Like many, I was intrigued to find the causes of the Minneapolis bridge collapse; and I was saddened by the tales of personal tragedies.
About a year ago, I wrote a series of articles on the physics and thermodynamics of the World Trade Center fires and collapses, on 11 September 2001. I did this as an effort to put into plain English the physics effects and engineering concepts I knew about — these being my fields — to help the average person interpret what they would see in video recording of these collapses.
Among engineers and physicists it is easy to convey the magnitude and nature of forces, heating and stresses.
However, people not trained in these disciplines can have a difficult time appreciating how much energy is stored up as “potential energy” in a tall building, and how much energy can be transferred as “impact” in a car crash or airplane crash.
Other ideas such as “creep”, “metal fatigue”, the volatilization of plastics into flammable and explosive gas mixtures, the heat capacity of materials, shock waves in air and stress waves in solids are all hard to evaluate “intuitively” without some technical education, and also some practical experience (laboratory tests or applications in the field).
I thought, naively I now realize, that many people would appreciate this type of “plain English” background to a discussion of the technicalities behind the physical phenomena of 9/11, and similar events.
As a scientist, I am the first to realize that “the actual cause” of any such event is only isolated — and always with some degree of uncertainty, or “error bar” — after a lengthy and careful analysis, which may involve several technical disciplines, e.g., chemistry and mechanical testing, computer modeling of stress and deformation, review of maintenance logs and other exercises in forensics. What armchair discussions prior to the findings of an official “inquest” can provide the public is some idea of the forces and phenomena involved.
The events of 9/11 triggered a vast outpouring of ignorance, usually described as the “9/11 truth movement”, by people who had no idea of any of the physical science.
This “movement” has nothing to do with science, or physics, or even the events of 9/11; but it has everything to do with the psychological needs of its cultists.
Today, there are hundreds of articles in technical and professional journals about the physics of the 9/11 collapses, and anyone interested to learn the details of that could read those articles, or find articles by science writers who have abstracted the scientific literature on the subject. This is work, and requires some education, perhaps quite a bit if you wish to review and critique the source material in the professional journals. How much easier to just fantasize, to “know” because “it is obvious” and you can “see it.” Just like flying saucers.
People who had fixated on 9/11 for their emotional and psychological needs did not like my “physics of 9/11” series because it did not lead to the conclusions they wanted, which were usually of two types:
1. the government did it, a masterful conspiracy to kill thousands of Americans, to instill fear and bring about a police state (not that I disagree with the view that many in government and corporations desire to bring about a police state);
2. I (the omniscient conspiracist) am a visionary and heroic person for seeing through this (imagined) masquerade, and shouting about it to “wake up the American people”, a modern Paul Revere deserving of recognition.
One letter-writer summed it up perfectly, dismissing my articles thusly: “I don’t understand any of your equations, but you’re wrong.”
In this I am only speaking of the polite to barely tolerable writers. There were many, many abusive and insulting letters, usually anonymous (not too much bravery here). I’m afraid I became quite disgusted with the “typical” level of thinking (I use the word hopefully) of the public, and especially that segment of the public that read my articles on 9/11 phenomenology.
So, on occasion, I indulge in a bit of prodding at the conspiracy theorists, not so much to attack their ideas (I use the word charitably), but because of their primitive intolerance. Theirs is a modern secular religion, intellectually shallow, and of medieval bigotry as regards other lines of thought. They hew to their beliefs “on faith” because the effort to actually learn physics, engineering, chemistry, and evaluate the 9/11 phenomena rationally, and with the benefit of known scientific ideas and methods is too time-consuming, difficult, and probably unlikely to fulfill their needs for psychological pampering.
Now about the recent bridge collapse note in CounterPunch. I wrote this, quickly, as my first impression of the Minneapolis disaster, and added a dig at conspiracy theorists. This was sent to CounterPunch in the spirit of a letter to the editor; it was not the submission of a Ph.D. thesis based on years of careful work.
Had I intended the article to be deeper and more thoughtful, it would have been longer, to elaborate all the “technical” terms and justify what would have to have been a broader and deeper analysis. The point of my quick note was to draw attention to photos (on the BBC news website) showing the tilted footing-foundation (undermined by river currents I wondered?–later news accounts suggest not), and the deformed end of a steel beam.
Extreme stress and deformation of metal can give the appearance of “melting” or “drawn taffy” to steel beams; a fact known to engineering, but frequently surprising to non-technical people. My point here is that the appearance — to non-experts — of a “heat effect” does not automatically mean that high heat, as in explosions, was applied.
My own analysis leads me to conclude that 9/11, like the Oakland freeway collapse by fire (earlier this year), like the Minneapolis bridge collapse, were all events whose causes were “natural,” in that known physical effects and the particular physical and environmental conditions at each site were responsible for the subsequent collapse. There was no sabotage (beyond the air crashes on 9/11), no intentional demolition by pre-emplaced explosives (the hidden conspiracy assumption, which is the Immaculate Conception of the 9/11 faith).
Why be petty and bait the 9/11 conspiracists? Why not drop the provocations and stick to presenting my views on substantive points, without sarcasm and insult?
Yes, it would be a good Buddhist and good Christian thing to do, to ignore the “slings and arrows” and just lay out the logic of whatever I wish to describe. Sarcasm and insult can spice up an article and provide some humor, but they can easily be overdone. However, they do act as deterrents to would-be letter writers of the conspiracy faiths, from sending me their lengthy efforts to convert me. I suppose I could take the high road for the benefit of the larger readership, and just avail myself of the “delete” button more often.
A final note; yesterday’s today’s New York Times (3 August 2007) articles on the Minneapolis bridge collapse point to a suspected weak point of the design: the major joints between metal bars in the truss, just over the columns that merge into the concrete footing at each riverbank. A suspicion is that metal fatigue (40 years of truck-induced vibration) may have opened unseen cracks within these joints (bolted and/or welded), and metal creep (slow deformation under the stress of a weight (gravity load)) led to a catastrophic failure.
This bridge was deemed to have a design deficiency, in that some of the major joints were unique, they had no redundancy. More recent designs provide for the redundancy of all joints, so in the event one fails, the loads (stresses) in the framework of the bridge are redistributed while continuing to maintain the integrity of the structure and the support of the intended traffic.
MANUEL GARCIA, Jr. is a recently retired physicist from a US Department of Energy laboratory. He is presently on holiday, and his technical interests involve fluids, electricity, heat flow and energy. His non-technical interests are varied, one being the social responsibility of scientists, another being the social dimensions of choices for the energy technologies that power a community. He can be reached at email@example.com.