"Inside Job": Hidden energy in reports by Prof. Bazant, Dr. Greening and D. Thomas

Ahoy ATS!

I hope you'll enjoy this "layman's open letter" to Professor Bazant et al: www.dugarun.de...

In short, the very calculations on which the whole "official conspiracy theory" rests are correct, as they manage to model a "collapse" within the given time. Truthers' calculation show that collapse should be arrested, ergo, these must be incorrect. So, instead of debating Bazants errors, we should take a closer look at what Bazant et al are actually doing in their equations.

They provide for a constant force of 58,000 t * 9,81m/s² * 31 all the way down to Ground Zero instead of an impulse. Energy is Force times Way. Greening does it the same way, and so does Thomas, just from slightly different approaches. Confronted with the fact that they've actually proven that 9/11 was an "inside job" (with energy already hidden INSIDE the towers, which they don't mention because they want to disprove that very theory), their reaction was somewhat... remarkable. After a short discussion, Dr. Greening replied: "The 'spring' you refer to was not compressed 400 meters! It was broken into a million pieces long before that, so your calculation is meaningless." So, first, it's unharmed except for the holes and the fires, then it's broken all the way down in such a way it couldn't even support itself.

What else do you need than experts contradicting themselves? Please share with the scientific community; experts who produce papers like these only two days after the tragedy and stick to their "mistake" ten years later, after thousands of people were killed and tortured based on their math, should be accused of lysenkoism by their colleagues for the un-light they shed on science and for the way they perpetuate superstition, blind belief and all that we thought to have left behind us in the "dark ages". Scientists around the world should uphold the torch of illumination passed to humanity ever since Archimedes, Galileo Galilei and Isaac Newton, whether it fits their policies and beliefs or not.

If you're young, please share with your teachers, and if you're old, check with your kid's text books, and don't be afraid of those seemingly complex formulae. All in all, it's not more than four basic principles of nature's laws.

We were told to pray to god, whilst we were deaf to the prophets and wise men that he sent us to explain that all beauty and complexity in his creation is based on just few rules (like actio=reactio, 2+2=4), and were subdued to a plethora vera of man-made laws instead.

Peace!

(If you're good at german, you might want to check Truth is Bunk and Warum das World Trade Center zerkrümelt ist (von einem Laien für Laien) too).

reply to post by Akareyon


What do you mean by "constant instead of impulse?" I'm not sure I understand.

reply to post by Varemia


continued versus sporadic

Originally posted by Panic2k11
reply to post by Varemia

 

continued versus sporadic

If the debris was impacting as a flood of material rather than a block-on-block scenario, as one might expect from a highly chaotic and destructive collapse, then it would not have a sporadic impact sequence. It would be continuous, wouldn't it?

I mean, the way I'm seeing it, only the first second or so of the collapse might be slightly sporadic, but after that, the weight of the non-uniform debris would be breaking trusses separately and tearing apart horizontal supports on the way down. That's why some of the debris was breaking out the windows seemingly "under" the collapse. Maybe I'm just seeing it wrong, but that's the way it looks to me.

Originally posted by Varemia
reply to post by Akareyon

 

What do you mean by "constant instead of impulse?" I'm not sure I understand.

It's the difference between hitting a nail once with a light hammer or putting a real big and heavy hammer on the nail so it slides into the wood under gravity's force.

Bazant/Zhou (2002), Bazant/Verdure (2007), Greening et al first calculate the force of the small hammer upon impact on the nail's head which would sink the nail a few millimetres into the wood. They say that the resulting force would be 31 times the weight of the small hammer, depending on the stiffness of the nail and the speed and weight of the hammer. Then they take a huge hammer which weighs 31 times as much as the small hammer and carefully put it on the nail's head to prove their point, because now, the nail slides into the wood. That's the whole trick, basically.

reply to post by Akareyon


That sounds like a gross simplification. I'm not sure if I follow. In the building collapse, was it not constant and impulse at the same time? You had impacts and gathering weight in an extremely rapid time-frame. It's kind of like impacting a person with a rubber bullet. Take the one impact, and you'll get a bruise, but will be fine. Do a hundred of those all over, and suddenly you're down.

reply to post by Varemia


Varemia, you may want to read the Bazant papers again to understand their model.

They "drop" the top floors above the impact zone from 3.7m height on the rest of the building which is perfectly fine, not burning, not weakened. This way, they "simulate" the onset or the "initiation" (which the NIST report of 2005 described in great detail) of the "collapse sequence" (which they blanked out as if that's the way buildings are supposed to behave nowadays because Professor Bazant said so ever since September 13th, 2001). Based on this premise, they show that global collapse was "inevitable".

Mathematically, they shoot 108 "invisible" rubber bullets to prove one single bullet could bring someone down.

Originally posted by Akareyon
reply to post by Varemia

 

Varemia, you may want to read the Bazant papers again to understand their model.

They "drop" the top floors above the impact zone from 3.7m height on the rest of the building which is perfectly fine, not burning, not weakened. This way, they "simulate" the onset or the "initiation" (which the NIST report of 2005 described in great detail) of the "collapse sequence" (which they blanked out as if that's the way buildings are supposed to behave nowadays because Professor Bazant said so ever since September 13th, 2001). Based on this premise, they show that global collapse was "inevitable".

Mathematically, they shoot 108 "invisible" rubber bullets to prove one single bullet could bring someone down.

edit on 13-11-2011 by Akareyon because: (no reason given)

The Bezant and MIT type papers appear to be written to explain how the OS could have occurred, rather than explain what actually occurred.

reply to post by septic

Actually, Bazant et al (2002, 2007) try to prove THAT a "gravitational collapse" could have occured after initiation. HOW and WHY, they make educated guesses (column buckling and so on).

NIST (2005), on the other hand, explained everything up to the point of collapse initiation, then the screen goes black ("this page is intentionally left blank") for half a minute or so and then the towers are gone, because, because... well, it's the most logical thing to expect!

reply to post by Akareyon


That's just because NIST's job was to provide suggestions on how to design a building to prevent a similar collapse. The Madrid building's fire and subsequent lack of collapse shows that those suggestions worked.

So, to make those suggestions, they worked out what could have caused the collapse to initiate. I don't think any of them anticipated that people would believe that the building would be able to hold itself up even though it has no vertical columns outside the core, and the core did remain standing for a moment after collapse, meaning it was mostly failure of the truss system that doomed the tower during the collapse. I mean, maybe I'm wrong?

reply to post by Akareyon

What else do you need than experts contradicting themselves? Please share with the scientific community; experts who produce papers like these only two days after the tragedy and stick to their "mistake" ten years later, after thousands of people were killed and tortured based on their math, should be accused of lysenkoism by their colleagues for the un-light they shed on science and for the way they perpetuate superstition, blind belief and all that we thought to have left behind us in the "dark ages". Scientists around the world should uphold the torch of illumination passed to humanity ever since Archimedes, Galileo Galilei and Isaac Newton, whether it fits their policies and beliefs or not

S&F

Hear, hear. Science magic for the masses, a sort of pseudo religion for the incurious. I don't pretend to understand the math, as I learned my physics by falling off bicycles, but I particularly liked this paragraph from the layman's guide:

The towers were „doomed“ and collapse was „inevitable“ only under the assumption that for each floor, the rules of Fig. 4a apply. It is hard to see why such a building would be allowed to be built in the first place, as its collapse bears features of a metastable system or a 19th century perpetuum mobile mechanism rather than of anything remotely statical; just a small impulse would trigger a huge mechanism that switches from decelerating earth’s 9.81m/s² to 0m/s to accelerating 500.000.000 kg structure of steel and concrete with 0.42 gs so it keeps moving all the way, folding into itself.

Originally posted by Varemia
reply to post by Akareyon

 

That sounds like a gross simplification...

An over used excuse to ignore facts. If you can't understand a simple explanation, how are you going to understand anything more complicated?

I'm not sure if I follow. In the building collapse, was it not constant and impulse at the same time? You had impacts and gathering weight in an extremely rapid time-frame. It's kind of like impacting a person with a rubber bullet. Take the one impact, and you'll get a bruise, but will be fine. Do a hundred of those all over, and suddenly you're down.

You just claimed an over simplification and then say that? double raised eyes for that one.

You really need to explain how this 'gathering mass' ended up all over lower Manhattan, before you can claim this 'gathering mass' ever existed in the first place.

Did all that mass stay in the footprint until the end, as claimed by the crush down crush up hypothesis? Is that what you're claiming?



The rubble pile of WTC 7 contained the majority of the building, and ironically you refuse to accept that building 7 did land mostly in its own footprint. Just shows you have an agenda to support the OS no matter what.



The majority of the towers mass landed outside of the footprints...

reply to post by Akareyon

then the towers are gone, because, because... well, it's the most logical thing to expect!

Of course. It is a natural phenomenon and you'd be crazy to think otherwise. You'll never get laid; you'll die alone, and everyone will laugh at you. Come, join the army.

reply to post by Varemia


I believe so, in any case I do not particularly care for the explanation, I know what I saw on the date, I listened to what surviver said, and I watched building 7 collapse in the same way. In my mind there is no doubt that the thing was engineered to go that way.

What I find unbelievable is that the population did not revolt, at least New Yorkers after the half-ass report the the government generated and the criminal activity involving the remains of the event.

The USA is doomed or more likely will doom us all...

Originally posted by Akareyon

Bazant/Zhou (2002), Bazant/Verdure (2007), Greening et al first calculate the force of the small hammer upon impact on the nail's head which would sink the nail a few millimetres into the wood. They say that the resulting force would be 31 times the weight of the small hammer, depending on the stiffness of the nail and the speed and weight of the hammer. Then they take a huge hammer which weighs 31 times as much as the small hammer and carefully put it on the nail's head to prove their point, because now, the nail slides into the wood. That's the whole trick, basically.

This is false.

While it is true that Bazant uses a homogenized equivalent force, it is NOT constant and it is derived via the well-accepted notion of a Maxwell construction from the non-constant load displacement response of steel columns in hinge buckling. Nor is the same peak initial force used throughout the collapse.

It seems I have to pull this graphic out a lot. Figure 3 from "Mechanics of Progressive Collapse: Learning from World Trade Center and Building Demolitions" (Bazant & Verdure):



In this load displacement graph, you can see the non-constant resistive force before your very eyes, so I trust there will be no further need to argue this point. From that curve with peak and tail-off, representing the well understood and empirically documented properties of columns undergoing three-hinge buckling, an energetically equivalent story-wise average force is obtained via integration and division by the displacement over the entire interval (that is to say - distance averaged).

This equivalent force is shown by the dotted line labeled "Maxwell Line" and is expressed in the diagram in units of mg, therefore scales with the load and capacity of each story. It is not constant, and it gets larger going down the structure.

The 31x overload is not propagated through the collapse. That figure refers to the insufficiency of the impacted supports to withstand the imposed dynamic loading. It falls straight out of fairly elementary calculations. It is not the force applied to the lower section since, by Newton's 3rd, there must be an equal and opposite force for each applied force, and the lower section simply was not capable of providing that resistance.

The magnitude of the Maxwell line in that diagram is 39% of the load, or 13% of the peak capacity assumed by Bazant. It means the average resistive force provided by columns which are overloaded to full compaction is about 40% of the static load above. Thus in this approximation, one would expect to see an average downward acceleration of about 0.6g and, funny, that's exactly what's observed in careful and detailed measurements of the early collapse displacement. However, similar measurements in the later progression unequivocally point to terminal velocity (i.e acceleration = zero) being reached fairly early on in the collapse. This would be due to velocity dependent sinks such as concrete comminution and perhaps other issues of mass retention within the leading crush zone footprint; nothing whatever to do with structural resistance.

As I noted a few weeks ago in another thread, all of this is moot since it's easily verified by direct viewing of any number of videos that the collapse mechanism was not an intact upper block buckling each and every column to full compaction all the way down.

I should clarify that my remarks above apply to the formulation of the resistive force. The applied force from above is dictated by the properties of the upper section and any accumulated debris. The force from static load of a given section is of course constant, but if there is accumulation of debris going down, then the mass - therefore the load - is increasing. Beyond that, the force which the upper section is capable of applying to the lower is dependent on momentum, which is composed of both mass and velocity.

Thank you for clarification, IrishWristwatch, and for perpetuating the idea that mass aggregation kept the collapse going (instead of "rubble" dampening any "crush" (up or down, who really cares)). You seem to have more than just a layman's insight into matters like Maxwell's demon, so, may I ask for your assistance in building a model that acts like the reverse bear trap from the SAW series? It goes like this: you activate it, than you give it a small momentum to start it, and even while you wonder what is going on, after just a few minutes, the thing goes off and your mouth stands open. Because that's exactly what the towers did, leaving us with our mouths open.

2.1 GJ triggered the potential energy of up to 1TJ.

Then along comes an expert and explains: yep, that's the way we build buildings, and he produces charts and diagrams and complex formulae that look all greek to us to show just how silly we've been to think that anything in the world could have stopped the collapse. Not even those professional desks and file cabinets that can usually be found in many offices, none of which were (allegedly) found in the rubble except for one.

While it is true that momentum is the product of mass and velocity, velocity goes squared in the equation for energy. When something hits something, the sum of all momentums in the system stay the same. Kinetic energy becomes internal energy. When you hit the nail on the head with a hammer, the nail will bend, the wood may get deformed, the hammer may get warmer, but the nail won't sink into the wood all by itself, and that's because of the friction force that it has to overcome. Velocity diminishes each time the mass has to accelerate or deform something else. Even if mass, in this case, becomes bigger by a tiny fraction because it takes another floor with it.

According to Newton's lex quarta, all the "upholding forces" in the towers need to be summed up and overcome by the fall of 58.000t from 3.7m height. It's not just one floor, it's the combined force of all 110 stories. The impact waves run through structural steel at 4500m/s, so all of this force would have been sent to the impact zone, while the impacting force would have gone the way of least resistance, maybe even cutting a bolt in the basement (actio_reactio). In nature, things take the least energy-consuming way through space-time, therefor, any impact would first shear the weakest bolts before bending a box column. Still, even every molekule in the way would slow down the falling block. But it didn't slow down. It accelerated downwards, just as shown in Fig 3+4a in "Mechanics of progressive collapse", because m*g was greater than F_c (the maxwell line or Force it needs to "crush" the plastic hinges) all the way down to Ground Zero.

Usually, it can easily explained how m*g could be greater than F_c. You just put a lot of mass on top. Or you hit something really fast, so that it is decelerated by a spring with 71GN/m, so that g=31*9.81m/s². But only for a fraction of a second, after a little [u], it would diminish back to g, at least in any other isotropic structure, so that m*g is smaller than F_c as shown in Fig. 4b. Like the nail and the wood slow down the hammer.

m*g was greater than F_c on all 110 floors because F_c was smaller than m*g. In other words, F_c of the building had to be weakened to a point that it could not sustain itself. Because usually, architecture is about providing for a F_c at least twice as big as any expectable m*g so that Fig 4c applies (that's when you jump out of your bed on the floor).

This is as far as I can go as a layman to explain Dr. Bazants trick and I hoped for experts to join the discussion to explain in greater detail all the stuff that is going on mathematically in those papers instead of insisting that it can be called sound sience to pretend you'd just input a little energy while really secretly hiding "inside" energy 100-fold in the equations and silent premises. That's what the "experts" have done in economics for at least a hundred years to enslave the people and keep them dumb. But please don't try this all over again in physics, we've gone a too long way to to turn back to believing that earth is flat and lightnings are the wrath of malevolent gods.

Originally posted by Akareyon
Thank you for clarification, IrishWristwatch, and for perpetuating the idea that mass aggregation kept the collapse going (instead of "rubble" dampening any "crush" (up or down, who really cares)).

If mass is not to accumulate, what then happens to it? You do not propose it disappeared, I'm sure, so your choices are over the side or down the throat of the core. With a 64x64m footprint and a floor diaphragm every 3.7m, migration of the majority of mass over the side is a little tough to swallow. So, yeah, damn straight it aggregates. Your suggested alternative?

Whether debris accumulates or not is an entirely separate matter from the issue of rubble "dampening" crushing action. I always find it odd when people give me that "you mentioned this but funny how you didn't mention that" (insert pet issue here). Actually, though, I did mention it. The energy dissipation of rubblized material is one of the categories of sinks mentioned above. Of course rubble slows down a collapse. It doesn't stop it.

You seem to have more than just a layman's insight into matters like Maxwell's demon, so, may I ask for your assistance in building a model that acts like the reverse bear trap from the SAW series? It goes like this: you activate it, than you give it a small impulse to start it, and even while you wonder what is going on, after just a few minutes, the thing goes off and your mouth stands open. Because that's exactly what the towers did, leaving us with our mouths open.

Yeah: www.youtube.com...

2.1 GJ triggered the potential energy of up to 1TJ.

It's called cascading failure.

Then along comes an expert and explains: yep, that's the way we build buildings, and he produces charts and diagrams and complex formulae that look all greek to us to show just how silly we've been to think that anything in the world could have stopped the collapse. Not even those professional desks and file cabinets that can usually be found in many offices, none of which were (allegedly) found in the rubble except for one.

Yep.

While it is true that impulse is the product of mass and velocity...

Momentum is the product of mass and velocity; impulse is the integral of force over time, or change in momentum.

...velocity goes squared in the equation for energy.

Yes.

Velocity diminishes each time the mass has to accelerate or deform something else.

No. The state of acceleration is dependent only on the net force acting on an object. Sufficient force can be applied to a member to cause it to fail without causing a loss in velocity. The acceleration must diminish, but the velocity need not.

Originally posted by Akareyon
According to Newton's lex quarta, all the "upholding forces" in the towers need to be summed up and overcome by the fall of 58.000t from 3.7m height.

Incorrect. Overload need only occur in the local region, then failure propagates downward. This is an iterative process, not an integrated one.

It's not just one floor, it's the combined force of all 110 stories.

Why stop there? Why not add the ground? If you do, there would never be a collapse of anything! The point is, localized failure occurs in materials undergoing plastic deformation and, due to the distribution of mass, this deformation is concentrated at the location of force application. When two vehicles collide head-on, does the rear bumper experience the same deformation as the front? Even if one of the cars is butted up against a wall? No.

The impact waves run through structural steel at 4500m/s, so all of this force would have been sent to the impact zone...

True, but not with the consequences you claim. First of all, the force transmission to which you refer is via elastic waves in the steel; plastic waves do not propagate through the medium. Therefore, by definition, the magnitude of force is limited to the elastic capacity of the medium. Second, in order for the force to displace mass at any point lower than the crush front, all the interstitial mass must also be displaced, so you're talking about the entire building displacing downward X amount to get the bottom to deform by X amount.

...while the impacting force would have gone the way of least resistance, maybe even cutting a bolt in the basement (actio_reactio).

Aside from the dodgy interpretation of the principle of least action made in language of force, I won't quibble with this except to say again that, in order to fail a bolt in shear, tension, or compression, it has to be displaced, and that means all the building above has displaced, too. Ya think that might break something up top first?

In nature, things take the least energy-consuming way through space-time, therefor, any impact would first shear the weakest bolts before bending a box column.

Now you're getting to the nitty gritty of why all this discussion about column buckling, peak capacity and FOS, and so on - is moot. The floor connections were NOT designed to support the entire tower load above, the columns were. If the debris manages to find itself on a floor pan (how could it not?), then we are concerned with the capacity of a floor, not the vertical members. Clearly the floors not only have significantly less capacity than the columns - that's why columns were used to hold the building up, not the floors - but the floor assemblies were of nearly uniform construction all the way down as opposed to getting stronger. And, one last thing: the floors were separated from each other so load applied to one was not applied to even the next one down.

Still, even every molekule in the way would slow down the falling block.

No. Every little molecule exerted a resistive force and that adds to the sum of forces. If the upwardly acting resistive force is less than the imposed force, it will accelerate downward. Period. The only way it will slow is if the resistive force exceeds the load.

But it didn't slow down.

There were a couple of noticeable jolts in there but, for the most part, you're right; it did not slow down.

It accelerated downwards, just as shown in Fig 3+4a in "Mechanics of progressive collapse", because m*g was greater than F_c (the maxwell line or Force it needs to "crush" the plastic hinges) all the way down to Ground Zero.

No, it did not accelerate all the way down. As I said above, terminal velocity has been measured for a good share of the leading progression. Bazant's model predicts acceleration all the way down. It did not happen.

I'm going to leave it at this. Something tells me I've not made a dent, and that's okay. Not necessary.

Just noticed your edit regarding impulse and momentum. I did not realize you were not a native English speaker (though I should have from your links). Your command of the language is quite excellent and I appreciate your efforts to discuss technical subjects in this manner. I'll be more mindful of this consideration in the future.