Here we go
http://911research.wtc7.net/wtc/analysis/wtc7/demolition.html
Observing the collapse of 47-story WTC 7 shows it to have all of the features of an implosion engineered by controlled demolition.
Not all of them. The explosions are lacking.
The collapse of the main structure commences suddenly (several seconds after the penthouse falls).
You know, things do tend to fall suddenly. Now, I don't want you to hurt yourself, but try this: Go to a gymn (they must have one in your school), find a barre, and hang in it by your hands (be sure it's not at a hight where falling will hurt you). Now, slowly relase your grip. At some point you fall. Will that be all of a sudden, or will you fall gradually?
Same with buildings. Buildings tend to stand till their structure cannot hold them up any longer. Then, suddenly, they fall.
The building sinks in a precisely vertical manner into its footprint.
This apparantly comes as a surprise to you, but things, and this absolutely includes buildings, when they fall, they fall, if at all possible, down. Straight down. The reason for this is that gravity works that way. Only if some sideways force, strong enough to divert the object, is in action, will it not fall straight down. A building like the WTC buildings weigh in excess of half a billion tons, so it will take a really big force to make it fall anything but straight down.
Puffs of dust emerge from the building's facade early in the event.
Despite its massive weight, the volume of a building is actually some 80% air. There is a good reason for this: We make bouldings in order to have things inside them. Things like offices, equipment, people. Now when a building collapses, these millions of gallons of air have to escape, fast! Air escaping fast is, ..... yes, a
puff. The dust? Do I have to explain to you how a collapsing building can generate dust?
The collapse is total, producing a rubble pile only about three stories high.
Remember I just told you about the 80% air? That rubble pile is what's left once the air is taken away.
The main structure collapses totally in under 7 seconds, only about a second slower than it would take a brick dropped from the building's roof to reach the ground in a vacuum.
Yeah, more or less. You see, when half a billion tons start falling, it takes quite a bit to slow them down.
.....
You know, collapsing buildings, especially 7WTC, look
a lot like controlled demolitions. You see, it is really only the events
leading up to the collapse that are different.
In a CD, the supporting structure is weakened at strategic spots by cutting away parts of it and finally blowing parts of it away with explosives.
In a case like 7WTC, the supporting structures were weakened by debris from the towers hitting the building and from extensive fires raging unchallenged for many hours.
Those were the differences. From the fraction of a second when the supports gave way and gravity took over, there is really no difference: Bereft of support, the structure collapses under gravity.
Interestingly, conspiracy theorists are always concentrating on this last phase. Instead, you should be explaining where the enorouos column of smoke billowing from the building came from, if not from extensive fires, and you should be explaining how and when demolishing engineers managed to rig the building for demolition, without anybody noticing, and you should explain the absense of the characteristic and very noticeable sharp high-explosive blasts needed to blow out dozens of heavy steel supports.
Remember that any explanations involving only a few, strategically placed charges, or the use of thermite, are an admission that it only took a little extra nudge to make the building fall, in which case you admit the high probability that it could have fallen due to the damages it received.
Hans
