WTC Concrete pulverization

For all of you engineer wana-bee types out there, I invite you to review and discuss the following article on the pulverization energy of the WTC concrete

911myths.com...

The author seems to have covered the bases pretty well in disproving the myth that there wasn’t enough energy in the collapse to pulverize the WTC concrete.

A gravity driven collapse would not 'pulverise' the building!

The degree of concrete pulverization observed during the destruction of WTC 1 would have required over 600 tonnes of high explosives.

600 tons of TNT or should we say 0.6kt nuclear device.

Anyhow, the buildings concrete was not pulverised as the 9/11 commision report would have us call it. Molecular dissociation would be a more accurate term and this is only possible with a nuclear device. Gravity and/or TNT will not cause Molecular dissociation. Gravity driven / pancaked buildings would have produced many large chunks of concrete debris at the base, it would not of even come close to the micron scaled devistation at WTC.

What about an explaination for the pools of molten iron too? I suppose the heat and friction generated by the gravity collapse did this? Charred and burnt out wrecks of cars around the building? Surely if this was true the explaination would tailor for all these 'unexplainable' events.


[edit on 9-11-2006 by Insolubrious]

Not to mention the steel beams sticking out of surrounding buildings,and the bone fragments on the rooftops,and the many eyewitness accounts of huge explosions.Why can't people accept that there were some sort of explosive devices in the wtc?All the evidence points in this direction.

So, can I take it that niether of you actually read the above link, or was it simply that the math was too hard for you to grasp?


Please be a bit more specific in your critique.

where is the math wrong?

What assumptions do you have problesm with.



[edit on 9-11-2006 by HowardRoark]

Originally posted by Insolubrious
A gravity driven collapse would not 'pulverise' the building!

The degree of concrete pulverization observed during the destruction of WTC 1 would have required over 600 tonnes of high explosives.

600 tons of TNT or should we say 0.6kt nuclear device.

Anyhow, the buildings concrete was not pulverised as the 9/11 commision report would have us call it. Molecular dissociation would be a more accurate term and this is only possible with a nuclear device. Gravity and/or TNT will not cause Molecular dissociation. Gravity driven / pancaked buildings would have produced many large chunks of concrete debris at the base, it would not of even come close to the micron scaled devistation at WTC.

No according to the calculations presented in that paper.

Please provide counter calculations and be sure to back them up with sources

What about an explaination for the pools of molten iron too? I suppose the heat and friction generated by the gravity collapse did this? Charred and burnt out wrecks of cars around the building? Surely if this was true the explaination would tailor for all these 'unexplainable' events.


[edit on 9-11-2006 by Insolubrious]

Where does that paper discuss the "pools?" of molten whatever?

IT DOESN'T.

Please do not try to critique a paper by discussing irelevent details. The paper is specificly about one thin, and one thing only.

If you can not stick to that subject, then I can only surmise that you are unable to critique it and that therefore you tacticly accept it as true.

Is this the case?

Originally posted by crowpruitt
Not to mention the steel beams sticking out of surrounding buildings,

How is this relevant to the discussion of the energy required to pulverize concrete?

If you have a specific comment about the above linked paper, then please reference the specific page number. The discussion is about the energy required to pulverize concrete, not how much energy was required to eject steel beams.

Originally posted by crowpruitt
and the bone fragments on the rooftops

Which I believe were the result of the airplane impacts, and which has nothing to do with the topic at hand.

Originally posted by HowardRoark

Originally posted by crowpruitt
Not to mention the steel beams sticking out of surrounding buildings,

How is this relevant to the discussion of the energy required to pulverize concrete?

If you have a specific comment about the above linked paper, then please reference the specific page number. The discussion is about the energy required to pulverize concrete, not how much energy was required to eject steel beams.

I haven't looked much into the paper yet. I would say this is relevant to the discussion because some of the energy needed to pulverize concrete would be lost to steel beam ejection, sound (I know minimal), tearing the tower apart...etc. So, does your paper include all this loss of energy? I didn't see anything about it while glancing through it.

The paper concludes that only a maximum of 15 % of the kinetic energy of the initial floor collapse would be needed to pulverize the concrete at the beginning of the collapse.

Since the amount of kinetic energy available would increase as the collapse progressed, this percentage would decrease.

That paper assumes that the full initial kinetic energy of the falling mass went DIRECTLY to crushing the concrete, NOTHING ELSE.

Thus we see that the first major energy transfer in the collapse of WTC 1 occurred when 2.1 gigajoules of kinetic energy was delivered to the 627 tonnes of concrete on the first impacted (~95th) floor. We now consider how concrete would behave under this degree of impact loading.

So if that paper were true, the uppermost floors would fall, concrete dust would go everywhere, and then nothing else would happen, because no force is exerted upon the steel beams or anything else.

Greening tends to make horrible assumptions like that, though. If anyone has seen his mathematical model for momentum transfer then you know what I'm talking about.


Another bad assumption:

In order to determine the energetics of this collapse we note that the drop distance was 3.7 meters and with the relation v = ?(2gh) we find the impact velocity, vi, was 8.52 m/s.

There was no 3.7 meter free-fall when either of the buildings gave out. It wasn't like 3.7 meters of structure just disappeared and the top parts just fell straight down through air. It was resisted the whole way down.


He also appears to assume no momentum transferred down the building, carrying energy away from the collapse zone.

Here's an experiment for you all to try:

Take a wood beam, stand it on your foot, and then nail the top of it with a hammer. Does the end of the beam you hit simply destroy itself with massive amounts of energy, or does much of the energy transfer downwards and squash your foot? For Greening, it all stays in the immediate impact region. I guess that's what you get from a chemist pretending to be a physicist.


I also see references in his paper to his other paper on WTC momentum transfer, which has already been shown to be total bunk on at least two counts: lack of momentum transfer down the building, and assuming all mass went directly to crushing with 100% efficiency, and each floor condensing back into a single body of twice the mass at each floor.


Convincing maybe to someone who isn't familiar with physics or engineering, but he makes a lot of bad assumptions. Anyone can make up numbers and fit them into whatever formulas they please. The issue is how accurately they reflect reality.

Originally posted by HowardRoark
Since the amount of kinetic energy available would increase as the collapse progressed, this percentage would decrease.

This is another example of a bad assumption Greening makes.

As posted on another thread:

This is what Greening's model assumes!



All mass went straight down, without significant resistance, without losing ANY mass, constantly re-condensing into a single body, etc.


This is what actually happened!




Based on these (FEMA and NOAA images):






Again, to someone who doesn't grasp Greening's manipulations, it may look convincing, but it really is garbage, and does not reflect the reality of the events at all.

Most of the mass was lost over the sides of both buildings during collapse, as can be gathered not only from Ground Zero, but the massive ejections DURING the collapses.

Thus, less and less mass, not MORE and MORE. And, the structures thickened on the way down, another variable Greening fails to include, surprisingly enough.

What part of that suggests that all mass just fell straight down, increasing from floor-to-floor, with none being lost or ejected over the sides?

I'll give you the benefit of a doubt, HowardRoark, that you simply did not understand what Greening was implicitly assuming in his numbers. Hell, I doubt he even knew what he was doing.





You're looking at ~80-90% of the mass of this building, floor by floor, being hurled right out of the building. That's less and less mass, not more and more. It "fell" OUTWARDS, the WHOLE WAY DOWN.

Thanks for illustrating so nicely BsBray11 what I was trying to say. We've come across Greening before and his manipulations.

Side note: Funny how Howard takes this chemists writtings as truth when it comes to physics, but a real physicist he won't take?

Edit: BTW just to let you know.

You have voted bsbray11 for the Way Above Top Secret award. You have one more vote left for this month.

[edit on 11/9/2006 by Griff]

Okay, I'm going to read through this, but I already have a question concerning a statement in it.

He says

In this report we will focus on the collapse of WTC 1 since the upper section of this Tower had much less kinetic energy available to pulverize concrete than the energy available from the collapse of WTC 2. It follows that the energy budget for the collapse of WTC 1, compared to WTC 2, represents the more stringent test of the “natural collapse” hypothesis. In other words, if the available evidence demonstrates that the collapse of WTC 1 released sufficient energy to account for the observed pulverization of the concrete in the building, the collapse of WTC 2 would have been even more energetically favorable to the pulverization of concrete.

And then he explains why he's making this statement:

As described in some detail in Greening’s “Energy Transfer in the WTC Collapse” the concrete on the 95th floor of WTC 1 was impacted by the mass of the 15-storey block of floors above the aircraft impact zone.

Uhhhhh...why is he saying that? Not even NIST claims the entire weight above the collapsing floor was falling on a given floor. NIST claims that a given floor collapsed on to the floor below it. Even you have taken that yourself and stated basically that individual floors were collapsing on to the one below them until there was insufficient support for the core to remain standing. But no one floor is theorized to have been smacked by a big block of floors above it.

Right?

Bein's as I only got to the first paragraph of the second page of the theory itself (ignoring the prefacing page), and his work has already fallen apart, am I required to stick with it further?

I hope not.

[edit on 11-9-2006 by Valhall]

bsbray11, you got my way above award for this excellent piece.
Always enjoyed your posts, keep it up

mr.jones

Originally posted by bsbray11
That paper assumes that the full initial kinetic energy of the falling mass went DIRECTLY to crushing the concrete, NOTHING ELSE.

Thus we see that the first major energy transfer in the collapse of WTC 1 occurred when 2.1 gigajoules of kinetic energy was delivered to the 627 tonnes of concrete on the first impacted (~95th) floor. We now consider how concrete would behave under this degree of impact loading.

Wrong. He started out by calculating the maximum total energy available, then he calculated the amount of energy required to achieve the specified degree of pulverization, then he compared the two.

Since the amount of energy required was an order of magnitude less then the amount of energy available, I think he proved his point.

Originally posted by bsbray11
Another bad assumption:

In order to determine the energetics of this collapse we note that the drop distance was 3.7 meters and with the relation v = ?(2gh) we find the impact velocity, vi, was 8.52 m/s.

There was no 3.7 meter free-fall when either of the buildings gave out. It wasn't like 3.7 meters of structure just disappeared and the top parts just fell straight down through air. It was resisted the whole way down.

By what? Buckling columns? Plastic hinges?

Provide some data that shows just how much this resistance energy was.

Originally posted by bsbray11
I also see references in his paper to his other paper on WTC momentum transfer, which has already been shown to be total bunk on at least two counts: lack of momentum transfer down the building, and assuming all mass went directly to crushing with 100% efficiency, and each floor condensing back into a single body of twice the mass at each floor.

No, it has been shown that the critiques of his earlier paper were wrong in the way that they “double dipped” into the energy expenditures.

But please, explain how you transfer momentum to the Earth again, I thought that that was funny.

Originally posted by bsbray11

Originally posted by HowardRoark
Since the amount of kinetic energy available would increase as the collapse progressed, this percentage would decrease.

This is another example of a bad assumption Greening makes.

So, are you claiming that a falling body does not gain momentum when it falls?

Originally posted by bsbray11
Most of the mass was lost over the sides of both buildings during collapse, as can be gathered not only from Ground Zero, but the massive ejections DURING the collapses.

Thus, less and less mass, not MORE and MORE. And, the structures thickened on the way down, another variable Greening fails to include, surprisingly enough.

That makes no sense whatsoever. The falling mass did not get lighter as it fell.


[edit on 9-11-2006 by HowardRoark]

Thanks, guys. Greening's stuff isn't really new, and it's been posted before, it's just that it was dropped as soon as it started becoming clear that this guy doesn't know what he's doing in trying to portray things like the WTC collapses with math.

Nice observation, too, Val. Those fallings upper floor would have been bearing down with the steel columns, not with a big stack of floors (with a total mass of the WHOLE BLOCK) falling down onto the trusses.

This is also the only guy, to my knowledge, to accept the Scholars' challenge to a public debate. NIST and the Kean Commission were petitioned, I think, but only Greening offered to show up. If that debate's still on, I would love to see it.

Originally posted by bsbray11

What part of that suggests that all mass just fell straight down, increasing from floor-to-floor, with none being lost or ejected over the sides?

Wait. Are you now claiming that that cloud is a mass of building debris and not just pulverized dust?

I thought that the claim was that it was all pulverized concrete, “blowin in the wind?”

Which is it?

Originally posted by bsbray11

So BS, what percentage of that dust cloud was concrete an what percentage was fiberglass or gypsum?

Originally posted by Valhall
Uhhhhh...why is he saying that? Not even NIST claims the entire weight above the collapsing floor was falling on a given floor. NIST claims that a given floor collapsed on to the floor below it. Even you have taken that yourself and stated basically that individual floors were collapsing on to the one below them until there was insufficient support for the core to remain standing. But no one floor is theorized to have been smacked by a big block of floors above it.

Right?

The issue is that at the start of the collapse, the entire top did drop as a whole unit.

His assumption is mearly a simplification of that which is why he clearly states it.

don't confuse the cause of the collapse with this. This paper is mearly looking at the energy requirments needed to pulverize concrete.

Originally posted by HowardRoark
Wrong. He started out by calculating the maximum total energy available, then he calculated the amount of energy required to achieve the specified degree of pulverization, then he compared the two.

If you go about something ass-backwards, it's still wrong because the process is flawed, all other problems with what he did aside. Without even reading through the full document we've already found plenty.

By what? Buckling columns? Plastic hinges?

Provide some data that shows just how much this resistance energy was.

No, it's not my job. Burden of proof is on Greening, or through Greening, you.

Prove that the falling masses would have free-fell 3.7 meters with NO resistance from the below structure, as Greening assumes.

No, it has been shown that the critiques of his earlier paper were wrong in the way that they “double dipped” into the energy expenditures.

You're talking about Greening, right? That's pretty much what he did. It wouldn't make any sense for anyone from the conspiracy side to argue that, as they would be trying to emphasize less energy.

So, are you claiming that a falling body does not gain momentum when it falls?

No. Is it your reading comprehension or understanding of physics to blame here?

The resistance was increasing while the falling mass was decreasing. Put one and one together, HowardRoark. I know you're not that stupid.

That makes no sense whatsoever. The falling mass did not get lighter as it fell.

Yes, it did, as there was LESS MASS.

Otherwise, you would have a HUGE PILE of debris in the footprints of the towers. Make sense?

It was all sent outwards, which means it wasn't falling straight down.


If you respond again, can you try to offer actual responses instead of misinterpretting or bringing in irrelevant crap in for every damned thing I've posted?