That is incorrect. Each floor was all open space. All of the load-bearing structure was either in the core or the perimeter.
That statement does not change the fact that there were countless tons of undamaged cold, hard steel below the upper block.
The fact that gravity will cause countless tons to squash things does not ignore conservation of energy.
Not only are you failing to acknowledge that there was countless tons of undamaged steel below the upper block, but you're also failing to acknowledge that the upper block was of the same composition as the lower structure.
As far as the law of conservation of energy is concerned, you are ignoring it. One thing that happens when a stationary object is hit by a moving object of the same composition is that the moving object is slowed down. That did not happen.
That's just a video of the second collapse. I don't see what the point is.
The point is what it's always been. The upper block begins descending, and its descent is completely unaffected by any resistance from the intact core structure below it, which mean that you believe that one structure can pass through another structure of equal composition as if it weren't there, which is impossible.
It doesn't take very long for countless tons to snap off weak connections that are not designed to carry anywhere near that weight.
Again you're assigning more structural integrity to the damaged upper block than to the undamaged structure below it.
Video of the collapse shows that there was a brief pause when each of the first few floors went, but once momentum got going the floors went faster and faster.
No it doesn't. The video I provided absolutely shows a smooth accelerating descent from the very beginning. I suggest you review it.
And as each additional floor collapsed, that added even more weight to the mass smashing down on subsequent floors.
And here you are equating floors with the core structure. This is the same mistake FEMA made with its pancake theory; they didn't take the core structure into account either.
That wouldn't arrest the collapse. Damage didn't make the collapsing mass any lighter.
It didn't make the intact core structure below it any less resistant either.
. . . the lower half of the core stood for about half a minute after the rest of the building had already collapsed.
So, at the beginning of the collapse when there was much less mass acting on the core structure just below it, the core structure is completely crushed, but when that mass acting on it is supposedly multiplied halfway down, the core structure is not destroyed. I see.
Also, what's your theory concerning the remaining spire just dropping down through itself instead of toppling? I trust you've seen a video. If not, here is one of them.