The Obligatory 9/11 Thread Part II

[Agi Hammerthief]

But then in two places it says that the distribution of weight is important to analysing the aircraft impact but then they don't do it.

quotation please so we can see the context.
Page referrence will do, I know the original reports don't allow coppy/paste.

[psikeyhackr]

So show us where the $20,000,000, 10,000 page NCSTAR1 report specifies the total amount of concrete in the towers.

What possible use to you (or anyone else) is a figure for the total mass of concrete in a tower?

Then what use was the total amount of steel and yet the NIST specified that in three places, 200,000 tons?

The steel did hold up the concrete didn't it?

So all you can come up with is rhetorical BS because the NIST left out that concrete data.

psik

[tolman]

Then what use was the total amount of steel and yet the NIST specified that in three places, 200,000 tons?

Just because a figure may be mentioned in the report doesn't mean that it's necessarily the slightest bit of use in calculations of the strength or resilience of the intact or compromised structure.

Are there any suggestions in the report that there was some formula that 'total mass of steel' could be plugged into that was at all relevant to the collapse?

So all you can come up with is rhetorical BS because the NIST left out that concrete data.

All you can come up with are things to try and divert attention away from the fact that there's fuck-all you could do in terms of actual engineering calculations if you had a figure for the total mass of concrete.

You're just pretending the figure is relevant so you can make a big whine about being denied it, in an attempt to claim 'cover-up!'.

[Agi Hammerthief]

You're just pretending the figure is relevant so you can make a big whine about being denied it, in an attempt to claim 'cover-up!'.

c'mon you can't stick it on Pisk that he's claiming anything

he's very carefully denying any form of claiming and is essentially Just Asking Questions

[psikeyhackr]

he's very carefully denying any form of claiming and is essentially Just Asking Questions

You mean I have never claimed that skyscrapers are bottom heavy and that we don't have accurate data on the distributions of steel and concrete?

psik

[quas]

What do the skeptics think when someone say that if the pancake theory is true, then there should be a stack of "pancakes" (a stack of neatly packed floors) left behind?

[tolman]

You mean I have never claimed that skyscrapers are bottom heavy and that we don't have accurate data on the distributions of steel and concrete?

You've gone on at length about how skyscrapers are bottom-heavy - something which is unlikely to greatly surprise anyone with even a basic understanding of structures.

However, you haven't rationally engaged with what that means.
You seem to have determinedly failed to understand and/or admit that a bottom-biased mass distribution is of limited relevance to the potential for progressive collapse, where that collapse is essentially based on the local performance of relevant structural features (such as floor connections) in the energy domain, rather than the 'strength of columns'.

Columns which you seem to insist had to be 'crushed' by the progressing collapse even when it's clear that they weren't.

From which long-clung-to misunderstanding/misrepresentation, you implicitly or explicitly claim that there must be some explanation much better than the official one, despite you signally failing to give much idea what you think such an explanation is, or showing much indication that you could ever hope to provide such an explanation from your own understanding of engineering, even if you had mass figures accurate to the nearest gram.

[tolman]

What do the skeptics think when someone say that if the pancake theory is true, then there should be a stack of "pancakes" (a stack of neatly packed floors) left behind?

Personally, I'd think that the 'someone' had fuck-all idea what the pancake theory involved, and quite possibly a decidedly limited understanding of physics.

[Dudely]

What do the skeptics think when someone say that if the pancake theory is true, then there should be a stack of "pancakes" (a stack of neatly packed floors) left behind?

I would say they have a laughably cartoonish picture of the way the world works.

As a side note I'm pretty sure us skeptics debunked the pancake theory a while back. Turns out that, contrary to popular belief, we don't just pick on conspiracy theorists.

[Dudely]

So show us where the $20,000,000, 10,000 page NCSTAR1 report specifies the total amount of concrete in the towers.

What possible use to you (or anyone else) is a figure for the total mass of concrete in a tower?

Then what use was the total amount of steel and yet the NIST specified that in three places, 200,000 tons?

The steel did hold up the concrete didn't it?

So all you can come up with is rhetorical BS because the NIST left out that concrete data.

psik

Consider the following:

T is the weight of the falling mass (increases as each collapsed floor (A) is added to it),
C is the force needed to collapse the next floor (increases as each floor gets heavier and more capable of holding up the tower above it),
N is a constant denoting how much energy the falling mass will gain as it falls to meet the next floor (increases in lockstep with T),
A is a constant denoting how much the weight increases by per floor (the distribution of mass, if you will). Could be combined with C but is technically a different number.

If T + N > C the floor will collapse. That is, if the weight of the top block + the energy it gains falling one story is great enough it will collapse the next floor.
For each floor collapsed T gains A but loses C. The proportion by which both A and C increase is the same, so this is sort of a 2+2-2 scenario. It also gains N every time, which increases as T increases from gaining A. Additionally, any energy gained from N that is not consumed by C is carried down to the next floor. T was initially enough to collapse the first floor, so the weight of that floor (A), plus the weight of T, plus N, plus the carryover is much greater than C and its proportional increase.

This means that not only can a tower collapse so long as the first floor gives out from the initial mass, once the collapse has started the tower must collapse the entire way. There is no possibility for the collapse to stop or even slow down.

The model you designed where the collapse stops after 6 or 9 floors (or whatever it was) is not correct. Why is it not correct? Because you dropped the initial mass from a great height! In your experiment the initial N your T gained was far, FAR greater than the N it would gain over each additional floor! If you wanted to make a model that was accurate you'd need to make one that collapsed the next floor due to the top mass falling the distance of only one floor, just like the WTC. However, in your videos you've often explained that you've made them as weak as you could. This should be a clue as to why engineers don't build tiny models of huge structures: because a steel rod 20 feet long doesn't work the same way one that's 2 inches does! It's not possible to make a scale model of the WTC and have it work the same way the one a mile high did.


Please keep in mind this is VERY rudimentary math. In order to be as simple as possible there are many things not taken into account. I hope I came across clearly.

[Agi Hammerthief]

he's very carefully denying any form of claiming and is essentially Just Asking Questions

You mean I have never claimed that skyscrapers are bottom heavy and that we don't have accurate data on the distributions of steel and concrete?

that is pretty much that's what it boils down to:
you are repeatedly Just Asking the Question why we don't have accurate data.
even though it has been explained to at you numerous times.

You just won't shut up about it AND you won't put up when you are being asked question whose answers might jeopradise your high opinion of your models.
You don't even offer an alternative mode of collapse.
Even if everybody, miraculously, was agreeing with you? sooo... what? next step? -- crickets chirping --
you actually don't have anything to show, exept those stupid models which have been taken apart repeatedly.
But of cause you invested a lot of time in your precious creations and having someone TALK them worthless just can't be, eh?

I mean that you are Concern Trolling intentional or not.

While "general conspiracy cheer squad" Galaxian is suspended, the only positive about your posting here is: apparently you are emberrasing all other 9/11ers away, lest thet be associated with being on your side.
I guess you don't give a FAQ about that either, but if you don't like our arguments for being "talk" the lack of 9/11 deniers jumping on your train should get you thinking.

[psikeyhackr]

Consider the following:

T is the weight of the falling mass (increases as each collapsed floor (A) is added to it),
C is the force needed to collapse the next floor (increases as each floor gets heavier and more capable of holding up the tower above it),
N is a constant denoting how much energy the falling mass will gain as it falls to meet the next floor (increases in lockstep with T),
A is a constant denoting how much the weight increases by per floor (the distribution of mass, if you will). Could be combined with C but is technically a different number.

Let's consider what you have chosen to ignore.

You have 'C' as the Force required to collapse a LEVEL.

But since each LEVEL is 12 feet high. C * 12 is the amount of WORK required to collapse a LEVEL. That takes energy. The only source of energy is the kinetic energy of the falling mass. That means it must SLOW DOWN.

You have the mass always gaining energy due to gravity but never losing energy in the process of collapsing LEVELS.

That is what my model demonstrates. It takes 0.118 joules to crush one of my single paper loops. Since the paper loop had to be strong enough to support the static load above it ends up taking more energy to crush the loop than the mass gains coming down. So it eventually STOPS.

You are distorting your math to justify your conclusion. Physics does not care about distorted math. You admit a Force was required to crush a level, so that force had to be applied for some distance though it may not be constant over that distance so you would need to know the average. But it would still be doing work which would mean energy loss.

So why don't you build a physical model that can completely collapse and PROVE your math?

psik

[psikeyhackr]

Accidental Dup. Screwy router.

[tolman]

Let's consider what you have chosen to ignore.

You have 'C' as the Force required to collapse a LEVEL.

But since each LEVEL is 12 feet high. C * 12 is the amount of WORK required to collapse a LEVEL. That takes energy. The only source of energy is the kinetic energy of the falling mass. That means it must SLOW DOWN.

So you're still pretending that the only way a building can progressively collapse is by crushing the vertical supports in-situ?

Even though you have been repeatedly shown that was not what happened at the WTC buildings, and you must have watched videos where outer wall column sections* could be seen to shear off largely intact, and seen innumerable pictures where blinding obviously vertically-uncrushed panels lie all over the place?

http://911research.wtc7.net/wtc/evidenc ... 3sep2.html
http://911research.wtc7.net/wtc/evidenc ... heli1.html
A lot of remarkably flat/straight pieces of column there.

(*which also hit various other buildings after falling off the WTC basically intact)
http://911research.wtc7.net/wtc/evidenc ... scue2.html

Your statements about column crushing are deliberate distortions of the truth to try and fit reality to your inadequate model.

[Agi Hammerthief]

Let's consider what you have chosen to ignore.

the irony, it's hilarious

[Dudely]

Consider the following:

T is the weight of the falling mass (increases as each collapsed floor (A) is added to it),
C is the force needed to collapse the next floor (increases as each floor gets heavier and more capable of holding up the tower above it),
N is a constant denoting how much energy the falling mass will gain as it falls to meet the next floor (increases in lockstep with T),
A is a constant denoting how much the weight increases by per floor (the distribution of mass, if you will). Could be combined with C but is technically a different number.

Let's consider what you have chosen to ignore.

You have 'C' as the Force required to collapse a LEVEL.

But since each LEVEL is 12 feet high. C * 12 is the amount of WORK required to collapse a LEVEL. That takes energy. The only source of energy is the kinetic energy of the falling mass. That means it must SLOW DOWN.

You have the mass always gaining energy due to gravity but never losing energy in the process of collapsing LEVELS.

That is what my model demonstrates. It takes 0.118 joules to crush one of my single paper loops. Since the paper loop had to be strong enough to support the static load above it ends up taking more energy to crush the loop than the mass gains coming down. So it eventually STOPS.

You are distorting your math to justify your conclusion. Physics does not care about distorted math. You admit a Force was required to crush a level, so that force had to be applied for some distance though it may not be constant over that distance so you would need to know the average. But it would still be doing work which would mean energy loss.

So why don't you build a physical model that can completely collapse and PROVE your math?

psik

I am subtracting C. Read it again. It's not C *12. That's insane. The falling mass will GAIN energy as it falls 12 feet to the next floor not lose it! (the walls are fairly inconsequential for what we are calculating, as they did not support anything) The main energy consumed in the collapse is in overloading the floor until it breaks away and collapses. This happens once for each floor; it does not happen every foot of the way as you suggested!
Once the floor collapses it joins the falling mass and it will gain energy as everything falls the next 12 feet. Each floor is, of course, heavier and harder to collapse than the last- this means that not only do you need more energy to cause it to fail, but once you do you get MORE energy traveling the next 12 feet than you did the last 12 feet! If you do that math this is a net GAIN of energy per level, not a net loss. This also explains why the collapse accelerated. If you cannot comprehend how a structure can be strong enough to support itself yet weak enough to collapse given these circumstances I'm afraid I can't help you. You're going to have to logic that one out on your own.

Paper loops don't work because they don't have a single point of failure like a floor does. Even after a paper loop collapses you need additional energy to collapse it further and further. This does not happen in a tower collapse! Ironically, this means that, given a collapse involving paper loops, the calculation really is C*12! So you are right on that point .

You also have not addressed my concern about the initial amount of energy and what that means.

I told you why I'm not building a physical model. It can't be done with any amount of accuracy. Instead I can prove it with simple logic.

[tolman]

Possibly it'd be better if energy-related arguments stuck to using energy exclusively rather than mentioning forces (or at least only sidestepped into forces when describing the details of particular energy-consuming interactions).

[psikeyhackr]

I am subtracting C. Read it again. It's not C *12.

You can regard it as insane all you want. Collapsing a level of the core means applying a force for a distance.

That is WORK. That requires ENERGY. The only source of energy is the Kinetic Energy of the falling mass. You just add mass like it is magic. Where did you take the conservation of momentum into account? The mass alone will slow the falling mass but you don't have calculations for velocity at all.

You just BELIEVE your DELUSIONAL math and don't know how to apply math to the physics.

I already provided a Python program and showed that mass alone slowed the falling mass down. So expending energy to collapse levels would slow it even more.

psik

[Wuffy]

Uh, I thought things that fell accelerated towards terminal velocity as they fall.

[tolman]

You can regard it as insane all you want. Collapsing a level of the core means applying a force for a distance.

If you're suggesting the columns were (or should have been) crushed the same way your paper rings were, I think you're indulging in wishful thinking.

I already provided a Python program and showed that mass alone slowed the falling mass down. So expending energy to collapse levels would slow it even more.

Well, what your program showed was that initial impact velocity is relatively unimportant (meaning that your 'I dropped a mass from N floors onto the tower' experiment is less impressive than it might first appear.

For your demands for 'crushing', you currently seem to be ignoring the columns in the outer shell and concentrating on the core.

However, you can't really be suggesting a direct parallel with your 'paper ring' model since in the WTC, the connections between an individual floor and the core seem unlikely to be strong enough to 'crush' the core however heavily the floor is loaded, assuming that the tower below that point is basically intact.

In your model the failure mechanism must be crushing, in the WTC it seems unlikely that it could be.

In reality it would seem that (ignoring any local impact damage) damage to the core would come from some combination of physical damage from the mass of falling debris, and buckling as a damaged core is loaded from above by the building section above the point of collapse initiation.
Such damage would seem to have potentially much lower energy absorption than crushing would.

If you're suggesting that for energy reasons a natural collapse of the speed observed at the WTC couldn't have taken out the core, you're necessarily claiming that the collapse was both unnatural and contrived by people less knowledgeable than you are in structural matters, who must (for some as-yet-unexplained reason) have gone out of their way to do extra work and destroy the core rather than leaving it standing.
Yet that 'obvious' fact which even you can see is somehow being ignored by any number of structural engineers and related engineers/physicists around the world.

Where were the 'crushed' columns at the WTC remotely analogous to your paper rings ?
I didn't see anything in the pictures beyond pieces with either gentle bends in, or with tight bends amid fairly straight sections.
Nothing that could really compare to a crushed paper ring in terms of damage, yet you seem to suggest that pretty much all the core uprights must have been 'crushed'.

If there weren't any 'crushed' columns seen, to most people that would at least suggest that your model might have been inadequate.

To you, it would seem to suggest some huge conspiracy - if there weren't 'crushed' columns, rather than trying to get your head around any other natural collapse mechanism not involving crushing such as the ones actually widely suggested as being what happened, you conclude that something is Dreadfully Wrong.

Well, I think something is Dreadfully Wrong, but with your reasoning, not the real world.