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Thanks, wildbill -- a metallurgist who doesn't understand that the force of gravity is straight down, or that unbraced columns buckle and break and that broken columns provide no support at all. On the topics of structural mechanics and physics, McGrade makes the same argument as Gage's other "experts": "I don't understand this, but it looks like a controlled demolition to me, so that's what it must be."
Unlike Gage's other "experts," however, McGrade at least tries to offer an excuse for ignoring actual experts, who not only understand those things but can explain them very well: Her excuse is that anyone who contradicts the conclusion she's apparently already jumped to about 9/11 must be lying to her. But take a closer look at the story she tells to support that excuse: Someone tried to sell her an engine that she didn't need; she looked under the hood for herself but couldn't find what was wrong; then apparently someone who understands engines told her she just needed a cam sensor. When I put that story in the context of the bullshit that Richard Gage is literally trying to sell, the lesson should be that if you don't really understand it then you should get a second opinion, and if it's different, then you should carefully consider the facts and logic before deciding who is right. But what you are really trying to tell us, wildbill, is that she should have just bought the engine because the person who was selling it was a mechanic. The lameness of McGrade's excuse for ignoring structural engineers and physicists, without actually understanding what they say, reveals the typical "truther" pattern of incomplete facts and faulty logic creating a feedback loop of spiraling delusions and paranoia. And furthermore, the hypocrisy in her "look under the hood" story is stunning.
McGrade has a BS in metallurgy, so we should expect at least a somewhat informed opinion about that subject. It's surprising, then, that her first "smoking gun" is the iron-rich microspheres. In the first place, she has clearly fallen for the fallacious argument that if the microspheres were found in the dust, then they must of been produced in the collapse -- oblivious to the possibility that they might have already been in the building before the collapse (e.g. from all the welding that was done in the construction). Overlooking such an obvious possibility is a clue that the conclusion was reached before the logic was attempted. Gage's "experts" would have us believe that we can safely assume that premise because the microspheres are so rare that it's unbelievable they could have already been there. But once again, a little actual research reveals that the things are very common because they are produced by a lot of different processes. Whereas Gage's "experts" would have us believe that the microspheres are a signature of thermite (Harrit: "spheroids have never been observed unless there was a thermite reaction"
, the undeniable fact is that they can be produced in a fire with an average temperature less than the melting point of iron or steel, such as a trash incinerator or coal-fired generator, and that they can be produced without any fire at all, such as by striking steel with flint or grinding truck brake pads on brake drums. McGrade would have no explanation for microspheres in fly ash, but other metallurgists and physicists do: Very small particles of iron or rust can actually melt at a temperature below the melting point of a large chunk (for this, you need to understand the subtle difference between heat energy and temperature); and the average temperature of a fire includes small, localized areas both above and below the average temperature. So, the second step in the faulty logic is falsely assuming that the microspheres could not have been produced in the WTC fires -- they could have been. Apparently McBride has followed her own advice to just look at the evidence and jump to conclusions, leaving out a step or two that a rational person should not. She is correct, however, that you don't need an engineering degree to understand these things, but again we get hypocrisy instead of valid argument.
McGrade's second "smoking gun" is David Chandler's 2.25 second free-fall for WTC7. We've already looked under the hood of that one; perhaps someone should point her to that 1.75 seconds, seven feet, of less-than-free-fall which preceded that. Then she could compare NIST's explanation for it -- it was the beginning of eight floors buckling -- with Chandler's complete lack of an explanation. She's correct that she doesn't need to be an engineer to understand it, but she really should find out what "it" is before offering "expert opinions" about it, and she has manifestly failed to do so. The NIST hypothesis explains the whole collapse sequence; the controlled demolition hypothesis does not, even if we pretend that magical silent explosives exist.
Her third "smoking gun" is Tony Szamboti's "missing jolt." Good news! It's been found, hiding under Tony's bad math and misguided assumptions. As you may recall, Dr. Bazant's analysis of the collapse compared the gravitational energy of the falling mass to the maximum energy that could be absorbed by the impacted columns as they were pushed into plastic buckling. Bazant did not say that was what actually happened to all the columns; in fact he explicitly said that it wasn't the only thing going on. But he was interested in the conservative "limit case," i.e. if every column offered it's maximum resistance to the falling mass, because he wanted to see if there was any chance at all that the collapse could have been stopped. (Answer: not even close even in his limit case, and even less so in reality, because the more likely failure modes would have absorbed less energy.) Szamboti took that limit-case model, however, and inferred that if that had happened, then there should have been a large "jolt" -- a rapid change in acceleration -- produced by the impact, because pushing all the columns into buckling required a "force amplification" (provided by the inertia) several times greater than the mass of the falling top section. Szamboti claims that the equal-and-opposite reaction force on the mass would therefore produce an upward acceleration greater than 1g. He then took Bazant's simplifying assumption of a rigid top block literally, ignoring that it was actually somewhat flexible and that what was actually impacting the lower structure was rubble acting more like a liquid than a rigid structure, and claimed the large jolt should be observable by measuring the roofline fall. He couldn't see such a jolt so he deduced that the columns must have been destroyed with magical silent explosives. Problem is, that limit-case scenario is not what actually happened, so Tony's premise is false. In the first place, what actually happened was that both towers failed on one side first, so the top sections tilted as they fell. One consequence of the tilt was that the columns were not impacted all at the same time, nor were they impacted squarely. So even if all the columns had been crushed, Tony's jolt would have been spread out over time, not one massive jolt. But even worse for Tony's inference is that the columns weren't all pushed into buckling. Instead, the predominate failure modes were floor joists and beams being ripped away from the columns and spandrel beams, and then the columns were simply pushed aside (because the floors that held them vertical were gone). That doesn't change the "unstoppable collapse" conclusion from Bazant's energy analysis, because as he points out, those failure modes would have absorbed even less energy than column buckling. But what all of that means for Tony's hypothesis is that we should really expect to see only small jolts, if any, at the roofline, spread out over time, not the massive jolt that he calculated. Then, when we look at his own data and see exactly that, his conclusion is dead meat, regardless of how impressed with it McGrade is.
Does Gage have any "experts" who know what they're talking about, wildbill?
Response to William Seger (Reply #4)
Response to wildbilln864 (Original post)
looks like one of your fellow CTer's has left the building.
Response to wildbilln864 (Original post)
Response to wildbilln864 (Original post)
Response to wildbilln864 (Original post)
Gyro's Second Law.
