psikeyhackr
Supposedly the north tower collapsed because the fire allowed the top portion to fall one level.  I didn’t use fire in my model I raised the top 4 levels more than a foot and allowed them to fall,

So you did NOT reconstruct the actual events and yet you yu can say with certainty that it was impossible for the towers to collapse because your flawed model shows that it cannot be done?  And that is scientific inquiry?

The paper loops in my model are separated by washers so a fire you start with a match may not spread from level to level.  Go ahead and try it.  Make a video.  I would like to see it.  But I am sure all you are going to do is TALK.

Can I spray the upper part of your model with generous amounts of lighter fluid before I strike that match? And in a previous discussion we discussed the possible failure of the thermodynamic washers used in the building between joists.  When they fail from heat the entire structural integrity of the building becomes compromised.

And yes, my talking about this is no less valid than you model which does not even simulate the same conditions as were present. Have you submitted your model for expert review and received consensus about you conclusions?

Write4U - 20 October 2012 03:18 PM

psikeyhackr
Supposedly the north tower collapsed because the fire allowed the top portion to fall one level.  I didn’t use fire in my model I raised the top 4 levels more than a foot and allowed them to fall,

So you did NOT reconstruct the actual events and yet you yu can say with certainty that it was impossible for the towers to collapse because your flawed model shows that it cannot be done?  And that is scientific inquiry?

I have admitted many times that my model is not a tube-in-tube structure like the WTC.

As far as I am concerned since there is no way of knowing the total strength of all of the connections around the edges of the floors outside the cores relative to the weight of the floor assemblies it is IMPOSSIBLE to make a good tube-in-tube model.  Were the connections strong enough to support the weight of two or three or five or more floor assemblies?

My model is built to demonstrate the PHYSICAL PRINCIPLES that had to be involved in any supposed top down gravitational collapse.  It also made it possible to make the supports AS WEAK AS POSSIBLE relative to the STATIC LOAD which is not how skyscrapers are constructed.  I also provided a computer program to simulate the effect on only the Conservation of Momentum slowing the collapse and mass distribution on that.

But even with crushable supports as weak as possible it came nowhere near complete collapse.  My mistake was in assuming that people had the brains to extrapolate and figure out the obvious from the demonstration of principles.  So instead I end up getting lots of debating sophistry.

People who either can’t understand or don’t give a damn about the physics and just try winning on the basis of debating points.

And present papers by supposed physicists who can’t even get the quantity of steel correct.

psik

Write4U - 20 October 2012 03:18 PM

Can I spray the upper part of your model with generous amounts of lighter fluid before I strike that match? And in a previous discussion we discussed the possible failure of the thermodynamic washers used in the building between joists.  When they fail from heat the entire structural integrity of the building becomes compromised.

And yes, my talking about this is no less valid than you model which does not even simulate the same conditions as were present. Have you submitted your model for expert review and received consensus about you conclusions?

What the hell are thermodynamic washers?

Are you talking about visco-elastic dampers?

http://www.designcommunity.com/discussion/7551.html

Google “thermodynamic washers” and let me know what you find.

It would be nice if you knew what you were talking about.

Go ahead and do the experiment of setting the top 4 or 5 loops on fire.  Make the video.  I bet that will do less damage to lower loops than my drop.  But experimental evidence is more important than talk so let’s see it.

psik

It’s so ‘nice’ to have our own resident WTC 9/11 ‘expert’ on the forum. 

Honestly, I thought maybe he was a high level troll (still wonder sometimes -.-) but the amount of time and thought put into it would seem to be counter-productive. I’ve come by quite a few of em elsewhere so that’s just my paranoia I guess

psikeyhackr - 21 October 2012 09:04 AM

Write4U - 20 October 2012 03:18 PM

Can I spray the upper part of your model with generous amounts of lighter fluid before I strike that match? And in a previous discussion we discussed the possible failure of the thermodynamic washers used in the building between joists.  When they fail from heat the entire structural integrity of the building becomes compromised.

And yes, my talking about this is no less valid than you model which does not even simulate the same conditions as were present. Have you submitted your model for expert review and received consensus about you conclusions?

What the hell are thermodynamic washers?

Are you talking about visco-elastic dampers?

http://www.designcommunity.com/discussion/7551.html

Google “thermodynamic washers” and let me know what you find.

It would be nice if you knew what you were talking about.

Go ahead and do the experiment of setting the top 4 or 5 loops on fire.  Make the video.  I bet that will do less damage to lower loops than my drop.  But experimental evidence is more important than talk so let’s see it.

psik

yes psik, I am the one who originally posted the link to the use of visco-elastic dampers as “washers”.  I didn’t want to look it up again, but you got the gist. A simple correction would have sufficed.  But the observation stands, unless you are willing to address the issue and prove that those washers (dampers) could not fail under the circumstances.

TimB - 19 September 2012 12:28 PM

I don’t understand the physics involved.  But I know that 3 buildings came down (pretty quickly once they started to collapse) with utter and complete destruction.  The sheer unlikelihood of such an event is enough to make a naive observer, like myself, wonder at the explanation.

Buildings collapsing isn’t ‘unlikely’. They just need to be damaged enough and lose too much of their support structures to remain standing.

Note this comment:

Why don’t these so called physicists just build a physical model that does what they say?  If it is so OBVIOUS according to them why can’t they duplicate it on a small scale?

Smaller scales have much lower mass to size ratios, and other variables like air pressure become greater forces relative to the scale of the model.

For a quick and easy example, say one cubic meter weighs one ton. Double the dimensions of that cube so that it is two meters cubed. Guess how much it’s mass increased? By a factor of eight. Said object now weighs eight tons instead of one, even though you only went from a one cubic meter cube to a two cubic meter cube. Increase the cube dimensions to three meters, and now it would weigh twenty seven tons. You made the cube’s dimensions three times bigger, and it’s mass increased by a factor of twenty seven. Look here:

(Sq Meters)  (Mass)
1x1x1         1 ton
2x2x2         8 tons
3x3x3         27 tons
4x4x4         64 tons
5x5x5         125 tons

To put that in perspective, if you create a model of a building that is 1/1000 scale in dimensions, it’s mass is actually a billion times less than the full scale model. And that assumes you deal with equal mass scaling, never minding a larger object must have even heavier construction materials that can support that kind of mass.

The bigger an object is, the greater its own mass becomes its own enemy.

Write4U - 21 October 2012 05:08 PM

yes psik, I am the one who originally posted the link to the use of visco-elastic dampers as “washers”.  I didn’t want to look it up again, but you got the gist. A simple correction would have sufficed.  But the observation stands, unless you are willing to address the issue and prove that those washers (dampers) could not fail under the circumstances.

The dampers did not support the weight of the floors.  The damper formed one side of a triangle between the bottom of the truss and the perimeter wall, with the actual support being the opposite corner from the damper.  As the building swayed the damper would be stretched and compressed as the angle at the support changed.  I have seen people imply that the dampers were a weak point before but I have yet to see anyone explain how they were.  I get the impression that most people who mention them did not really investigate what they did.  I presume fire would affect the elastic material but since they were not actual supports they would not weaken the building.

It is like I am supposed to tolerate being portrayed as stupid while I shoot holes in things that people haven’t bothered to investigate in 11 years and yet they must be right and I am supposed to be so tolerant while reading some physicist say a tower had 80,000 tons of steel in 2011 when the NIST said there was roughly 200,000 tons in both towers in 2005 while neither of them specifies the concrete.  But thermodynamic washers is just a trivial error that does not matter. 

You think I was supposed to just instantly guess what you meant?  Actually I finished the post and was about to submit it when it occurred to me what you might have meant and then I went back and added the line.

You guys can make any ridiculous comments you want but I’m the supposed to be the dummy who is always wrong.

[3793]
psik

Robert Walper - 21 October 2012 05:43 PM

TimB - 19 September 2012 12:28 PM

I don’t understand the physics involved.  But I know that 3 buildings came down (pretty quickly once they started to collapse) with utter and complete destruction.  The sheer unlikelihood of such an event is enough to make a naive observer, like myself, wonder at the explanation.

Buildings collapsing isn’t ‘unlikely’. They just need to be damaged enough and lose too much of their support structures to remain standing.

Note this comment:

Why don’t these so called physicists just build a physical model that does what they say?  If it is so OBVIOUS according to them why can’t they duplicate it on a small scale?

Smaller scales have much lower mass to size ratios, and other variables like air pressure become greater forces relative to the scale of the model.

For a quick and easy example, say one cubic meter weighs one ton. Double the dimensions of that cube so that it is two meters cubed. Guess how much it’s mass increased? By a factor of eight. Said object now weighs eight tons instead of one, even though you only went from a one cubic meter cube to a two cubic meter cube. Increase the cube dimensions to three meters, and now it would weigh twenty seven tons. You made the cube’s dimensions three times bigger, and it’s mass increased by a factor of twenty seven. Look here:

(Sq Meters)  (Mass)
1x1x1         1 ton
2x2x2         8 tons
3x3x3         27 tons
4x4x4         64 tons
5x5x5         125 tons

To put that in perspective, if you create a model of a building that is 1/1000 scale in dimensions, it’s mass is actually a billion times less than the full scale model. And that assumes you deal with equal mass scaling, never minding a larger object must have even heavier construction materials that can support that kind of mass.

The bigger an object is, the greater its own mass becomes its own enemy.

It’s not unlikely, it is impossible.

It is called the square cube law.  Galileo explained it 400 years ago.  So the people who began designing skyscraper 100 years ago knew all about it.

That is why my physical model has supports made of paper even though the weights are steel.  I wanted then AS WEAK AS POSSIBLE relative to the weight they support.  But skyscrapers are not designed to be as weak as possible, they have a safety margin.  Crushing a single paper loop takes 0.118 joules.  So the falling mass loses kinetic energy every time it crushes a loop.  So although a number of loops get damaged at the top the mass increases but slows down and loses more kinetic energy through reduced velocity than it gains from increased mass and the conservation of momentum slows it down as mass increases also.  So the continuous collapse from less than 15% of the top cannot happen.

psik

psikeyhackr - 21 October 2012 06:22 PM

It’s not unlikely, it is impossible.

It is called the square cube law.  Galileo explained it 400 years ago.  So the people who began designing skyscraper 100 years ago knew all about it.

That is why my physical model has supports made of paper even though the weights are steel.  I wanted then AS WEAK AS POSSIBLE relative to the weight they support.  But skyscrapers are not designed to be as weak as possible, they have a safety margin.  Crushing a single paper loop takes 0.118 joules.  So the falling mass loses kinetic energy every time it crushes a loop.  So although a number of loops get damaged at the top the mass increases but slows down and loses more kinetic energy through reduced velocity than it gains from increased mass and the conservation of momentum slows it down as mass increases also.  So the continuous collapse from less than 15% of the top cannot happen.

psik

Your model is at the wrong scale and therefore invalid.

Robert Walper - 21 October 2012 07:18 PM

Your model is at the wrong scale and therefore invalid.

There you go confusing the issue with facts. psikey don’t need no facts when it come to this troofer stuff.

psikeyhackr - 21 October 2012 06:10 PM

Write4U - 21 October 2012 05:08 PM

yes psik, I am the one who originally posted the link to the use of visco-elastic dampers as “washers”.  I didn’t want to look it up again, but you got the gist. A simple correction would have sufficed.  But the observation stands, unless you are willing to address the issue and prove that those washers (dampers) could not fail under the circumstances.

The dampers did not support the weight of the floors.  The damper formed one side of a triangle between the bottom of the truss and the perimeter wall, with the actual support being the opposite corner from the damper.  As the building swayed the damper would be stretched and compressed as the angle at the support changed.  I have seen people imply that the dampers were a weak point before but I have yet to see anyone explain how they were.  I get the impression that most people who mention them did not really investigate what they did.  I presume fire would affect the elastic material but since they were not actual supports they would not weaken the building.

It is like I am supposed to tolerate being portrayed as stupid while I shoot holes in things that people haven’t bothered to investigate in 11 years and yet they must be right and I am supposed to be so tolerant while reading some physicist say a tower had 80,000 tons of steel in 2011 when the NIST said there was roughly 200,000 tons in both towers in 2005 while neither of them specifies the concrete.  But thermodynamic washers is just a trivial error that does not matter. 

You think I was supposed to just instantly guess what you meant?  Actually I finished the post and was about to submit it when it occurred to me what you might have meant and then I went back and added the line.

You guys can make any ridiculous comments you want but I’m the supposed to be the dummy who is always wrong.

[3793]
psik

I admitted it was an error, a misnomer (though not quite so far off the mark as you present it to be).

Also, your observation of the importance of the vertical load bearing supports, I agree, but to then dismiss the integrity of the horizontal load bearing structure as somehow a trivial aspect of the equation, you are engaging in an argument from authority.

All stress bearing parts of a structure should be considered in the equation. Both a washer and a damper occupy space. An inherent weak point in any structure is in the spaces, the angles, the joints that keep it all “true”. When compromised for any reason or by any means may cause the entire structure to lose integrity.

I sincerely hope that somebody is going to settle this once and for all and can come up with a model which covers all possible eventualities at both physical and metaphysical, motives, actions, but seriously doubt it. There are too many potentials involved in events of this size and we have seen what a gentle breeze can do to a suspension bridge that is not “well tuned”.
Here we started with a pretty big bomb and a firestorm from the unspent fuels. Several hours later the towers went down.

In reality, I am satisfied with my perhaps a little more than casual knowledge (despite the misnomer) on the chronology of events on that fateful day. 
 
History will record a terrorist attack in the US on 9/11, resulting in the destruction of the WTC towers. The videos show the events as they happened in real time.  After having given it some serious thought, it seems entirely possible (and therefore probable) that the events happened as generally accepted by the scientific community. I am satisfied with that. It allows me to move on.

DarronS - 21 October 2012 07:33 PM

Robert Walper - 21 October 2012 07:18 PM

Your model is at the wrong scale and therefore invalid.

There you go confusing the issue with facts. psikey don’t need no facts when it come to this troofer stuff.

I don’t think he grasps basic concepts like how air pressure at his scale model is magnitudes greater a force to be taken into account when trying to model something billions of times more heavy.

To try putting it simply, it’s similar to how water tension affects an object falling into water. An insect falling into water would find water tension to be an extremely strong force to be dealing with. A human falling into water doesn’t even realize it’s there.

The water tension is the same in both cases, but one model is heavily influenced by it’s presence, the other is not.

Furthermore his claim that falling floors would be ‘losing energy’ is complete and utter nonsense that fails to take into account the rapidly increasing mass of falling material as it accumulates on the way down.

That is as absurd as claiming that the smaller a snow ball is, the easier it will roll down a snow packed hill rather than the reverse.

Write4U - 21 October 2012 08:32 PM

I admitted it was an error, a misnomer (though not quite so far off the mark as you present it to be).

Is there such a thing as a thermo-dynamic washer?

There may be a little similarity in the sound but what is there in relation to reality.

They are both kind of weird names and that make you go “What the hell is that?” so that is probably what made me remember it.

psik

Robert Walper - 21 October 2012 07:18 PM

psikeyhackr - 21 October 2012 06:22 PM

It’s not unlikely, it is impossible.

It is called the square cube law.  Galileo explained it 400 years ago.  So the people who began designing skyscraper 100 years ago knew all about it.

That is why my physical model has supports made of paper even though the weights are steel.  I wanted then AS WEAK AS POSSIBLE relative to the weight they support.  But skyscrapers are not designed to be as weak as possible, they have a safety margin.  Crushing a single paper loop takes 0.118 joules.  So the falling mass loses kinetic energy every time it crushes a loop.  So although a number of loops get damaged at the top the mass increases but slows down and loses more kinetic energy through reduced velocity than it gains from increased mass and the conservation of momentum slows it down as mass increases also.  So the continuous collapse from less than 15% of the top cannot happen.

psik

Your model is at the wrong scale and therefore invalid.

Since we are talking about a model that does physics how can one be made to the right scale if we don’t even know the total amount of concrete in the tower?

Curious how that does not seem to bother people who can believe in a collapse.

Is that the Ignorance is Bliss trick?

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psik