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Politics : Bush-The Mastermind behind 9/11? -- Ignore unavailable to you. Want to Upgrade?

To: sea_urchin who wrote (9140)	12/4/2004 9:45:15 PM
From: Don Earl	Read Replies (1) \| Respond to of 20039

Going back to a previous discussion on powdered concrete. This page on the site you posted shares your views: "Clearly the speed of the falling top relative to the building was insufficient to convert concrete to fine powder. You can prove this to yourself by dropping a concrete block from a height of, say, 20 feet. The block may break into several pieces, but it will not turn to powder. Even if you were to drop a piece of concrete from the height of the towers -- 1360 feet -- it would not turn to powder when it hit the ground." 911research.wtc7.net This is the kind of argument I hate to see presented as smoking gun evidence for controlled demolition. First off, anytime a person starts a sentence with "clearly", I assume they don't have a speck of justification to back up whatever follows. Okay, lets say we experiment by climbing onto the roof of the garage to drop off a 10 pound chunk of concrete. At 32 feet per second per second, at 20 feet, your chunk of concrete has accelerated to something around 15 feet per second. That would give you 150 foot pounds of energy, which is considerably less than that needed to compress your typical 3000 psi rated concrete sold by the bag in most hardware stores. Now, if you are able to find a 1300 foot tall building, and manage to drop your 10 pound chunk of concrete off the top before being detained by security, in the approximately 10 seconds it will take to hit the ground, it will be traveling at about 320 feet per second. If you multiply that by 10 pounds, you get 3200 foot pounds of energy. While your chunk of concrete is bound to distribute that energy over an area larger than 1 square inch, ASMI ratings aside, I sincerely doubt it will stand up to that sort of abuse. So, let's move on to the WTC. If 30 floors of trade center weigh 50,000 tons, you'd be looking at about 15 pounds per square inch distributed over the acre surface 30 floors below the top. Using Ray's figure of 300 psi for light weight concrete, you'd reach its rated compression strength once the falling building hit 20 feet per second. In other words, in about 3/4 of a second, the building's kinetic energy in foot pounds would be sufficient to compress the concrete in the floors, turning it into dust. Pick up a bag of cement (the stuff without rocks and sand mixed in), pour it in a bucket, and drop a big rock in the middle of it. It will splash, scattering dust all over the place. To a certain extent I'm playing Devil's advocate here, but the point I'm trying to make is reaching the right conclusion, based on the wrong evidence, is still wrong. Once you get outside a venue such as this board, where everyone has already reached similar conclusions about what happened, you'll get torn to shreds on the weaker arguments. With a few exceptions, most of those writing articles about a controlled demolition of the towers don't appear to have done even a tiny bit of research into the mechanics of how buildings are imploded. There are endless pieces based on detonating something the size of a nuke to bring down the towers, but the plain fact of the matter is it doesn't take anywhere near that amount of explosive power to drop a building. On top of everything else, this theoretical explosion, which supposedly reduced the towers to atomic particles, would also have produced a ball of light visible for twenty miles. In the absence of a blinding flash of light, I think the big bang theory has to be abandoned in favor of something a little more conventional, such as taking out the core at strategic points, with charges not much bigger than needed to cut the supporting columns. It's not that I doubt such charges would powder some concrete in the immediate vicinity, I just don't believe it would powder a whole building's worth.