Originally posted by -PLB-
You are making extraordinarily little sense to me.
Yes, you mentioned something like that a few times and I'm beginning to suspect that by
now, even if I tried to explain - with sources, links to Wikipedia and quotes by Newton - that a rock will fall down if dropped from a high building,
you would make a puzzled face and wonder what I'm trying to say. I'll try again.
I am saying that uniaxial collapse in all tall buildings is inevitable once 2% or more of the structure are damaged. The mass of the building's
section above the damaged floors will be accelerated towards the center of the planet's mass. All the parts of the structure in the path between the
falling body and ground level will be cut, torn, sheared, ripped, pulverized and buckled out of the way, a process which takes up only 30% of the
acceleration, therefor, the structure will not have the slightest chance to withstand the tremendous force of the dynamic load. It is because of the
high velocity of the impacting mass that the momentum is great enough to accelerate every particle it encounters. When the top section hits the first
floor, it does so with many times the force of its static load, way beyond the design strength, destroys all connections and accelerates it. After
that, it picks up speed again, together with the mass of the first floor, and crashes into the second floor. Again, the dynamic load is so huge after
that one-story freefall that it easily buckles and bends all connections, investing only a small portion of its momentum, accelerates that mass as
well and crashes into the third floor and so on.
As you can see, there is no way any part of the structure could have stopped the collapse. Which is quite logical too, if you look at it
mathematically. Due to gravity, the sum of forces acting downwards was much greater than the strength keeping the structure in place. The towers
consisted of tons and tons of steel, concrete, glass, plumbing, elevators and so on, of course there was a huge force pulling the whole structure
down. And since they were never designed to cope with the load of one third of their own weight pushing down on the other two thirds, in technical
terms, the towers stood under so much stress with all their own weight and the live load, that a certain amount of additional weight would inevitably
result in a disproportionate progressive-compressive collapse.
So when the mass of the top section became dynamic, it was as if the mass on top of the building had been multiplied by a factor of 30, in other
words, it was as if ten towers had been stacked on the roof! It would be insane to suggest that any structure in the world could withstand that. You
don't expect a wooden cottage to survice a rock being hurled on it, would you? The redundancy required for that would come close to carving caves
into a solid block of steel, but that would have little in common with modern, economic, light-weight steel architecture. Suggesting that the towers
were brought down by a controlled demolition team ignores the fact that there are only a few firms world wide who specialize on tasks like this one
and that it would have required months of preparations, calculations and rigging the whole building without anyone taking notice, and since you
suggest the towers were brought down by magic, it is only because of your lack of imagination.
Otherwise, you would easily see before your inner eye how when the top fell, its floor slabs accreted and crashed into the other floor slabs, tearing
them from their connections, while the core floor crashed down on the core columns and the other way round (since everything was totally out of plumb
now). The core beams were not designed to hold any vertical weight, so they sheared each other off, leaving the columns without support so they
buckled under their own weight and crashed down on the next level, repeating the process until only the spire was left. The spire video proves that
all horizontal connections were damaged, otherwise, the long shard couldn't have fallen over without buckling, and hidden in the dust cloud is the
part of the core that forms three plastic hinges, allowing for a vertical descent of the last erect splinter of the structure.
And of course the same goes for WTC7. Although office fires wouldn't be hot enough to actually melt
steel, they would easily compromise the
yield strength of the columns and it is not unusual that once one or more columns fail due to stress, the load is distributed to other columns which
then are also stressed beyond their design load and fail simultaneously, initiating a progressive collapse very similar to those seen in conventional
I hope this makes more sense now.