty sure I was thinking WSJ

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

https://www.youtube.com/watch?v=BKorP55Aqvg

faq731-376 forum1529 Entire Forum list

http://www.eng-tips.com/forumlist.cfm

 

[btrueblood]

"I remember when Bill Nye debated Ken Ham regarding evolution. Many people who understand evolution were irritated that Bill Nye would debate Ken Ham because it simply gave him a level of respect that his opinions (Creationism, specifically Young Earth) did not deserve, which may 'legitimize' Ham's opinions beyond their merit."

Many of us who have met Bill Nye are irritated that people give him a level of respect that his qualifications do not deserve. And he's a bit of a twit...

 

[JNieman]

I don't know much more than that he's a TV celebrity, champions scientific endeavors, and worked as a mech eng for Boeing, years ago. I don't think he gets much more consideration than that. I don't think anyone believes he's our generations Einstein. He's just popular.

 

[WARose]

Nye isn't my favorite skeptic.....that would go to Michael Shermer. I've been impressed with him most times I've seen him.

 

[MrHershey]

Am I reading this right? The profession is afraid to talk about the controlled demolition theory as evidenced by a lack of support for it in the literature? There's probably not much discussion on or support for the Flat Earth Theory in geology literature or heliocentrism in astronomy literature either. Not because those professions are afraid to tackle those ideas, but because the ideas are nonsense and not worth discussing.

Surely it can't be that the profession is afraid of talking about the collapse in general, given it's at worst the second most studied case in progressive collapse design behind the Murrah Building. A search of "progressive collapse" "world trade center" brought up 1240 results on Google Scholar just now. For reference, a search of "progressive collapse" "murrah building" brings up 337 and "progressive collapse" "oklahoma city" brings up 705.

 

[JohnRBaker]

There's probably not much discussion on or support for the Flat Earth Theory in geology literature or heliocentrism in astronomy literature either.

Don't you mean 'geocentrism'...

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[BadgerPE]

I haven't spent a lot of time pondering this, but I did receive a publication from this organization a while back. It does seem strange to me, if the evidence they provide is true, that the building accelerated downward and there was no "pancaking" at each floor. If this was a top down collapse, wouldn't there be a momentary pause as the columns at each floor absorbed the additional weight from above before buckling? A thought I have to oppose this theory is that there is in fact a pause as the top 20+ floors slammed into the lower portion of the standing structure. This impact force was significantly more than the columns below could withstand, and therefore, wouldn't buckling be initiated at all/most levels simultaneously?

https://www.youtube.com/watch?v=ydu9M_64lRU&feature=youtu.be&list=PLUshF3H0xxH2FFyiA3OZnLA7WfjNxJmcO

 

[JAE]

....therefore, wouldn't buckling be initiated at all/most levels simultaneously?

Yes.



Check out Eng-Tips Forum's Policies here:
faq731-376

 

[WARose]

[blue]BadgerPE[/blue]

If this was a top down collapse, wouldn't there be a momentary pause as the columns at each floor absorbed the additional weight from above before buckling?

I pondered that one once myself. However, given how quickly buckling can occur, it isn't that suspicious.

[blue]BadgerPE[/blue]

A thought I have to oppose this theory is that there is in fact a pause as the top 20+ floors slammed into the lower portion of the standing structure. This impact force was significantly more than the columns below could withstand, and therefore, wouldn't buckling be initiated at all/most levels simultaneously?

https://www.youtube.com/watch?v=ydu9M_64lRU&fe...

Let me say first: I am no impact guru. However, as I understand such a collision, the elastic portion that propagated very quickly would likely not buckle anything (by my numbers). The follow up plastic wave front (with much higher stresses and slower propagation) is likely what did it. That is why there was buckling not that far from the impacted points (as it snowballed).

By the way (regarding your YoutTube clip) I'd be careful listening to AE911Truth for much. (If you will notice, just about everyone they cite is not a structural engineer.) I've seen a lot of questionable claims from them at times.

 

[MrHershey]

Don't you mean 'geocentrism'...

LOL. Yes. Can't even refer to it correctly when I try.

 

[BadgerPE]

WAR

I certainly don't believe much of what AE911 puts out, but rather thought this video brought up a point worth discussing. I have never been a believer of the controlled demo argument, but I paused a bit with this theory because I never considered that possibility before.

 

[Compositepro]

" If this was a top down collapse, wouldn't there be a momentary pause as the columns at each floor absorbed the additional weight from above before buckling?"

No, because this is a dynamics problem not statics. The floors moving down have tremendous momentum and have already collapsed together so they basically act as a huge hammer with stored energy. By the same token each floor below also has mass and some spring so the floor being impacted bears the brunt of the impact, progressively. Thus progressive collapse.

 

[hokie66]

It was not a top down collapse. The middle collapsed due to the impact damage and fire, causing the entire top section to fall on the bottom part. The only progressive collapse mechanism in play was the top section collapsing from the bottom up, and the bottom section collapsing from the top down, as the two came together.