To: Raymond Duray who wrote (609 ) 5/11/2003 3:07:26 PM From: Don Earl Read Replies (1) | Respond to of 20039 Ray, <<<This is a fascinating comment, and I haven't seen it written about anywhere before. Is this analysis original to you or are you citing some other research?>>> It's something I ran across. I don't have the numbers in front of me but it was something like 12 seconds for the tower vs. 13 seconds for free fall. Basically it's a fairly simple math problem. Acceleration for gravity is 32 feet per second per second. The first second an object falls 32 feet. At 2 seconds the object has fallen 96 feet and is traveling at 62 feet per second, etc. All the information needed to run the numbers is known; how long it took the building to fall, the height of the buildings and so forth. The technology used for building implosions is kind of interesting. There are a number of ways it can be done. Usually dynamite is used because it's fairly cheap, and holes are drilled in the supports to get the best benefit from the charge. From what I understand the two most commonly used methods for setting off the charges is time delayed detonators where each charge is calculated to take place at a certain time after the first charge goes, or each level triggers the charge on the level below so it's pretty much automatic. A good sized building takes maybe 200-300 pounds of dynamite. "IF" someone with access wanted to make it look more accidental, I think it would go something like this: Replace the dynamite and drilled holes with shaped C4 charges, set to go off automatically with the progress of the implosion. Then either use incendiaries, or load the plane with something that burns hotter than jet fuel, to set off the first link in the chain. The small cutting charges wouldn't be noticed in the rumble of the building falling, and if there was a way to get rid of the steel before it could be examined, the speed of the collapse would go unnoticed by the average person with math skills limited to making change on a dollar. I'm not an engineer, but I think it's pretty hard to explain why a structure where each floor is designed to support the weight of all the floors above, provided almost no resistance whatsoever to the rate of collapse.