On Jan 16, 2008, at 6:14 PM, Angela Mailander wrote:
But there actually was molten steel in the basement for weeks, wasn't there?
I believe so. There are huge sets of other factors involved in the mechanics of such a huge collapse that could very likely contribute in some manner to condition where the originally merely pliable (I've heard estimates that the initial collapse, the steel had already lost 80% of it's material strength). Imagine a straw between two very thick books and putting a small weight in the center: when that straw bends loose, it has somewhat of a spring effect, like a leaf spring being suddenly released. Such a force could theoretically propel the floors above more rapidly than the usual inertia might allow--thereby accelerating the fall of the floors. And who could calculate the incredible numbers of variables in the ensuing fall: jet fuel, gas, materials stored in parts of this very large building, flammable paper, thermite, etc. all in the mix. It will be interesting to see what engineers will come up with, but I found the NOVA animations quite convincing. And even if that theory failed, I could already see there would be several other variations even I could imagine.
One things for certain, the structure of this building is unusual (as shown in the NOVA simulations) and I don't know that we've ever seen a building of this type and size ever fall before. The way it's so built into it's outer shell, I can easily imagine huge spring like forces which could result.
