Originally posted by: kylebisme
What brought down WTC7 was a near instantaneous removal of approximately 8 stories of structural support. This is proven by the following two facts; (1) acceleration indistinguishable from free fall is only possible in absence of any notable resistive force, (2) WTC7 dropped with period of acceleration indistinguishable from free fall for approximately 105 feet. To substantiate these facts:
And How do you know that the supports were simply not providing negligible resistance? Show me the math to show that the supports would have provided enough resistance to cause an 8 story fall to be indistinguishable from free fall.
1) This is simply inherent to the definition of the term free fall, as
documented here:
free fall
?noun
1. the hypothetical fall of a body such that the only force acting upon it is that of gravity.
Yep, that's a definition all right.
Note they say "hypothetical" as there is always at lease some air in the way preventing a falling object to accelerate at the full acceleration of gravity, and the absence of even the any resistive force of air is only possible in the hypothetical case of a complete vacuum, but acceleration indistinguishable from free fall means that what little mass is in the way is not enough to provide any observable resistive force. For those who don't understand why this is, but would like to, I recommend starting
here, and feel free to ask questions on this matter as needed.
Ok, So now we know that free-fall technically doesn't happen on earth. That's nice and all. But where is the fact that the structural supports simply were minimal? Heck, So long as each support failed or was near failing before the falling portion hit it, it would appeared to free fall.
2) While WTC7's period of free fall acceleration was previously denied by the government agencies which investigated the event, due to the widely available video evidence NIST was eventually persuaded to to admit this fact,
as documented here:
You just said free fall was impossible. And they agreed, it is impossible. But a big enough group of people got together and found a number reasonably close to free fall that they conceded and used the term.
In Stage 1, the descent was slow and the acceleration was less than that of gravity. This stage corresponds to the initial buckling of the exterior columns in the lower stories of the north face. By 1.75 s, the north face had descended approximately 2.2 m (7 ft).
In Stage 2, the north face descended at gravitational acceleration, as the buckled columns provided negligible support to the upper portion of the north face. This free fall drop continued for approximately 8 stories or 32.0 m (105 ft), the distance traveled between times t = 1.75 s and t = 4.0 s.
...
From these facts, NIST suggests distinct stages where an initial buckling of columns on one face of the building allowed the point on the they measured roofline to drop approximately 7 feet, which then allowed for 105 feet of free fall to happen next. Note that while NIST only refers to the one point on the roofline, any video of the event will show that after the initial sagging of the roofline towards the middle, the entire roof falls symmetrically though the period of free fall and beyond, until notably asymmetrical resistive force well further down causes it to tilt. You can observe the fall of WTC7 from best two angles I've seen, compared to what little NIST released of their simulations, in
this video.
And this proves? Yes, the building fell faster at a period of time. Again, I will call your attention to the fact that you have yet to prove that the resistive force of a failing support or even a full blown support would have been strong enough to slow the top section from falling.
Even two floor support failing would have been enough for the top portion to fall for several stories in a fashion indistinguishable from free fall.
Any other video of the event in existence will show the same period of free fall, and please don't hesitate to dig up more to see for yourself, and post whatever videos of the event you like. Regardless, such video evidence demonstrates that for the period of free fall, not only were the north face columns not providing any notable support, neither were those of any other face, or all of the mass that made up the floors and everything else in the building.
Gee, a column that is failing doesn't stop a huge hunk of mass from falling. Imagine that.
How exactly that complete removal of structural resistance was accomplished would require a proper investigation, as the ones we've had so far have only obscured the fact that impact damage and office fires simply can't explain anything of the sort. To view clearly visible examples of a near instantaneous removal of multiple stories of structural support for comparison sake, see the hydraulically initiated demolitions in
this video. As for examples of where free fall acceleration can be observed without removal some distance of structural support by an outside force; you simply won't find even a one, as it is physically impossible.
And here you jump into the land of fiction. You simply assume that complete removal is the ONLY way without even considering the possibility of a weakened support frame. Tell me, Have YOU ever seen a steel building collapse due to weakened structural support? By what authority can you claim that this never happens? Are you a demolitions expert?
So, we are all left with a choice here; have faith in the offical story of the fall of WTC7, or accept the fact that the offical story stands in contradction to demonstrable physical reality. Which do you choose?
Or option three, accept that this post proves nothing and your continual reference to it only shows what an idiot you are.
You have shown 1 tangible piece of evidence to support your claims, you only say that it can't and shouldn't have happened.
And without showing an sort of math, your post is more worthless then the bits it takes up on the forum hard drive.
Again, Prove it. You've made these wild assertions, prove them.
