There are many theories for that but your conclusion that jet fuel took the towers down is laughable. Where did you get that idea? Are you an expert on melting metal and temperatures?
Where did YOU get the idea that it's "laughable"? And where did you get the idea that the Official Explanation involves "melting metal"? I'm fairly sure that the Official Explanation says that structural steel weakens at temperatures significantly below the temperature of burning jet fuel (which is, in turn, significantly below steel's melting point).

The claim that hot steel смягчается at temperatures far below the температура плавления should not exactly be controversial -- after all, it's why "Smith" (literally "кузнец") is one of the most common American surnames!