Oh, you haven't received your serving of whoop-ass today? Well then...
This is a bizarre an irrelevant figure. An "average" drop for 100+ floors? Why do you need that?
Because that is what
actually happened. 100+ floors did
in fact drop. They did
in fact drop, on average, 200+ meters, and all their potential energy of about 200 meters times their total mass times g was
in fact mostly converted to destruction.
Thus, it is a highly relevant figure if you want to get a feel for why all that stuff was destroyed in a gravitational collapse.
No, the first floor to "collapse" was 3.5 metres high.
Wrong, the first floor in the North Tower that dropped on another floor was about 300 meters high, and by the time it stopped dropping, it was about 300 meters lower, having most of its potential energy = 300 meters x mass x g converted to destruction.
No free fall drop is possible in your model, and certainly not one lasting 2.2 seconds. You are borrowing a calculation from 9/11 researchers and trying to fit it into your model and it's illogical.
It isn't illogical - you just don't understand the logic. Ok, blame it on me. I should have known better: You are a truther, therefore you have trouble with sound logic.
What matters is that the collapse front moved at an average speed of about 21.5 m/s - on account of the collapse taking about 15 seconds to reduce a 415 m high tower to little over 0 m.
So my model calls for masses colliding at that average speed of 21.5 meters. That's all there is to that bot of the model.
There are many ways to bring a mass to that speed - you could haul it with a truck, have an army of midgets push it, attach rocket engines to it - or let it drop from a height of 23.5 meters. After falling freely from 23.5 m up, which takes about 2.2 seconds, it has attained a speed of 21.5 m/s - and that's all that matters.
I figured having you imagine such a fall would give you a good feel for how fast that is.
You seem to want to use the word "concrete" a lot, which is strange since 9/11 bedunkers go to great lengths to ensure everyone is aware of how little concrete there was in the towers. But if you acknowledge you are also talking about core box columns (leaving out the perimeter columns for these purposes), support walls, partition walls, 100+ storeys of office furniture, steel floor assemblies, carpeting and fixtures, then we are at least on the same page.
Red herring, handwaving...
I said "
steel, concrete and stuff"
If you have troubles getting in your head that it doesn't even matter at all, only thing that matters is mass, velocity, hight, energy, try this:
Imagine the tower wasn't made of "steel, concrete and stuff" but "frozen chicken meat, kauri wood and kryptonite" instead. Drop 150,000 tons of that from 200 meters up unto yourself, and observe.
So bedunkers agree on a pancaking model? Does Ryan Mackey agree? Would Major Tom agree with this model?
You're playing the wrong goal posts here.
It would be mildly interesting to know if YOU agree that
in fact floors ended up on top of each other, with little to no air left between them, AND that the collapse occurred from the top down, such that Floor 70 would be deflated of all its air before Floor 69, and that before Floor 68, etc. In other words, that the floors did
in fact pancake onto one another.
But even if you don't, you could try to tell me what you think happens when 110 floors drop an average of 200+ meters, and experience lots of collisions in the process as potential energy get converted to kinetic energy, and eventually almost completely to destruction.
Actually, filled with core box columns, support walls, partition walls, 100+ storeys of office furniture, steel floor assemblies, carpeting and fixtures.
Correct. Mostly.
You know of course that many of the core box columns did get to bear much of the collapsing mass - you know very well that significant parts of the cores remained standing for many seconds after all the office floors had pancaked to the ground, and perimeter columns had peeled off.
Just picture what happens to support walls, partition walls, 100+ storeys of office furniture, steel floor assemblies, carpeting and fixtures when you drop 100,000 tons of floor slabs from, say, 23.5 meters up on them.
Yes they get pretty flattened, even after a drop of 23.5 metres, which of course never happened in the towers.
The
equivalent of a drop of 23.5 metres (on average) happened 100+ times in the towers.
So they get "pretty flattened", hahaha. How about "destroyed beyond recognition"?
That's the same energy. From gravity. And there's no free fall.
No. You forgot to add the potential energy that gets converted to destruction eventually, to the tune of 3.6 meters of free fall every 3.6 meters - it doesn't matter by the way if free-fall actually happened. Every time your 100,000 tons worth of building structure drop 3.6 meters - and come to a full stop eventually, no matter what the effective acceleration, it all (mostly) gets converted to destruction.
Well, it's a rough sketch made with crayons, as yours was. I was indeed even assuming somewhat of the Bazantian crush-down model, where the top section of building does not get obliterated before collapse progresses through the intact lower building.
Strictly speaking, in your model, collapse arrest would have occurred earlier.
Nope, because (as Bazant's very first limiting case model showed) the actual load-bearing steel structure could never absorb the 3.6 meters worth of potential energy that get converted to destruction each time the top part drops another 3.6 meters, let alone absorb the kinetic energy already accumulated. That's why kinetic energy / speed increases floor by floor by floor.
No new effect. As in real world physics, one has to account for energy dissipation through normal resistance and deformation. Let alone pulverization.
Exactly. This has been accounted for. By Bazant (limiting case for deformation/buckling of steel structure) and Greening (adding pulverization). The energy thus dissipated per story is less than the potential energy differential released by the fall through the height of one story.
And that is why kinetic energy increases floor by floor by floor.
That's right, they didn't, and there were not.
Strange. Two answers - but you quote five questions! Could you please answer all five of them separately - here, I'll number them for you (and reword them, to avoid double negations):
The collapse in fact arrest on the ground - TRUE or FALSE, ergo?
The collapse did in fact progress all the way down, at an average speed of 21.5 m/s (give or take some) - TRUE or FALSE, ergo?
All floors had, on average, a mass of more than 100,000 tons above them, that eventually dropped down on them - TRUE or FALSE, ergo?
All floors did in fact drop an average of about 200 meters from their original height to where they eventually came to a full stop - TRUE or FALSE, ergo?
There were in fact 109 floor-on-floor collisions in that collapse, as all 110 floors fell to the ground, none were magically removed from the pile before the collapse was over, and no two floors ended up separated by as much as an inch of air - TRUE or FALSE, ergo?
If we're talking about pancaking, we're talking about contents being squashed and flattened. How does this pulverize into fine particles and spew them laterally and upward at an average rough rate of 0.18 seconds per floor? What you are seeking is some kind of grinding action. There simply wasn't enough time or energy for that. And even if you found grinding action, this would not really occur along with propulsive action.
No. If you slam thousands of tons of hard stuff on tiles, wallboard, concrete, fire-resistant foam, and do so repeatedly, your gonna crush much of that to crumbles and dust.
Most of the dust was from such materials.
The only mystery here is your inabilty to imagine 300,000 tons of all sorts of stuff, including gypsum, fire-protection fibers and light-wiehgt concrete, falling 200 meters down, and that this will crush a lot of that stuff.
The particle-ization of all the buildings' contents does not suggest flattening or pancaking.
It appears that you have never read Greenings papers on the topic of concrete comminuition in the WTC, or else you wouldn't write such ignorant nonsense.
On the contrary, yes, the particle-ization of
all some of the buildings' contents,
particularly concrete and gypsum, suggests exactly that. It has been shown that this is PRECISELY what must be expected from just that sort of collapse.
The fact that many witnesses reported hearing and seeing explosions take place,
...corroborates what every investigator knows perfectly well already: That many witnesses describe things inadequately, and that many witness testimomies must be interpreted with care.
the fact that furnishings and bodies were fragmented into pieces less than an inch
Absolutely expected considering the forces and energies involved that are far far far beyond anyone's human experience and even farther beyond your personal comprehension, as you amply demonstrate in this thread.
Oh, by the way, those fragements "less than an inch" of human bodies, they make up what percentage of the mass of all human bodies crushed in the events? Do you know?
Some were, sure. You are aware that many people were already in tiny shreds before the collapses even began, right? Those humans affected by the plane crashes (passengers and office workers in the plane's path).
Why should such human shreds,
particularly the smaller ones, not get ejected with the air that's pushed out the windows as the volume of air in a floor is reduced from over 14,000 cubic meters to nothing in a fraction of a second?
Can you estimate the average wind speeds thus produced?
and the obvious explosive appearance of the buildings' destruction suggests to normal people that explosions took place.
Nothing obvious here: There were no audible detonations loud enough to be ascribed to explosive charges sufficient to sever structural steel.
To all but the deluded fringe, the appearance of the towers was that of gravitational collapses. Especially to the experts. Remember Danny Jowenko? What he thought about the twin towers and CD? You think you are smarter about the look of CDs than Danny Jowenko was?
To Danny Jowenko, it was
obvious that the twin towers could
not possibly have been explosive demolitions.