Momentum Transfer in WTC

[Pardalis]

The subject of this thread was (generally) the collapse of the towers, so NIST is not an authority at all, as they did not study the collapses.

So why blame them?

Well, according to NIST logic, not very much. According to them, all that would be needed is enough explosive to break the vertical supports on one floor, and gravity would do the rest.

I (and Gordon Ross) happen to think that is absurd. But if you agree with NIST's findings, then this it follows logically.

 

[Foolmewunz]

1) "It is clear from photographs, such as the one on the right, that the core columns were abundantly cross-braced." http://911research.wtc7.net/wtc/arch/core.html

2) Observe the construction picture here

http://nomoregames.net/911/trouble_with_jones/core_2.jpg

Those appear to be the steel columns supporting the kangaroo cranes. There are people on this forum who know much better than I, but I believe the cranes were moved up after 6 or so floors of construction. If this was part of the integral structure of the building why are they so far apart and only, obviously (to coin one of your favored terms) only where the cranes are?

I'm not sure, but I don't think the crosss-hatched (x-like diagonals) columns stayed in place. They brought in the support beams when the moved the cranes up.

Can anyone provide direct cites on the above. I got part of it from the narrative to the Ken Burns documentary.


ETA: Not speaking for anyone, but I believe this is why R.Mackey asked you to highlight just what structure you were referring to when you first posted the picture.

 

[jhunter1163]

OK, I'm going to risk being labeled a total idiot here and suggest that maybe one of our sharp math guys (surely not me) could calculate how much material was actually released into the dust clouds. Assume a density of 1 g/m^3, multiply by that 3-4x the volume of the towers that the CTs are so fond of quoting, and you'd have a figure that would be at least in the ballpark (or maybe would mean nothing at all-I may be way off base here)

Source for 1g/m^3 figure:

http://www.springer.com/cda/content...333536#search="mass of 1 cubic meter of dust"

This article states that 1g/m^3 or more is observed in major dust storms, so it's probably silica dust and not powdered concrete. However, I did also look at some OSHA figures for dust exposure and the highest density they obtained was on the order of 200 mg/m^3, which was taken from visible clouds of wood dust. I'm trying to establish an upper limit here, I guess.

(hoping he's just not made a fool of himself...)

 

[Belz...]

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

Should they have stacked up like in cartoons, again ? You do know that concrete tends breaks upon impact. And that WAS an impact.

Please retract your error, or lose credibility.

Now you're starting to sound like chris.

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

Looks pretty hollow to me.

ETA: Those structures inside the core were removed after construction. Try to imagine the building without them, now.

 

[chran]

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

When will you guys stop lying? The caption on the picture is wrong and misleading.

First of all. The quote appears on page 541 of the report (but page 558 of the PDF-file).

Second, the quote is incomplete (I know, what a shocker!). The complete quote is:

The interior core of the buildings was a hollow steel shaft, in which elevators and stairwells were grouped.

Doesn't sound hollow to me!

 

[Belz...]

Where is your evidence that they were not?

Doesn't work that way, son.

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

Ah! Asking for impossible proof. The core argument of any self-respecting CTer.

all that is needed is to initiate local collapse on one floor, gravity would do all the rest. Right?

I would think that one floor dissapearing suddenly would cause tremendous damage, depending on which floor we're talking about. 78 ? Near-total collapse, to be sure.

 

[Belz...]

Gravy has given us a picture of a chunk of something inside a room somewhere that appears to be concrete, and might weigh, oh, 1 ton. Assuming it is from WTC, this represents on the order of 1/100,000 of the concrete, and zero of anything else. Where is the rest of it?

You want pictures of ALL the chunks ? Impossible standard of evidence it is.

Wong, if you wish to consider the energy imparted by a falling mass onto something else, you must consider surface area to mass ratio, and air resistance. A 10 pound brick falling 1000 feet will take a person's head off. 10 lbs of fine dust will not.

Oh, yes it will, if it stays relatively compact. In the case of the WTC, I would think that most of the tower's mass, staying in the middle of the collapse, would still carry the same destructive force.

Mackey, where is your evidence that concrete ricocheted?

Well it sure as hell didn't stick.

Well, according to NIST logic, not very much. According to them, all that would be needed is enough explosive to break the vertical supports on one floor, and gravity would do the rest.

Not according to NIST, according to YOU, since you claim that NIST's assertion is impossible.

We could just as easily say that the OCT's are arguing from incredulity: It couldn't have been a controlled demolition because I can't believe "my" government would do such a thing, I can't believe so many people would keep the secret, etc.

RIght?

Please provide page number for this paraphrase.

My evidence that some very large percentage of the non-metallic contents of the twin towers was converted to powder is as follows:

THe entire body of photographic and video evidence.

From that distance, you could't tell a truck-sized chunk from a lump of Robin Hood powder.

Arkan, showing calcs of how much energy and time is required when something happens is not the same as showing that it did happen.

Again CTer mentality at work: calculations and logic are useless. They use common sense and "pictures".

 

[Belz...]

No. I'm saying that I (and anyone with eyesight) observe pulverization taking place. Except for the metallic components, the pulverization appears to be very thorough. I don't know exactly what percentage, but it is very thorough. I have looked and found no evidence of the hundreds of thousands of tons of non-metallic content of these huge buildings. Where did it go?

Any other hunch you wish to share with us ?

Therefore, these observations must be explained.

Non-sequitur.

No, the controlled demolition did not only occur at the bottom, that does not fit the observations.

You don't think that things go boom when they hit lower floors ?

Evidentally large explosions did take place in the basements before the collapses.

And, there we have it. "Evidently" presumes evidence. Please present it.

Observe in WTC1 how the 97th floor and everything below do not move as the floors above collapse to half their original height. Then, the next phase begins, and the tower begins collapsing from the impact zone downwards.

I hope that answers your question.

Here's that common sense at work, again.

Mackey, I'm still waiting for you to admit that you are wrong that the core columns of the towers were not cross braced. Yes, they were, all the pictures show it.

Seeing things in the pictures that aren't there ? That's not a good sign, as we've seen, twice, where that leads us.

Look, if a very tall building could "collapse" completely, the debris would be a tall pile in roughly a pyramid or cone shape.

Oh, like a kid dropping a handful of sand on the beach ?

I began this thread by asking if anyone had done calcs like Gordon Ross, except shown that collapse would continue, as opposed to Ross' conclusion.

Who cares ? It's pictures you want, as you've repeatedly shown.

I am not advancing a particular theory.

Controlled demolition is not a theory ?

I know intuition is not science, but when calculations corroborate intuition, it is pretty strong stuff.

No, it isn't, because calculations always win over intuition, so even if it confirms the intuition, said intuition was worthless, anyway.

1) "It is clear from photographs, such as the one on the right, that the core columns were abundantly cross-braced."

Clear ?

 

[T.A.M.]

Those are a couple, there are more...but CLEARLY there is more that metallic objects in those piles. The Photographers, I don't think, were not looking for "concrete" chunks, so it is not the focus. Anyone who say that only "metal" objects comprise these piles is just foolish.

Here are links to two more with large chunks of concrete at the bottom

http://www.w3.org/People/Jacobs/2001/10/wtc/pdrm1943.jpg
http://www.w3.org/People/Jacobs/2001/10/wtc/pdrm1956.jpg


TAM

 

[T.A.M.]

My physics and Engineering knowledge is limited to 1st year college, so I have a question.

Is it possible that the large mushroom cloud of "ash/concrete/drywall/etc" we see as the building is coming down could be 95% drywall, with the concrete still relatively (relatively) intact, and then upon impact with the ground, the concrete is largely pulverized, creating the larger cloud that appears after complete collapse.

An honest question?

TAM

 

[Belz...]

Is it possible that the large mushroom cloud of "ash/concrete/drywall/etc" we see as the building is coming down could be 95% drywall, with the concrete still relatively (relatively) intact, and then upon impact with the ground, the concrete is largely pulverized, creating the larger cloud that appears after complete collapse.

I don't see why the concrete wouldn't break into smaller and smaller pieces until the end of the collapse. I don't think it needs to hit the ground to pulverise. That's a simplification.

My opinion, of course.

 

[T.A.M.]

True, but if we are to understand that the building underneath offered little resistance to the collapse, I just thought that large parts of the concrete at the top of the building would have less damage done to it until it reached the bottom, or the "effective" bottom of the fall so to speak, and then it would become pulverized.

 

[kevin]

Well, according to NIST logic, not very much. According to them, all that would be needed is enough explosive to break the vertical supports on one floor, and gravity would do the rest.

and you would be wrong. According to NIST to bring down WTC you need severed columns, removed fireproofing AND massive multi-floor fires.

Their load analysis on the building shows that with fires and intact fireproofing the building would've remained standing. Even with removed fireproofing the fires probably wouldn't have brought it down. Only with all three does the load capacity drop to zero.

Oh, and do you have those pictures showing complete pulverization yet? I can't find any.

 

[Shrinker]

True, but if we are to understand that the building underneath offered little resistance to the collapse, I just thought that large parts of the concrete at the top of the building would have less damage done to it until it reached the bottom, or the "effective" bottom of the fall so to speak, and then it would become pulverized.

TAM, I've got no credentials in this topic but I alwasy assumed that most of the pulverisation happened when the floors hit 'the ground'. Firstly because the ground would offer more resistance and secondly because the cloud of dust arising and the end of the collapse seems much more dense than the cloud that appears during the collapse. That also explains how the building can almost freefall and smash itself to bits.

 

[tsig]

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?

good old gravity

 

[David Wong]

OK.

h t t p://www.acebaker.com/KingdomCome/Tower%20Explodes.jpg

h t t p://www.acebaker.com/KingdomCome/mushroom.jpg

h t t p://911research.wtc7.net/papers/dustvolume/volumev3.html

Now, please show me significant carpet, curtain, floor, or ceiling tile that remained macro.

No, no. I expressed myself poorly. I mean, in other known controlled demolitions, with explosives, is all of the non-metallic material turned to powder? I ask because the "pulverization" of all the non-metals to tiny chunks seems to be your primary indication of controlled demolition...

...But I don't think such pulverization is typical in those demolitions.

I'm not getting into whether you're right or wrong about the pulverization. I'm not qualified. I'm just trying to understand what you're saying.


I mean, if you could indeed prove the concrete had all been pulverized, my first reaction would be to ask if the concrete had been mixed properly at the time of construction, if there wasn't some kind of flaw in the process that made it brittle. Maybe there could be an investigation into that, for safety concerns.

But I would not draw the connection from that to controlled demolition unless someone could demonstrate that pulverization is common in other controlled demolitions. Right?

 

[TruthSeeker1234]

I said I was

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

and bellz claimed I was

Asking for impossible proof. The core argument of any self-respecting CTer.

Impossible proof? Nonsense. How about a GZ pic like this

or like this

 

[Belz...]

Okay, let me get this straight. You're comparing a 110-storey building with a 5-storey building and expect them both to collapse in the same manner ?

 

[Arkan_Wolfshade]

I said I was
and bellz claimed I was
Impossible proof? Nonsense. How about a GZ pic like this[qimg]http://www.msnucleus.org/membership/html/k-6/pt/hazards/6/images/carcus.jpg[/qimg]or like this[qimg]http://www.terradaily.com/images/pakistan-earthquake-building-collapse-bg.jpg[/qimg]

How about accepting that there is valid, corroboratable, objective evidence beyond that which is photographic in nature?

 

[gumboot]

Okay, let me get this straight. You're comparing a 110-storey building with a 5-storey building and expect them both to collapse in the same manner ?

The concrete in those buildings appears to be fairly structural too...

I'm not sure if this helps, but the NIST report on the towers mentioned how the "spider web" floor trusses were stacked up together at GZ in enormous piles (which supports the "pancake" theory).

I recall it clearly, because NIST had wanted to pull out specific floor trusses, but the clean up crews had found it hard to deal with enormous stacks of steel grids, so they'd rolled them up into gigantic balls. As a result NIST ended up having the take the entire balls of 20 or so floor trusses as one piece (it was too hard to work out which truss was which floor) and as a result ended up with far more steel than they needed.

That story just stuck in my mind because it was so strong a visual image.

-Andrew