Quote:
Originally Posted by Brokinarrow
Conspiracy theories, heh. found a VERY good scientific answer to that whole 'melting point of steel is higher than jet fuel can burn' point here: http://answers.yahoo.com/question/in...0010454AAEhMIJ (labeled as best answer).
To sum: yeah, jet fuel doesn't burn at the temperature that steel melts at. but, the burning jet fuel keeps adding heat to the steel. if the steel isn't able to dissipate this heat faster than more heat gets added, the temp of the steel continues to climb even if the temp of the fire remains the same.
I don't think I did that explanation justice with my very limited understanding of physics, so be sure to read the actual thing and form your own opinions off of that, not my horrible summary of it.
Anyway, back on topic, those are some powerful photos there. But I like how they included the pic of the new tower going up towards the end  |
Not to mention that the steel didn't even have to melt. If you've ever worked with steel then you would know that as it gets hot it becomes very, very malleable (as with all metals) - basically the steel kept heating and heating and eventually the reinforcements were able to bend, deform, etc - this initiated the upper levels falling, at which point their cumulative impulse (the measure of force as it is delivered over time - i.e. resting a 20 pound weight on a surface has less impulse than dropping it) was able to overcome the reinforcements of the lower levels.
Also - you don't have to bring a structure down from the bottom, its just easier that way.
- Bryon