The Difference Between "Speed" and "Acceleration"
The first point Mr. Nobles makes is one I happen to agree with. It is clearly more appropriate to say "acceleration" rather than "speed" when discussing the issue of free fall. However, I have often felt that trying to determine if the WTC fell at free fall acceleration is in itself somewhat misleading. If we are trying to establish whether or not the buildings were controlled demolitions, then the question really should not be "did the buildings fall at free fall?" The question should be "did the buildings fall in time intervals consistent with controlled demolitions?" That of course begs the question of whether or not buildings destroyed through controlled demolition fall in free fall. More on this will be discussed below.
Rate of Collapses
Mr. Nobles features this photo to demonstrate how the debris coming off from the Towers is falling faster than the Towers themselves.
While the debris is certainly falling faster than the actual collapse, the wave of the destruction appears to be keeping up with the majority of the debris. David Chandler has outlined this characteristic of the collapses very accurately.
What's more, the rate of fall for some of the pieces of steel has itself been shown to be a smoking gun.
It has already been established that the total time for the Towers to come down was approximately 15 seconds in either case.
Mr. Nobles then presents this video to demonstrate that Building 7 actually took close to 16 seconds to collapse.
This is an issue that has been addressed several times already, but many debunkers still think the fall of the east penthouse invalidates the idea that WTC 7 was a demolition. I myself have already shown the collapse of column 79 and the penthouse is problematic enough. And it is not impossible that roof elements can collapse in a demolition before the main structure.
Sure, there was a much shorter gap between the two events than with Building 7. But clearly the idea of sections of the roof falling in a demolition before the main structure is not unheard of.
Oddly, Mr. Nobles refers to the main structure of WTC 7 as a "portion" of the collapse. That makes it sound like it was a very small part of the building that collapsed. The east penthouse could be more accurately described as a "portion."
Measurements of the Fall Rates
Mr. Nobles attempts to demonstrate that the rate at which the buildings fell has already been well accounted for by several sources.
He first cites a statement made in NIST's FAQ on the WTC, ignoring the fact that nowhere in NIST's report do they explain the actual total collapse of the buildings.
As 911research.wtc7.net points out:
NIST's assertion that the Tower's intact structure was "unable to stop or even to slow the falling mass" is absurd:
-It requires us to believe that the massive steel frames of the towers provided no more resistance to falling rubble than air.
-It ignores the fact that most of the rubble fell outside the towers' footprints, and hence could not contribute to crushing.
-It is unsupported by any calculation or logical argument.
Mr. Nobles then cites the work of Bazant et al. He refers to Bazant's work as providing "more rigorous calculations" and that his papers have been published in "respected scientific journals." However, several refutations to Bazant's work have been written over the years. Two refutations have even been peer reviewed and published in the same journal Bazant's papers have been published in. Those can be viewed here and here.
Although Mr. Nobles portrays NIST and Bazant as having explained that "the acceleration of their descent was not mathematically unusual," there are phenomenons in the collapses of both buildings that neither NIST nor Bazant account for.
One of which is the instant acceleration of the upper section of WTC 1. Debunkers have yet to provide any rational explanation for this event.
Another phenomenon is the disintegration of the upper section of WTC 2 as it collapsed. 911research points out that:
"It is clear that that the top section itself must be disintegrating. Otherwise the top section would have extended far into parts of the building that are clearly as yet unaffected by the collapse."
And video evidence confirms this.
Mr. Nobles makes some mention of the fact that portions of the cores of both Towers remained standing after the collapses. However, video evidence shows that the remaining core of the South Tower included neither north nor west columns.
And there was hardly anything left of the North Tower's core.
Despite Mr. Nobles' claims to the contrary, the rate at which the Towers fell is greatly at issue.
The Fall of WTC 7
Mr. Nobles lastly attempts to refute many arguments made about the collapse of WTC 7. Mr. Nobles believes that the main structure of WTC 7 also did not fall in 6.5 seconds. He features this diagram to illustrate this point.
I've never particularly liked using pictures to track the fall of any of the buildings. I feel that the videos speak for themselves.
Mr. Nobles makes quite a remarkable statement in regard to the collapse of the building.
"As shocking as it may be to our inexperience in large buildings falling, this is how quickly buildings of this size fall when they begin to collapse."
Oh really? If that's the case Mr. Nobles, then why did these buildings, all known controlled demolitions, take as long and even longer to fall than Building 7? Considering the fact that all these buildings are shorter than Building 7 and supposedly fire, not explosives, brought Building 7 down.
Controlled demolition clearly doesn't always cause a building to fall at free fall.
Finally, Mr. Nobles attempts to explain the period of free fall Building 7 underwent in its collapse. And like all other debunkers, he attributes this to the alleged buckling of eight of the lower floors. I recently demonstrated in two previous posts that these claims are clearly unfounded.
Conclusions
Mr. Nobles has clearly not explained the collapse anomalies of the Twin Towers and Building 7. Nothing will ever accurately explain what happened to those buildings until a new investigation is finally launched. One thing is for sure though: fire cannot cause a steel framed building to fall at the incredible rate at which the WTC fell in. The only example of a top-down progressive collapse initiated by fire is one in which a 13 story building took 10 seconds to partially collapse.
