Path of Greatest Resistance
1- It has been argued that when the first impacted floor suddenly had to bear the weight of a fallen floor plus the rest of the building that the floor trusses and thin layer of concrete were in no way able to slow down the momentum or such weight and that, thus, if the floors below can't hold the falling weight, then the path of resistance is straight through.
However, if you take a look at the debris, you'll notice that a lot if not most of the upper debris had the texture of dust or at best sand.
2- It has been argued that the top part of the building held together for at least some of the collapse and that just because one can see concrete breaking up doesn’t mean its just a bit of sand and doesn't weigh anything.
Ofcourse all matter weighs -something-. Spread out dust, however, doesn't weigh all that much per cubic meter.
3- It has been argued that the top thirty floors of WTC2 were not mostly dust and did weigh quite a lot.
That's true, but they were pulverized into dust in mid air; these buildings had no need to 'pancake'; as they were disintegrating in an explsosive manner outwards.
4- In post 32 of the WTC Collapses thread, KennyJC has argued that just because most of what I believe to have seen was dust, does not mean that everything that is falling is dust.
I agree, there were certainly some steel girders being ejected out. But in terms of the concrete, it was mostly pulverized, as 9/11 research makes clear.
5- In post 32, KennyJC also mentions the recovery folk who far from simply having to hoover stuff up, spent years removing actual solid building-type things.
I believe that 'solid buliding-type' stuff was mainly metal, but by all means, attempt to show me evidence that it was otherwise.
6- It has been argued that they didn’t fall into thin air.
Clearly it did.
7- The question has also been asked as to whether concrete can simply be 'pulverized' during a fire induced collapse.
I believe the answer is no. In post 32, KennyJC asks me to "Watch any building collapse whether it be controlled or accidental; they produce tremendous amounts of dust. 10 story apartment building appeared to have its concrete completely disintegrated in mid-air as it fell."
I have asked him to provide me with a video of this supposed no explosives mid-air concrete disintegration.
In post 32, KennyJC states that the majority of concrete that was used in the WTC was very thin, and thus, very easily broken down. I have asked him to provide evidence for that claim.
Imagine dumping dust on a structure- would it demolish the structure beneath it or would it simply run off the sides of the structure?
It was argued that a bucket of sand will, but that the top thirty floors of WTC2 were not sand.
This is true. However, a lot of the steel was ejected outside
of the WTC2 footprint and the concrete was pulverized into fine dust, much of
which -also- was ejected outside of the WTC2 footprint.
If you want a technical argument as to why the pancake theory is hopelessly flawed, you may want to attempt to understand an article from Gordon Ross, who holds degrees in both Mechanical and Manufacturing Engineering:
I personally don't understand it, but I've seen other arguments regarding the conservation of momentum that are certainly simpler, such as physicist Steven Jones' argument:
The rapid fall of the Towers and WTC7 has been analyzed by several engineers/scientists http://911research.wtc7.net/wtc/analysis/proofs/speed.html; Griffin, 2004, chapter 2). The roof of WTC 7 (students and I are observing the southwest corner) falls to earth in less than 6.6 seconds, while an object dropped from the roof would hit the ground in 6.0 seconds. This follows from t = (2H/g)1/2. Likewise, the Towers fall very rapidly to the ground, with the upper part falling nearly as rapidly as ejected debris which provide free-fall references (http://911research.wtc7.net/wtc/analysis/proofs/speed.html; Griffin, 2004, chapter 2). Where is the delay that must be expected due to conservation of momentum — one of the foundational Laws of Physics? That is, as upper-falling floors strike lower floors — and intact steel support columns — the fall must be significantly impeded by the impacted mass. If the central support columns remained standing, then the effective resistive mass would be less, but this is not the case — somehow the enormous support columns failed/disintegrated along with the falling floor pans.
How do the upper floors fall so quickly, then, and still conserve momentum in the collapsing buildings? The contradiction is ignored by FEMA, NIST and 9-11 Commission reports where conservation of momentum and the fall times were not analyzed. The paradox is easily resolved by the explosive demolition hypothesis, whereby explosives quickly remove lower-floor material including steel support columns and allow near free-fall-speed collapses (Harris, 2000).
There is apparently one example in the collapses where the explosives weren't detonated quite fast enough to avoid a bit of angular momentum.
Shaman has argued that when you have more behavior which shows that explosives weren’t involved, I just know that they were there but they didn’t detonate. The above mentioned behaviour shows no such thing; it only shows that a part of the WTC tower didn't have sufficient explosives to get it to yield at a certain point quickly enough; thus, the partial toppling that was arrested by the top part of the structure simply disintegrating in mid air (yet more evidence of explosives being used).
Steven Jones explains the issue of angular momentum very well
in his article "Why Indeed
Did the WTC Buildings Collapse?". Here is an excerpt:
Consider the collapse of the South WTC Tower on 9-11: http://www.911research.com/wtc/evidence/videos/docs/south_tower_collapse.mpeg
[A picture of the event:]
Top ~ 34 floors of South Tower topple over.
What happens to the block and its angular momentum?
We observe that approximately 34 upper floors begin to rotate as a block, to the south and east. They begin to topple over, as favored by the Second Law of Thermodynamics. The torque due to gravity on this block is enormous, as is its angular momentum. But then — and this I’m still puzzling over — this block turned mostly to powder in mid-air! How can we understand this strange behavior, without explosives? Remarkable, amazing — and demanding scrutiny since the US government-funded reports failed to analyze this phenomenon. But, of course, the Final NIST 9-11 report “does not actually include the structural behavior of the tower after the conditions for collapse initiation were reached.” (NIST, 2005, p. 80, fn. 1; emphasis added.)
After the above statements, shaman wondered if there was anything
explosives couldn't do.
For those who are interested in finding out what -else- thermate/nano-thermite
can do, you may want to ask NIST. You see, they know quite a bit about it:
The Top Ten Connections Between NIST and Nano-Thermites