quote:

WTC 7 collapsed mainly at the bottom. This could have been achieved either by disconnecting all supports throughout the building simultaneously or by a series running up the building. The effect would have been similar. There was a bit of collapse at the very top also, suggesting a slightly earlier charge there.

It is clear that the center of the building went first. Only then did the left and right sides collapse, unable to support the extra load. "disconnecting all supports throughout the building simultaneously or by a series running up the building" would have resulted in a level collapse. "The effect would have been similar." I agree.

quote:

WTC 7 collapsed mainly at the bottom. This could have been achieved either by disconnecting all supports throughout the building simultaneously or by a series running up the building. The effect would have been similar. There was a bit of collapse at the very top also, suggesting a slightly earlier charge there.

Ok so we all agree that building suffered from a central structural failure caused by something, either fire or explosives. Which one we will probably never know.


Food for thought. Did the CIA have any offices there, covert or otherwise? Could there have been explosives set years ago as a contingency. It seems to the the most plausible of the conspiracy theories, all things considered.

I don't think we'll ever know.

I must agree with txChris. The sum of the potential energy cannot be calculated merely by the weight and height of the building, you must take into account all of the potential energy stored in the individual components during construction in ADDITION to their height and weight.

The politics of destruction are very scary.

My theory:

During the first world trade center bombing investigation, while the workers were out of the building, the charges were planted by the Clinton Admin. which were actually triggered by the Bush administration immediately following the disaster we were all witness to and thereby creating the need to go off to war. The people that were tried and convicted were probably actually innocent?

Bin laden and his helpers just took too long to try again, otherwise we would all hate Clinton now for starting this unjust war. In all actuality Bin Laden may not have been involved at all?

Both parties were involved fully and neither is clean. Our system of government is bad. Very, Very, Bad.

Yes, there were CIA offices in that building. Now here is a conspiracy theory I can get behind. Would the CIA want sensitive doccuments blowing around for anyone to see? I think not. Perhaps explosives and or incindiary devices were installed long ago as sort of a self-destruct measure in case anything ever happened.
This does not however lend itself to the idea that the whole 9-11 was a conspiracy.

quote:

This does not however lend itself to the idea that the whole 9-11 was a conspiracy.

Well, then your theory cannot possibly work. If this 9-11 thing was not a conspiracy, then, some of us would have no reason to continue in this life. Without conspiracy politics is useless. Without conspiracy business is futile. Without conspiracy hollywood has nothing to complain about and therefore the product - movies - would be boring and would not generate enough revenue to be worthwhile. The Oliver Stones, Michael Moores, Stuart Smalleys, and Jeanine Garafalos {sp?} of this world would have absolutely nothing to spew forth and this would be a very boring world to live in.

There must be conspiracy.

Long live conspiracy!!!!

There are many conspiracies. Everything is not a conspiracy.

A couple nights ago, someone dug through my trash. I suspect that since I began posting on this thread, the IBMAAUKBAC (International But Mostly Austrailia And UK Bureau Of American Conspiracies) has found out that I posess knowledge that can disprove their theory about 9-11. They must be hoping that I have thrown out some of my notes on the matter and they can recover them and use them against me. Yah I know that there was food in the garbage and the neighbors dog had it all over his face but that's what they want me to think. How can I beleive that a dog, having no opposable thumbs was able to remove the lid to the trash can simply by knocking it over. There would not be enough potential energy in an upright garbage can for the lid to be ejected from the can just from the fall alone. The real bandits obviously used a knife made of dog teeth to tear open the trash bag once they removed the lid. Then, they took the food and smeared it all over the poor dog's face.

All joking aside, that would be a pretty good movie. More of a comedy though.


Before I get blasted, I do not mean any offense here. I am simply trying to lighten the mood with a little humor.

quote:

The column explodes like a bomb sending dust flying as the rebar uncoils with terrifying force.

I'd like to clear up a couple of points here.

First.
The steel re-enforcing in a vertical concrete column isn't under compression or tension. It is placed in the column shuttering and the concrete is poured around it. when the concrete sets the whole strength of the column is due to the concretes strengh in compression. The re-enforcing is there to prevent catastrophic failure if something should apply undue forces to the column in any direction except straight down (as in earthquakes) and to enable the various horizontal parts to be tied to the verticals.
A long time ago I was in the area then a 60 foot long concrete re-enforced bridge span was being loaded onto a truck. Much to everyones dismay, it rolled off. When it hit the ground it broke in the middle. No drama, simply cracked right across. There as a very small gap between these two halves, so the pre-tension on the steel re-enforcing only stretched the steel by millimetres at the most.

Also, if you ever watch demolition people smashing up concrete structures with a ball or with hydraulic jack hammers you will notice that the re-enforceing doesn't fly apart like a spring. The analogy of a clock spring doesn't apply as the re-enforcing actually helps to hold the concrete together even as the applied forces try to force it apart.
regards
dva

quote:

Perhaps the fans of conspiracy theories can explain why those people who would benefit the most from exposing the 'truth' have not given conspiracy theories any credibility.

Maybe it's a case of people who live in glass house not wanting to throw stones.

Or even 'let he who is without guilt throw the first stone', which adds up to the same thing.

Government denial even operates at a local level. That much I can say from experience.
regards
dva

Notwithstanding Dva, we are talking about a lot more force being exerted than a 5 foot drop or a jackhammer. Even with my example before with the pencil sized reinforced concrete, using a needle sized jackhammer, one could chip away at the concrete without total failure. A jackhammer applies a very small amount of force. It is simply concentrated in a very small area. The force is not applied to the reinforcement therefore it has no affect on the rest of the concrete. As for the fall from the truck bed, I imagine this span fell on a flat surface since it fell from a truck which was likely on some type of dirt or gravel roadway. The re-inforcement must not have been stressed much as if it had, there would have been crumbling of the entire structure.


Re:
"The re-enforcing is there to prevent catastrophic failure if something should apply undue forces to the column in any direction except straight down (as in earthquakes) and to enable the various horizontal parts to be tied to the verticals."

The re-inforcing serves to increase the amount of force needed to break the colomn by tying the whole structure together thus allowing other parts of the structure to lend strength to the area that is being exerted upon. When this new higher level of force is reached, it does cause failure at the point of most pressure first but under most circumstances this force continues through the structure. After the first instance of failure, the entire structure is weakened considerably. If the force is allowed to continue, crumbling will result. In most cases, the force cannot be stopped because it is already at a strength capable of breaking the uncompromised structure, not to mention the newly weakened one. In the case of the span falling off of the truck, the force was stopped within microseconds and milimeters of the time and place it began. The force was strong enough to crack the concrete but it was of insufficient strength and duration to continue through the span and have a significant effect on the re-inforcement.

I remember when I was a kid, we would take an empty soda can and carefully stand on top of it. If you were careful enough, you could stand on it without it crushing. Then someone else would lightly thump the side of the can and the can would instantly be crushed. This illustrates my earlier point about potential energy and activation energy.

quote:

Maybe it's a case of people who live in glass house not wanting to throw stones.

Or even 'let he who is without guilt throw the first stone', which adds up to the same thing.

Government denial even operates at a local level. That much I can say from experience.

This is a good point, but all of them?

The New York Times invented the glass house and has lived in it for a long time. They have never been shy about throwing stones. And to explore this metaphor further, they usually pull the stones from their own foundation. Have they ever given credit to the theory?

Weeks before 9-11 the towers had various 'power downs', whole sections were without electricity (security cameras, etc.) or public access. There were elevators taken out of service for the use of 'maintenance personnel' - there was access to place explosives during that time.

The fires were not all that hot. There is a recorded call from the South Tower by the Firechief in charge of fighting the fire. He states on the tape that there were only two small areas left. He requested another couple of hoses to knock those fires out. There is no urgency in his voice, everything appears under control - shortly after, and before the smoke stopped from those last two fires, the destruction of the South Tower began.

If you look at close-ups of the gash in the South Tower caused by the aircraft, you will see people standing there looking out of the hole. They are not on fire, they are not jumping, they are just looking out the hole. The heat required to soften that much structural steel (and the conduction of the heat through the steel away from such a heat source) would be much more than is required to cause a person to collapse from heat.

And instead of sitting at a keyboard and theorising about softening steel or explosives, you can actually listen to people who were there at the time discuss it -

Firemen

quote:

Weeks before 9-11 the towers had various 'power downs', whole sections were without electricity (security cameras, etc.) or public access.

I'm sorry but power downs are not uncommon. Transformers do get replaced as do switch gears and other electrical items from time to time, I have worked enough of them to know.

Furthermore, Security Systems do have batteries as a backup power supply.

Not a very plausible theory that explosives are placed while construction is taking place and live security is heightened. Give Me a Break.

A slight clarification,

The reinforcement I am referring is known as "Spiral Containment" It keeps the concrete in the column from bulging outward under strain.

Containment Failure
Here is a look at a failure.

Now, it's really a moot point as I seem to recall that much of the building was steel girder construction anyway. But it demonstrates how chunks of rebar etc may be thrown.

Here is another example of what we Aussies are dealing with in this 'terror war'

Terror card

Terry, everyone here agrees that it looked like a controlled demolition. Even the firemen. That video is evidence of nothing.


"And instead of sitting at a keyboard and theorising about softening steel or explosives, you can actually listen to people who were there at the time discuss it -"

Are you suggesting that we not form our own theories? That we should let someone tell us what to beleive without thinking it through? These men stated what they thought it looked like. They were in no way advocating your position.

All fire is hot enough to weaken steel. It is just a question of duration. I suspect that fire cheif was referring to the two small fires left on that floor, I haven't heard the tape. There is a tremendous amount of smoke and there are still visible flames at the start of the collapse. Even if the fire was completely out at that point, the damage was done. The collapse was eminent.

Be nice.

branw, you asked for a specific reference to the energy calculations involved in falling, pulverizing and expanding the material in the towers. Here is one.
This is a long paper. Go to the bottom for a summary of the results. I think this may overestimate the amount of energy required because the volume of the dust cloud is taken after it has swirled up and kinetic energy from the material striking the ground has become available. That is why I concentrate on the early part of the fall where no kinetic energy can be released. Even here the expansion is large suggesting that extra energy has been added.

Several places in this thread have suggested that the buildings were supported by concrete. This is not the case. The concrete was only in the floor.

I know that I am going to regret this. This may seem like an ignorant question, and I tried unsuccessfully to ignore this, but what does any of this have to do with "Biodiesel Politics"?

Neutral, I have skimmed through the paper and I have a few questions. I realize it would be very difficult to accurately measure everything involved ie the dust cloud volume, but this is pretty important. He makes very ambiguous estimations in his calculation of this. There are many gramatical errors throughout the paper (not that my posts don't have any) which seems amateur. Why not have someone proof read it before releasing it? His conclusion is that the extra energy required is the equivalent to 10 times that of the potential of the building. This would mean that the explosives used produced the same amount of energy as if you were to drop a weight weighing the same as 9 WTC towers on top of the tower. A bit overkill don't you think? As I have pointed out earlier, it requires so much less to reach the activation energy. Why use so much explosives and risk getting caught? I think it may be more likely that his calculations are wrong. If I pour a pitcher of flour on the kitchen floor, it's going to be everywhere. There will be a quite large dust cloud. If the only energy is potential then as soon as the flour got to the floor it should stay there. That is not what happens though. There is something here we are missing. There are many avenues to explore for the explanation. Entropy and heat death of the universe for example. Think about this, a gas will expand to fill whatever container it is in due to intermolecular oposing forces. Without the addition of any energy. This is called equalibrium. It happens automatically. Has anyone done an analysis on the role of static electricity charges and oposing forces between dust particles?

It appears that I will no longer have the time to post so regularly. I will check in once in a while though.