9-11 Presentation at NMSR, May 19 2010

I don't know if it can or not. Any directed stream of loose material or liquid can destroy things. We know somewhat the effects of a fire hose jet on the human body, but it's not of much relevance, imo, to our discussion, because rubble being crushed between two floors (if we are talking about an upper block) is not a directed stream, and if we are not talking about an upper block, rubble sitting alone on top of an intact building will not descend much anyway. Hence, no force. And certainly no directed stream.
 
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I don't know if it can or not. Any directed stream of loose material or liquid can destroy things. We know somewhat the effects of a fire hose jet on the human body, but it's not of much relevance, imo, to our discussion, because rubble being crushed between two floors (if we are talking about an upper block) is not a directed stream, and if we are not talking about an upper block, rubble sitting alone on top of an intact building will not descend much anyway. Hence, no force. And certainly no directed stream.
When more than 11 floors drop on to a lower floor, the floor fails, no matter how carefully it is placed on the lower floor. You failed to read NIST. You need help with your physics; are you going to get a physics course?

http://wtc.nist.gov/pubs/factsheets/faqs_12_2007.htm

The individual connection capacities ranged from 94,000 lb to 395,000 lb, with a total vertical load capacity for the connections on a typical floor of 29,000,000 lb (See Section 5.2.4 of NIST NCSTAR 1-6C). The total floor area outside the core was approximately 31,000 ft2, and the average load on a floor under service conditions on September 11, 2001 was 80 lb/ft2. Thus, the total vertical load on a floor outside the core can be estimated by multiplying the floor area (31,000 ft2) by the gravitational load (80 lb/ft2), which yields 2,500,000 lb (this is a conservative load estimate since it ignores the weight contribution of the heavier mechanical floors at the top of each WTC Tower). By dividing the total vertical connection capacity (29,000,000 lb) of a floor by the total vertical load applied to the connections (2,500,000 lb), the number of floors that can be supported by an intact floor is calculated to be a total of 12 floors or 11 additional floors.

It would not matter if it was dust, the mass of 11 floor would instantly fail the lower floor. Your no mass debris dies here.
 
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I don't know if it can or not. Any directed stream of loose material or liquid can destroy things. We know somewhat the effects of a fire hose jet on the human body, but it's not of much relevance, imo, to our discussion, because rubble being crushed between two floors (if we are talking about an upper block) is not a directed stream, and if we are not talking about an upper block, rubble sitting alone on top of an intact building will not descend much anyway. Hence, no force. And certainly no directed stream.

What directed stream?

There was NO directed stream in the video I posted. Not one.

Yet we have a crushed car. From millions of loose particles of water.

You are the one saying that loose particles cannot impart the same mass/force that a intact item will (your bowling ball example)

I say that if I drop a 10lbs bowling ball from 10 feet on your skull it will kill you. I"m also saying that if I then drop 10lbs of sand from 10 feet it will also kill you. You are the one saying that the smaller amount of sand won't do it.

I provided you a video showing that water will crush steel. How is that possible in your world?
 
When more than 11 floors drop on to a lower floor, the floor fails, no matter how carefully it is placed on the lower floor. You failed to read NIST. You need help with your physics; are you going to get a physics course?

http://wtc.nist.gov/pubs/factsheets/faqs_12_2007.htm



It would not matter if it was dust, the mass of 11 floor would instantly fail the lower floor. Your no mass debris dies here.

What you wrote here is is plainly rubbish Beachnut.

Beachnut wrote.
'' When more than 11 floors drop on to a lower floor, the floor fails, no matter how carefully it is placed on the lower floor. You failed to read NIST. You need help with your physics; are you going to get a physics course? ''

Bear in mind the type of structure we are dealing with. An assembly of 12 spaced single floors above and a more strongly built assembly of 98 spaced single floors below. These assemblies are natural pre-made shock absorbers. Both assemblies will suffer local damage as they mash together with each absorbing the other's energy and almost immediately reaching a new equlibrium as the collapse arrests..

This will mean that whatever is left of the falling assembly that originally amounted to one-tenth of the building will end up sitting on top of the assembly amounting to nine-tenths of the building plus some rubble that the building had always carried for the previous 40 years anyway.

'' One does not dash the rocks to pieces: One is dashed to pieces on the rocks '
 
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Bear in mind the type of structure we are dealing with. An assembly of 12 spaced single floors above and a more strongly built assembly of 98 spaced single floors below. These assemblies are natural pre-made shock absorbers. Both assemblies will suffer local damage as they mash together with each absorbing the other's energy and almost immediately reaching a new equlibrium as the collapse arrests..

No, sorry. The lower floors are not an infinite energy sink. Since we're in the real world and not imagination land, there's only so much energy they can dissipate over a period of time before they fail. The building was designed for static loads, not dynamic. Not to mention the lower floors were weakened by fire.
 
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No, sorry. The lower floors are not an infinite energy sink. Since we're in the real world and not imagination land, there's only so much energy they can dissipate over a period of time before they fail. The building was designed for static loads, not dynamic. Not to mention the lower floors were weakened by fire.

In a building where the top one-tenth and the somewhat more heavily built lower nine-tenths are of exactly the same construction you cannot say that the top 12 floors are a single block while the lower 98 floors are an assembly of spaced single floors. It must be treated as either two blocks or it must be treated two assemblies of spaced single floors. You cannot mix and match.

Otherwise I could say for instance that the lower,more heavily built 98 floors were a single block with a lighter built assembly of 12 spaced single floors falling on that block .


So do you opt for two blocks or do you opt for two assemblies of spaced single floors ? Remember that you cannot mix and match.
 
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In a building where the top one-tenth and the somewhat more heavily built lower nine-tenths are of exactly the same construction you cannot say that the top 12 floors are a single block while the lower 98 floors are an assembly of spaced single floors. It must be treated as either two blocks or it must be treated two assemblies of spaced single floors. You cannot mix and match.

Otherwise I could say for instance that the lower,more heavily built 98 floors were a single block with a lighter built assembly of 12 spaced single floors falling on that block .


So do you opt for two blocks or do you opt for two assemblies of spaced single floors ? Remember that you cannot mix and match.

It was 12 floors falling on 1 floor. That floor failed. Then it was 13 floors falling on 1 floor. That floor failed. Then it was 14 floors falling on 1 floor. That floor failed. The building was not designed to handle dynamic loads. The falling mass impacted the floor with more force than it could handle, and the floor failed.

Calling it a "block" or an "assembly of spaced single floors" is irrelevant. It's a falling mass. Your attempt to play handwaving semantic games isn't going to make your assertions any more credible.
 
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1. The layer between the falling section and the lower section is rubble.
Being driven by an intact upper block. I asked how rubble alone could crush the lower part of the building.
Tell me what significant difference it would make to be driven by an intact upper block or by more rubble.

Also, the "falling floors"? You seem to be uncertain, again, whether you are talking about a discrete upper block or rubble. In any case, you also forget that not only the intact structure must absorb the force of "impact" (crushing)--as you correctly state that the ground does--but the upper block must also absorb it. Which is why it crushes up before crushing down is ever allowed to occur.
You didn't reply to post #269, which is very relevant in this respect.

ETA: I repeat it here for your convenience:

Being driven by an intact upper block.
Interesting. So, are you saying that the upper section of each building remains intact until it reaches the floor?

Even in the last building? Here's that one alone, again:


 
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As for force instead of object, you are correct. Please explain what you mean by "forces are counterintuitive".
What flubs many students is that they try to use their intuition too much when first starting out in physics. Rather than allowing mathematics to inform their intuition, they try to imagine to far into the problem and end up getting the wrong answer. I spent most of graduate school as a teaching assistant for Statics and Dynamics, and I saw this failure time and time again. I don't mean to be insulting when I tell you this, but you're making exactly the same mistakes and using exactly the same flawed reasoning that I heard from 100 different students. I'm spending my time trying to get you to understand the same way I got them to understand.
With an opposing 5 N. Not a "further". This is a common "debunker" sleight of hand.
Semantics. Let's try and elevate the level of this debate above such comments, shall we?
Even high school physics teaches as a first principle the frame of reference. You're not going to somehow forget that a shopping cart has wheels. So I have no objection with what you say. Nor would any other skeptic.
But so few students get my shopping cart question right, and your comment indicates to me that you missed the point. The problem has nothing to do with "forgetting" that a shopping cart has wheels. The error most students make is that they assume the shopping cart can't supply 5 N of opposing force, and still allow the cart to move forward. About half of my students would tell me that the cart is not moving if you push on it and it pushes on you. It can if you specify the forces in the appropriate reference frame.
This doesn't follow. I haven't made these errors.
If we're going to continue with this, we need to agree on something. I'm writing thoughtful, well directed responses to your argument. If you're going to simply contradict me without providing an opposing argument, this is a waste of my time.
Thank you for acknowledging this. A lot of "debunkers" miss this point.
Reference frames. The point of my statement is to point out that you're not using the correct reference frames when you state your bowling ball argument. The reaction of the bowling ball and the floor is meaningless until you expand the reference frame to include the structure and the reaction from the ground.
But here you wig off into woo. That the energy can be transformed is correct. That the transformed energy will still destroy the structure is not true in our case. Heat and sound did not cause failure of building components.
Please read my statements carefully. Not all of the energy of the falling towers went into destroying the structure. Some of it was transformed into heat and sound (vibration), but the rest had no place else to go but into the structure. That's the point.
Comparing human bodies to steel-framed structures is invalid. A few of you continue to assert this logical fallacy.
Why?
Thank you for your reasoned approach and attempting to have an intelligent conversation about this. I appreciate it. However, your analysis is largely incorrect.
Please understand that I'm not trying to be glib about this. Contradictory assertions such as this one are not conducive to an argument. The way to prove me wrong is with math. Failing that, please quote from any relevant physics textbook you have. Failing that, explain to me what your precise issues are with my analysis.
 
It was 12 floors falling on 1 floor. That floor failed. Then it was 13 floors falling on 1 floor. That floor failed. Then it was 14 floors falling on 1 floor. That floor failed. The building was not designed to handle dynamic loads. The falling mass impacted the floor with more force than it could handle, and the floor failed.

Calling it a "block" or an "assembly of spaced single floors" is irrelevant. Your attempt to play handwaving semantic games isn't going to make your assertions any more credible.


Above was an assembly of 12 spaced single floors and below it was another assembly of 98 spaced single floors. This cannot be argued with. It is the literal description of the reality of the situation.

Now picture the upper assembly falling on the lower in super slow motion. The bottom floor of the top part impacts the top floor of the lower part. This is the ONLY point of contact at this time.

Isaac Newton says that whatever force the upper floor imparts on the lower floor will be exactly given back by the lower floor. (Equal and opposite reaction) Thus they will obviously destroy each other. Then on to the next two contender floors. Soon the top part will be too small to exert sufficient force to carry on the attrition and collapse arrest will ensue.

Forget the block above and the assembly of spaced single floors below as you are transparently and hopelessly promoting. Accept the reality.
 
Ergo, I've bolded statements that are detracting from your argument. Consider eliminating such statements in your response.

In a closed system.
Correct.
Incorrect.
Again, let's elevate this debate above childish one liners, shall we?
If you mean that energy is neither created nor destroyed, you are correct. If you are trying to claim that the system we are talking about does not lose energy, you are incorrect.
Of course the system loses energy, but that energy has to go somewhere. If it doesn't turn into heat and vibration, then where does it go?
The Almond said:
The falling floors of the twin towers had kinetic energy, and when they impacted the structure of the twin towers, nearly all of the energy went into the structure.



This has nothing to do with what you just said above. Leaps and gaps in logic seem to be really common with "debunkers". You're trying to use physics for your argument, but because your argument is not supported by physics, you have to make these ridiculous leaps to arrive at your destination.
Please try to understand: The kinetic energy has to go somewhere. If it wasn't turned into heat and sound, what happened to it? Tell me where the energy of 13 falling floors went.
Also, the "falling floors"? You seem to be uncertain, again, whether you are talking about a discrete upper block or rubble. In any case, you also forget that not only the intact structure must absorb the force of "impact" (crushing)--as you correctly state that the ground does--but the upper block must also absorb it. Which is why it crushes up before crushing down is ever allowed to occur.
So all this crushing occurs. Where does the mass go? Does that mass have potential energy because of its height above the ground? Is that mass being accelerated towards the ground?
I'm not even sure what point you're attempting to make here,
The comments you've made so far indicate that you are unable or unwilling to consider my arguments in full. Rather, you would prefer to dismiss them outright:
but it's probably irrelevant.
You're striding towards "troll" classification. If your intention is to simply find an expedient way to dismiss my arguments (for instance, by not reading them), then I would suggest talking to a cat. Cats rarely have intelligent opinions, and those that they have are usually regarding trivial subjects such as the quality of canned tuna fish. You have my permission to dismiss all opinions that come from cats.
Oh, wait. You're probably attempting to suggest that not much mass or energy was lost to the system. The debris ejected upwards and outwards had the same potential energy as all the other debris. The energy required to eject this matter upwards and outwards, supposedly through "crushing", is energy lost to any further crushing.
Sadly, no. That's not what I'm saying. What I'm telling you is that the tower had some potential energy. When it began to fall, the potential energy was converted to kinetic energy. That kinetic energy, minus the energy that went into the production of sound and heat, was transferred to the structure. That energy went into destroying the structure, and the total energy is integrated over the entire reference frame of the towers, meaning that its shape mattered very little.
This is saying nothing, except perhaps you're trying to sound like you know what you're talking about.
I understand that you're rationalizing not considering my arguments. If you've decided that I'm an idiot, we don't need to continue this.
Incorrect. Friction affects different materials differently. This is also high school physics.
Which weighs more, a kilogram of bricks, or a kilogram of feathers? Mass is what determines kinetic energy, force of gravity and momentum. Properties like friction are not at issue in such calculations.
This is so utterly false as to be bizarre. All modern structures are designed to arrest their own collapse.
As a civil engineer with a bachelors and master's degree, I can assure you that no structure is designed to arrest a collapse of one floor falling onto another. Structures are designed to support static loads, and while a structure may be able to stop such a collapse due to factors of safety and over-design, it is not a design consideration. See Structural Analysis by R.C. Hibbeler, 5th ed.
This is what modern engineering and building design are about.
Modern building design is about estimating and then designing for static loads caused by people and things. There are design considerations to prolong building survival in the event of fire, and new design considerations to prevent floor failure due to fires, but we don't design to prevent collapse if one floor of a building falls onto another.
There are no building codes existing today that would allow a highrise structure to self-pulverize, to collapse completely within seconds of free fall, to disintegrate in mid-air.
Upon what evidence do you make that assertion? Or perhaps you make it on your vast experience as a civil engineer? How many structures have you designed?
This is why demolition companies exist. Holy ****.
Ergo, I'm just curious about something. What would it take to convince you that the collapse of the twin towers was exactly the result of known, quantifiable physical processes? And what has convinced you that the towers were blown up by an explosives demolition company?
 
Above was an assembly of 12 spaced single floors and below it was another assembly of 98 spaced single floors. This cannot be argued with. It is the literal description of the reality of the situation.

Now picture the upper assembly falling on the lower in super slow motion. The bottom floor of the top part impacts the top floor of the lower part. This is the ONLY point of contact at this time.

Isaac Newton says that whatever force the upper floor imparts on the lower floor will be exactly given back by the lower floor. (Equal and opposite reaction) Thus they will obviously destroy each other. Then on to the next two contender floors. Soon the top part will be too small to exert sufficient force to carry on the attrition and collapse arrest will ensue.

Forget the block above and the assembly of spaced single floors below as you are transparently and hopelessly promoting. Accept the reality.

Whatever you say, I'm weary of trying to explain simple physics to idiots and trolls who don't want to learn and are content to sit and play semantic games and try and use their horribly warped interpretation of reality as if it were fact.
 
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Whatever you say, I'm weary of trying to explain simple physics to idiots and trolls who don't want to learn and are content to sit and play semantic games and try and use their horribly warped interpretation of reality as if it were fact.

It's your call Readers.
 
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I don't mean to be insulting when I tell you this, but you're making exactly the same mistakes and using exactly the same flawed reasoning that I heard from 100 different students. I'm spending my time trying to get you to understand the same way I got them to understand.

You're failing to indicate what and where these "mistakes" are occurring. You're just saying this in the hopes that anyone else reading this will take your word for it. You have also not explained how "forces can be counterintuitive".

Semantics. Let's try and elevate the level of this debate above such comments, shall we?

If you can't get your words right, your argument will not be understood.

The error most students make is that they assume the shopping cart can't supply 5 N of opposing force, and still allow the cart to move forward. About half of my students would tell me that the cart is not moving if you push on it and it pushes on you. It can if you specify the forces in the appropriate reference frame.

I don't care about the mistakes your students made.

If we're going to continue with this, we need to agree on something. I'm writing thoughtful, well directed responses to your argument. If you're going to simply contradict me without providing an opposing argument, this is a waste of my time.

I have clearly provided my explanations with my objections. You have not indicated specifically what and where I make these so-called "mistakes" in my arguments. I sincerely doubt you have the expertise you claim to.

Reference frames. The point of my statement is to point out that you're not using the correct reference frames when you state your bowling ball argument. The reaction of the bowling ball and the floor is meaningless until you expand the reference frame to include the structure and the reaction from the ground.

My bowling ball argument is based on reality. How the impact from the bowling ball refers through the person's body to the ground is irrelevant to the point I was making. The bowling ball falling on someone's head clearly will fracture their skull. The fragments of bowling ball will not. There is no unconsidered factor here. If there is, please identify it specifically.

Not all of the energy of the falling towers went into destroying the structure. Some of it was transformed into heat and sound (vibration), but the rest had no place else to go but into the structure. That's the point.

Please specify what you mean by "falling towers". Are you referring to an upper block crushing through 80 and 90 storeys, or are you referring to rubble?

I already pointed out where energy is lost in the system. To say that it was only converted into "heat" and "sound" is too stupid to comment to. Do civil engineers not have to know any physics? I don't think you're an engineer. If you are, you are knowingly lying.

Please understand that I'm not trying to be glib about this. Contradictory assertions such as this one are not conducive to an argument. The way to prove me wrong is with math. Failing that, please quote from any relevant physics textbook you have. Failing that, explain to me what your precise issues are with my analysis.

Please re-read my post. If you understand the math, please provide the calculations showing that rubble alone can crush through 80 and 90 storeys of intact highrise.
 
Ergo, I've bolded statements that are detracting from your argument. Consider eliminating such statements in your response.

I'll make whatever statements I deem fit for my argument. Thanks.

Of course the system loses energy, but that energy has to go somewhere. If it doesn't turn into heat and vibration, then where does it go?

It has been explained ad nauseum what happens to the energy in the crush-down, crush-up model. It is referred both through the upper and lower blocks. It is expended in crushing and pulverizing. It is expended in ejecting matter upwards and laterally. It is mitigated through the alleged layers of rubble.

Please try to understand: The kinetic energy has to go somewhere. If it wasn't turned into heat and sound, what happened to it? Tell me where the energy of 13 falling floors went.

So you are talking about an upper block that crushes down. See my comment immediately above.

So all this crushing occurs. Where does the mass go? Does that mass have potential energy because of its height above the ground? Is that mass being accelerated towards the ground?

[kindergarten tone] The mass is meeting the resistance of the intact 80 and 90 storeys. [/kindergarten tone]

The comments you've made so far indicate that you are unable or unwilling to consider my arguments in full. Rather, you would prefer to dismiss them outright:

You have failed to point out specifically where my argument is wrong. I suspect you don't even know yourself.

ergo said:
You're probably attempting to suggest that not much mass or energy was lost to the system. The debris ejected upwards and outwards had the same potential energy as all the other debris. The energy required to eject this matter upwards and outwards, supposedly through "crushing", is energy lost to any further crushing.

What I'm telling you is that the tower had some potential energy. When it began to fall, the potential energy was converted to kinetic energy. That kinetic energy, minus the energy that went into the production of sound and heat, was transferred to the structure.

Please indicate where NIST, or Bazant, or any reputable scientist for that matter, discusses the conversion of kinetic energy into heat and sound in the WTC collapses.

That energy went into destroying the structure, and the total energy is integrated over the entire reference frame of the towers, meaning that its shape mattered very little.

The bolded is correct. The rest does not follow logically. In fact, is gibberish, as it doesn't address a single thing I said in my argument.

I understand that you're rationalizing not considering my arguments. If you've decided that I'm an idiot, we don't need to continue this.

Fine with me. You can bow out now.

Which weighs more, a kilogram of bricks, or a kilogram of feathers? Mass is what determines kinetic energy, force of gravity and momentum. Properties like friction are not at issue in such calculations.

:rolleyes: Which falls to the ground faster, Mr. Civil Engineer?

Modern building design is about estimating and then designing for static loads caused by people and things.

Static and dynamic loads, Mr. Civil Engineer. (What do civil engineers do, anyway?)

There are design considerations to prolong building survival in the event of fire, and new design considerations to prevent floor failure due to fires, but we don't design to prevent collapse if one floor of a building falls onto another.

Real engineers do. I don't know what you do.

ergo said:
There are no building codes existing today that would allow a highrise structure to self-pulverize, to collapse completely within seconds of free fall, to disintegrate in mid-air.
Upon what evidence do you make that assertion? Or perhaps you make it on your vast experience as a civil engineer? How many structures have you designed?

If building codes don't attempt to prevent buildings from self-destructing, what do they do? And why don't we see buildings collapsing all the time?

How many structures have you designed, and which ones?
 
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Isaac Newton says that whatever force the upper floor imparts on the lower floor will be exactly given back by the lower floor. (Equal and opposite reaction) Thus they will obviously destroy each other. Then on to the next two contender floors. Soon the top part will be too small to exert sufficient force to carry on the attrition and collapse arrest will ensue.

I've bolded the part you're getting flat wrong for you. Even if I grant you each floor of the lower section destroying a floor from the upper section, that still leaves you with two floors of rubble. At approximately 4 million kg per floor, that's 8 million kilograms of mass you are waving away.

Got news 4 U, that mass still packs a punch, hitting "LIKE A TON OF BRICKS." (Or in this case, 'bout 9000 tons).

You can wave your hands in the air all you want, but you're not gonna convince anyone that you can make 9000 tons of material disappear into thin air.
 
I've bolded the part you're getting flat wrong for you. Even if I grant you each floor of the lower section destroying a floor from the upper section, that still leaves you with two floors of rubble. At approximately 4 million kg per floor, that's 8 million kilograms of mass you are waving away.

Got news 4 U, that mass still packs a punch, hitting "LIKE A TON OF BRICKS." (Or in this case, 'bout 9000 tons).

You can wave your hands in the air all you want, but you're not gonna convince anyone that you can make 9000 tons of material disappear into thin air.

I don't see the problem. The building had always carried that weight anyway. It's not as if it was new weight added from outside the system. In fact that weight was very much diminished by the pulverisation of the concrete and the shedding of masses of rubble spilling from all four sides of the building as can be seen in many videos. Chandler's analysis in particular gives the idea..
 
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Bill Smith an ergo are the perfect example of why the "truth" movement only got as far as it did. They also explain why it will never receive any serious attention.


Physics is not a variable that can be molded to fit a flawed view, ever!
 

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