9/11 Conspiracy Theories Persist, Thrive

Sept. 11 commission vice chair Lee Hamilton, left, and chairman Thomas Kean, right, pause during a meeting with reporters on Friday, July 23, 2004, in Washington. (AP Photo/Evan Vucci, FILE) (Evan Vucci - AP)

Members of the group don't consider themselves extremists. They simply believe the government's investigation was inadequate, and maintain that questioning widely held assumptions has been part of the job of scholars for centuries.

"Tenure gives you a secure position where you can engage in controversial issues," Fetzer said. "That's what you should be doing."

But when asked what did happen in 2001, members often step outside the rigorous, data-based culture of the academy and defer to their own instincts.

Daniel Orr, a Princeton Ph.D. and widely published retired economics chair at the University of Illinois, said he knew instantly from watching the towers fall that they had been blown apart by explosives. He was reminded of watching an old housing project being destroyed in St. Louis.

David Gabbard, an East Carolina education professor, acknowledges this isn't his field, but says "I'm smart enough to know ... that fire from airplanes can't melt steel."

When they do cite evidence, critics such as Greening contend it's junk science from fellow conspiracy theorists, dressed up in the language and format of real research to give it a sense of credibility.

Jones focuses on the relatively narrow question of whether molten metal present at the World Trade Center site after the attacks is evidence that a high-temperature incendiary called thermite, which can be used to weld or cut metal, was involved in the towers' destruction. He concludes thermite was present, throwing the government's entire explanation into question and suggesting someone might have used explosives to bring down the towers.

"I have not run into many who have read my paper and said it's just all hogwash," Jones said.

Judy Wood, until recently an assistant professor of mechanical engineering at Clemson University, has been cited by conspiracy theorists for her arguments the buildings could not have collapsed as quickly as they did unless explosives were used.

"If the U.S. government is lying about how the buildings came down, anything else they say cannot be believed," she said. "So why would they want to tell us an incorrect story if they weren't part of it?"

In fact, say Greening and other experts, the molten metal Jones cites was most likely aluminum from the planes, and any number of explanations are more likely than thermite.

And the National Institute of Standards and Technology's report describes how the buildings collapsed from the inside in a chain reaction once the floors began falling.