Ed Truthers: Structural Engineering and Physics Expertise in the Analysis of the WTC

Architect

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A number of the current supporters of 911 Truth are extensively quoting their interpretation of Newtonian theory and making references to physicists' interpretation of the collapse sequence; Ergo is perhaps the most prominent example.

This is a question for those individuals. I'd be grateful if the rest of you could hang back a bit, give them some clear space without the usual sniping and the like.

What I want to ask is why you're hanging your hat on physics in lieu of structural engineering expertise.

Structural engineering is, of course, the analysis of loads through built structures, based physical factors and empirical knowledge of the performance of materials. Structural engineers require a comprehensive understanding of such issues in order to satisfy both functional and statutory criteria.


By way of example, let's look at the main modules for a fairly typical MSc course in structures:
  • Concrete materials
  • Cold-formed steel design
  • Design and construction
  • Design of steel bridges
  • Design of steel buildings
  • Finite element analysis
  • Non-linear structural analysis
  • Plated structures
  • Prestressed concrete
  • Reinforced concrete I
  • Reinforced concrete II
  • Steel components
  • Structural analysis
  • Structural assessment and Loading
  • Structural dynamics
  • Structural stability
  • Structural steel technology
  • Time and temperature-dependent behaviour of concrete structures
These are complex areas; an undergraduate degree course will typically take 3-4 years, depending upon the country of study, in addition to which there will be at least a further 2 years of postgraduate and/or practical training before registration is permitted. Specialist areas such as bridges or tall buildings will typically require further practical experience.

Physics, in contrast, is a much wider field which can focuss on a huge range of issues. It does not, as a matter of course, include the kind of detailed analysis and interpretation of the structural performance of either individual elements or complex composite structures.

So why do a number of you clearly believe that such a broad understanding of the subject is the preferred method of analysis in contrast to structural engineering? Are you claiming that education in physics includes a sufficient grounding in materials performance for one to carry out such analyses? And if this is indeed the case then why do structural engineers need to develop appropriate modelling and and design systems?

I put it to you that a degree in physics no more equips one for such structural work than, say, a BA in Linguistics will mean you can speak French. It might give you an idea of a general framework or background, but does not provide the kind of detailed information one requires to rigorously interrogate or understand the topic at hand.

Let's break this down into three main questions then?

1. Do you believe that a thorough grounding in physics will provide you with sufficient technical expertise to analyse the performance (and failure) of a complex structural system such as the WTC collapse?

2. Do you agree that structural engineering is a more relevant and necessarily complex means of analysing such structures, and if not then why not?

3. Assuming that you concur with (2), then why do many members of the Truth Movement continue to attempt to apply broad physics issues (for example Newtonian Theory) without regard to more appropriate and focussed structural analysis techniques?

Let me stress that for the purposes of this thread I'm not interest in an argument about facts and figures, or calculations. This is about what Truthers consider to be the core analytical skills necessary to comment on structural collapse issues.


Ergo, MM, I would especially welcome your views.
 
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I'll do my best to stay out of Architect's way in this thread. But I wanted to highlight something I really think is important:
Physics, in contrast, is a much wider field which can focuss on a huge range of issues. It does not, as a matter of course, include the kind of detailed analysis and interpretation of the structural performance of either individual elements or complex composite structures...

... I put it to you that a degree in physics no more equips one for such structural work than, say, a BA in Linguistics will mean you can speak French. It might give you an idea of a general framework or background, but does not provide the kind of detailed information one requires to rigorously interrogate or understand the topic at hand.
Logically, what engineering amounts to is physics applied specifically to a field or set of problems. That is why Architect's post here is so relevant to the discussion of analyses regarding the Twin Towers collapses. Issues of how forces act on matter is still of course dominant, but applying basic, undergraduate physics to matters such as how a single constructed unit's worth of trusses, columns, braces, studs, etc. interact under loads is treading ground that was already trod decades ago (or longer). The field of engineering has been able to encapsulate all those individual interactions into an overall discipline and provided intellectual tools, so to speak, for how to deal with those myriad and complex calculations involved in dealing with all those interactions in a single, constructed unit.

That's why, when architects and engineers put up a basic framework for a building, they talk about analyzing a "moment frame": While each individual constituent element's reactions in the framework still follow the laws of physics, it's almost certain to drown a person in details if the analysis of the framework is conducted on the level of basic, elementary physics. You use the tools and processes generated over decades of experience shared in the field to conduct the analysis, instead of reinventing the wheel and starting from ground zero each time you're presented with a complex set of interactions in a structure.

And this is why I say that Architect's point is important, and must not get lost: When, for example, a truther talks about momentum (often phrasing their complaint as a violation of Newton's Second Law), you wonder if they either 1. Applied engineering principles to truly calculate how momentum came into play on elements of the overall structure, or 2. Took a laymans approach and calculated the myriad forces on each individual element of even a simplified model, then iterated those calculations over time as loads shifted. You wonder that, because you don't see any explanation beyond a broad stroke one, but more importantly, what you don't see is justification for why the analysis is superior to the more detailed ones conducted by NIST, Bazant and Zhou, Arup, University of Edinburgh, etc. You don't see any explanation of why or more importantly where the more detailed, more in-depth applications of physical laws - i.e. the engineering analysis - is flawed. You only see a broad stroke analysis with no reference to where knowledge gained over decades of engineering experience has been applied.

And that's why it's important to understand why this argument is being made, and also why it should not be construed as an Appeal to Authority. If a claim is made, then the background for such a claim can (and should, when demanded) be provided, but because human intellectual progress depends not only on the identification of fundamental principles, but the application of such principles and the cumulation of knowledge gained from such application, it is important to recognize why engineering instead of basic, fundamental "Physics 101", is the more correct discipline to use when analyzing the details of the Twin Towers collapses. It is not contradictory or incorrect to insist on engineering analyses instead of broad-stroke physics. Rather, it is a realization that physics as it's applied in practical construction is complex enough to where the knowledge gained from applying those fundamental principles absolutely must be taken into account. Using engineering as your analysis mode is the same thing as using physics. It's simply being smart about how you are applying it.

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This'll be my last post in this thread. And I'll echo Architect's plea: Let's keep the field as clean as possible. It's best if the truthers can deal with Architect directly on this matter. If anyone has a correction for my post, or further discussion, I'm happy to participate in a different thread, but we should honor Architect's request to keep this one on the subject he's wanting.
 
A very helpful post, ElMondo, which is very much in the vein I was aspiring to.

So, supports of the alternative theories and proponents of broad-brush physics in lieu of structural analysis, over to you...
 
And my offer to you to come over to the physicsforum still stands. Over there they should not have any problem letting the two of us converse in our own thread. And everyone over here can still see the exchange.
 
Should add in expertise in firefighting/fire protection systems as it was the fires which
caused the collapse of WTC 1, 2, 7
 
NJ; that is a separate issue. I specifically wish to explore with Truthers why they beleive that a broad-brush physics-based analysis should be preferred in lieu of a detailed structural appraisal. This is about methodology and approach.
 
Should add in expertise in firefighting/fire protection systems as it was the fires which
caused the collapse of WTC 1, 2, 7

I'd be happy to start a thread in that regard. It will take me some time to build an OP, but I'll put one up sometime soon.

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Architect I don't think you will get much traffic from the twoofer crowd in here. You are asking about "core analytical skills necessary to comment on structural collapse issues", something which they have zero experience with.
 
I can think of at least one rationale for applying broad physics issues in lieu of structural analysis techniques. That rationale would be completely valid if the argument were consistent with the actual facts.

However, the question was posed for Truthers, so I will leave it to them to answer.

Respectfully,
Myriad
 
Are you serious?

All daves are serious. It's one of our more endearing charms.

And, in all seriousness, the laws of physics and structural engineering don't really care which internet forum is used to discuss them (they're not proud), whereas the person asking the question and the persons the question is directed at frequently frequent this forum
 
enik - If you're worried about people interfering in the thread...I would have to say that we are all civil enough to not post anything to the thread...you and Architect can have at it without worry of being ganged up on.
 
I am simply asking Architect if he is willing to answer a few of my questions on another forum, free of distractions. I don't understand his refusal.
 
enik - If you're worried about people interfering in the thread...I would have to say that we are all civil enough to not post anything to the thread...you and Architect can have at it without worry of being ganged up on.

I am worried of being banned from JREF. If he has another forum, then fine.
 
I like my JREF membership. What is the big deal about asking a few questions to an Architect on another forum?
 

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