Loose Change

[WildCat]

After reviewing the paper once more, three things are clear:

1. Dr. Greening uses seismic data to determine the approximate collapse times.

2. Dr. Greening assumes the energy of each collapse is being applied to one or two floors.

3. #2 is a huge mistake, because #1 proves the energy was being transmitted to the ground.

So the search for a workable theory explaining the collapse time without explosives continues...

Hold on for a minute: You claimed not to understand the math, but yet you're able to find fault in it?

And isn't the final collapse a collision w/ the ground? I really don't see your objection here, nor your expectation of a slow-motion collapse.

 

[aggle-rithm]

But I am going to hazard an uneducated guess and call it a $hitload of energy.



After reviewing the paper once more, three things are clear:

1. Dr. Greening uses seismic data to determine the approximate collapse times.

2. Dr. Greening assumes the energy of each collapse is being applied to one or two floors.

3. #2 is a huge mistake, because #1 proves the energy was being transmitted to the ground.

So the search for a workable theory explaining the collapse time without explosives continues...

After reveiwing your post, three things are clear:

1. You're not very good at math.
2. You're not very good at reaching rational conclusions even when the math is done for you.
3. No amount of evidence will ever change your mind.

 

[bunker]

Much more detailed simulations have been done, but they would take both you and me several years of study to fully understand. This study is a simplified version a layman can understand. If you want to go more in depth, read some of the links others have provided in this thread (especially the NIST links,) e-mail genuine experts (structural engineers would be a good place to start,) and start crunching some numbers yourself!

Here is the sum total of NIST's contribution to the free fall problem, which they apparently only included to respond to criticism of the preliminary draft:

9.3.3 Events Following Collapse Initiation

Failure of the south wall in WTC 1 and east wall in WTC 2 caused the portion of the building above to tilt in the direction of the failed wall. The tilting was accompanied by a downward movement. The story immediately below the stories in which the columns failed was not able to arrest this initial movement as evidenced by videos from several vantage points.

The structure below the level of collapse initiation offered minimal resistance to the falling mass at and above the impact zone. The potential energy released by the downward movement of the large building mass far exceeded the capacity of the intact structure below to absorb that through energy of deformation.

Since the stories below the level of collapse initiation provided little resistance to the tremendous energy released by the falling building mass, the building section above came down essentially in free fall, as seen in videos. As the stories below sequentially failed, the falling mass increased, further increasing the demand on the floors below which were unable to arrest the moving mass.

The falling mass of the building compressed the air ahead of it, much like the action of a piston, forcing material, such as smoke and debris, out the windows as seen in several videos.

NIST found no corroborating evidence for alternative hypotheses suggesting that the WTC towers were brought down by controlled demolition using explosives planted prior to September 11, 2001. NIST also did not find any evidence that missiles were fired at or hit the towers. Instead, photographs and videos from several angles clearly showed that the collapse initiated at the fire and impact floors and that the collapse progressed from the initiating floors downward, until the dust clouds obscured the view.

So, after hundreds of pages of dissection to explain the collapse initiation, they offer not one number to explain the free fall. Case closed?

 

[WildCat]

Here is the sum total of NIST's contribution to the free fall problem, which they apparently only included to respond to criticism of the preliminary draft:

It's the Cliff Notes version for the mantally impaired.

So, after hundreds of pages of dissection to explain the collapse initiation, they offer not one number to explain the free fall. Case closed?

 

[bunker]

Hold on for a minute: You claimed not to understand the math, but yet you're able to find fault in it?

And isn't the final collapse a collision w/ the ground? I really don't see your objection here, nor your expectation of a slow-motion collapse.

You need to read the paper. Dr. Greening clearly uses seismic data to determine both the start and the end of each collapse. This proves that the falling mass is, in fact, literally impacting the entire support structure through the foundation, NOT just one floor.

His math is fine as far as I can tell, but he completely ignores the above fact in his calculations. And that is where I find fault.

 

[bunker]

It's the Cliff Notes version for the mantally impaired.

Sticks and stones...

 

[bob_kark]

Changed my mind, I'm going to leave it alone.

 

[WildCat]

You need to read the paper. Dr. Greening clearly uses seismic data to determine both the start and the end of each collapse. This proves that the falling mass is, in fact, literally impacting the entire support structure through the foundation, NOT just one floor.

His math is fine as far as I can tell, but he completely ignores the above fact in his calculations. And that is where I find fault.

It is accounted for:

Having made these adjustments to the timelines of the 911 seismic data we are able to conclude that the small ripples in the traces of the WTC collapse events - ripples that precede the period of large oscillations - represent the first stage of collapse as defined more precisely below. The seismic signal for this first stage is small, as would be expected, since kinetic energy is being transmitted to the ground only through the steel support structure. Furthermore, a significant fraction of this kinetic energy is being absorbed as the energy needed to buckle and crush the structural elements of the buildings. The major seismic signal of each collapse is generated by the ground impact of falling debris, and constitutes what we will call a second stage of collapse. Given the above considerations and a careful evaluation of the seismic data, it is estimated that the first stage of collapse took 11.3 +/- 1.5 seconds for each WTC tower. We will show in the following Section that the second stage of collapse added 1 – 2 seconds to the total collapse times.

 

[bunker]

This proves that the falling mass is, in fact, literally impacting the entire support structure through the foundation, NOT just one floor.

I should clarify: The existence of the seismic data proves this, not Dr. Greening's use of it.

I'll put it this way, much like every single particle in the universe was acting on those buildings, every single support in the structure was absorbing each impact. Saying a 14 story structure can crush a 96 story structure is like saying one bus can crush seven others stacked on top of each other when dropped from a few meters above.

 

[bunker]

It is accounted for:

He acknowledges the fact that the energy is being transmitted through the whole building. He doesn't think this should have any effect on the building's ability to withstand the collapsing floors.

 

[WildCat]

He acknowledges the fact that the energy is being transmitted through the whole building. He doesn't think this should have any effect on the building's ability to withstand the collapsing floors.

Why should it? When a train goes by the ground shakes, I doubt this slows the train down by any significant amount.

 

[bunker]

Why should it? When a train goes by the ground shakes, I doubt this slows the train down by any significant amount.

Ah yes, but when one train impacts another, it is impacting the entire train, not just one car.

 

[WildCat]

Ah yes, but when one train impacts another, it is impacting the entire train, not just one car.

You miss the point, the energy transmitted through the columns as vibrations is minimal compared to energy of the floors impacting. Intuition tells me this would be related to the square footage of the supporting columns compared to the square footage of each floor (for example, if the the column was 2'x2' and supported 400 sq. ft. of floor, only 1% of the force would be transmitted through the column), but I could be (and probably am!) waaaay off on that.

I'm not knowledgable in this subject, maybe someone else here can do the math.

 

[TjW]

We may have to agree to disagree, but this looks like a significant amount of material to me.

Shots of North Tower:

Did you read the appendix, where the calculated distance vs time from the model are compared with observations from multiple camera angles?
It's a very nice match.
The model does not take into account every possible variable, but that level of match pretty much rejects the idea that demo charges would be necessary for the towers to fall that fast.

 

[delphi_ote]

I'm sorry, I didn't mean to upset you. I was genuinely asking your opinion.

I'm not upset. I was just trying to be funny. Please don't worry!

And I've been addressing my questions to you because you seem like the most intelligent person here.

I appreciate your compliment, but that is certainly not true. I'm just willing to spent a lot of time going back over my freshman college physics (1999... I can't believe it's been over 6 years!) You are capable of the same. All of the homework I'm about to do to answer one of your questions you could've very easily done yourself.

Dr. Greening's explanation is deficient.

As I said before, the analysis is a simplification. It's necessary to simplify. If we factor in too many details, we won't be able to work all the math!

All that's left to do is calculate how much energy it takes to cause a 2.x earthquake, and then we will know how much energy he left out of his calculations. Don't worry, I'm not going to ask you to do that. But I am going to hazard an uneducated guess and call it a $hitload of energy.

This seems like an interesting thing to try to calculate. According to Wikipedia entry, we're dealing with roughly 1 metric ton of TNT, which is equal to 4.184 × 10^9 J according to the Wikipedia. There was certainly enough energy in the collapse to cover that.

On the other hand, if none of the energy was disappated (i.e. if the mass of the two towers fell in free fall) 20^12 J. would have been two kilotons (the energy of a small nuclear weapon!) and registered a 4.0! Clearly that hypothesis is not correct.

So the search for a workable theory explaining the collapse time without explosives continues...

No workable theory explaining the destruction WITH explosives has been presented at all.

 

[Euromutt]

ETA: Or even dirty bombs. With the power the cabal would supposedly have, obtaining some depleted uranium or some old fuel rods wouldn't be that difficult. Imagine 10 hospitals in New York all hit with dirty bombs at the same time.

I doubt DU is radioactive enough for a dirty bomb; it's actually used as a liner to transport more radioactive materials, like strontium, cesium and cobalt. The latter are used for medical applications such as radiotherapy, and the resulting waste might be better suited for dirty bomb-making purposes, as well as being more easy to get hold of without leaving indications of DoE or NRC involvement in the plot.

 

[rwguinn]

<<<Snip to the important bit>>


No workable theory explaining the destruction WITH explosives has been presented at all.

The "objective analysts" who use seismic data to determine the fall spped have forgotten one big item:
The explosives would have registered on a seismograph. So where are the signatures?
1 stick of dynamite will register. That's how they used to find oil-bearing formations. A geophone in one spot, dynamite a couple of miles or more off. Now, they just drop big weights.

 

[emperorchaos]

Well, I was away for a few days and missed out a bit. But I read what I had missed on this thread and I also headed over to the Loose Change forum and read what's been going on there. I won't register or post there myself because I don't want the government to know that I know what's really going on (yeah, I think I might make up my own conspiracy theory).

All I know is that this is really getting nowhere. I'm fairly certain that most of us here at JREF would be more than willing to change our minds should someone provide actual evidence of a conspiracy, but as that is not likely to happen and as it looks like nothing will change the mind of Alek or anyone like him, is it all really necessary?

By the way, reading the Loose Change forum, I noticed that I at least agree with Alek on something. That being the ridiculousness of the two party system of the US.

That was a lot of reading to catch up on. My eyes hurt now. Time for something easier. A movie perhaps. I'm going to see "V for Vendetta". Yeah, that's the ticket.

 

[DevilsAdvocate]

Wow! 21 pages. Thierry Meyssan sure got his money's worth on this one. Want to "fight the man" and disparage government? Easy.

1) Find a catastrophe.
2) Blame it on the government.
3) If you really need to, find or create any little inconsistencies in any thing in any way and call it a conspiracy.
4) Hope people concentrate on the disparagement of government by associating it with the tiny details.
5) Raise and argue the tiny details endlessly.

Expected results:

1) People will distrust government (or at least be suspicious of government).
2) People will believe government officials secretly kill people to avoid distrust of government.
3) People will hate government.
4) People will overthrow government.
5) People will live free.

Come on. There is not even an established alternative theory for the 9/11 attacks. The best that is available is: maybe it wasn't terrorists, maybe was the goernment, but we don't know how or why. This is what Thierry Meyssan promoted.

Before even tiny detail of the "official story" has to be justified, the conspiracy theorists should at least provide a "conspiracy story" that is more probable.

In summary: this is stupid.

 

[Graham S1]

3) There were some military training exercises carried out (as well as a DOJ exercise and a response to some Russian bomber movements) on 9/11.

Is that generally agreed on, on this forum?