The 9/11 Forum

by **OneWhiteEye** » Wed May 05, 2010 6:21 am

Darkwing wrote:Can't imagine it should matter too much. Except if you are deliberately misleading.

No, not intentionally, but I see how it could be viewed as a deal breaker. I sorta think I should tell you.

Let's put it this way: I am not going to assume that the law is obeyed globally, since that is what we are trying to ascertain. Make sense?

Yes. Or that the law is obeyed, but only with or without energy assistance beyond PE. It is a collapse example.

by **Darkwing** » Wed May 05, 2010 6:27 am

Sorry didn't see the new page.

No, not intentionally, but I see how it could be viewed as a deal breaker. I sorta think I should tell you.

I couldn't say, I can't think of anything immediately that would constitute a deal breaker. It is like a famous puzzle isn't it?

It might take a while depending on what exactly it is you are thinking.

Yes. Or that the law is obeyed, but only with or without energy assistance beyond PE. It is a collapse example.

Seems fair.

by **OneWhiteEye** » Wed May 05, 2010 6:34 am

Darkwing wrote:I only need to know if the system in question has changed in terms of information/energy/force distribution at a particular level of detail and in which way it has.

I may have to get my hands on another example, I can answer rough qualitative questions on this but that's about it. In some respects, that's similar to the situation with the towers, who can say what (e.g.) the actual KE is at any given time?

I can tell you are going to make this a hard one though lol, I'm off for a little while.

I won't try to make it hard. It already seems hard to me. It's not the sort of challenge I'd take because I'm not sure I could come to any real conclusions through this avenue. I'm pretty sure I couldn't, but I think your process is amenable since it doesn't seem to require a lot of detail.

Go ahead whenever you're ready.

You start, when you're ready, by asking for whatever you need to know. Size, shape, composition. You can always bail with no penalty and we can give up or try another one. I'm not sure that I can always give adequate answers on this one, we'll see.

By passing all information through the pipe of postings, I get a good feel for what information you need. By asking why, I get to see how it fits in the picture. By restricting it, you obtain only that information you believe you need and not more subliminally or whatever. I've no objections to showing you the visuals, but only if you feel you need it.

Given: a structure has collapsed
Question: is it solely gravity-driven?

by **OneWhiteEye** » Wed May 05, 2010 6:37 am

How about this? I won't tell you, but if it proves a deal-breaker later, I'll concede it without protest. I think it could be informative, and the example may need to be abandoned in favor of another if I can't adequately satisfy queries anyway.

by **Darkwing** » Wed May 05, 2010 6:47 am

Given: a structure has collapsed
Question: is it solely gravity-driven?

Okay.

Let me start at the start then:

If all we know is that the system started at rest | came into motion / and ended at rest | then we need to explain what caused the initial change in distribution of forces.

Was the building stable before this event?

If it was on the verge of collapsing in any case then nothing more needs to be explained from this perspective and we can assume (if that is all we know) that gravity alone was involved ala Occam. The push from stable to collapse can then be assumed to be some breath of air or quantum event.

We don't need to explain /->| because | is taken as representing all the forces, particles, energy being symmetrically distributed in terms of Minkowski boxes in phase space. Information is minimized in this state and Entropy maximized for our system.

by **OneWhiteEye** » Wed May 05, 2010 6:58 am

I will tell you if happen to hit upon the 'secret' just by asking questions. This is like a Turing Test for collapses, kind of. No win or lose, no "too many questions", and really - no wrong answer. I've already said I don't think I can do it so there'll be no nyaa nyaa nyaa crap. It's to probe and learn, maybe all the way around.

(cross-post, let me read yours)

=>Was the building stable before this event?
There is an upper and lower portion, upper falls onto lower. Aside from this defect which is responsible for an initiating event, the two pieces are initially intact and were once part of a self-supporting structure (edit: once composed the whole of a stable, self-supporting structure). I give this much information because, as you can see, it's a little of this and a little of that. In yes or no terms, no.

If it was on the verge of collapsing in any case then nothing more needs to be explained from this perspective and we can assume (if that is all we know) that gravity alone was involved ala Occam.

Damn. OK. That was fast! Read my answer above... I guess we're done. It was fun, though. If you give me time I can come up with an example with a little more staying power.

See edit, if that matters.

by **Darkwing** » Wed May 05, 2010 7:02 am

Damn. OK. That was fast! Read my answer above... I guess we're done. It was fun, though. If you give me time I can come up with an example with a little more staying power.

Hehe, I love the idea that there is nothing intrinsic in physics that prevents a boot from appearing above my head at any moment and clobbering me over the head.

One can only assume it is unbelievably unusual for such a thing to happen and then hope for the best lol.

Keeps you honest :shock:

by **OneWhiteEye** » Wed May 05, 2010 7:08 am

What I can't come up with, though, is an example of something that is totally and integrally stable while it collapses. That's by definition. There has to be an initial defect, however small, although I might be able to come up with an example of quasi-static decay of integrity rather than a discretely imposed defect (projectile, cut, etc).

by **Darkwing** » Wed May 05, 2010 7:26 am

What I can't come up with, though, is an example of something that is totally and integrally stable while it collapses. That's by definition. There has to be an initial defect, however small, although I might be able to come up with an example of quasi-static decay of integrity rather than a discretely imposed defect (projectile, cut, etc).

Well, I can see how one can treat something as behaving that way for all intents and purposes the way Bazant does.

What I can't see is what Bazant is using to make it stop behaving that way all of a sudden.

The only force that is unaccounted for is this object hitting the floor at speed at which it was traveling through the building and coming to a rest (i.e. the change in force distribution which is acting on the "object").

I simply can't see how this "object" can crush the whole building with no deformation and then that force have it tip into a catastrophically unstable state. Unstoppable force: Meet immovable object.

But I can see the the remainder can be quantified though if you define it in probabilistic terms, you could figure the MINIMUM energy input that it would take for such an object to discombobulate to the desired granularity by chance. That would also represent the minimum amount of explosives needed.

My feeling is that it would be a rather large number.

You can for example estimate the required grain size, you can estimate how big this "object" needed to have been to have crushed the whole building and you can estimate how coherent it must have been to have not disintegrated in the process.

by **OneWhiteEye** » Wed May 05, 2010 7:30 am

A most interesting post.

If I gather, your primary objection (not only, maybe) revolves around the rigidity of the upper block which can be switched on/off as convenient?

by **Darkwing** » Wed May 05, 2010 7:32 am

If I gather, your primary objection (not only, maybe) revolves around the rigidity of the
upper block which can be switched on/off as convenient?

That is the whole kaboodle of my objection.

by **OneWhiteEye** » Wed May 05, 2010 7:33 am

That is a legitimate objection.

by **Darkwing** » Wed May 05, 2010 7:36 am

That is a legitimate objection.

But I can't do the math on it though hehe, that's what you guys are good at.

I reckon Bazant's why of describing the thing is actually quite brilliant to be honest, it is very neat. Just that he assumes that the block is rigid and is not rigid in the the argument.

Given that set of postulates I can prove that manta rays off the coast of Papua New Guinea did it with their psychic powers. Perfectly logically too.

This is what I came up with for the equation so far, I still need to refine a bit more:

I propose, therefore, that the next step in the investigation should be to define a lower limit for the size of the "pile driver" if it is considered as a single homogeneous entity.

In order to satisfy the requirements the pile driver must be able to effect a total collapse without being dropped onto the intact lower structure since it represents an amalgam of all the relevant forces already. This can be done with accurate FEA analysis (or other other similar techniques). Properly constructed physical modelling can also be used to find the minimum size object required to achieve this.

The number can be calculated by first working out the number (N) of dust sized particles present in a block of the required mass and average density of the material available in the building. The average particle, I suggest, should small enough to be able to be carried by the wind, but observation can be used to establish a rough average size estimate.

Then the minimum amount of energy required to dissociate this number of particles will be given by the energy required to dissociate two particles (eD) multiplied by the number of particles minus one.

One particle is already dissociated O, two require 1(eD) to dissociate OO -> O O, three requires 1(eD)+1(eD) = 3-1(eD) to dissociate OOO -> OO O -> O O O; and so forth. The energy needed to dissociate the particles must be able to at least overcome enough cohesiveness for the block to not deform in the descent through the building.

The calculation will then be given by E=(eD)(N-1).

This value can be subtracted form the energy involved in the final impact of the upper portion of the building with the ground to give the minimum energy required to effect the collapse as observed. The forces involved in crushing the the building has already been accounted for and were not sufficient to deform the object, so they may be disregarded.

That energy can be expressed as the probability for that amount of energy to be spontaneously generated as a result of quantum processes or alternatively as the amount of explosives involved or some combination of the two.

It might not be an exactly correct formulation, but I think something along those line would do the trick.

by **OneWhiteEye** » Wed May 05, 2010 7:54 am

But I can't do the math on it though hehe, that's what you guys are good at.

That's all I'm trying to do, really. I've no beef with your objection, I started two threads which specifically address the issue, one simulation-oriented and one analytical.

This objection was addressed by Bazant&Le in their reply to James Gourley. Having read the rebuttal and reply, I'd have to say that Bazant came out on top. That's not to say I'm satisified, but between the two Bazant was able to provide a far more convincing argument framed (naturally) in terms I could understand, that common language of physics and mathematics that we both speak. Gourley's points were less concrete and, while he grappled to express (admittedly solid) intuitive notions in a precise way, Bazant went straight to assumptions, model, equations, and results like a jackhammer.

I don't agree with the assumptions as being at all representative. In a nutshell, I think Gourley's points were basically right but for entirely different reasons than given and Bazant's reply correct but inapplicable. And none of it really and truly addressing the question at hand.

No matter what theory might say, I see the disintegration of the upper block, and cannot deny the evidence. A successor theory must emerge which accounts for observables.

My hypothesis is that the rigidity is not required to effect complete collapse. Many others share that, it's hardly unique. Some have a real hard time swallowing the highest rates observed, and I'm having a very hard time accounting for that, but continuation/completion is treated differently around here than rate which is also distinct from initiation. Usually.

by **OneWhiteEye** » Wed May 05, 2010 8:02 am

Then the minimum amount of energy required to dissociate this number of particles will be given by the energy required to dissociate two particles (eD) multiplied by the number of particles minus one.

On the particles, I offer this:

http://the911forum.freeforums.org/henry-couannier-vs-greening-concrete-pulverization-calcs-t298.html#p7812

That thread's a doozy, low energy nukes come up at one point. BUT, great stuff on comminution. Maybe not exactly what you're after, but there's plenty of good reference.

The 9/11 Forum

Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Re: Much Ado About Nothing

Who is online