Some of the 911 conspiracy theories talk a lot about the temperature needed to melt steel and the temperature at which jet fuel burns, and saying there is no way the fire was hot enough.
Temperature only tells a small part of the story. The burning fuel, and the burning building contents all obviously provide heat. The steel absorbed this heat. What is critical is the difference between how much and for how long heat can be pumper into the steel by the fire, and the rate of heat being dissipated by the steel. If the steel can dissipate heat faster than the fire can provide heat, nothing critical is going to happen. If, however, the steel is unable to dissipate the heat fast enough, it will become hotter. What can happen in this case is that the heat absorption can cause the steel to rise ABOVE the temperature of the fire. How much above depends upon the rates of dissipation and absorption. You can easily demonstrate this by trying to solder a copper pipe with a propane torch. By keeping water in the pipe, dissipation is fast enough to keep the solder from bonding with the copper. Draining the water reduces dissipation, thereby increasing absorption. A body will continue to absorb heat as long as heat is being applied.
Also, the steel never has to get hot enough to melt, but simply lose its strength. Demonstrate this with a metal coat hanger. Straighten out the hanger. Now try to bend the wire. You can bend it, but feel the resistance. Now, use a torch to heat this wire until it begins to glow. Try bending the wire again. It is much easier.
Another argument is the collapse itself. When a section of the steel fails, the building above it is going to collapse into the section. Now we have mass and momentum. What happens is some product of mass and momentum. Ever watch the car crash test videos? Pretty devastating. In the case of a car, there isn't much mass, but a lot of momentum. In the case of the towers, there initially isn't much momentum, but there is one heck of a lot of mass. As to the lower floors, momentum continues to build, so the forces build on each floor as the building collapses. The steel framework of the building was indeed sufficient to support the building --- under normal conditions of stress. The falling building put unusual stresses on the structure which exceeded design limits. Tensions, torsions, compressions, and sheers. Was a pancake effect possible? A second year engineering student, having completed a class on the mechanics of deformation will tell you yes.
The video linked to above has reference to thermite being found at the scene. What was found was sulfur, which would be expected. The presence of sulfur is not proof of thermite.
Anyway, just some more to think about.
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