I don't happen to believe that the discussion of how hammers and eggs interact has much relevance, nor the behaviour of a yardstick nailed to a pair of desks with force exerted on it. Yes it will cause the desks to pull towards eachother - is that relevant to a discussion of what a skyscraper would do? Do we know what else was supporting it / the load-bearing properties of all the materials involved and the structure / the actual loads involved? No. So idle remarks about sticks and desks are (no special offence intended to the original poster) - for the purpose of this discussion - utterly ****ing useless.
Maybe it's good enough for you though. It seems very simple explanations are generally appealing to you.
people have debunked them with facts. The problem is, you call your theories facts while others call the rebuttal fact. How can that work? You'll never reach an agreement that way because you are equally unable to accept facts. But you don't call them facts. just like people don't call your theories facts....
Regarding the hammer and the egg, I'm simply (over-simply, I think, but I remember this shit from school) trying to explain impact forces. The towers fell vertically onto themselves, so you have essentially 1/3 of a building falling on 2/3 of a building, and 1/4 of a building dropping onto 3/4 of a building.
20 tonnes exerts a force of 20 tonnes, obviously. However, drop it at a rate of ~2kph and its effective weight is ~40 tonnes (as far as anything underneath it is concerned). Drop it at 10kph and you're effectively exerting 200 tonnes of force on something using only 20 tonnes. This is why I think the towers collapsed. They were designed to withstand the impact of jet airliners hitting them, and they did that. The burning furnace effect was unforseen, I think, and the resulting drop-hammer effect of the collapse was unforeseen as well. I'm just not convinced there's anything more to it than that.
You talk a lot about science, the scientific theory, and the ignorance of others but never actually make any concrete claims in your own words. It seems strange that you cannot believe that a 300 ton plane is unable to destroy a steel structure building and that two 110 level buildings falling would not destroy every building in the immediate area. Remember that as the buildings fell, they released unfathomable amounts of energy, enough to heat the steel even more than it was already heated by the jet fuel. It is similar to rapidly bending a paper clip times billions for every inch of metal that was also rapidly bent. I bet that could create the type of heat evident.
None of the steel actually melted, it softened with the heat. The paper clip will eventually break if you bend it enough.
I personally observed the other day that if I'm pissed while tugging on giant Jenga blocks the tower will usually fall over (this is similar to a plane strike on a skyscraper in lots of ways) but it always falls over sideways - never into its own footprint. Thus, a plane strike on a skyscraper should've made it fall over sideways, which is how I know for sure that the world trade centre was actually destroyed by a large force from above. Probably a second, invisible, skyscraper that materialised on top of it at precisely the wrong moment.
Like I said in my first post, I don't really have a "take" as such. Just a bunch of questions which I don't expect to be answered, skepticism regarding the official story/stories and some deep suspicion of Bush & Co's actions, immediately following the attacks & leading up to right now. Naturally, when there's a vaccuum, people speculate and gravitate towards things to make sense to them. Some people think the official story is true, some think the opposite is true - I just see a big gaping hole waiting for an answer to fill it.
I don't believe satisfactory answers will come any time soon - it took 40 years for people to learn the truth of the Gulf of Tonkin fabrication, which the US used to commence hostilities in Vietnam.
To me, the biggest conspiracy theory surrounding 9/11 is the one that blamed it on Iraq & Afghanistan, has cost countless lives and made people like Dick Vader Cheney & various US mercenary contractors (there are as many mercenaries in Iraq as there are regular troops) incredibly wealthy.
Interestingly enough, the very first WTC attack (a massive truck bomb in the underground carpark in 1998) was intended to do exactly what you said: weaken the foundations of one building, toppling it sideways onto its neighbour.
I would imagine that the top storys of the tower had too much inertia to want to fall off to the side. At the time of collapse, no force was pushing laterally on the building, but a huge force was acting downwards (the entire weight of the top storys on the weakened steel support below) This is also why it is impossibe to recreate the collapse in a small scale. When you tug on a jenga block, you apply frictional force to pull the tower laterally.
Al-qaeda blamed itself for 9/11. But I'm sure the U.S. is friendly enough with them to persuade them to incriminate themselves....
Anyway I've refuted your theories with physics. Satisfied?
You, my friend, are an idiot. I will try to explain this to you, so that you understand what we are pointing out, but I have very little faith that you will actually understand:
Uhmm - if you can't understand what he was trying to demonstrate, well I really can't help you there. The point was that the lower portion of the building was easily capable of supporting the weight of the upper portion at rest. However, it was no match for the combined momentum/inertia of the upper half as it started to fall.
First off, you have no idea how much I know about anything, so let's not jump to conclusions. I happen to know quite a bit about the construction of the WTC. Part of this is due to the fact that my dad knew the chief designer of the project. He knows them because my grandfather was an architect. He designed the Colosseum in new york that was recently knocked down. It was chosen to be Madison Square Garden, but at the last minute, the deal went to another contractor for reasons I don't quite remember. He was, however, the first architect to use sound-absorbing tiles, and air curtains in a building. Nothing fantastic, but definitely innovative. He also designed many other things, such as many Macy's buildings and other department stores. My grandmother designed the interiors of these buildings and also worked on the electrical schematics of the USS Missouri battleship. So, yes, my family actually does have quite a bit of engineering background.
However, the majority of my knowledge comes from the History Channel, as well as a decent amount of online research regarding this topic, as I was very interested in the design of the towers and why they collapsed following the attack.
Let me describe, in a bit more detail, the construction of the North and South Towers, so that you may understand what I am trying to explain. The towers were designed to provide the maximum amount of open space on each floor as possible. Up until then, all large buildings needed a multitude of internal support pillars in order to distribute the weight of the building in a feasible manner. If you've ever been in a tall building, particularly an older one, you'll notice that the usable space inside is actually fairly small. This makes the building terribly inefficient, not only space-wise, but in terms of the actual interaction between the people who work inside them.
The WTC designers solved this problem using the innovative design that not only freed up interior space, but is most likely the reason they were able to withstand the impacts they were subjected to on 9/11. To create space on each floor, the designers decided to focus the majority of the support structure at the center and at the exterior of the building. The resulting design consisted of a concrete central core (housing stairs/elevators/etc...) and an exterior skeleton to transfer the load. This design (of primarily steel - as opposed to heavy masonry) was lightweight and created what is (was) one of the most redundant structures in the world.
The central core actually supported most of the weight of the building. The outer skeleton transferred the loads of the supported floors UP, to the top of the structure, where a massive series of trusses transferred the weight to the central core. In other words, the building was "hung" on the center core. This design was very redundant mainly because the vertical support columns that made up the interior were very close together. This meant that if one or two of them were damaged, the load could be transferred to adjacent columns and up to the top.
The floors of the building were supported on trusses (I assume you know what those are) stretching from the central core to each vertical support column on the outer skin. These served two purposes. First, as stated, was to support the floor, but second - and crucial to understanding why the towers collapsed - they held the outer skin to the building. If you take a sheet of paper and try to stand it on it's edge, it will flex and flop and fall over. The same goes for this external support structure. The trusses supporting each floor also served to hold the skin against the building.
Each truss was attached by a series of bolts. It actually was not that complex of a setup. This is where my ruler analogy comes in. One desk is the central core, the other is the external skeleton. The ruler, nailed to both desks, will support a given load, and also keep the desks at a specific distance. When the heat from the fire warped these trusses, the bolts, which had been designed ONLY to support a vertical load, were over-stressed and snapped. One by one the trusses started to fall. When enough trusses collapsed, the outer support structure buckled as it was no longer held in place. When this happened, all the floors above suddenly lost their support and collapsed. The floors underneath also lost a significant amount of support, which is part of the reason why the building collapsed so quickly once this happened.
If you have any doubts about anything I described, feel free to look it up, but don't jump to conclusions that just because you are not an engineer, that no one on this forum has any background on the topic.
I agree with you. In fact, I find that, generally, the amount of swear words and personal attacks in a post is directly proportional to the stupidity of the person posting. However, I simply cannot believe that you are that narrow minded that you don't have the ability to understand simple, and extremely relevant analogies, so I couldn't resist a little. I promise there are no other derogatory remarks in the rest of the post
So presumably the plane strike took out the central concrete column on the floors it damaged? And the force of the concrete column section that was still intact on the floors above - when the trusses gave way and it began to fall - was enough to crush the intact concrete column on the floors below to dust? All the way to the ground?
And - despite there only being one central support that was made from anything other than steel trusses - you believe it would be normal for the whole structure to fall perfectly vertically for 400 metres? Is it not likely that throughout that drop - if it wasn't a controlled demolition - there would have been some sort of deviance created by resistance encountered on the way down that would've pushed the falling mass in some direction other than straight down?
Anyway I'm glad we're now talking in terms of skyscrapers and not piddly little examples that bear no relevance at all. Although I see Sam is now concerned with melting nails by pulling them out of planks...
I don't know. However, there are other factors to consider. First, I can definitely see a decent portion of the central core underneath being pulverized not only by some of what was left of the core, but by 20 floors worth of also solid concrete floors. there would also have been significant lateral stresses imparted on the core further down as the outer skin peeled away - before the bolts failed. Also consider that there is the possibility that the impact did damage the core much farther down. The building was reported to have swayed something like 10 feet if I recall. There are people who recall windows being shattered from the stress, and seeing cracks in the drywall. It is likely the core was not at 100% strength for at least part of the way down.
Well, first off, if you look at the video, it is fairly evident that the portion of the tower that did collapse is still a VERY heavy piece of building, and it's very unlikely that anything that big and heavy is going to be pushed very far off course. Also, you have to consider that the only significant resistance to this falling motion would have been the VERTICAL core, as the floors surrounding it would not offer much resistance. If anything - the core would have likely punched a hole through the falling portion, rather than shove it in another direction. The majority of the building was turned to jelly when the top part initially broke free, so it offered much less resistance than it would have offered, were the support structure not completely destroyed. I cannot back this argument up with fact, but, in MY OPINION, it really just doesn't look like there was much of anything that would have caused the building to fall at an angle.
The WTC was designed to take the impact of an airliner, the plane's both hit fairly high up the buildings. For a building to collapse in free fall, ie at the speed that equals zero resistance, something removed the resistance of everything below the aircraft strike. For a better explaination I suggest you read the report by Professor Steven Jones ( http://www.journalof911studies ... ngsCompletelyCollapse.pdf) as being a physics professor his knowledge regarding the impossability of what is alledged to have happened is far greater than mine.
It has also been mentioned in this thread before, but I'll say it again, Building 7 was NOT hit by any debris, the best reason for it falling was given by the building owner, Larry Silverstien when he said it had to be pulled !!
"I remember getting a call from the, er, fire department commander, telling me that they were not sure they were gonna be able to contain the fire, and I said, 'We've had such terrible loss of life, maybe the smartest thing to do is pull it.' And they made that decision to pull and we watched the building collapse."
Which is in itself interesting if only with regards to when were the explosives placed in Building 7?
That last statement is one of the major smoking gun points regarding the whole event. For some bizzare reason people seem to repeatedly overlook this statement whenever Building 7 is discussed.
Also remember that the 911 Commission specificly DID NOT LOOK AT BUILDING 7. Coincidence, ?? of course - ROFL !!!!!
I actually think I'm not narrow-minded enough - then I'd be comfortable with whatever people told me, and I'd be able to get some sodding sleep at night FTR I read the whole thing, very interesting. Also FTR, I'm still not satisfied that two jetliner impacts and fast-burning methanol fires managed to turn a billion tons of concrete and steel - engineering to withstand exactly such things - to dust in mere seconds. I'm no structural engineer or even the son of a structural engineer, but I am the son of a scientist and I know enough about physics to be skeptical of this virtually no-resistance free-fall theory. That doesn't mean I have an alternate theory though - sometimes you have to have the balls to say "I just don't know, so I refuse go out on a limb and speculate". And I still remain suspicious of the decision to remove and destroy all the evidence from the crime scene. CSI's Grissom would be appalled.
Also, FTR, it wasn't me who professed problems with the analogies on offer.
Obviously they add nothing to the ongoing argument, but pics 4 and 5 really put into perspective what this is all about
One question about the fall of the towers. If it was a controlled demolition, then it could only have been a top down job. Every other one i've seen has been from the bottom up. If it was a top down job, then synchronising every level to blow at exactly the right time must have called for one hell of an experienced demolitions expert. And as far as i'm aware, no demolitions experts have stated it could have been done this way with so much precision, and without preparing the building before hand. Every other controlled demolition there's ever been has required the building to be completely gutted before being brought down.