That's not an explanation. That's a stupid graphic that doesn't explain a damn thing about how Newton's 3rd law applies.
Please quote whatever in Bazant's paper you belive suggests that.
What I quoted from myself above the graphic is the explanation.
Rather, I'm just addressing the official story for how the towers came down which is Bazant's hypothesis, and he treats both the top and bottom sections as monolithic objects.
You are confused. Your quote is not an explanation, it's an exclamation. You exclaim that that collapse without explosives violates Newton's 3rd law. You never actually explain why in any sort of detail whatsoever.
Actually, Bazant does not treat them as monolithic, which is why he divides the towers into sections in his explanation. He also explains it in this paper:
Right, including the bottom section which he claims crushes down before the top section crushes up, as if they were two monolithic objects which didn't apply equal and opposite force to each other when interacting, as I've explained all along.
And that's where you are wrong and why it shows that you really don't comprehend what you are talking about in regard to physics and/or structural engineering. They don't apply "equal and opposite force" because the upper section is dynamic while the bottom section is static. Each floor of the bottom part of the tower would have to be able to absorb the kinetic energy of the 20+ floors above crashing down on it and, particularly for the floors that were already structurally compromised, there is no way they are going to be able to tolerate such a dynamic load. They simply were not designed to do that even when not structurally compromised.
A pound of feathers and a pound of cheese each have differing densities. Because of that they have differing deformation properties, hence differing energy absorbsion upon impact. If you mashed both into masses that had identical densities there would be no difference in impact between the two.
The claim is all throught the paper, but the most direct statement of it is here:
Note that I'm quoting the more recent Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions paper, though the earlier one is based on the same argument.
As Newton explained:
That goes for both dynamic and static bodies, always, which again is why nobody can produce any physical demonstration to the contrary.
You are correct, yet Bazant claim of an upper block crushing down ignores the force imparted on that block by what it is supposedly breaking up, in flagrant violation of Newton's third law. This is why you can't defend your assumption that his is expiation his accordance to physical requirements by quoting him, let alone providing a physical demonstration; because Bazant's explanation stands in flagrant violation to the laws of physics.
It depends on how tightly the feathers might be bundled together and how dense the cheese is, as depending on those factors either could do more damage than the other. To exemplify this, take a steel ball just heavy enough to crush a table from a given right. Then take that steel spring of the same mass and drop on that on another such table from the same height, and of course the spring will bounce on the table rather than crushing through it.
No unique signature, particularly in the case of nano-thermite, as that can tailored to react in a wide rage of ways. Unfortunately, the tiny flakes in the dust can't simply be gathered up and packed into a cutter charge to get an idea of what that sounds like, and it's far to complex for all but a few labs in this world to make more.
I've already explained this to you. Each floor of the lower, static portion cannot exert an equal force on the upper, dynamic portion because the force of the upper portion far, far exceeds that of each lower floor. That's why each floor progressively fails.
Rather, while no single story could take as much force as the 20 or so stories above it, the forces exerted between the two are always equal and opposite, which is why you can't crush the 90 stories below with only 20 stories above. Besides, there's no place to build up the acceleration to crush even a single story simply by working the steel by fire anyway, as that leads to gradual sagging rather than anything like the period of free fall Bazant in fanciful claims. In realty, one could have sawed off the top 20 stores off the towers and dropped them from hundreds of feet above the bottom 90 stories, and both sections would have simply shredded into each other through perhaps 10 stories of each, with the remaining 80 stories below remaining perfectly fine.
No it is not equal. A single, static story does not have the potential energy to exert a force equal to the dynamic energy of 20+ stories crashing down on it. Not even close. Each floor will fail trying because the kinetic energy of the dynamic mass FAR exceeds the load bearing capabilities of any individual floor. As each floor collapses even more mass is added to the dynamic portion of the collapse which increases the kinetic energy of that mass. It's not going to slow down or stop like you believe. In fact, it's going to gradually accelerate.
Have some pie (Man, that does look like a good pie)
