petermac33 said...
how they did it [turn the towers into micro dust before towers even hit the ground]we may never know exactly.
You see Pweet, you have touched on the critical failure point of the controlled demolition argument right here.
For the building to come down at "near free fall speed" to be a convincing argument for a controlled demolition, you would have to show that almost every bit of the energy required for the demolition process came from the planted explosives.
And that is a ridiculous proposition because even in controlled demolitions of large buildings, they actually use a surprisingly small amount of explosives.
The majority of the energy required for the demolition is derived from the building itself. i.e. the potential energy due to the mass of the building and its height above ground level.
This is a huge amount of stored potential energy just waiting to be released.
Once a collapse is initiated by a small amount of explosives at critical points, the building completes the demolition process itself.
So you see that unless so much explosive was used that it literally turned all the understoreys to dust in perfect sequence as it fell, the rate of fall of the building would be the same regardless of what initiated the collapse, a controlled demolition starting on the 85th floor or a plane flying into the building and initiating structural failure on the 85th floor.
There is no logical way round this flaw in your argument.
You have tried to evade this dead end by the statement ;
" how they did it, turn the towers into micro dust before towers even hit the ground, we may never know exactly."
That is not in any way an acceptable answer to the critical point of the whole 'controlled demolition' theory.
I agree, the building did come down surprisingly fast.
It is worth looking at why.
The fact is, there were no concrete vertical support columns in the floor area of the building.
It was a tubular construction and as far as the vertical support structure is concerned, the entire building was hollow from top to bottom.
All floors were of lightweight horizontal support beams from the outer walls to the elevator shafts in the centre, with 4 inch concrete floor slabs on top of the light support beams.
There were no internal vertical steel or concrete supports for the floors at all.
All it needed to bring it down was enough heat to make the horizontal support beams soft enough to bend under the weight of just one or two floor slabs.
If you want to know if that is possible, just see how quickly a steel framed house roof buckles and then caves in with a normal house fire under it. And they are very lightly loaded.
Once just one floor fell in, the horizontal beams of the next floor down had to support the weight of 2 concrete floor slabs.
The first floor to collapse probably made the sound reported as an explosion. I can't imagine it would have been a silent process.
The next floor under it would have also been subject to the heat of the fire and would have buckled and fallen seconds afterwards.
As the floor beams buckled downwards, they pulled the sides of the building inwards.
The strength of the side frames relied on the structure remaining vertical and intact.
Once the collapse started, neither of these conditions was met.
After the next floor fell, this presented a load of 3 floors to the floor beneath and worse still, it was a shock loading. i.e. by now it had kinetic energy. It was moving downwards at an increasing rate.
With this loading being presented to the lower floors, they didn't need to be subject to any heat to fail. They failed simply because of a loading greatly in excess of their design capacity.
With the weight of three, then four, then five, then etc up to 85 floors falling down on top of each other, the restriction to the fall would have been minimal because each floor was designed to take the load of just one floor.
Once the collapse started, every floor which fell contributed to the mass demolishing the floors beneath as it was all contained by the tubular construction. Plus the upper floors acted as a battering ram as they followed the destruction down.
The only slow part of the process would have been the collapse of the first two floors.
The remainder failed at a rapidly increasing rate, and that's pretty much how I saw it on tv.
The few sideways ejections were the result of the huge downrush of air and demolition products down the outer tubular structure of the building, sort of like the wadding in a shot gun cartridge.
I find this a more convincing explanation rather than saying it was a controlled and sequenced demolition with the key point of your explanation being
"how they did it, turn the towers into micro dust before towers even hit the ground,we may never know exactly."
Tell me if you are swayed by this explanation even just a little bit.
