What brought down WTC7

[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:

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.

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.


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:

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.

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.

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.

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?

-----------------------------------------

There is a post from Pulsar on the NIST report.
Please refute that report to allow this thread to continue

Senior AnandTech Moderator
Common Courtesy

---

I'm not as tolerant of this BS as Common Courtesy. LOCKED.

Harvey
Senior AnandTech Moderator


Thread doesn't break any rules, lock retracted.

Anandtech Senior Moderator
Red Dawn

 

[Wheezer]

OH GOODY! another "The WTC was a giant conspiracy" thread...can't get enough of those...no siree.

 

[First]

Your arguments amounts to "But the video evidence clearly shows..." and the end result is that, no, it doesn't show anything of the sort. NIST was correct in their assertion because they know gravity demands that objects fall at rate of roughly 9.8 m/s^2 in a vaccum on planet earth, they did the correct calculations and made the correct conclusions based on the evidence given, which is more than Truthers can say because they have no evidence to support an alternative theory; merely theories based on grainy video and innuendo.

 

[MikeMike]

could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

 

[First]

Originally posted by: MIKEMIKE
could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

No, since the density of free is nothing like the vacuums you find, say, in space. But the environment for free fall certainly existed and certainly can't be disproven with any mathematics.

 

[kylebisme]

Originally posted by: First
Your arguments amounts to "But the video evidence clearly shows..." and the end result is that, no, it doesn't show anything of the sort.

Rather, I explained what the video evidence clearly shows, and what NISTs admission of free fall supports, and your response amounts to "na'ah!" If you want to claim the videos show something different than I stated, then iterate your contention. However, I get the impression simply want to believe what I said is wrong, and hence cannot iterate anything of the sort.

Originally posted by: First
NIST was correct in their assertion because they know gravity demands that objects fall at rate of roughly 9.8 m/s^2 in a vaccum on planet earth, they did the correct calculations and made the correct conclusions based on the evidence given...

They sure did do the right calculations, and I said nothing to suggest otherwise. What I did note is that they didn't explain how there was no notable resistance to slow the fall of the roof to observably bellow the 9.8 m/s^2 acceleration of gravity for the approximately 105 feet for which it did undergo free all. Neither can anyone show anything of the sort while still supporting the official story.

This is why NIST couldn't show the fall ofthe models they made, as they can't fall the way the building did while simulating the official story. That is why they can't release the model to the public either, as we could make it fall like seen in all the videos, but we would have to simulate an outside force removing all the structural resistance from about 8 stories of the building to do so. Hence, instead of NIST proving their claim, they have let it you people like yourself to take their argument on faith.

Originally posted by: MIKEMIKE
could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

Some air, not all. However, even it if was in a complete vacuum, you still aren't explaining what happened to all the other mass which had previously held the building up across the 8 stories where it experienced a period of free fall.

 

[MikeMike]

Originally posted by: kylebisme
Cooky Text

perhaps because they have no frickin clue what the insides of the WTC looked exactly like the day it was it. perhaps because they have no frickin clue what sort of wear and tear was on the steel beams of the WTC after the numerous years of use.

 

[cubby1223]

Originally posted by: MIKEMIKE
could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

You do know what fire is, right?

 

[kylebisme]

Originally posted by: MIKEMIKE
perhaps because they have no frickin clue what the insides of the WTC looked exactly like the day it was it. perhaps because they have no frickin clue what sort of wear and tear was on the steel beams of the WTC after the numerous years of use.

There are plenty of clues for those who understand the physics in question. The fact that it was standing until it fell proves that until the fall started the structure had over 100% of the resistive force to hold up the roof. The fact that shortly after their roof started to sag it fell with a period of free fall acceleration over a distance of approximately 105 feet proves that what had previously been over 100% of the resistive force to hold up the roof lost the ability to provide any notable resistive force at all. These facts together prove that an outside force removed approximately 105 feet of structural resistance, though I understand that it is a fact which many find difficult to accept.

 

[theflyingpig]

Your entire post is nothing but garbage. Stop trying to sound intelligent. You aren't. Everyone knows this.

 

[theflyingpig]

Originally posted by: kylebisme

Originally posted by: MIKEMIKE
perhaps because they have no frickin clue what the insides of the WTC looked exactly like the day it was it. perhaps because they have no frickin clue what sort of wear and tear was on the steel beams of the WTC after the numerous years of use.

There are plenty of clues for those who understand the physics in question. The fact that it was standing until it fell proves that until the fall started the structure had over 100% of the resistive force to hold up the roof. The fact that shortly after their roof started to sag it fell with a period of free fall acceleration over a distance of approximately 105 feet proves that what had previously been over 100% of the resistive force to hold up the roof lost the ability to provide any notable resistive force at all. These facts together prove that an outside force removed approximately 105 feet of structural resistance, though I understand that it is a fact which many find difficult to accept.

Your internet physics education is pathetic.

 

[MikeMike]

Originally posted by: cubby1223

Originally posted by: MIKEMIKE
could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

You do know what fire is, right?

yes, its the combustion of oxygen and other things... however theoretically if the insides of the WTC were on fire completely as in, every where... and the only available oxygen was being brought in from the outside... or could what i just stated not happen?

 

[guyver01]

Originally posted by: MIKEMIKE

Originally posted by: cubby1223

Originally posted by: MIKEMIKE
could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

You do know what fire is, right?

yes, its the combustion of oxygen and other things... however theoretically if the insides of the WTC were on fire completely as in, every where... and the only available oxygen was being brought in from the outside... or could what i just stated not happen?

So.. you're saying that the inside of WTC is a hemetically sealed environment and fire starts which consumes all oxygen, and no OUTSIDE oxygen gets in, even as the building collapses?

yea.. i can see it being possible :roll:

 

[WildHorse]

Well the owner said this.

So what's the deal with adolescent cat calls like

Originally posted by: Wheezer
OH GOODY! another "The WTC was a giant conspiracy" thread...can't get enough of those...no siree.

Originally posted by: MIKEMIKE

Originally posted by: kylebisme
Cooky Text

perhaps because they have no frickin clue what the insides of the WTC looked exactly like the day it was it. perhaps because they have no frickin clue what sort of wear and tear was on the steel beams of the WTC after the numerous years of use.

Originally posted by: theflyingpig
Your entire post is nothing but garbage. Stop trying to sound intelligent. You aren't. Everyone knows this.

Summary: WTC 7 OWNER publically declared it was intentionally demolished.

Soon one hand you have the OWNER OF THE WTC 7 openly stating that he decided to intentionally demolish it,
vs. on the other hand some AT P&N greybeards arrogating to themselves "superior" knowledge of why WTC 7 fell.

Oh yeah, the AT P&N guys know better!
Simply ignore their ignorant noise. They fuel each other< and posts such as quoted above are less than worthless, because they are tantamount to intentional disinformation, intent on dissuading public discourse.

911 was done with full complicity of a cabal of maniacal kooks who got power, especially Dick Cheney, & the others who rode along on the certifiably loony PNAC mindset, which was openly expressed in publications. Monsterous crazed failed ideologues all, may they rot in Judecca, which was Dante's Fourth Ring of the Ninth Circle of Hell and the lowest depth.

The part the spin meisters seek to squash public discussion of is that the mere fact Silverstine decided to intentionally demolish WTC 7, which he openly declared, MEANS WTC7 was ALREADY PRE-PLANTED with the explosive charges necessary to accomplish that job. If the public gets going on that noncontroversial indisputible FACT, it will suggest that claims the other towesr also were pre-planted with explosives are plausible. That's undercut the "burning airplanes collapsed the towers" lie.

 

[Moonbeam]

Originally posted by: Wheezer
OH GOODY! another "The WTC was a giant conspiracy" thread...can't get enough of those...no siree.

The fact that something irritates you because you have categorized it as belonging to a set of ideas you feel is OK to sneer at means nothing at all other than to announce your pride in a capacity any child has.

 

[Moonbeam]

Originally posted by: First
Your arguments amounts to "But the video evidence clearly shows..." and the end result is that, no, it doesn't show anything of the sort. NIST was correct in their assertion because they know gravity demands that objects fall at rate of roughly 9.8 m/s^2 in a vaccum on planet earth, they did the correct calculations and made the correct conclusions based on the evidence given, which is more than Truthers can say because they have no evidence to support an alternative theory; merely theories based on grainy video and innuendo.

Boy that's convincing. You have an opinion. Great.

 

[manowar821]

"CDI & other demolition companies should learn from 9/11 and use jet fuel to bring down buildings.

1.? Fast. No weeks and months to rig a building for demolition, just light a fire, let it burn for 7 hours and then we watched the building collapse!

2. Safer. if C-4 & detonation cord is touched off, boom!

3. Success rate! 3 incidents 3 successful collapses! You can't beat 100%.

4. Cost! I could be wrong, but isn't C-4 or whatever is used & weeks of man hours is much higher than kerosene?"

Made me laugh pretty good.

It's hard to believe, but I can't really put it past the US population to take THIS MANY FUCKING YEARS AFTER 9/11 to realize when they've been had.

 

[Moonbeam]

Originally posted by: First

Originally posted by: MIKEMIKE
could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

No, since the density of free is nothing like the vacuums you find, say, in space. But the environment for free fall certainly existed and certainly can't be disproven with any mathematics.

Anybody know the density of free? Or what the environment for free fall is?

If you drop a feather air resistance is a factor. If you drop a brick or a building, not much.

 

[Moonbeam]

Originally posted by: MIKEMIKE

Originally posted by: kylebisme
Cooky Text

perhaps because they have no frickin clue what the insides of the WTC looked exactly like the day it was it. perhaps because they have no frickin clue what sort of wear and tear was on the steel beams of the WTC after the numerous years of use.

Or perhaps not, eh?

 

[dmcowen674]

Originally posted by: kylebisme
Topic Title: What brought down WTC7

Maybe I can put this to bed for you.

I worked there, well six stories below ground level where there was a Telecom switch.

We had massive storage tanks of diesel for the backup generator.

Flames from the collapsing two Twin Towers filled the connecting cable pipes.

The fires made it all the way to WTC7 infrastructure after obviously quite a while.

The flames had to travel horizontal through the interconnects.

When it got to the data center all hell broke lose.

When the diesel tank erupted in flame the temps went above the structural integrity for the supporting steel for the office building above.

That switch had to be rebuilt from scratch 30 blocks further uptown.

That solve the mystery for you?

 

[Moonbeam]

Originally posted by: theflyingpig
Your entire post is nothing but garbage. Stop trying to sound intelligent. You aren't. Everyone knows this.

your internet physics education is pathetic.

You make noise and your post was garbage. And everyone knows YOU are an idiot because you announce it over and over with you stupid posts.

Lets see some physics that isn't pathetic please.

 

[Moonbeam]

Originally posted by: guyver01

Originally posted by: MIKEMIKE

Originally posted by: cubby1223

Originally posted by: MIKEMIKE
could a fire not cause all air to be removed, thereby creating a vacuum like environment in which free-fall is accelerated because of no air resistance?

You do know what fire is, right?

yes, its the combustion of oxygen and other things... however theoretically if the insides of the WTC were on fire completely as in, every where... and the only available oxygen was being brought in from the outside... or could what i just stated not happen?

So.. you're saying that the inside of WTC is a hemetically sealed environment and fire starts which consumes all oxygen, and no OUTSIDE oxygen gets in, even as the building collapses?

yea.. i can see it being possible :roll:

Hehehe, The fire created a black hole.

 

[WildHorse]

Originally posted by: dmcowen674

I worked there, well six stories below ground level where there was a Telecom switch.

Were you working there and present onsite when the towers fell, so that you are a firsthand witness?

Originally posted by: dmcowen674
The fires made it all the way to WTC7 infrastructure after obviously quite a while.

That's the part which people say is not supported by video evidence or witness testimony.

 

[Moonbeam]

Originally posted by: WildHorse
Well the owner said this.

So what's the deal with adolescent cat calls like

Originally posted by: Wheezer
OH GOODY! another "The WTC was a giant conspiracy" thread...can't get enough of those...no siree.

Originally posted by: MIKEMIKE

Originally posted by: kylebisme
Cooky Text

perhaps because they have no frickin clue what the insides of the WTC looked exactly like the day it was it. perhaps because they have no frickin clue what sort of wear and tear was on the steel beams of the WTC after the numerous years of use.

Originally posted by: theflyingpig
Your entire post is nothing but garbage. Stop trying to sound intelligent. You aren't. Everyone knows this.

Summary: WTC 7 OWNER publically declared it was intentionally demolished.

Soon one hand you have the OWNER OF THE WTC 7 openly stating that he decided to intentionally demolish it,
vs. on the other hand some AT P&N greybeards arrogating to themselves "superior" knowledge of why WTC 7 fell.

Oh yeah, the AT P&N guys know better!
Simply ignore their ignorant noise. They fuel each other< and posts such as quoted above are less than worthless, because they are tantamount to intentional disinformation, intent on dissuading public discourse.

911 was done with full complicity of a cabal of maniacal kooks who got power, especially Dick Cheney, & the others who rode along on the certifiably loony PNAC mindset, which was openly expressed in publications. Monsterous crazed failed ideologues all, may they rot in Judecca, which was Dante's Fourth Ring of the Ninth Circle of Hell and the lowest depth.

The part the spin meisters seek to squash public discussion of is that the mere fact Silverstine decided to intentionally demolish WTC 7, which he openly declared, MEANS WTC7 was ALREADY PRE-PLANTED with the explosive charges necessary to accomplish that job. If the public gets going on that noncontroversial indisputible FACT, it will suggest that claims the other towesr also were pre-planted with explosives are plausible. That's undercut the "burning airplanes collapsed the towers" lie.

I thought what was to be pulled were any efforts by the fire department to save the building, as in pull the firemen.

 

[Moonbeam]

If my knees buckle I fall. My bones don't have to melt and my asshole pucker doesn't suck me down. I fall at the acceleration of gravity. I personally see nothing odd about the building falling and although I have some natural ability in physics all the crap about the mathematics involved in any analysis of that building could be done really, in my opinion by a very small number of demolition experts. For me to watch some video and conclude one way or the other, is folly, in my opinion. I would have to acquire an enormous amount of data and information I am not interested in, to form any real intelligent opinion.

I don't know what happened to make that building fall in the way it did and I will stay that way. You can think as you like. But if you think you know I think you're nuts, provided, of course, you're aren't a real pro.

PS: Something stands until it falls. That means that the force holding something up, at the moment it starts to fall, is at that moment insufficient to do so. Seems to me too that if a first floor gives out, the shock from falling one then maybe two floors would be sufficient to completely destroy the integrity of the building. No integrity and every piece falls like a stone because gravity acts on everything.