jvincent

To be clear, I didn't say that I know everything. I said that I have training and background in engineering that gives me some ability to analyze technically the absurd claims that the OP made. To address your snide commentary, "many others" have failed to explain the collapsing buildings the same way Jenny McCarthy has established that vaccines cause autism. Which is to say, by lying about what's real and through the magic of confirmation bias. For instance, check out the post about the out of focus camera above. To answer your question, no. I could write out some of the mathematical relationships between these things, but for one thing, you and others like you can't understand anyway. For another, it's no help because you've already decided that the whole thing is an inside job... or whatever. That said, I will add this: structural members in buildings rely on the integrity of one another. A single failure can easily change the load conditions on other members such that they suddenly fail, and so on. Like falling dominoes. In a structure like the WTC, one such failure would obviously not bring down the whole building. The other members would pick up the slack. In this case, fire weakened a large enough section that a single failure (say, at the point where the fire was hottest) could start such a lightning-quick series of catastrophic failures and allow the uppermost floors begin to fall onto the lower ones. It shouldn't be hard to grasp that once this began, stopping it from continuing would require much more structural integrity from the undamaged lower floors than was required for them to simply hold the falling floors in place, like they had been for decades.They were not intended for that much load and they failed... one after another, again like dominoes, as the weight of the falling section steadily increased. Disagree? Take a few calculus classes and get a structures book. This is, maybe year 1 stuff. Shouldn't take long. In the meantime, there is not a single shred of credible forensic evidence in existence which calls into question the widely understood fact that airplanes which were intentionally crashed by men of ill intent into the WTC started fires that weakened the towers and caused their collapse. More importantly though, as we've all seen in the effects of millions of daytime-TV'ers inexplicably taking medical advice from an aging whore, take a moment and ask yourself if you're even qualified to have an opinion on the subject before you espouse one on the internet. I don't go around telling people how to groom their Irish Setter. I don't think I've even seen one in person. I don't have kids, so I don't talk about the best way to raise them. Roll that around for a while. Still think it's me that's gullible? Make your case. That's what we're about here, right? Reason and evidence. So put up or shut up, but be warned that if your case betrays a total inability or unwillingness to understand physical principles, someone like me will call you out for it. Not me, though. I'm done.

Wow. This thread absolutely dropped my jaw. The ignorance of physical principles is simply staggering. It sounds like, in your quest to resist what you think are the sheeple instincts so common in your lesser opponents, you've wound up tricked way harder than they were ever in danger of being. Sometimes the obvious answer is that because it's true, folks. Full disclosure: I'm a licensed, professional engineer in the aerospace industry and I hold BS degrees in mechanical engineering and theoretical mathematics. 1) Aluminum can absolutely cut steel. Under some conditions and therefore admittedly not often. Most alloys of aluminum are too soft to be useful for abrasive tooling, so while I agree that there's no reason to expect to find aluminum blades on anything that isn't silverware, that's not the same as the stunningly ignorant claim that it can't be done. It's literally 100% as ridiculous to claim that as it was for Rosie O'Donnell to say that never in human history had fire melted steel. Briefly, in this case the aluminum got to win by virtue of coming into the fight with the steel pillars with overwhelming kinetic energy. The velocity term in the kinetic energy equation is squared, and all that energy had to go somewhere. Again, briefly, it went into the steel pillars as a kind of load that they were not intended for, and they failed. That's what happens. 2) This isn't even really a point, but I'll address it anyway. You seem to be hung up now on the nature of the failures that you don't believe could have occurred at all, but setting that aside for a moment, an airplane is not a solid object. The space between the wing ribs is essentially hollow, so if one of these bubbles happened to hit a particular pillar, the pillar would slice cleanly through the spars and control surfaces, severing the wing at that point and leaving only deformation instead of of complete failure visible in the pillar. This did not happen often, as you can see in the photo, but it would be more odd if it didn't happen at all. The severed wing section, by the way, would continue into the building on its own. Newton's First Law. Also, the nature of metallic fracture mechanics do not provide for your "push in" theory. The pillars would laterally flex under the crash shear until they passed out of their elastic load strain, at which point they begin to deform and ultimately fail. At such a speed, this would happen beyond fast. The external pillars that were going to fail would have done so in thousandths of a second. Remember that fundamentally, metals are crystalline materials. 3) You can absolutely "simply fly into" buildings. Admittedly the airplane isn't going to survive the encounter, but that was the point. They flew the jets into the buildings in the hopes of causing them to collapse. You've got some pictures of airplane getting beat up by mild accidents and it's true that that happens. I have personally designed thousands of fixes for mild to severe service damage on a half dozen models. However, that does not even begin to prove that these jets couldn't also have damaged the building. Firstly because you can literally watch it happen on Youtube, but also, check out your bird up there. He's pretty dead. Newton's Third Law. 4) Not so punchy, really. Again, I'm not sure I understand your point here. The B-25 was a tiny bomber meant to carry a very small payload at a relatively low speed. Even if, while lost in the fog and unable to see where they were going the bomber pilots had it at its top speed for some reason, there's no evidence to suggest it carried enough energy to penetrate the building. Your argument seems to be that since a single B25 couldn't accidentally bring down the ESB, a pair of much larger and heavier jets at much higher speeds couldn't intentionally bring down the WTC. It's absurd on its face. These things are unrelated. As for your engine comments: modern turbofans contain much more empty space than the turboprops of old. They are hot and heavy, but would not neccessarily punch cleanly through the building like a bullet through a gummy bear. They are, after all, attached to the airplane. Finally, steel may not melt at 980C, but you do not need to melt steel to cause failures in structural members that currently under load. The fact is that the fire persisted long enough to overcome the design limitations of the fire resistant material sprayed on the members themselves. This caused them to soften enough that they would no longer be rated for the load conditions they were under, leading to sudden, catastophic, and cascading failures. Just like we all saw. 5) Crash speeds were not even difficult. Familiar with potential energy? Drop a rock off a building, and it's going pretty fast when it hits the ground. The same rules apply to planes. It may be that the plane is designed to fly straight and level at a certain speed for a given altitude, but diving and achieving an overspeed condition is not hard at all. Such a condition is outside design performance limitations and very unsafe, but not necessarily fatal. A plane diving overspeed into a building is in no way implausible; it wouldn't even be hard to do. Check out SilkAir 185. 6) You are beyond delusional... ...if you honestly believe that your wake vortex theory invalidates the videos, eyewitness accounts, and the accounts of those tasked with the cleanup and reconstruction. People now have terrible cancers and lung diseases from breathing the air in that place. Seriously, I could go over the math here, but I'm so disgusted that I'm just going to say this: get a goddamn life. Or at least a basic background in math, science, and writing.