Public Lecture – The Collapse of the Seventh Tower: A Physical & Chemical Analysis
Niels H. Harrit, Center for Molecular Movies, Copenhagen University
When: Wednesday, November 16, 2011 @ 7:15-9:15 p.m.
Where: Morrison Hall 007
Departmental Sponsors: College of Arts and Sciences, American Studies Program
To most people, the image of the World Trade Center (WTC) is confined to the famous twin towers, which dominated the New York skyline until September 11th, 2001, when they collapsed after each one being hit by an airliner. However, the trade center was an assembly of seven buildings around a plaza. The youngest of these, WTC7, was a huge office building, reaching 186 meters and 47 stories into the air. The ground-plan area was little less than a soccer field.
WTC7 was not hit by an airliner. Still, it collapsed seven hours after the twin towers in a totally symmetric movement with free-fall speed. It was the most unexpected collapse in the history of modern building construction.
The talk outlines the factual circumstances around this event. These facts are held up against the official account of the event as it has been presented in a report from National Institute of Standards and Technology. According to this report, WTC7 collapsed due to fire. But never before – or since – in history has a steel-framed high-riser collapsed due to fire.
In the second part of the talk it is proposed that the collapse of WTC was due to controlled demolitions using explosives. In addition, unambiguous evidence points to the use of thermite, which is an energetic material used to cut and weld steel. The newest findings in the dust include still-reactive remains of so-called nano-thermite.