Kevin Barrett believes the U.S government might have destroyed the World Trade Center. Steven Jones is researching what he calls evidence that the twin towers were brought down by explosives detonated inside them, not by hijacked airliners.

These men aren't uneducated junk scientists: Barrett will teach a class on Islam at the University of Wisconsin this fall, over the protests of more than 60 state legislators. Jones is a tenured physicist at Brigham Young University whose mainstream academic job has made him a hero to conspiracy theorists.

Five years after the terrorist attacks, a community that believes widely discredited ideas about what happened on Sept. 11, 2001, persists and even thrives. Members trade their ideas on the Internet and in self-published papers and in books. About 500 of them attended a recent conference in Chicago.

The movement claims to be drawing fresh energy and credibility from a recently formed group called Scholars for 9/11 Truth.

The organization says publicity over Barrett's case has helped boost membership to about 75 academics. They are a tiny minority of the 1 million part- and full-time faculty nationwide, and some have no university affiliation. Most aren't experts in relevant fields. But some are well educated, with degrees from elite universities such as Princeton and Stanford and jobs at schools including Rice, Indiana and the University of Texas.

"Things are happening," said co-founder James Fetzer, a retired philosophy professor at the University of Minnesota Duluth, who maintains, among other claims, that some of the hijackers are still alive. "We're going to continue to do this. Our role is to establish what really happened on 9/11."

What really happened, the national Sept. 11 Commission concluded after 1,200 interviews, was that hijackers crashed planes into the twin towers. The National Institute of Standards and Technology, a government agency, filed 10,000 pages of reports that found fires caused by the crashing planes were more than sufficient to collapse the buildings.

The scholars' group rejects those conclusions. Their Web site contends the government has been dishonest. It adds: the "World Trade Center was almost certainly brought down by controlled demolitions" and "the government not only permitted 9/11 to occur but may even have orchestrated these events to facilitate its political agenda."

The standards and technology institute, and many mainstream scientists, won't debate conspiracy theorists, saying they don't want to lend them unwarranted credibility.

But some worry the academic background of the group could do that anyway.

Members of the conspiracy community "practically worship the ground (Jones) walks on because he's seen as a scientist who is preaching to their side," said FR Greening, a Canadian chemist who has written several papers rebutting the science used by Sept. 11 conspiracy theorists. "It's science, but it's politically motivated. It's science with an ax to grind, and therefore it's not really science."

Faculty can express any opinion outside the classroom, said Roger Bowen, general secretary of the American Association of University Professors. However, "with academic freedom comes academic responsibility. And that requires them to teach the truth of their discipline, and the truth does not include conspiracy theories, or flat Earth theories, or Holocaust denial theories."

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.

"We respect the opinions of others, but we just didn't see any evidence of what people are claiming," institute spokesman Michael Newman said.

Wisconsin officials say they do not endorse the views of Barrett, an adjunct, but after investigating concluded he would handle the material responsibly in the classroom.

That didn't mollify many state legislators.

"The general public from Maine to Oregon knows why the trade towers went down," said state Rep. Stephen Nass, a Republican. "It's not a matter of unpopular ideas; it's a matter of quality education and giving students their money's worth in the classroom."

In a July 20 letter obtained by The Associated Press in an open records request, Wisconsin Provost Patrick Farrell warned Barrett to tone down his publicity seeking, and said he would reconsider allowing Barrett to teach if he continued to identify himself with the university in his political messages.

BYU's physics department and engineering school have issued statements distancing themselves from Jones' work, but he says they have not interfered.

At Clemson, Wood did not receive tenure last year, but her former department chair, Imtiaz ul Haque, denies her accusation that it was at least partly because of her Sept. 11 views.

"Are you blackballed for delving into this topic? Oh yes," Wood said. "And that is why there are so few who do. Most contracts have something to do with some government research lab. So what would that do to you? The consequences are too great for a career. But I made the choice that truth was more important."

"If we're in higher education to be trying to encourage critical thinking," Wood says, "why would we say 'believe this because everybody else does?'"