> -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On > Behalf Of Dave Land > Sent: Wednesday, June 28, 2006 8:07 PM > To: Killer Bs Discussion > Subject: Re: Physics Prof Finds Thermate in WTC Physical Samples > > > On Jun 28, 2006, at 11:18 AM, Warren Ockrassa wrote: > > > I'm with Dan on this one (!). That a fully-loaded 737 can cause, > > after impact, buildings to fall down is not even remotely shocking. > > Of course, the buildings were scarcely damaged by the planes' impact. > Big chunks of the planes went clear through the building and landed > on the other side. Some didn't even strike the core of the building. > > > This is an aircraft that carries enough jet fuel to cover a > > football field to the depth of one foot with highly combustible > > fluid (do the math; check me -- this is what I recall from working > > out the figs myself about four years ago). What's amazing, in this > > light, is that the buildings didn't fall before they did. > > Fuel that, when burning, generates less than 800 degrees C, about a > third of the temperature needed to melt the steel used in the WTC. > > And, of course, it doesn't matter how much fuel there was. They could > have FILLED every floor of building with a couple of feet of Jet A > and replaced the air with pure oxygen, and it still couldn't possibly > burn hot enough to bring the buildings down.
I've posted a number of studies by mechanical and structural engineers on the collapse. A plethora of potential mechanisms were given. The most reasonable conclusion that I saw was that it was probably a combination of many of them. Many of them were published by folks who analyzed data that were provided to them. I just found one that was quickly published, based more or less on public knowledge. It's at: http://www.tms.org/pubs/journals/JOM/0112/Eagar/Eagar-0112.html The lead author was Thomas Eagar, the Thomas Lord Professor of Materials Engineering and Engineering Systems at MIT. My guess is that he has considerable experience in the field. He suggests that differential heating was part of the problem. It makes sense to me. Every professional work that I've read on this has discussed the weakening of steel in the 500C to 800C range. The steel doesn't have to melt for there to be a problem. > So: "Sorry. Bullshit.", to coin a phrase. > > We don't know what the hell happened on 9/11. The administration's > "just-so story" is no better or worse than the conspiracy theorists': > they're all wild-ass guesses based on too little information and too > many jumped conclusions. But, it's not just the administration's "just so story" The overwhelming professional consensus is that the data are consistent with the impact of the planes and the resultant fire causing the collapse. That is a fact....in the exact same sense that there is professional consensus on anthropological global warming. These are not imaginary people. These are professions, with very reasonable looking training and jobs who have investigated the problem. I've referenced a number of them, and quoted some at length. Let's assume, hypothetically, that there was a problem reconciling the collapse with what was known. In that case, the nature of the debate would be different. People would search for unconsidered factors in the details. Instead, we have an overabundance of possible causes. It is true that the collapse of these high rises were singular. But, so was the event. I cannot think of any other high rises that suffered similar damage, and then a prolonged 500C+ fire at the point of the fire. Indeed, the impact was greater than the impact it was designed for, a 707 IIRC. Finally, out of curiosity, are you familiar with the kind of stress modeling that mechanical and structural engineers do regularly, and have applied to this problem. I've quoted, earlier, web sites that discuss this modeling work. Having managed projects that involved extremely rugged environments, I have some feel for the finite element analysis programs that have been used. I have a feel for shock and vibration problems, having had to design for 1500 g shock and 20 g rms vibration at elevated temperatures (just 175 C, but that still has an effect). My tool, alas, has failed in a well where the drill string resonance was so bad, bolts with 15,000 ft-lbs of torque were backed out by vibration. With this background, what they write makes sense to me. I would like to suggest that these, very real and often quoted, mechanical and structural engineers, modelers, etc. have a decent understanding of the dynamics. I'm not taking them on pure faith. Indeed, your arguments contradict what I know, while their arguments do not. In essence, I'm trying to understand why you feel it's impossible for your intuition to be wrong, and professionals to be right. I know the results are unique, but so are the circumstances. Unique circumstances can produce unique results. Now, if you can show 10 buildings that have gone through similar trauma, and remained standing, then that's a different story. But, as long as the circumstances are unique, unique results should not be surprising. Dan M. _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
