Originally posted by bsbray11
Page 5 of the paper says,
We note in concluding this Section that the values for tc given above represent the calculated values for the time of collapse of the WTC towers
neglecting the energy required to crush or otherwise destroy the support structure of each floor. This energy, which we will call E1, is
considered in detail in Section 4.2. For now it is sufficient to note that the collapse times calculated without allowing for E1 are already in
reasonable agreement with the observed collapse times. This suggests that E1 is relatively small compared to the kinetic energy associated with the
falling blocks of floors;
So, in other words:
The time it would've taken for the floors to fall with no resistance is already approaching the total amount of time it took the towers to fall,
so then they assume that, therefore, there was not much resistance from the structure! Now, that's bias at best. At worst, they're
doing something pretty much equivalent to lying outright, if not worse.
With that paragraph taken out of context is does appear that way, however you notice that he isn't leaving it at that assumption. He clearly states
that he goes into it in depth in section 4.2. In that section he actually calculates the value for E1.
4.2. IMPACT ENERGY REQUIRED TO COLLAPSE ONE WTC FLOOR
A crucial question that is frequently asked concerning the collapse of the WTC towers is why did the localized damage near the impact levels in WTC 1
and 2 cause the collapse of the entire buildings? In order to answer this question we need to move beyond our simple momentum transfer collision
theory and consider how much energy is needed to bring about the collapse of one floor. We call this energy E1. Once we have a reliable estimate for
E1 we will be in a position to compare it to the kinetic energy, Ti, associated with the free fall of particular blocks of floors. If Ti is found to
be significantly larger than E1, a self-sustaining total building collapse is possible. If the converse is true, only a collapse of floors severely
damaged by the initial aircraft impact is possible. A comparison of our estimates of E1 and Ti is made in Section 6.0. For now we will focus on a
reliable determination of E1.
So as you can see he is not just guessing or lying about the value for E1. In fact he is breaking down his position peice by peice to fully account
for all of his figures something completely lacking in the Jones paper.
Now I'd like to address your four problems with Greenings conclusions.
Originally posted by Bsbray11
Four problems with this that make it irrelevant, and wrong (just as this conclusion has ALWAYS been wrong, and always will be unless you guys
come up with something better):
- The impacted floors did not remain intact and become additional driving weight for the collapsing "blocks." They were destroyed and
ejected outwards, with an average of around 80% of the mass of each floor being ejected outwards radially and thus not adding on to the mass of
falling materials at all.
Where does this 80% of the mass figure come from? I would agree that 80% of the debris was ejected outward. However the steel, which was most of the
mass, ended up in a huge pile at the base of the towers.
[IMG]
[/IMG]
So while the floors did not stay completely intact, that mountain of steel shows that the mangled steel did infact contribute to the mass of falling
materials.
Originally posted by Bsbray11
The "blocks" of falling floors broke up and lost their integrities during the collapses, with large chunks falling over the side at various times
somewhat early in the collapses.
See my response to your first point. While debris was falling off, mass was still being added to the collapse through the steel.
Originally posted by Bsbray
Because of the above points A and B, it can be assumed, by their own reasoning, that the relative amount of energy lost to heat through each
impacting of a floor would be an increasingly large fraction of the total energy available – NOT AN INCREASINGLY SMALL ONE.
Well, if both your points are incorrect assumptions, then no this cannot be assumed.
Originally posted by Bsbray11
The collapse speed did not slow, immediately indicating that (1) absolutely no resistance from the structure, or that (2) explosives (third source
of energy) were used to blow out each floor.
How does the collapse speed not slowing immediately indicate that?
As you can see from the graph Greening made from his figures the resistance is readily apparent.
Starting at the same speed and then slowing is exactly what we should expect from the resistance as the collapse proceeded.
It seems to me that what you are presenting is totally unrealistic, and
did not happen.
Sorry Bsbray.
[edit on 29-1-2006 by LeftBehind]