I knew it! I knew it made no sense that the much lighter top would collapse the whole "supposedly" undamaged bottom. Now I found scientific engineering papers to PROVE IT! Did you know that the WTC were designed to so that they were holding only 30% of their capacity by weight? That means the WTC towers could hold up to almost 300 more floors! And just 18 floors collapsed the whole building?
Here's the paper: with some quotations:
http://www.journalof911studies.com/volume/2008/TheMissingJolt7.pdf
The rigidity of the upper block of stories is crucial to this explanation. If the upper block were to break, disintegrate or flow on impact it would certainly not threaten the 92 intact floors beneath it. In addition, the rigid block had to fall onto the rest of the building. Although this seems obvious, the NIST authors are often shy about saying it. We hear about the rigid block’s “descent.”[5] We hear of tilting and “downward movement.”[6] We have to look carefully to find the NIST authors using the language of falling. Whatever the reasons for their reticence, it is clear that it will not do for the upper block to ease itself onto the building beneath it, with a gradual creaking of buckled columns and sagging floors. If this were to happen, why would the structure beneath collapse?
If the upper block didn't just rest down onto the remaining intact structure and therefore do nothing...it would have either bounced off (as a block) or pulverized on top of the remaining structure and fallen away like a water balloon hitting a post.
There was nothing special about the weight of the upper block, rigid or otherwise. The lower part of the Tower had held up this weight without difficulty since 1970. The lower block had 283 cold steel columns, with less than 30% of their total load capacity being utilized for gravity loads, because of the factors of safety designed into the structure and the need to withstand high winds—and gravity loads were essentially the only loads the columns would have been subject to on a day such as 9/11 with little wind. The lower block was not weak, nor (excluding stories 93-98) was it damaged by plane impact or fire. The weight of the upper block posed no threat to it. If there were to be a threat, it had to come from the momentum of the upper block. But momentum is a product of mass and velocity, and since the upper block could not increase its mass it had to increase, if it were to become a threat, its velocity. Since NIST’s theory assumes the only energy at play at this stage of events was gravitational, the upper block had to fall, and the greater its velocity the greater its momentum. The longer and the less impeded its fall, the greater would be its impact on the lower structure. So it is no surprise that the NIST authors, however shy they are about affirming it, eventually come out in favour of the falling of the upper block. [7]
But I'm not willing to be a
TRUTHER
I have an alternative theory how the towers fell.
Instead of cutting the core, like most imagine it happened, with pancaking floors which would in fact have just bounced off the rest of the 93 floors below them.
The core remained intact, and loosened by fire and outer shell damage to those support columns, the structure did something it was NEVER designed to do.
It twisted, from top to bottom, head to foot, root to crown.
For an hour, subtle by inches or less and impossible to see by the eye, hundreds of thousands of tons were stuck to the rest of the building fastened by the core columns and these columns were twisting.
What happens when you move a steel beam only centimeters or an inch, in a direction they aren't allowed to move, in a structure held together by super brittle grains of sand we call "Cement"?
It fits all the ground-zero witness descriptions.
Groaning, cracking, explosive sounds, floors giving way at multiple levels, elevator shafts sheering and breaking apart.
As that steel moves the concrete under the pressure of its own structure starts blowing out of the walls like artillery rounds, just like a prybar hitting concrete only with 1,000,000 pounds twisting it.
The towers were designed to sway, not to twist.
So, this is the only reasonable explanation I can come-up with other than explosives, to explain why when the top fell, the rest of the tower was barely able to resist the pancake collapse. Because after an hour the whole interior was already broken up and the shockwave passing through the remains was able to knock floors loose before they were even hit by the floors above
(which explains the near free fall speed).
SUPPLEMENTAL EDIT:
What I'm describing is Torsion and is the most dangerous movement a building can sustain. Torsion occurs without symmetry and when mass is significant to one structural support versus another. My theory is that the planes damaged the symmetry and the core still intact, the torsion ripped the building apart at all levels and so the damage WAS in fact complete and through-out the entire structure.
Why has no one discovered this so far?
Because those who aren't looking already accepted a simplistic official answer, those who are looking are looking for the wrong biased reasons such as the building was rigged with explosives.
Here's an explanation of torsion.
HOW BUILDINGS TWIST DURING EARTHQUAKES?
FURTHER SUPPLEMENTAL EDIT:
The structure of the floors was a prefabricated unit of open web steel joists with an insitu structural concrete slab. The floors tied together the exterior perimeter columns and the interior steel frame to resist twisting, or torsion, of the tower
http://web.mit.edu/civenv/wtc/PDFfiles/Chapter I History.pdf
I have been hunting for evidence about how the WTC towers are built with regards to torsion and SURE enough we see here that (as would be expected) they are built to resist torsion but look how they are built to resist torsion.
The FLOORS tie together the core and exterior columns!
So this supports my hypothesis in several ways.
With the floors collapsed and severely damaged at the top, the top acts like a giant torsion wrench pulling on the ENTIRE STRUCTURE.
After the core fractures in what is called "Spiral fracturing" and has many green stick fractures running through the whole top to bottom, and the top does collapse...I hypothesize the collapse was so orderly because there was a twisting motion the whole way down.
As each floor broke away the building twisted apart like a zipper coming undone.
It wouldn't have made a 180 degree turn, or 360 degree twist or anything dramatic, but enough to just peel the building down like peeling a banana.
THIRD SUPPLEMENTAL EDIT: (High Density Polymer)
In the above paper it also cites that High Density Polymer was used to absorb lateral oscillation of the floors against the walls. So hunting it down I found its flammability characteristics.
I believe it to be possible to explain why there were continuous explosions heard internally, the polymer as it burns (also at a higher temperature than most office products) gives off explosive gasses.
Here is the data sheet:
http://www.ntepa.nt.gov.au/__data/assets/pdf_file/0013/20371/appendix5.pdf
I'm guessing there are 3 tons of ass to be kicked in this thread (and that's a conservative estimate); but take it from someone who's been there and done that: it ain't worth it.
