Frank Greening Refuted Easily

[beachnut]

It sure looks that way, yes.

The above picture of WFC 2 and 3 is already in HUNT THE RUBBLE, but thank you. I think it is safe to say that this rubble landed outside the footprint. Way outside the footprint.

You must be a bad music writer, cause any high school grad could follow the studies and figure this out. You should have listened in physics class.

 

[Roger_Harris]

No, it isn't. For the fifth time, at least. Maybe 6th. Greening's calculations are to be ignored because his assumptions, as he explains them, are totally at odds with observed reality. The top block does not stay intact as it "falls" down through the structure. This is Greening's assumption, and I reject it.

Ignore and reject? That's quite a let-down after you said you were going to "refute" them, but oh well...

Thought of a new handle yet? If not, I have some suggestions.

 

[Roger_Harris]

It sure looks that way, yes.

Go back to the animation you posted. Several storeys have collapsed between those two frames, so even Gordon Ross would have to agree that the collapse is going to continue under its own momentum at that point.

Now, does it really look to you like several floors worth of debris have been ejected at that point?

You have argued yourself into a corner here, where I suspect you'll feel forced to answer "yes" despite the obvious answer. But if that's your answer, the only thing you're proving here is that you are certainly no "truth seeker."

"Hunt the rubble"? Got any explanation yet for the 1.7 million tons of debris they trucked out of Ground Zero? Seems like a "truth seeker" wouldn't have so much trouble finding the rubble.

 

[TruthSeeker1234]

Go back to the animation you posted. Several storeys have collapsed between those two frames, so even Gordon Ross would have to agree that the collapse is going to continue under its own momentum at that point.

Now, does it really look to you like several floors worth of debris have been ejected at that point?

The videos I posted are to be looked at again. Yes, several stories have collapsed. Pay careful attention to the sequence.


First, the break is between 97 and 96.
The whole top block falls down one floor, to 96. 96 holds.
Then 97 fails. The whole top block falls down one floor, to 96. 96 holds.
98 fails. The whole top block falls down one floor, to 96. 96 holds.
99 fails. The whole top block falls down one floor, to 96. 96 holds.
100 fails. The whole top block falls down one floor, to 96. 96 holds.

At this point, the top 14 floors are behaving like a standard controled demolition of a 14 story building. It is bottom-up collapse, with floor 96 representing the "ground". Only after the top block has become about half its original height does the next phase begin, where 96 finally breaks and the top-down destruction proceeds.

This is the precise opposite of the Greening assumption upon which his paper is predicated.

 

[einsteen]

Another thing that strikes me is tat Greening does not explicitly tell how he computes the collapse time, if you assume free fall between two floors (not taking into account the merging of mass that looses energy a factor n/[1+n] each time, this gives a time difference of 0 in a valid theoretical model) but the fact that the energy to break a floor takes time. In general energy conservation equations say nothing about the time, it's like a ball that you drop, if you know an amount of energy E is lost then you can calculate the speed after that, that is simply

v -> sqrt(v^2+2(gh-E/m))

but what is the time it takes ? If you assume the force working on it is constant than it is different then only a force that is in fact a kind of delta function (working at one moment in time but infinitely strong, sounds absurd but is valid in physics and even in mathematics), in the last case you lose some energy and the time is in fact the same time as in free fall, and that is what the guy (forgot his name) used in his script and probably Greening in his excel sheet, if you use a more realistic model, maybe a force that goes with F=kx (like a spring) it will influence the collapse time.

 

[defaultdotxbe]

The videos I posted are to be looked at again. Yes, several stories have collapsed. Pay careful attention to the sequence.


First, the break is between 97 and 96.
The whole top block falls down one floor, to 96. 96 holds.
Then 97 fails. The whole top block falls down one floor, to 96. 96 holds.
98 fails. The whole top block falls down one floor, to 96. 96 holds.
99 fails. The whole top block falls down one floor, to 96. 96 holds.
100 fails. The whole top block falls down one floor, to 96. 96 holds.

At this point, the top 14 floors are behaving like a standard controled demolition of a 14 story building. It is bottom-up collapse, with floor 96 representing the "ground". Only after the top block has become about half its original height does the next phase begin, where 96 finally breaks and the top-down destruction proceeds.

This is the precise opposite of the Greening assumption upon which his paper is predicated.

and what about AFTER this? then does it behave as greening predicts? if that is the case, which mechanism would make up the vast majority of the collapse sequence, adn thus be preffered for a implistic model?

 

[stateofgrace]

The videos I posted are to be looked at again. Yes, several stories have collapsed. Pay careful attention to the sequence.


First, the break is between 97 and 96.
The whole top block falls down one floor, to 96. 96 holds.
Then 97 fails. The whole top block falls down one floor, to 96. 96 holds.
98 fails. The whole top block falls down one floor, to 96. 96 holds.
99 fails. The whole top block falls down one floor, to 96. 96 holds.
100 fails. The whole top block falls down one floor, to 96. 96 holds.

At this point, the top 14 floors are behaving like a standard controled demolition of a 14 story building. It is bottom-up collapse, with floor 96 representing the "ground". Only after the top block has become about half its original height does the next phase begin, where 96 finally breaks and the top-down destruction proceeds.

This is the precise opposite of the Greening assumption upon which his paper is predicated.

BS. I will make this simple for you.

The video you posted does not show the floors it shows the external superstructure.

The floors and the external steel superstructure are not the same.

Unless you have developed X ray vision and can see what is going on inside the external steel super structure to the floors, please stop posting you tube videos to prove your point.

If you don't understand Greenings work, get in touch with him.

 

[Horatius]

Now, does it really look to you like several floors worth of debris have been ejected at that point?

First, the break is between 97 and 96.
The whole top block falls down one floor, to 96. 96 holds.
Then 97 fails. The whole top block falls down one floor, to 96. 96 holds.
98 fails. The whole top block falls down one floor, to 96. 96 holds.
99 fails. The whole top block falls down one floor, to 96. 96 holds.
100 fails. The whole top block falls down one floor, to 96. 96 holds.

At this point, the top 14 floors are behaving like a standard controled demolition of a 14 story building. It is bottom-up collapse, with floor 96 representing the "ground". Only after the top block has become about half its original height does the next phase begin, where 96 finally breaks and the top-down destruction proceeds.

This is the precise opposite of the Greening assumption upon which his paper is predicated.

Why is it surprising to you that the floors that were most damaged in the impact, and most weaked by the fires, would fail before the relatively undamaged floors just below?

And in any case, it doesn't matter, because as pointed out above, at this point very little of the mass of the upper floors had been ejected, and so would have been available to help crush the lower floors. The upper floors may have collapsed onto the lower floors until so much mass was acculated that the lower floors started to fail. Once that happened, all the floors below this level are pretty much doomed.

Mathematically, it doesn't really make that much difference. Quibbling over which particular floors failed in what order still dosn't change anything.

Oh, and while I'm at it, how does the Death Ray O' Doom hypothesis explain a collapse that starts at the 97th floor? If it had been hit by a space-based weapon of some sort, shouldn't the "disintegration" have started at the roof level? Or was it a bank shot off the glass front of another building?

 

[Loss Leader]

BS. I will make this simple for you.

The video you posted does not show the floors it shows the external superstructure.

The floors and the external steel superstructure are not the same.

Unless you have developed X ray vision and can see what is going on inside the external steel super structure to the floors, please stop posting you tube videos to prove your point.

If you don't understand Greenings work, get in touch with him.

Thank you, SoG. This same point has been made numerous times by me and BS1+1=3 just goes on ignoring it.

The towers were not traditional skelatal steel buildings. They were built on a central core with the floors tethered to the core. As the core failed, it pulled the floors in and down. This has the effect of making the external steel facing the last thing affected.

ParanoiaSeeker2468 never appears to understand this no matter how many times it's explained.

 

[Arkan_Wolfshade]

...
First, the break is between 97 and 96.
The whole top block falls down one floor, to 96. 96 holds.
Then 97 fails. The whole top block falls down one floor, to 96. 96 holds.
98 fails. The whole top block falls down one floor, to 96. 96 holds.
99 fails. The whole top block falls down one floor, to 96. 96 holds.
100 fails. The whole top block falls down one floor, to 96. 96 holds.
...

You are assuming too much. All that you could say is that the facade at 96 does not show failure. You have no way of knowing what is going on inside the building itself.

 

[Roger_Harris]

The videos I posted are to be looked at again. Yes, several stories have collapsed. Pay careful attention to the sequence.


First, the break is between 97 and 96.
The whole top block falls down one floor, to 96. 96 holds.
Then 97 fails. The whole top block falls down one floor, to 96. 96 holds.
98 fails. The whole top block falls down one floor, to 96. 96 holds.
99 fails. The whole top block falls down one floor, to 96. 96 holds.
100 fails. The whole top block falls down one floor, to 96. 96 holds.

At this point, the top 14 floors are behaving like a standard controled demolition of a 14 story building. It is bottom-up collapse, with floor 96 representing the "ground". Only after the top block has become about half its original height does the next phase begin, where 96 finally breaks and the top-down destruction proceeds.

This is the precise opposite of the Greening assumption upon which his paper is predicated.

We've already been through that: You're simply misinterpreting where the collapse starts. It starts almost half-way between where you drew the red line and the roof. As I said before, you seem to be unable to even accurately describe what the video shows, yet you claim to somehow know what's going on inside the building.

So let me ask again the question that you quoted and then ignored: Does that second image appear to you to show several floors worth of debris being ejected from the building?

 

[TruthSeeker1234]

and what about AFTER this? then does it behave as greening predicts?

No. Greening says the top block stays intact until it has powered its way down through the entire intact structure, all the way to floor 1. Then, and only then, does the top block begin to "collapse".

In reality, the top block is gone by the time the "collapse" reaches about floor 70.

 

[TruthSeeker1234]

So let me ask again the question that you quoted and then ignored: Does that second image appear to you to show several floors worth of debris being ejected from the building?

Yes. Here is a picture of a collapse about 1/3rd over. Yes, it appears that about 1/3rd of a tower's worth of material has been rendered into fine powder and ejected.

 

[rwguinn]

Another thing that strikes me is tat Greening does not explicitly tell how he computes the collapse time, if you assume free fall between two floors (not taking into account the merging of mass that looses energy a factor n/[1+n] each time, this gives a time difference of 0 in a valid theoretical model) but the fact that the energy to break a floor takes time. In general energy conservation equations say nothing about the time, it's like a ball that you drop, if you know an amount of energy E is lost then you can calculate the speed after that, that is simply

v -> sqrt(v^2+2(gh-E/m))

but what is the time it takes ? If you assume the force working on it is constant than it is different then only a force that is in fact a kind of delta function (working at one moment in time but infinitely strong, sounds absurd but is valid in physics and even in mathematics), in the last case you lose some energy and the time is in fact the same time as in free fall, and that is what the guy (forgot his name) used in his script and probably Greening in his excel sheet, if you use a more realistic model, maybe a force that goes with F=kx (like a spring) it will influence the collapse time.

You and BSer1...n are as qualified to refute Greening as I am to do the same to Steven Hawking...
Neither of you has shown any grasp of the concepts of physics, structural analysis, video analysis, or even life.
Kinda like Russell P.--once you run out of arguments, you get defensive and post like crazy. Is that Argumentum ad infinitem?

welcome back to ignore...

 

[Horatius]

Yes. Here is a picture of a collapse about 1/3rd over. Yes, it appears that about 1/3rd of a tower's worth of material has been rendered into fine powder and ejected.

[qimg]http://www.acebaker.com/KingdomCome/mushroom.jpg[/qimg]

That's not the second image he's talking about.

Out of a 110-story building, how many stories constitutes 1/3? Hint: it's more than 14.

Once the collapse gets going there's no reason it will stop. We're talking about the first second of the collapse, the first few floors, not 1/3 of the way down. Please try to stay focused. How much mass was ejected in the first second of the collapse?

And once again, your "about 1/3rd of a tower's worth of material" is just pulled out of the air, with no justification other than it supports your delusions.

 

[R.Mackey]

Another thing that strikes me is tat Greening does not explicitly tell how he computes the collapse time, if you assume free fall between two floors (not taking into account the merging of mass that looses energy a factor n/[1+n] each time, this gives a time difference of 0 in a valid theoretical model) but the fact that the energy to break a floor takes time. In general energy conservation equations say nothing about the time, it's like a ball that you drop, if you know an amount of energy E is lost then you can calculate the speed after that, that is simply

v -> sqrt(v^2+2(gh-E/m))

but what is the time it takes ?

There is almost no time lost to breaking structures. On contact, the floors hit accelerate to match the impacting floors almost instantaneously, according to conservation of momentum. The actual fracture is transmitted at the sound speed of the materials, once the lower floor hits its plastic limit.

There is an energy cost, and this is reflected in the kinetic energy of the moving, combined mass after the new floor fails, as a reduction. There is no additional timing correction necessary or missed by Greening.

 

[Regnad Kcin]

Yes. Here is a picture of a collapse about 1/3rd over. Yes, it appears that about 1/3rd of a tower's worth of material has been rendered into fine powder and ejected.

[qimg]http://www.acebaker.com/KingdomCome/mushroom.jpg[/qimg]

Y'know, the sun in the sky "appears" to be about the size of a 50-cent piece.

 

[defaultdotxbe]

No. Greening says the top block stays intact until it has powered its way down through the entire intact structure, all the way to floor 1. Then, and only then, does the top block begin to "collapse".

In reality, the top block is gone by the time the "collapse" reaches about floor 70.

no, thats not what he says, as i have already pointed out to you

 

[Trigood]

No. Greening says the top block stays intact until it has powered its way down through the entire intact structure, all the way to floor 1. Then, and only then, does the top block begin to "collapse".

In reality, the top block is gone by the time the "collapse" reaches about floor 70.

I haven't read Greening's paper and so cannot defend it, but you do realize that for a top-powered collapse it matters not at all at what time "the top block is gone."

The mass will still be almost all there. The crushed rubble falling down on the lower floors still constitutes enough mass to ensure continued collapse.

What don't you understand about the reality that breaking up floors does not make all the mass go "poof"?

 

[Trigood]

Y'know, the sun in the sky "appears" to be about the size of a 50-cent piece.

Hey sometimes when the moon is rising, it looks like it's about the size of a bowling ball. Does that mean the moon is about 50 times the size of the sun? Kool....