9/11 conspiracy theories

[ivan_astikov]

I’m not sure what that means, but if it were possible to remove the central core, would the “outer skin” remain standing? What if you could remove the outer structure, would that have weakened the core?

[ironbender]

@Ibanez

According to www.asce.org when it reviewed the report it did. You realize your implicating this organization with over 120 000 members as part of the conspiracy now ?

I’m not implicating anybody. Read my posts. I had a doubt about one thing, and it made me start digging. I got attacked here, so I defended myself. I don’t know what happened, nor do I calim to. There is, IMHO, compelling evidence that the offical story is BS. With every thing that has happened since 9/11, I think I must investigate more, since I have a doubt.

By the way, it only takes a small number of people to conspire. The rest are just robots, just doing their job, never questioning.

[Bryan_Ekers]

@ironbender

Yes, fire will soften steel. I never said it wouldn’t.

I understand, but I think it best not to make any assumptions and slowly proceed with clearly-described points of agreement until we find a variation.

Given that fire can soften steel, is it fair to say that several hours into a large fire, a building’s steel support members could be significantly weakened?

Free-fall speed is important because the building can’t fall through its self without encountering its main structural members. This will cause resistance, and slow the speed of the fall down. This was especially the case with the WTC; the support was bundled tightly in the middle of the buildings. The outside was a facade.

Though I’d greatly prefer to follow the slow points-of-agreement discussion described above, I admit I don’t get the significance of the fall speed. How much slower than free-fall should it have been, and assuming the speed was faster than it should have been, what does that prove or disprove?

[AndrewL]

@ivan_astikov

I’m not sure what that means, but if it were possible to remove the central core, would the “outer skin” remain standing? What if you could remove the outer structure, would that have weakened the core?

The answer is actually pretty complex. Neither the central core or the outer columns would stand on their own. The inner core is too slender to stand as a freestanding structure without bracing. If you could somehow instantly remove the rest of the structure, the central core would stand briefly, then bend or buckle and collapse. The outer skin by itself would also collapse for much the same reason. The columns would be able to stand in compression, but without lateral bracing would bend outwards and fail. The floor pans inside the tower provided this lateral bracing by connecting the core columns to the skin columns. Only when the entire structure was intact could everything stand.

You can see the result of this if you carefully watch the collapse sequence. The collapse started where the structure had been weakened by the airplane impacts and resulting fires. Much of the falling debris would have hit the floor pans of each floor. Each floor pan was really only intended to hold the weight of that floor’s contents, so would have failed instantly. As the floor pans failed the outer columns lost lateral bracing and peeled outwards (though they acted as a bit of a funnel to channel the falling debris inside the tower as they did). The central core may have remained standing for a few seconds before buckling and collapsing. It is exactly the collapse sequence you would expect from that structural design.

[ironbender]

@ivan_astikov

I’m not sure what that means, but if it were possible to remove the central core, would the “outer skin” remain standing? What if you could remove the outer structure, would that have weakened the core?

No, other way around. Remove the outer skin, aka facade, and the core will remain standing. Remove the inner core, and the outer skin would crumble to the ground. Of course, I’m not claiming that the core of the WTC would have should have stood 110 stories after the buildings were attacked.

Look, AndrewL, I’m not going to post a link. Look up Modern Marvels on the History Channel. The Sears Tower was built the same way.

[AndrewL]

@ironbender

Look, AndrewL, I’m not going to post a link. Look up Modern Marvels on the History Channel. The Sears Tower was built the same way.

That’s not how it works here. You make a claim, you back it up. Although I will point out that 5 minutes of research shows multiple sources showing that the Sears Tower is a bundled tube style structure in which much of the load is carried by the outer shell of the building, rather than being carried by a central core as you claim.

[Ibanez]

@ironbender

I’m not implicating anybody. Read my posts.

You stated office fires couldn’t do what it did, The ASCE states it did, so your just saying that they are incompetent engineers all 120 000 of them and not part of the cover up, understood. Are you a Civil Engineer by chance ?

@ironbender

By the way, it only takes a small number of people to conspire. The rest are just robots, just doing their job, never questioning.

The bigger the bang, the more people that would of had to of been involved to pull it off, nothing small about who would of had to be involved in order to pull this off.

-The Bush Administration
-The NYC Fire fighters
-The courts
-The NYC Police department
-The NYC port Authority
-All the people in the Pentagon
-The more than 1,600 widows and widowers of 9/11
-The media
-The photographers
-Popular Mechanics
-PBS Nova
-Everyone in the NIST
-NY Governor Pataki
-The NY city scrap yards
-Every Structural Engineer in the world
-Structure Magazine
-The liberals who don’t believe the towers were brought down.
-The CIA
-The FBI
-FEMA
-The American Society of Civil Engineers
-NORAD
-The FAA
-The Silverstein Group
-Silverstein’s Insurance Company
-American Airlines (Pentagon)
-United Airlines (Pentagon)
-Logan, Newark and Dulles Airport
-Scientists and engineers
-Scientists and engineers who developed the new demolition technology
-Installers of the demolitions devices
-People who worked at the company(s) the installers used as cover
-Airphone etc employees who said they got calls from passengers (Pentagon)
-Faux friends and relatives of the faux passengers or just the faux relatives who claim to have been called by their loved ones or just the psyops who fooled relatives into thinking they really were their loved ones. (Pentagon)
-People who detonated the buildings

[XT]

Debunking the free fall fallacy:

n every photo and every video, you can see columns far outpacing the collapse of the building. Not only are the columns falling faster than the building but they are also falling faster than the debris cloud which is ALSO falling faster than the building. This proves the buildings fell well below free fall speed. That is, unless the beams had a rocket pointed to the ground.

Just look at any video you like and watch the perimeter columns.

Deceptive videos stop the timer of the fall at 10:09 when only the perimeter column hits the ground and not the building itself. If you notice, the building just finishes disappearing behind the debris cloud which is still about 40 stories high.

The time required to strip off a floor, according to Frank Greening, is a maximum of about 110 milliseconds = 0.110 seconds. It is rather the conservation of momentum that slowed the collapse together with a small additional time for the destruction of each floor.

Below are calculations from a physics blogger...

When I did the calculations, what I got for a thousand feet was about nine seconds- let's see,
d = 1/2at^2
so
t = (2d/a)^1/2
a is 9.8m/s^2 (acceleration of gravity at Earth's surface, according to Wikipedia), [He gives this reference so you can double check him.]
d is 417m (height of the World Trade Center towers, same source)
so
t = (834m/9.8m/s^2)^1/2 = 9.23s
OK, so how fast was it going? Easy enough,
v = at
v = (9.8m/s^2 x 9.23s) = 90.4m/s
So in the following second, it would have fallen about another hundred meters. That's almost a quarter of the height it already fell. And we haven't even made it to eleven seconds yet; it could have fallen more than twice its height in that additional four seconds. If the top fell freely, in 13.23 seconds it would have fallen about two and one-half times as far as it actually did fall in that time. So the collapse was at much less than free-fall rates.
Let's see:
KE = 1/2mv^2
The mass of the towers was about 450 million kg, according to  this. Four sources, he has. I think that's pretty definitive. So now we can take the KE of the top floor, and divide by two- that will be the average of the top and bottom floors. Then we'll compare that to the KE of a floor in the middle, and if they're comparable, then we're good to go- take the KE of the top floor and divide by two and multiply by 110 stories. We'll also assume that the mass is evenly divided among the floors, and that they were loaded to perhaps half of their load rating of 100lbs/sqft. That would be
208ft x 208ft = 43,264sqft
50lbs/sqft * 43264sqft = 2,163,200lbs = 981,211kg
additional weight per floor. So the top floor would be
450,000,000 kg / 110 floors = 4,090,909 kg/floor
so the total mass would be
4,090,909 kg + 981,211 kg = 5,072,120 kg/floor
Now, the velocity at impact we figured above was
90.4m/s
so our
KE = (5,072,120kg x (90.4m/s)^2)/2 = 20,725,088,521J
So, divide by 2 and we get
10,362,544,260J
OK, now let's try a floor halfway up:
t = (2d/a)^1/2 = (417/9.8)^1/2 = 6.52s
v = at = 9.8*6.52 = 63.93m/s
KE = (mv^2)/2 = (5,072,120kg x (63.93m/s)^2)/2 = 10,363,863,011J
Hey, look at that! They're almost equal! That means we can just multiply that 10 billion Joules of energy by 110 floors and get the total, to a very good approximation. Let's see now, that's
110 floors * 10,362,544,260J (see, I'm being conservative, took the lower value)
= 1,139,879,868,600J
OK, now how much is 1.1 trillion joules in tons of TNT-equivalent? Let's see, now, a ton of TNT is 4,184,000,000J. So how many tons of TNT is 1,139,879,868,600J?
1,139,879,868,600J / 4,184,000,000J/t = 272t

Now, that's 272 tons of TNT, more or less; five hundred forty one-thousand-pound blockbuster bombs, more or less. That's over a quarter kiloton. We're talking about as much energy as a small nuclear weapon- and we've only calculated the kinetic energy of the falling building. We haven't added in the burning fuel, or the burning paper and cloth and wood and plastic, or the kinetic energy of impact of the plane (which, by the way, would have substantially turned to heat, and been put into the tower by the plane debris, that's another small nuclear weapon-equivalent) and we've got enough heat to melt the entire whole thing.

I think this particular aspect has only been address 5 or 6 times in the past, so it probably bears repeating. I mean, if it was one of the things that had been brought up dozens of times, that’s one thing, but only 5 or 6? It’s still practically virgin territory…

-XT

[ironbender]

@Bryan_Ekers

I understand, but I think it best not to make any assumptions and slowly proceed with clearly-described points of agreement until we find a variation.

Given that fire can soften steel, is it fair to say that several hours into a large fire, a building’s steel support members could be significantly weakened?

Though I’d greatly prefer to follow the slow points-of-agreement discussion described above, I admit I don’t get the significance of the fall speed. How much slower than free-fall should it have been, and assuming the speed was faster than it should have been, what does that prove or disprove?

Yes, I agree that it is fair to say that several hours into a large fire, a building’s steel support members could be significantly weakened. I’ll even go further and say that the building could collaspe.

We are talking about tenths of second in the case of the WTC. But they are very important tenths.

Structural engineers have things mapped out. A good number of them are saying that the speed of the WTC collaspe approached that of controlled demolitions, in which case they cut lower structural supports.

They take exception due to the fact that the WTC supposedly had no damage to its lower supports. So the speed of the fall should have been decreased due to the resistance of the intact supports.

[BlakeTyner]

@ironbender

Structural engineers have things mapped out. A good number of them are saying that the speed of the WTC collaspe approached that of controlled demolitions, in which case they cut lower structural supports.

Thus, we can conclude that they are talking out of their asses.

The speed of the collapse is an unknown. The building disappears into its own debris cloud long before the building had finished falling.

Remember, the CT’ers think the building fell at “free-fall” speed, which they quote as 9 seconds. Here’s a little video of the collapse:

Linky

At 9 seconds, the camera is pointed at the sidewalk as the person filming started running. But the camera pans back around to catch the Trade Center tower still intact to around 30 stories (we have the 22-story Marriott Hotel in frame for comparison.) By this point, we’re 11 and a half seconds into this “free fall” collapse.

This camera cuts out before the building is all the way down (as evidenced by the sound) and thus, the video switches to a sound source from the other tower, which ends at 15.28 seconds.

And, surprise surprise, that amount of time fits squarely with the NIST report. No fuzzy math needed.

ETA: Still, the point remains that nobody really knows an exact number–what we do know is that the 9-second-freefall speed number is bullshit.

[ironbender]

The first parargraph of your quote is telling. Explosives are highly suspected in the case of the WTC, no one has every deined that. The millatary has expolvise thermite.

The rest can be considered jeberish to cover it up.

[XT]

@ironbender

We are talking about tenths of second in the case of the WTC. But they are very important tenths.

One building burned for nearly an hour, the other for over an hour before they collapsed. Controlled demolitions take seconds, not nearly an hour. How do you explain this?

Structural engineers have things mapped out. A good number of them are saying that the speed of the WTC collaspe approached that of controlled demolitions, in which case they cut lower structural supports.

Prove it. Let’s see ‘a good number’ of certified structural engineers who are making this claim.

They take exception due to the fact that the WTC supposedly had no damage to its lower supports. So the speed of the fall should have been decreased due to the resistance of the intact supports.

Again, where is your proof? AFAIK, NO (as in zero) actual, certified structural engineers are making this claim or the one you made above. So, let’s see a ‘good number’ of them who are making this claim.

-XT

[AndrewL]

@ironbender

The millatary has expolvise thermite.

Thermite is not an explosive. You have yet to provide any evidence otherwise.

[Bryan_Ekers]

@ironbender

Yes, I agree that it is fair to say that several hours into a large fire, a building’s steel support members could be significantly weakened. I’ll even go further and say that the building could collaspe.

Having established that:

1. Fire can soften steel.
2. A large fire burning for several hours can soften the steel members of a building.

Then the next step, I’d guess, is to establish that a large fire was occurring in the WTC and that it lasted for several hours. We have video, and since these were office buildings, we can fairly assume a large quantity of furniture and carpeting. I’m not aware that any of these materials were specifically fireproof, so can we agree that there was a large amount of combustible material in the towers that could sustain a large fire for hours?

If agreed, my next question would be about how the fire started, and if a large spray of jet fuel would be a sufficiently potent accelerant.

We are talking about tenths of second in the case of the WTC. But they are very important tenths.

Structural engineers have things mapped out. A good number of them are saying that the speed of the WTC collaspe approached that of controlled demolitions, in which case they cut lower structural supports.

They take exception due to the fact that the WTC supposedly had no damage to its lower supports. So the speed of the fall should have been decreased due to the resistance of the intact supports.

Well, until you can establish how much the decrease should have been, we don’t really know what the significance is, do we? It’s comparable to declaring a roulette wheel imbalanced with a claim that #21 is coming up more often than it should but without establishing, for baseline comparison purposes, how often #21 should come up on a balanced wheel.

Further, what is the most precise measurement of the collapse available (seriously, I don’t know)? I understand that in laboratory studies, engineers can set up high-speed cameras and record with great fidelity what is happening in a stress test, but do we have any recordings precise to 0.1 seconds of the WTC collapses? How accurate is the timing on a commercial video camera?

[XT]

@ironbender

The millatary has expolvise thermite.

There is no such thing as ‘expolvise (sic) thermite’. Thermite isn’t an explosive, it uses a chemical reaction to burn through a material. Even the mythic ‘nanothermite’ is just thermite with the oxidizer more tightly incorporated into nano sized particles in order to make the chemical reaction less chaotic and more predictable.

-XT

[ironbender]

xtisme, the engineer in the video I linked to has credentials. Watch the first video. In addition to him, there are at least 15,000 more on their on web site.

AndrewL, I know that normal thermite, as shown in the video, is not explosive. I will give you video proof that the miltary not only has explosive thermite, but they can also apply it like paint with a roller.

[AndrewL]

@ironbender

AndrewL, I know that normal thermite, as shown in the video, is not explosive. I will give you video proof that the miltary not only has explosive thermite, but they can also apply it like paint with a roller.

Please do. I would love to see this magical substance in action.

[Mr.Miskatonic]

@ironbender

Structural engineers have things mapped out. A good number of them are saying that the speed of the WTC collaspe approached that of controlled demolitions, in which case they cut lower structural supports.

They take exception due to the fact that the WTC supposedly had no damage to its lower supports. So the speed of the fall should have been decreased due to the resistance of the intact supports.

Really? Who? Where are the exact quotes and what are these Structural Engineer’s experience with tall buildings?

[ironbender]

@Bryan_Ekers

Having established that:

1. Fire can soften steel.
2. A large fire burning for several hours can soften the steel members of a building.

Then the next step, I’d guess, is to establish that a large fire was occurring in the WTC and that it lasted for several hours. We have video, and since these were office buildings, we can fairly assume a large quantity of furniture and carpeting. I’m not aware that any of these materials were specifically fireproof, so can we agree that there was a large amount of combustible material in the towers that could sustain a large fire for hours?

If agreed, my next question would be about how the fire started, and if a large spray of jet fuel would be a sufficiently potent accelerant.

Well, until you can establish how much the decrease should have been, we don’t really know what the significance is, do we? It’s comparable to declaring a roulette wheel imbalanced with a claim that #21 is coming up more often than it should but without establishing, for baseline comparison purposes, how often #21 should come up on a balanced wheel.

Further, what is the most precise measurement of the collapse available (seriously, I don’t know)? I understand that in laboratory studies, engineers can set up high-speed cameras and record with great fidelity what is happening in a stress test, but do we have any recordings precise to 0.1 seconds of the WTC collapses? How accurate is the timing on a commercial video camera?

I’d submit that that the quality of the cameras pointed at the WTC were just as good as any a demolition company would use.

Fine, I’ll be back with cites, and I’d give you a baseline to compare and contrast with, including seismographs. I’ll compare 2001 tech to 2001 tech.

[Mr.Miskatonic]

I am seeing a lot of claims. I am not seeing a whole lot or real evidence.