Mcluhan said:
The floors were blown to smithereens. the building mass as it came down met ZERO resistance.
Not true. You yourself just said it took 13 seconds to come down, but it takes less than 10 seconds for an object in freefall to hit the ground from that height. It came down 30-40% slower than that, which represents resistance.
It actually took 25 seconds before all the supporting structures hit the ground--the floor material fell past.through much of it.
Anyway I don't know what plant you're on, but where I'm from 30-40% resistance is pretty significant and not ordinarily called "ZERO".
Exploded in downward sequence.
I don't think anyone is technically capable of setting off a chain of explosions like that, especially not in a building that has just been severely structuraly damaged by an airplane collision.
You know that your mythical explosives would have to detonate floor by floor at an accelarating pace, roughly 9.8 meters per second-squared, plus some resistance factor. So a linear series of detonations wouldn't cut it, it would have to be a series of detonations designed to go off one after another at the same rate that gravity would accelerate a falling body. Worse, you don't even know the timings in advance because you wouldn't know which floor the plane impacted, namely, the point from which the acceleration begins.
Oddly enough that rate of acceleration is the one at which the building would collapse were it just plain old gravity pulling it down under its own weight.
Anyway you don't need this bizarre explosion theory when ordinary forces would bring it down the same way, without any explosives being necessary. The internal support columns just weren't ever built to hold up that much weight, even if you call them over-engineered, they weren't THAT over-engineered.
Had they been that over-engineered they would have looked like standard compression architecture columns, meaning, they would have taken up almost all the floor space.
The concrete dust slurry, right from the beginning moment, down thru the next 13 seconds (about), shows EXACTLY what happened. Its in plain view. Furthermore, the chemistry of the dust (220 acres of dust) defines EXACTLY which pyrotechnics where used.
I already debunked your source for that. It turns out he is not an expert in any of those things, he's a family doctor, and in reality knows nothing more about this stuff than you or I do. That guy was just talking out of his ass.