Weird Stuff Happened to the WTC Steel
Yet metallurgical studies on WTC steel brought back to WPI reveal that a novel phenomenon--called a eutectic reaction--occurred at the surface, causing intergranular melting capable of turning a solid steel girder into Swiss cheese.
Materials science professors Ronald R. Biederman and Richard D. Sisson Jr. confirmed the presence of eutectic formations by examining steel samples under optical and scanning electron microscopes. A preliminary report was published in JOM, the journal of the Minerals, Metals & Materials Society. A more detailed analysis comprises Appendix C of the FEMA report. The New York Times called these findings "perhaps the deepest mystery uncovered in the investigation." The significance of the work on a sample from Building 7 and a structural column from one of the twin towers becomes apparent only when one sees these heavy chunks of damaged metal.
A one-inch column has been reduced to half-inch thickness. Its edges--which are curled like a paper scroll--have been thinned to almost razor sharpness. Gaping holes--some larger than a silver dollar--let light shine through a formerly solid steel flange. This Swiss cheese appearance shocked all of the fire-wise professors, who expected to see distortion and bending--but not holes.
I suppose it's good to see that they are saying something unusual happened to the WTC steel-- because it really shouldn't have given way in those fires-- but as usual, they ignore the idea that there was intentional demolition which caused this abberrant steel deformation.
Professor Jones says thermite brought down the towers.
Videos of an apparent thermite reaction in the south tower right before it collapsed here
I don't think thermite explains everything about the tower collapses (for instance the pulverization of concrete), but thermite was probably used.
I like Webfairy's idea that the demolition of the WTC was sort of like the JFK assassination, where they brought in every shooter from all over the country to be in the area. The demolition of the WTC may well have involved multiple different technologies, from conventional explosives, to thermite, to microwave weaponry.
A copnventional demolition simply doesn't explain how all the filing cabinets and elevator doors and doorknobs that existed in the WTC were vaporized.