National Geographic - 9/11 Science and Conspiracy (2009)

Conspiracy theories are put to the test. How well do they stand up against the visual simulations of professional engineers? See how science supports official stories and debunks the conspiracies below. The capture is from Discovery but since the show was done solely by National Geographic, I gave it that name as to avoid confusion.

CONSPIRACY VS. SCIENCE
Conspiracy theories are put to the test. How well do they stand up against the visual simulations of professional engineers? See how science supports official stories and debunks the conspiracies below.

THE COLLAPSE OF THE BUILDINGS
Official Story: The collapse was caused by fire initially fed by the jet fuel from the planes. Testing the Official Story: Using original construction blueprints, photographs, and construction data, Purdue University, along with the American Society of Civil Engineers, created a model structure of the north World Trade Center tower and a scaled 767 jetliner. To model the fuel load, Purdue launched aluminum cans filled with liquid to represent an airline wing colliding with a steel column. The final simulation showed the internal destruction of supporting columns, the disintegration of the jetliner, the atomizing of the fuel, and the resulting fires that softened the steel framework of the building and brought it down.
Conspiracy: The fire could not have gotten hot enough to melt the steel. Science: The Energetic Materials Research and Testing Center (EMRTC) designed explosives to test the effects of burning jet fuel on steel. EMRTC used a bare steel beam because the National Institute of Standards and Technology reports that much of the any fireproofing material would have been knocked off at the moment of impact. Within two minutes of igniting the fuel, the temperature peaked just above 2,000 Fahrenheit and complete structural failure occurred in less than four minutes.
Conspiracy: The collapse was caused by controlled demolition. Science: The film crew recorded the demolition of a college dormitory building to learn all that is involved in the process of prepping and loading. The first step was to expose the columns in order to attach explosives to them. The World Trade Center had 47 inner core columns that would have needed to be prepared. To cut the steel beams the demolition team used a shape charge, which is piece of copper apportioned to a shape-charged weapon. When an explosive is attached and ignited, the device implodes and forms a stream of liquid copper that cuts through the steel. A demolition of this scale would leave clear evidence behind, but no such traces were found at Ground Zero.
Conspiracy: Thermite, which is less traceable, was used in the controlled demolition that brought down the towers. Science: Some Truthers claim that pulverized dust found by some New Yorkers after the attack contained the checmical signature of thermite. Scientists assert that even if this dust did contain thermite, it would be impossible to determine whether the thermite came from a controlled demolition or simply from the melting of the airplanes. EMRTC designed an experiment to see if thermite was a plausible option in the collapse of the towers. The thermite in the test was not even able to melt a column much smaller than those in the World Trade Center.

THE ATTACK ON THE PENTAGON
Official Story: Hijackers caused a commercial airplane to crash into the building. Testing the Official Story: Purdue University created a visual simulation of the crash, which indicated the victims’ bodies would have been pushed forward in relation to one another, just as they were in the actual attack. To further investigate, EMRTC launched a projectile into a simulated structure. They did not include wings in the projectile model because Purdue asserted they were of little consequence as the Pentagon was so heavily reinforced. The experiment created a hole in the structure the approximate size of the projectile - similar to photo evidence from the actual attack.
Conspiracy: The Pentagon was either bombed or hit by a missile. Science: EMRTC also planted an explosive in the same model structure and compared the results to photos of the Pentagon after the crash. The explosive test demonstrated a different sort of damage. The structure blew out from the point of the explosion, causing complete destruction of floors and walls. This dispersed debris did not match the photo evidence.