http://georgewashington.blogspot.com/2007/10/mars-murder-and-making-most-of-what.html

Some people get confused by the different theories of what caused the World Trade Centers to collapse on 9/11. And some people assume that "we'll never really know" what happened.

But it is important to understand that scientists can often determine whether or not something occurred even when the direct evidence is no longer available. Moreover, sometimes the most important thing is understanding what did not happen.

Mars and Murder

Scientists often have to test things in clever ways because the thing they're looking for isn't available for testing. In such cases, scientists create tests to see if there is indirect evidence which proves the existence of what they're looking for.

For example, when looking for evidence that life once existed on Mars, scientists look for chemical compounds that are by-products of life. Walking around with a petri dish probably won't yield any samples.

Similarly, when coroners are looking for evidence that the victim was poisoned, they test for by-products produced by the interaction of the poison with the body. This is especially true where the murderer used a poison that would quickly disappear and so be harder to find. Directly testing for the poison in such cases will be fruitless.

In both of these examples, the primary evidence is no longer available. In the Mars example, the microbial life being looked for probably hasn't existed for millions of years. In the example with the coroner, the poison has broken down and is gone.

The destruction of the Twin Towers and WTC7 is similar. Most of the steel was shipped to Asia for recycling, investigators were barred from the crime scene and saw little of the steel, many of the photographs and and videos have been held and not released by NIST, and many witnesses in the Twin Towers died when the Towers collapsed.

So the exact same question which scientists ask regarding whether there was ever life on Mars or whether a victim was poisoned applies to the Trade Center: are there signatures we can examine?

In fact, there are.

Symmetrical Collapses

The Twin Towers and Building 7 collapsed in an even, symmetrical fashion. But buildings collapsing due to gravity usually fall over to one side.

Whatever caused Building 7 to collapse symmetrically, such symmetry is a clear signature for a destructive mechanism other than simply gravity and fire.

Pulverized Dust, Heat, Shooting Beams and Pyroclastic Flows

The Twin Towers were pulverized into dust in mid-air. See this essay, these photos, and this photo.

The dust clouds exhibited unusual properties generally only seen in hot ash clouds coming from volcanoes. See also this essay.

Indeed, there are even reports that the dust from the Twin Towers, like volcanic ash, was hot. For example, New York Daily News photographer David Handschuh recalled:

Instinctively I lifted the camera up, and something took over that probably saved my life. And that was [an urge] to run rather than take pictures. I got down to the end of the block and turned the corner when a wave-- a hot, solid, black wave of heat threw me down the block. It literally picked me up off my feet and I wound up about a block away.

And photographer Don Halasy said:

As I turned to run, a wall of warm air came barrelling toward me. I tried to outrace it, but it swept me up and literally blew me into the wall of a building. By the time I regained my footing, a hailstorm of debris was falling from the sky.

In addition, heavy steel beams shot out sideways up to 500 feet as the buildings collapsed

Gravity and jet fuel could not possibly have provided enough energy to have created the observed pulverization of dust, volcano-like dust flows or sideways ejection of steel beams observed in the destruction of the Twin Towers.

Whatever caused the tremendous dust, heat and pyroclastic at ground zero, they are clear signatures for a destructive mechanism other than simply gravity and jet fuel.

As Dwain A. Deets, with masters degrees in both Physics and Engineering, and former Director for Research, Director for Aeronautical Projects, and Flight Research Program Manager at NASA Dryden Flight Research Center concludes:

The many visual images (massive structural members being hurled horizontally, huge pyroclastic clouds, etc.) leave no doubt in my mind explosives were involved.

Free-Fall Speed

The tops of the Twin Towers fell virtually at free-fall speeds, as if they were falling through air. This is impossible, given that the massive steel cores and frames of the Twin Towers, along with the concrete flooring, trusses, and other systems should have significantly impeded the speed at which the towers fell.

Whatever caused the Twin Towers to start falling, the near free-fall speed is a clear signature for destruction of all of the support structures prior to the tops of the towers collapsing.

Molten and Evaporated Metal

It is beyond disputable that there was molten metal under ground zero for months after 9/11.

And an expert stated about World Trade Center building 7, "A combination of an uncontrolled fire and the structural damage might have been able to bring the building down, some engineers said. But that would not explain steel members in the debris pile that appear to have been PARTLY EVAPORATED in extraordinarily high temperatures" (pay-per-view). Note that evaporation means conversion from a liquid to a gas; so the steel beams in building 7 were subjected to temperatures high enough to melt and evaporate them.

There have never before or after 9/11 been reports of partly evaporated metal or months-long metal fires in buildings destroyed by fire and gravity.

Whatever caused (1) metal evaporation and (2) molten metal to burn for months at ground zero, these unique phenomena are clear signatures for a destructive mechanism other than simply gravity and jet fuel.

If you don't believe that there are clear signatures for controlled demolition, read what these highly-credible scientists say.

Certainly, people like Dr. Steven Jones have tested dust samples collected from the World Trade Center and found evidence of high-explosives. And there is other evidence preserved from 9/11 which indicates controlled demolition. But this essay focuses solely on the indirect signatures for demolition.

And while I believe that Dr. Jones has proven with reasonable certainty that thermate, or some related explosive, was the main cause of the destruction of the trade center, focusing on the signatures of demolition avoids the whole debate about what exactly caused the Towers' collapse. In other words, whatever caused it, it was clearly not just jet fuel and gravity.