The government’s lead investigator of the collapses, Dr. S. Shyam Sunder, told an interviewer on NOVA that the towers fell in 9 seconds and 11 seconds, and that this was freefall. The government report says that WTC1 fell in “less than 12 seconds.”
A few weeks before the release of the government’s report on WTC7, Dr. Sunder told a press conference that a free-fall collapse was impossible, because that would mean there was no structural support underneath.
In following weeks a high school physics teacher, David Chandler, was able to demonstrate that WTC7 had in fact fallen in pure freefall for a period of 2.25 seconds. The government was forced to acknowledge this in their report.
The government report about the towers states that “the building section above” came down “essentially in free fall”. It’s an ambiguous statement, and some people claim that it refers to “panels”, sections of the external wall structure, that fell outside the building footprint and thus experienced no structural resistance. The actual report makes no reference to “panels”. It seems to say that the upper structure collapsed the lower structure nearly in free fall. That is consistent with Dr. Sunder’s statement and with the 12-second estimate given in the report. Some will try to litigate the meaning of the word “essentially,” claiming that “essentially in free fall” means “not in free fall.” Such people only demonstrate the desperation of their attempts to protect their delusions.
The First Law of Thermodynamics requires that the Energy In of a system (such as a collapsing building) equals the Energy Out.
In the case of the Towers, the Energy In was mostly the Potential Energy of the towers’ structure—all those tens of thousands of tons of structural steel and concrete hoisted up 1360 feet in the air.
Bringing the towers down required a whole lot of work—breaking up the structure, pulverizing 180,000 tons of concrete floors, mashing and bending massive steel components, and sending multi-ton steel structural units flying laterally at 55 miles an hour. These phenomena required enormous amounts of energy—and the laws of physics demand that this energy come from somewhere. If the Potential Energy (gravity) produced these phenomena, then the energy required to produce the work should have slowed down the collapses.
One commenteer to this answer very ingeniously claimed that strain energy in various forms (I’ll suppose he’s talking about slightly mis-sized components, slightly overtightened bolts, and slightly off-angle connections) stored spring energy that helped to blast the building apart. My bullshit-detector does not take this idea seriously. Maybe yours has a different calibration.
Some have proposed that additional energy must have been injected into the system in the form of incendiaries and/or explosives to disrupt the building structure.
The government report did not address the issue of the towers’ rapid collapses. That was only one of the ten essential mysteries that the government dodged. We need thorough, complete, honest, scientific reports that address ALL the mysteries of 9/11. Democracy dies when the government lies.by brian good.
