I just came across something that might be of interest to you. It is a
paper by a "Dr. Frank Greening" here:
http://www.911myths.com/WTCREPORT.pdfIn it, he attempts to calculate the feasibility of the collapse of the
towers but I believe I have found an error.
Here he states:
we have an initial mass nmf
falling onto the
floor below and becoming mass (n+1)mf. This new, enlarged, block of
floors descends
with velocity v2 = {n/(n+1)}v1 through a distance hf at which point it
strikes the floor
below and becomes mass (n+2)mf moving at velocity {n/(n+2)}v2, and so on
The problem is, in a hypothetical tower collapse, the only thing that
would change is the velocity of any mass above the collapse points. The
total mass would not change. If he
wants to add the mass of each floor to the upper mass with each
collapse, that is fine but he also has to then subtract the same mass
from
the lower floors.