A Brigham Young University physicist said he now believes an incendiary substance called thermite, bolstered by sulfur, was used to generate exceptionally hot fires at the World Trade Center on 9/11, causing the structural steel to fail and the buildings to collapse. It looks like thermite with sulfur added," Steven Jones, professor of physics at BYU, told a meeting of the Utah Academy of Science, Arts and Letters. Jones is co-chairman, with James H. Fetzer, a distinguished professor of philosophy at the University of Minnesota of Scholars for 9/11 Truth, a group of college faculty members who believe conspirators other than pilots of the planes were directly involved in bringing down New York's Trade Towers. The group, which Jones said has 200 members, maintains a Web site at www.st911.org. A 40-page paper by Jones, along with other peer-reviewed and non-reviewed academic papers, are posted on the site. Last year, Jones presented various arguments for his theory that explosives or incendiary devices were planted in the Trade Towers, and in WTC 7, a smaller building in the Trade Center complex, and that those materials, not planes crashing into the buildings, caused the buildings to collapse. Jones said his studies are confined to physical causes of the collapses, and he doesn't like to speculate about who might have entered the buildings and placed thermite and sulfur.