Momentum Transfer in WTC

[TruthSeeker1234]

Mackey, you are simply incorrect about the floor trusses being the only cross-bracing for the core columns. Look here, for instance:

http://www.peaceproject.com/graphics/postcards/CA2-huge.jpg

(add needed h t t p and w's)


Please retract your error, or lose credibility.

 

[R.Mackey]

You're correct that Ross does not get into the dissociation of the non-metallic mass of the towers. He has calculated that global collapse is not possible under the circumstance. Figuring in the other observaions, such as the pulverization, only makes the "gravity did it" explanation more absurd. I will make that a sepearate thread, and name it the "TruthSeeker Challenge". Perhaps there will be a reward.

Except, as my posts referenced above point out, as does Greening, he did the calculation wrong. It's really a very bizarre argument that Ross is trying to promote.

No need for a "challenge." No stunts are necessary. If you can find holes in my reasoning, I'd like to hear about them. I am a scientist and I want to learn. But keep in mind that I will defend my opinions, trying to find out which of is right.

Many observes at ground zero, such as governor Pataki, commented on the near-complete absence of macro-concrete in the rubble, and the presence of powder "from river to river". I observe very dense clouds of powder falling very fast to the ground, and swelling out into rapidly progressing pyroclastic flows quickly became 3-4 times the volume of the intact tower. It certainly appears that entire towers were rendered almost totally into fine powder. If not, where did the concrete go? Where is the carpet? The computers? The pictures? Why was the biggest piece of non-metal that a rescue worker saw only "a half a keypad"?

Can someone link us to some photographic evidence of some stacked up concrete floors?

I might remind you that concrete made up only a small fraction of the WTC tower mass.

The flows were not in any way "pyroclastic." I fear you are getting your information from disreputable sources. We've seen this misnomer for a long time.

If you're claiming 100 micron particles from the size of the debris cloud and eyeballing it, as in your "four to five times the volume of the intact tower" statement, then you need to research the debris much, much more carefully. No way you can make that claim.

Again, if you are serious about debating Ross's paper, please do so. You've seen my criticisms. But you will have to do much better than you have so far.

 

[DavidJames]

You're correct that Ross does not get into the dissociation of the non-metallic mass of the towers. He has calculated that global collapse is not possible under the circumstance. Figuring in the other observaions, such as the pulverization, only makes the "gravity did it" explanation more absurd. I will make that a sepearate thread, and name it the "TruthSeeker Challenge". Perhaps there will be a reward.

Many observes at ground zero, such as governor Pataki, commented on the near-complete absence of macro-concrete in the rubble, and the presence of powder "from river to river". I observe very dense clouds of powder falling very fast to the ground, and swelling out into rapidly progressing pyroclastic flows quickly became 3-4 times the volume of the intact tower. It certainly appears that entire towers were rendered almost totally into fine powder. If not, where did the concrete go? Where is the carpet? The computers? The pictures? Why was the biggest piece of non-metal that a rescue worker saw only "a half a keypad"?

Can someone link us to some photographic evidence of some stacked up concrete floors?

So much for science Now you can see why the tread was (correctly) moved

 

[R.Mackey]

Mackey, you are simply incorrect about the floor trusses being the only cross-bracing for the core columns. Look here, for instance:

peaceproject.com/graphics/postcards/CA2-huge.jpg

(add needed h t t p and w's)


Please retract your error, or lose credibility.

Fighting words indeed. None of this idiocy is necessary, if you are sincere. I won't back away from a friendly debate.

I note your image was taken during construction -- and is of extremely low quality. Please answer these questions first:

1) Which cross-bracing elements are you referring to in your picture?

2) What evidence do you have that they were permanent, rather than temporary bracing needed for construction?

3) What material are those elements made of? Your photo is in sepiatone and appears to be photocopied.

4) How are these elements attached to the columns?

After that, perhaps we can talk about credibility.

And you really should read my entire critique of Ross's paper. Your quote of me, out of context, only points out that Ross treated the problem one-dimensionally, assumed the columns would compress to failure, and that he is assuming columns are pinned on both ends.

As NIST has recently clarified, the actual collapse mechanism was highly three-dimensional in nature, with the columns being twisted into the interior, pulled in by sagging floor trusses at each floor.

If there are such huge cross-braces as you claim, these braces would be part of the load-bearing structure. Funny that not even Ross accounts energy to break them, as he would have to do, if they were real.

 

[TruthSeeker1234]

Mackey, of course pictures of the core are during construction. How could we photograph it after they were finsished? Come on. There is ample photographic evidence that the 47 core columns were horizontally and diagonally braced. Where is your evidence that they were not?

Next, there was about 100,000 tons of concrete per tower, which is about equal to the mass of the steel. Regardless, It appears almost everything besides the steel was rendered into fine powder. Otherwise, where is it?

Still waiting for the pictures of stacked up floors, or desks, or . . .anything.

Someone else upthread was wondering how much explosives it would take to bring the tower down, speculating it would take a nuke. Bear in mind that, using NIST logic, it would not take very much at all. NIST would have it that all that is needed is to initiate local collapse on one floor, gravity would do all the rest. Right?

Greening did point out what he felt were errors in Ross, which is why I linked his paper. Ross answered that even if Greening was right, it would only delay the halt of collapse by a fraction of a second.

 

[kevin]

Mackey, you are simply incorrect about the floor trusses being the only cross-bracing for the core columns. Look here, for instance:

http://www.peaceproject.com/graphics/postcards/CA2-huge.jpg

(add needed h t t p and w's)


Please retract your error, or lose credibility.

You do know those corner columns that are cross-braced are the kangoo jacks supports and were dismantled when the job was complete right?

Most of the rest of the columns were straight braced against each other with some cross-bracing.

If you look at the framing plan and model NIST used you'll see they had the proper bracing in place.

 

[R.Mackey]

Mackey, of course pictures of the core are during construction. How could we photograph it after they were finsished? Come on. There is ample photographic evidence that the 47 core columns were horizontally and diagonally braced. Where is your evidence that they were not?

Nope. Please answer my questions. Awfully hard to do the calculation without that information.

Next, there was about 100,000 tons of concrete per tower, which is about equal to the mass of the steel. Regardless, It appears almost everything besides the steel was rendered into fine powder. Otherwise, where is it?

The total mass per tower is about 500,000 tons. It most certainly does not appear that "everything besides the steel" was rendered into 100 micron powder. If you have evidence for this, present it. Otherwise you're wasting all of our time.

Still waiting for the pictures of stacked up floors, or desks, or . . .anything.

I don't deal in pictures. If you have something to say about my criticisms, please say it.

Someone else upthread was wondering how much explosives it would take to bring the tower down, speculating it would take a nuke. Bear in mind that, using NIST logic, it would not take very much at all. NIST would have it that all that is needed is to initiate local collapse on one floor, gravity would do all the rest. Right?

Greening's work suggests that this is correct. But it's irrelevant, since there is no sign of explosives either before, during, or after the event.

ETA: I might add that a quick calculation of the gravitational energy reveals that each tower contained the equivalent of 0.16 kilotons of gravitational potential -- far, far more than chemical explosives could provide under any faintly rational scenario. If that's not enough energy for you, you need to bring many truckloads of high explosive to make a significant difference.

Greening did point out what he felt were errors in Ross, which is why I linked his paper. Ross answered that even if Greening was right, it would only delay the halt of collapse by a fraction of a second.

Which is true, except all of the structural members would have failed before that half-second could elapse. Ross requires 3 meters of linear deformation in ALL of the columns, in addition to energy absorption that already takes them to their plastic limits, and on top of that removes two floors worth of crushing energy that wouldn't have happened until later. Ross's answer is quite silly. That's all outlined in my critique of his rebuttal.

 

[apathoid]

Truthseeker, have you any idea how much explosives would be necessary to micronize 50% of the floor slabs? Have you any idea why said explosives were so quiet? Did you know that in CD, the explosives are used to cut columns, not blow the floor slabs to smithereens?

 

[TruthSeeker1234]

Still waiting for any evidence of any significant macroscopic objects at ground zero, apart from steel. I think 50% dissociation is generous. More like 99% of the non-metallic mass was pulverized.

Mackey, I will study your critique of Ross. On first read, I got to the false statement about the floor trusses and stopped.

 

[apathoid]

Still waiting for any evidence of any significant macroscopic objects at ground zero, apart from steel. I think 50% dissociation is generous. More like 99% of the non-metallic mass was pulverized.

Mackey, I will study your critique of Ross. On first read, I got to the false statement about the floor trusses and stopped.

Truthseeker, have you any idea how much explosives would be necessary to micronize 99% of the floor slabs? Have you any idea why said explosives were so quiet? Did you know that in CD, the explosives are used to cut columns, not blow the floor slabs to smithereens?

 

[R.Mackey]

Still waiting for any evidence of any significant macroscopic objects at ground zero, apart from steel. I think 50% dissociation is generous. More like 99% of the non-metallic mass was pulverized.

Mackey, I will study your critique of Ross. On first read, I got to the false statement about the floor trusses and stopped.

Given that you've already made several serious errors in your first seven posts, I'm not interested in your guesses. Show me that 99% was pulverized, and show me the average fragment size by species. Until then, you're whistling Dixie.

You have yet to demonstrate my statement is false. You also have yet to demonstrate that you understand the point it makes.

 

[Pardalis]

Truthseeker, are you Terrocell on the LC forum by any chance?

 

[kevin]

does truthseeker1234 remind anyone else of christophera? Only wants pictures. Pulverization/atomization of concrete. Massive core (I'm just waiting for the claim it was concrete 7 floors below that picture.)

 

[TruthSeeker1234]

kevin wondered

What weighs more 100lb of concrete or 100lb of concrete power 100 micron average diameter?

The mass is the same, the "weight", in the real world, would actually depend on a few things. Surface area to mass ratio, for instance. The bigger that ratio, the more air will resist it from falling.

If the implication is that puverized mass will push down on intact structure as well as non-pulverized mass, you must consider that the majority of the mass in each twin tower lander well outside the footprint of the building, thus making it unavailable to push down on the intact structure.

 

[David Wong]

Truthseeker, have you any idea how much explosives would be necessary to micronize 99% of the floor slabs?

Guys... I don't think he's talking about Controlled Demolition. I seriously think he's saying the buildings were empty mock-ups. I think that's why he's harping on the lack of furniture in the rubble.

After all, is there ANY method ever devised by mankind that could micronize 99% of a building's non-metal mass? Why would you want to?

 

[kevin]

kevin wondered

The mass is the same, the "weight", in the real world, would actually depend on a few things. Surface area to mass ratio, for instance. The bigger that ratio, the more air will resist it from falling.

I said a 100 pounds vs. 100 pounds. That is already weight. And the conversion of mass to weight does not in anyway involve the surface area to mass ratio.

If the implication is that puverized mass will push down on intact structure as well as non-pulverized mass, you must consider that the majority of the mass in each twin tower lander well outside the footprint of the building, thus making it unavailable to push down on the intact structure.

Says who? With what calculations?

 

[R.Mackey]

If the implication is that puverized mass will push down on intact structure as well as non-pulverized mass, you must consider that the majority of the mass in each twin tower lander well outside the footprint of the building, thus making it unavailable to push down on the intact structure.

I just got done correcting einsteen about this in another thread.

There is some fractured mass, even some big chunks, that spills over the sides early. However, most mass that eventually lands outside the footprint gets there by first smashing into the structure, so it does contribute.

This is irrelevant vis-a-vis Ross's paper, since he is considering collapse initiation. There are no large chunks or small chunks to fall away at that time. Once the upper mass has a few floor's worth of momentum, collapse is inevitable even if a significant fraction of it ricochets off to the sides.

Please provide evidence for how much mass was ejected. And keep in mind that the debris pile after collapse would itself spill over the footprint, so a single post-collapse picture is not precise enough.

 

[stateofgrace]

Truthseeker1234 are you Gordon?

If you are,did you do as I suggested? Did you get your work reviewed by the bodies I suggested ?

 

[R.Mackey]

I don't believe this is Gordon Ross. He is not sufficiently familiar with Ross's papers.

 

[Gravy]

Many observes at ground zero, such as governor Pataki, commented on the near-complete absence of macro-concrete in the rubble, and the presence of powder "from river to river".

AFAIK, no analysis was done of how much concrete was reduced to what size. George Pataki, who works in Albany, did not spend significant time down in the rubble pile.

Now, there was about 60,000,000 pounds of gypsum drywall in the towers. (at 19% sulfur content, that's 11.4 million pounds of sulfur...something smells like rotten eggs, Steven Jones). What do you think happened to it? Which do you think pulverized faster and finer, the concrete or the drywall? How about the 6,000,000 pounds of ceiling tiles and the millions of pounds of fire insulation? Which pulverized faster and finer those or the concrete?

I observe very dense clouds of powder falling very fast to the ground, and swelling out into rapidly progressing pyroclastic flows quickly became 3-4 times the volume of the intact tower.

Please do some research on what a pyroclastic flow is. Hint: "Pyro."

It certainly appears that entire towers were rendered almost totally into fine powder.

No, it doesn't, and you'll learn that arguing from incredulity ("It couldn't happen because I don't believe it could happen") is dealt with swiftly and savagely by the JREF ninjas here.

If not, where did the concrete go? Where is the carpet? The computers? The pictures? Why was the biggest piece of non-metal that a rescue worker saw only "a half a keypad"?

Most went down, some went out. Here's a question: if most everything turned to dust, what comprised the 1.6 billion pounds of debris that was meticulously sorted on conveyor belts for evidence and remains at Fresh Kills landfill?

Here's a related post of mine, with a report from someone who did spend months in the pile, on what the rubble looked like to him: http://www.internationalskeptics.com/forums/showpost.php?p=1902661&postcount=20

Can someone link us to some photographic evidence of some stacked up concrete floors?

I apologize for not having the link to this handy. Maybe someone can remember where it came from. IIRC, this museum display shows 8 tower floors compacted to four feet high.