9-11 Presentation at NMSR, May 19 2010

[TruthersLie]

Are you going to explain how that 1.36 gigaJoules of kinetic energy should have been dissipated or will you admit that the collapse was self-sustaining after it was initiated?

It used the flux capacitor and went back to the future!!!!

 

[TruthersLie]

Anyone who understands science will understand that those experiments are demonstrating conservation of momentum. If you think that conservation of momentum only works for some materials, but not mysteriously for "special" ones, then you clearly don't understand the concept. The structural strength or composition of materials in these experiments are irrelevant. Why? Because the upper block in the WTC was made of the same components and designed the same way as the lower block. Both had equal strength. Actually, the lower block had more strength because it was designed to. You could do the same experiments with glued-together toothpick structures and you would see the same results.

<facepalm>

Here is a small hint... you might want to look it up (after you learn how to use a stopwatch). It is called SCALE.

The experiments demonstrated that, because of conservation of momentum, crush down does not occur before crush up, and his main point was that there is a visible deceleration of the upper moving body upon impact.

Look up scaling errors... it might help.

how did that water crush the car again?

 

[DaveThomasNMSR]

Grizzly Bear: Demonstrating conservation of momentum does not equate to exact results between two very different assemblies.

Please explain why.

From another thread:

You must also consider the scale of physical models being used to study something much larger.

The pressure exerted by beams depends on the size of the structure. As linear size is increased, the footprint increases as the square of the linear expansion, and volume increases as its cube.

So, a quantity like pressure, force per area, at a constant density in the volume, would increase linearly, as pressure = force/area = weight/area = volume*density/area. If density is constant, pressure increases as volume/area = cube(increase)/square(increase) = linearly increasing.

If a man was made twice as big, but with the same density of bones, muscles, and such, the pressure on his leg bones would be twice the normal-sized man's. A ten-times bigger man would have ten times the pressure on bones of similar density and capability; they would be CRUSHED.

Please, do not confuse the behavior of verinage of a building of ten stories or so as indicative of the behavior of a 110-story skyscraper. They are different things.

Look at a spider's legs, then at an elephant's. The elephants legs must be much thicker, relative to body size, to support its weight. A tiny spider-sized miniature elephant would be much stronger structurally, with less pressure on its bones, than the real elephant.

This is why Cole's scale models are a joke, and don't prove anything except truthiness cluelessness.

 

[ergo]

Because the forces seen by structural members in the model and in the original are a function of mass and cross-section, and those two properties do not scale the same. Mass scales as a function of the cube of the scale factor, and cross-section scales as a function of the square, therefore a scale model of the WTC towers will not have dynamic similitude.

All material is subject to the law of conservation of momentum. Correct?

 

[TruthersLie]

From another thread:



This is why Cole's scale models are a joke, and don't prove anything except truthiness cluelessness.

We already know that he doesn't read very well... so lets have his favorite professor speak ...youtube.

(this is the one on scale IIRC)

Scale matters...

 

[AZCat]

All material is subject to the law of conservation of momentum. Correct?

Yes, but showing conservation of momentum applies to a model does not imply dynamic similitude.

 

[ergo]

Yes, but showing conservation of momentum applies to a model does not imply dynamic similitude.

In other words, you are saying that showing that conservation of momentum applies to a model does not show that it applies to the WTC.

Does it apply to the WTC or not? And if so, why and how would the WTC express this dynamism differently from anything else?

 

[carlitos]

Thanks

Because the forces seen by structural members in the model and in the original are a function of mass and cross-section, and those two properties do not scale the same. Mass scales as a function of the cube of the scale factor, and cross-section scales as a function of the square, therefore a scale model of the WTC towers will not have dynamic similitude.

As a layman, that is a description of scale that I can understand. I am not optimistic that the poster in question will understand the relevance, but I appreciate it.

 

[AZCat]

In other words, you are saying that showing that conservation of momentum applies to a model does not show that it applies to the WTC.

Does it apply to the WTC or not? And if so, why and how would the WTC express this dynamism differently from anything else?

No, that's not what I said. Conservation of momentum applies both to a scale model and to the original, but that does not imply dynamic similitude between the two.

As I said before, the forces in the scale model and the original are different, therefore the dynamics are different, particularly so in our case because we care about the relationship between those forces and the properties of the materials of construction.

 

[AZCat]

As a layman, that is a description of scale that I can understand. I am not optimistic that the poster in question will understand the relevance, but I appreciate it.

You are welcome carlitos.

 

[ergo]

No, that's not what I said. Conservation of momentum applies both to a scale model and to the original, but that does not imply dynamic similitude between the two.

As I said before, the forces in the scale model and the original are different, therefore the dynamics are different, particularly so in our case because we care about the relationship between those forces and the properties of the materials of construction.

So, why and how would the WTC express this dynamism differently from anything else? Where specifically is conservation of momentum demonstrated in the Twin Towers collapses?

 

[TruthersLie]

In other words, you are saying that showing that conservation of momentum applies to a model does not show that it applies to the WTC.

Does it apply to the WTC or not? And if so, why and how would the WTC express this dynamism differently from anything else?

No... the scale is off, as such the results are off. Dur.

Again and again, watch this and tell me what R Mackey got wrong... and how the video you tried to pass off takes scale into account.

 

[AZCat]

So, why and how would the WTC express this dynamism differently from anything else?

As Dave Thomas pointed out above, the difference is in failure of structural elements. Typically strengths of materials are expressed in units of force per units of area, like pounds per square inch (psi). A36 steel, for example, has a minimum yield strength of 36,000 psi. Since the scale model will produce smaller forces than the original, the structural elements of the model (if composed of the same material) will not fail at the same point in the sequence as in the original. They might not fail at all, if the forces are reduced enough because of the scale factor. This will change the outcome of the test using the scale model.

Where specifically is conservation of momentum demonstrated in the Twin Towers collapses?

Everywhere. Really. No matter if the collapses were caused by damage from the impacts and subsequent fires, explosives, thermite, lasers, whatever - the collapses would still be subject to conservation of momentum.

 

[Slartibartfast]

It used the flux capacitor and went back to the future!!!!

The flux capacitor requires 1.21 gigaWatts, so that would only be enough energy to power it for a little over a second (although that's at least enough energy to move you 30 years in time...).

 

[Slartibartfast]

So, why and how would the WTC express this dynamism differently from anything else? Where specifically is conservation of momentum demonstrated in the Twin Towers collapses?

All of the structural and non-structural elements in the WTC obeyed conservation of momentum on 9/11 as did all of the experiments on the video. That doesn't change the fact that the structures experimented on behaved extremely differently than the Twin Towers (for reasons of scaling that others have pointed out). The lower portion of the building doesn't get crushed all at once - it gets crushed one floor at a time (and the proper context to look at conservation of momentum is in the floor-floor collisions - otherwise you're just talking about momentum being conserved between the building and the Earth). One floor can't stand up to the force of 14 floors crashing down on it so it fails providing an even bigger challenge for the next floor and so on. It's very clear that your lack of understanding of physics is causing you to make assertions that are ridiculous on their face. The choice is up to you to either learn about physics and try to understand what's going on or to continue reveling in your own ignorance and I see no indication that you intend to choose the former.

 

[beachnut]

In other words, you are saying that showing that conservation of momentum applies to a model does not show that it applies to the WTC.

Does it apply to the WTC or not? And if so, why and how would the WTC express this dynamism differently from anything else?

The person doing the video is either dumb or a liar. The models he makes up are not valid for the WTC.

A floor on the WTC can not hold more than 12 floors. Show me his model which models a floor failing with 12 floors on it? FAILURE

You can't scale down to his tiny model and expect it to be a correct model for the WTC, and it is not.

The person doing the video has fools you into thinking he has something which applies to the WTC. His model is not accurate for the WTC and he talks about physics but it is not true when applied to the WTC. He is the worse kind of nice guy, he misleads others out of his own ignorance; a false prophet for 911 truth! 911 truth batting zero for 8 years; a perfect recored of failure; you joined the wrong team unless you wanted to fail.

 

[TheRedWorm]

I love the smell of buckshot in the morning.

 

[beachnut]

I love the smell of buckshot in the morning.

Particles can't do that! Special Paranoid Conspiracy Edition Physics says so.

 

[ergo]

QUESTION ASKED: So why and how would the WTC express this dynamism differently from anything else? Where specifically is conservation of momentum demonstrated in the Twin Towers collapses?

As Dave Thomas pointed out above, the difference is in failure of structural elements. ... the structural elements of the model (if composed of the same material) will not fail at the same point in the sequence as in the original.

The model structure may indeed not fail at the same point "in the sequence" as the original, but this doesn't change the fact that the upper portion must still decelerate in transferring the force of impact, and that it would crush up before it could crush any larger (and stronger) lower block--on any scale.

Scale actually has nothing to do with it.

They might not fail at all, if the forces are reduced enough because of the scale factor. This will change the outcome of the test using the scale model.

Indeed. They might not, but not because of scale.

Everywhere. Really. No matter if the collapses were caused by damage from the impacts and subsequent fires, explosives, thermite, lasers, whatever - the collapses would still be subject to conservation of momentum.

"Everywhere"? Describe to us where in the video evidence of the Twin Towers' collapses we see the effects of conservation of momentum in action.

 

[ergo]

All of the structural and non-structural elements in the WTC obeyed conservation of momentum on 9/11 as did all of the experiments on the video.

Please describe where in the Twin Towers' collapses conservation of momentum is evident.

That doesn't change the fact that the structures experimented on behaved extremely differently than the Twin Towers (for reasons of scaling that others have pointed out). The lower portion of the building doesn't get crushed all at once - it gets crushed one floor at a time

Please show us where in the videos of the collapse the bolded is evident.

(and the proper context to look at conservation of momentum is in the floor-floor collisions - otherwise you're just talking about momentum being conserved between the building and the Earth).

If that's the way you want to play it, we have one floor on the upper block hitting one floor on the lower block.

One floor can't stand up to the force of 14 floors crashing down on it so it fails providing an even bigger challenge for the next floor and so on.

I love the "...and so on." Very "scientifical". Just like Bazant.

Um, no. As has already been explained to you folks ad nauseum, fourteen floors are not crashing onto just one floor. They are crashing onto the combined upward resistance of the entire lower block. You cannot have an impact from above affecting only one lower floor in isolation. That would mean that that first lower floor is not in any kind of contact with the structure it is attached to. Are you suggesting that each floor is levitating?

I'll just hand your silly statement right back to you: It's very clear that your lack of understanding of physics is causing you to make assertions that are ridiculous on their face.