Judy Wood

[chek]

A Sharp Major asked Chek

Are you saying that Judy Wood is doing her profession a favour by not flagging up Fetzer's junk science? Or do you not believe in the existence of supercooled water?

Chek didn't answer. Now everyone is talking billiard balls and Chek will be pleased.

You are in Critics' Corner Chek. It behoves you to answer your critic.
Are you saying that Judy Wood is doing her profession a favour by not flagging up Fetzer's junk science? Or do you not believe in the existence of supercooled water?

Thanking you in anticipation.

Firstly, I have no idea what supercooled water is relevant to.
Secondly I have no context of how it arose in the Wood/Fetzer conversation.
It's obviously symptomatic of a big deal to you.

So what is the relevance?
Was a definition of every possible state of water pertinent to their exchange or not?
If it was - bad, bad Judy Wood.
If not, who cares? (Apart from you)

[Johnny Pixels]

Yet there is still the problem of 'stutter' to overcome as each floor is broken free and can only then accelerate from rest.
How many milliseconds did this process take per floor?
The one thing that is certain is it can't be instantaneous, yet that's exactly what the actual observed collapse demands.

Of course it can be instantaneous. Not every object comes to a stop when it strikes another object. When a car hits a pedestrian, does it stop, even for an instant?

Of course, I recognize that it's possible that if the momentum was just right in relation to the resistance, that an object might stop for an instant, or even rebound, before it continues on its way. However, in order to demonstrate this, you would have to show actual numbers in terms of momentum and resistance, and show that one is sufficient to stop the other.

Oh I get it, so when car manufacturers do crash tests, they actually know what is going to happen because they have calculated everything before hand.

But wait a minute. Why do the crash tests then if they know the only possible outcome in advance?

They design and model cars using computer simulation. They do know what the outcome should be, but they also have to be able to prove it physically. Something that CTists know nothing about, scientific methods and all that.

Also funny how you trust car designers to use computer simulation to make cars, but if NIST use it to model structural failure then suddenly it becomes a load of nonsense.

And yes, it is the same thing. NIST even used the same software package that car designers do.

[chipmunk stew]

Chek said

The more likely explanation being that it was not directly relevant to the issue under discussion, rather than it's empirical status as a non-related factoid.

Judy Wood's integrity and or knowledge of engineering science is directly relevant. And in the interview, Fetzer's unscientific statement (unchallenged by Wood) sets the scene for the interview. Relevant whatever way you look at it.

Chek mocked

Or curses, have you discovered the true CT plot to deceive the world on the true physical properties of water.

No Chek, just another example of all conspiracy theorists (even your champions) being nonsense at physics/engineering science, analysis, conceptualising, telling the truth, answering the question an so on.

I was right about Steven E Jones (before your time Chek but check my posts). JW is heading the same way.

Two things occur to me - firstly what way has Steven Jones 'gone'?
Politically motivated professional assassination? Quelle suprise.
and
secondly, despite the assertion, Wood's 'billiard balls' example is a good one.

Each floor has to accelerate from rest - the uncalculated 'imparted momentum' criticism is only valid in explaining the unprecendented speed of collapse when trying to fit the OCT myth to observed reality.

I've yet to see her physics discredited other than by implying she's somehow 'wrong'.
State what your alternate case is, and I'm sure a way can be found for her to consider them.

1. Wood's model is of a series of balls suspended in space, one over top of the other, that are only set into motion when struck by the ball above.

2. The first ball drops, accelerating at freefall. It then strikes the ball below it elastically, setting it into motion.

3. At the point of impact, the first ball STOPS momentarily as it imparts its energy to the second ball, then the two balls continue on at freefall FROM REST.

4. This process continues on down to the bottom.


There are several problems with her model aside from the fact that it's simply a poor representation of the towers.

In step 1, she ignores the fact that gravity is already acting on each of the balls. She simply assumes that gravity kicks in as soon as the balls come into contact with one another. The problem would have made more sense if she had set up a counteracting force that had to be overcome by the collision before the ball could be set into motion. But we'll assume the force to be overcome is just this side of zero (in other words, the counteracting force is capable of resisting the weight of one ball, plus a tiny smidge)

In step 2, she should have been using an inelastic collision. The elastic collision is not realistic. But we'll ignore the fact that this is supposed to model a real-world scenario and just focus on the analysis of the model.

In step 3, this is where she makes her huge error. She fails to factor in that when the first ball strikes the next, it imparts its current velocity to the next by accelerating it in the split second it takes the balls to compress and expand in their elastic collision. This means that the next ball begins freefalling, not AT REST, but at almost the velocity the first ball had reached by the time of the collision.

In step 4, unless she's making the ridiculous assumption that a natural collapse would be perfectly elastic (and therefore that the time can be extended by factoring in a lot of bouncing) the outcome of repeating step 3 on down is a collapse time greater than freefall, but not by much (depends on how much allowance you give to inelastic deformation, heat, etc.)

[chipmunk stew]

How about this? The billiard balls in the example do not have a force applied to them that causes them to continue to accelerate once they are put in motion. Perhaps if the cue ball was set in motion with a continuous jet of compressed air rather than a stick, the analogy would be more apt.

Yet there is still the problem of 'stutter' to overcome as each floor is broken free and can only then accelerate from rest.
How many milliseconds did this process take per floor?
The one thing that is certain is it can't be instantaneous, yet that's exactly what the actual observed collapse demands.

Of course it can be instantaneous. Not every object comes to a stop when it strikes another object. When a car hits a pedestrian, does it stop, even for an instant?

Technically, it's not instantaneous. In an inelastic collision (like a car hitting a pedestrian) the car does not stop, no, even for an instant. However, the pedestrian takes time to accelerate. Zero to sixty in a millisecond. That's why inelastic collisions do so much damage.

Of course, I recognize that it's possible that if the momentum was just right in relation to the resistance, that an object might stop for an instant, or even rebound, before it continues on its way. However, in order to demonstrate this, you would have to show actual numbers in terms of momentum and resistance, and show that one is sufficient to stop the other.

[Bushwacker]

Judy Woods treats her billiard balls as if they were runners in a relay race, who can only start running when they have received the baton. In actual fact, it is more as though the first runner runs straight into the second, and they continue together, both running into the third and so on. Or sticking to balls, balls made of putty would be more apt, the first being 12 or 28 times as heavy as the second and sticking to it when they meet, so their combined weight is 13 or 29 times as heavy as the third, and so on. (apart from an indeterminate amount of putty breaking away each time)

[Anti-sophist]

Judy Woods treats her billiard balls as if they were runners in a relay race, who can only start running when they have received the baton. In actual fact, it is more as though the first runner runs straight into the second, and they continue together, both running into the third and so on. Or sticking to balls, balls made of putty would be more apt, the first being 12 or 28 times as heavy as the second and sticking to it when they meet, so their combined weight is 13 or 29 times as heavy as the third, and so on. (apart from an indeterminate amount of putty breaking away each time)

Just for the record, conspiracy theorists, this is a description of the distrinction between elastic and inelastic collision.

Here is some further reading...
http://hyperphysics.phy-astr.gsu.edu/hb ... ol.html#c4
http://hyperphysics.phy-astr.gsu.edu/hbase/inecol.html

It should be obvious to anyone who understands the concepts that for the WTC, perfectly inelastic collisions are far more accurate than elastic ones. If you disagree, we can construct both models and prove that the towers collapse is much more accurately modeled by inelastic than elastic conditions.

[A Sharp Major]

Chek said

Firstly, I have no idea what supercooled water is relevant to.

I've told you.

Secondly I have no context of how it arose in the Wood/Fetzer conversation.

I gave you a link to the interview

It's obviously symptomatic of a big deal to you.

It is. Andrew Johnson got Judy Wood on my case when I called her unreliable.

So what is the relevance?

I am demonstrating that she is unreliable.

Was a definition of every possible state of water pertinent to their exchange or not?

Fetzer used phases to set the scene. I gave you the link

If it was - bad, bad Judy Wood.

You and others in the consiracy movement will still cite her as an expert engineer though fence-sitters will hopefully get my point.

If not, who cares? (Apart from you)

It was and you should care about knowledge and ethics. She has allowed a non engineer (Fetzer) to spread falsehood. Without getting in to her billiard balls (it has been done) she is unreliable.

[chek]

Chek said

Firstly, I have no idea what supercooled water is relevant to.

I've told you.

Secondly I have no context of how it arose in the Wood/Fetzer conversation.

I gave you a link to the interview

It's obviously symptomatic of a big deal to you.

It is. Andrew Johnson got Judy Wood on my case when I called her unreliable.

So what is the relevance?

I am demonstrating that she is unreliable.

Was a definition of every possible state of water pertinent to their exchange or not?

Fetzer used phases to set the scene. I gave you the link

If it was - bad, bad Judy Wood.

You and others in the consiracy movement will still cite her as an expert engineer though fence-sitters will hopefully get my point.

If not, who cares? (Apart from you)

It was and you should care about knowledge and ethics. She has allowed a non engineer (Fetzer) to spread falsehood. Without getting in to her billiard balls (it has been done) she is unreliable.

I'll decide for myself who is being unreliable when I've listened to the interview.

[chek]

I've yet to see her physics discredited other than by implying she's somehow 'wrong'.
State what your alternate case is, and I'm sure a way can be found for her to consider them.

1. Wood's model is of a series of balls suspended in space, one over top of the other, that are only set into motion when struck by the ball above.

Ok so far.

2. The first ball drops, accelerating at freefall. It then strikes the ball below it elastically, setting it into motion.

Right

3. At the point of impact, the first ball STOPS momentarily as it imparts its energy to the second ball, then the two balls continue on at freefall FROM REST.

Seems a fair assumption for the first two balls/floors

4. This process continues on down to the bottom.
There are several problems with her model aside from the fact that it's simply a poor representation of the towers.

In step 1, she ignores the fact that gravity is already acting on each of the balls. She simply assumes that gravity kicks in as soon as the balls come into contact with one another. The problem would have made more sense if she had set up a counteracting force that had to be overcome by the collision before the ball could be set into motion. But we'll assume the force to be overcome is just this side of zero (in other words, the counteracting force is capable of resisting the weight of one ball, plus a tiny smidge)

In step 2, she should have been using an inelastic collision. The elastic collision is not realistic. But we'll ignore the fact that this is supposed to model a real-world scenario and just focus on the analysis of the model.

In step 3, this is where she makes her huge error. She fails to factor in that when the first ball strikes the next, it imparts its current velocity to the next by accelerating it in the split second it takes the balls to compress and expand in their elastic collision. This means that the next ball begins freefalling, not AT REST, but at almost the velocity the first ball had reached by the time of the collision.

In step 4, unless she's making the ridiculous assumption that a natural collapse would be perfectly elastic (and therefore that the time can be extended by factoring in a lot of bouncing) the outcome of repeating step 3 on down is a collapse time greater than freefall, but not by much (depends on how much allowance you give to inelastic deformation, heat, etc.)

Firstly, may I thank you for explaining the ineleastic collapse (nee pancake) theory so clearly.

Several problems arise however - the over-engineering of the building is not allowed for - factors of a minimum of 5 times being commonly quoted.
And as can be seen in the attached photos of the South Tower, the building resists the fall of the 30 storey upper portion well, until the explosives -indicated by the line of light coloured smoke - knocks the stuffing out of its support.





Which by a startling coincidence, is what is seen on the North Tower.




The concept of pancake collapse, whether inelastic or not, is beside the point.
The Towers were plainly blown up by an unconventional demolition method.

[James C]

Of course it can be instantaneous. Not every object comes to a stop when it strikes another object. When a car hits a pedestrian, does it stop, even for an instant?

Of course, I recognize that it's possible that if the momentum was just right in relation to the resistance, that an object might stop for an instant, or even rebound, before it continues on its way. However, in order to demonstrate this, you would have to show actual numbers in terms of momentum and resistance, and show that one is sufficient to stop the other.

Oh I get it, so when car manufacturers do crash tests, they actually know what is going to happen because they have calculated everything before hand.

But wait a minute. Why do the crash tests then if they know the only possible outcome in advance?

They design and model cars using computer simulation. They do know what the outcome should be, but they also have to be able to prove it physically. Something that CTists know nothing about, scientific methods and all that.

Also funny how you trust car designers to use computer simulation to make cars, but if NIST use it to model structural failure then suddenly it becomes a load of nonsense.

And yes, it is the same thing. NIST even used the same software package that car designers do.

Designing and modelling cars is different to testing crashes. No wonder NIST has got it so wrong if it's using the same software for cars. Besides, it's the data that goes in which is important. A computer is only as good as the numbers which are fed into it.

You talk rubbish however. There are many articles on the net which discuss the need for crash tests in order to establish a database of how cars react in real events. This data is then used to refine computer models; computer modelling is preferred because it is cheaper than lifesize crash tests but is only accurate due to the data used from the real life tests performed. Computers cannot predict situations where no real life test has been performed due to the lack of data.

Read here for example;

http://www.tfhrc.gov/pubrds/janfeb01/improving.htm

Furthermore, none of the existing models have been validated against full-scale crash tests for the wide range of impact conditions that have to be studied. In addition, the detailed vehicle models now in use still have some significant limitations, especially in the suspension and tire representations. These areas of the vehicle models are especially critical for simulation of run-off-road accidents because of the strong correlation between tire and suspension damage and vehicle rollover.

Therefore, significant effort must be directed toward refining existing vehicle-modeling techniques to provide better tools for analyzing run-off-road impacts. It also is critical that these models be kept up to date with respect to current trends in the vehicle fleet.

The high cost of full-scale crash testing precludes a dramatic expansion of existing programs to address these issues. Computer simulation appears to be the only practical means for addressing these problems in the near future.

To achieve the objective of investigating these difficult roadside safety issues, significant effort must be devoted toward improving the capability of computer simulation for modeling run-off-road crashes. These efforts should focus on developing better vehicle and roadside safety hardware models and on developing better links between vehicle kinematics and occupant risk. If a comprehensive effort is directed toward achieving these overall goals, we can continue our quest to reduce the injuries and fatalities associated with run-off-road crashes.

There are plenty more examples. Go check it for yourself.

[aggle-rithm]

The concept of pancake collapse, whether inelastic or not, is beside the point.
The Towers were plainly blown up by an unconventional demolition method.

I'll say it's unconventional. Those have to be the laziest explosives in history. If all they can do is kick up a dust cloud, how did they possibly compromise the structural integrity of the buildings?

I still think it would have been simpler to just fly airliners into the buildings. But that's just me.

In case you've missed it, here's what an explosion looks like. Note the difference in speed:

http://www.metacafe.com/watch/55259/bomb_explosion/

[Johnny Pixels]

Designing and modelling cars is different to testing crashes. No wonder NIST has got it so wrong if it's using the same software for cars. Besides, it's the data that goes in which is important. A computer is only as good as the numbers which are fed into it.

Shows how much you know about computer modelling. The software I was referring to is an industry standard across all engineering disciplines.

You talk rubbish however. There are many articles on the net which discuss the need for crash tests in order to establish a database of how cars react in real events.

That wouldn't be very useful because car designs vary so much. What matters is how materials behave under impact.

This data is then used to refine computer models; computer modelling is preferred because it is cheaper than lifesize crash tests but is only accurate due to the data used from the real life tests performed. Computers cannot predict situations where no real life test has been performed due to the lack of data.

Not true. The major problem with car crash testing is the way that people behave in the crash, not the car. That is why the worlds (probably) most expensive piece of software is one that models human behaviour under impact. That's where real life data comes in handy. Crash testing of cars depends on material properties. Otherwise they would have to design a car, build it, crash it, and then redesign it, then crash it again, because every time you change the design you'd have to validate your model. That doesn't happen.

[aggle-rithm]

Not true. The major problem with car crash testing is the way that people behave in the crash, not the car. That is why the worlds (probably) most expensive piece of software is one that models human behaviour under impact. That's where real life data comes in handy. Crash testing of cars depends on material properties. Otherwise they would have to design a car, build it, crash it, and then redesign it, then crash it again, because every time you change the design you'd have to validate your model. That doesn't happen.

This reminds me of a Calvin and Hobbes cartoon where Calvin's dad messed with his mind by telling him the weight limit on bridges was determined by driving increasingly heavier trucks over the bridge until it collapsed, then weighing the last truck and rebuilding the bridge.

[chek]

The concept of pancake collapse, whether inelastic or not, is beside the point.
The Towers were plainly blown up by an unconventional demolition method.

I'll say it's unconventional. Those have to be the laziest explosives in history. If all they can do is kick up a dust cloud, how did they possibly compromise the structural integrity of the buildings?

I still think it would have been simpler to just fly airliners into the buildings. But that's just me.

In case you've missed it, here's what an explosion looks like. Note the difference in speed:

http://www.metacafe.com/watch/55259/bomb_explosion/

Airliners wouldn't do it, that was already established back in 1964.
That's just a Bush science story for the feeble minded - haven't you sussed that much yet?
In any case, I'll believe Skilling's analysis over your neocon-friendly conjecture anyday, thanks.

Also, the location, type and amount of explosive affects
what we saw externally.
Strangely strategic timing, those smoke emissions.
On both occasions.
Maybe Mr. Roberts can come up with another humdinger of a
disappointing non-explanation.
Or did Charles 'brains' Thornton beat him to it?

[James C]

Designing and modelling cars is different to testing crashes. No wonder NIST has got it so wrong if it's using the same software for cars. Besides, it's the data that goes in which is important. A computer is only as good as the numbers which are fed into it.

Shows how much you know about computer modelling. The software I was referring to is an industry standard across all engineering disciplines.

You talk rubbish however. There are many articles on the net which discuss the need for crash tests in order to establish a database of how cars react in real events.

That wouldn't be very useful because car designs vary so much. What matters is how materials behave under impact.

This data is then used to refine computer models; computer modelling is preferred because it is cheaper than lifesize crash tests but is only accurate due to the data used from the real life tests performed. Computers cannot predict situations where no real life test has been performed due to the lack of data.

Not true. The major problem with car crash testing is the way that people behave in the crash, not the car. That is why the worlds (probably) most expensive piece of software is one that models human behaviour under impact. That's where real life data comes in handy. Crash testing of cars depends on material properties. Otherwise they would have to design a car, build it, crash it, and then redesign it, then crash it again, because every time you change the design you'd have to validate your model. That doesn't happen.

Have you bothered to read the article I gave you? Obviously not since you continue to spout complete rubbish.

Of course driver behaviour is relevant but so is the road type, tyre type, the speed, the object the car hit, the direction of travel, the weather, and so on and so on. Of course you don't design a car by crash testing it. I never once designed a building (using AutoCAD) when I was working as an architect by watching it be built then letting it be destroyed. Again you talk nonsense because frankly you don't actually know what you're on about. How the hell can a computer simulate what happens to a car in a crash situation if there is no data to tell the computer what to think? Go read that article again.

Why the hell do you think the transport industry bothers to do crash tests at all if a computer can do the job so well? Go think about that one before making anymore stupid remarks!

Why do I bother discussing matters with you and the fluffy owl when the pair of you talk utter nonsense.

[aggle-rithm]

Airliners wouldn't do it, that was already established back in 1964.
That's just a Bush science story for the feeble minded - haven't you sussed that much yet?
In any case, I'll believe Skilling's analysis over your neocon-friendly conjecture anyday, thanks.

Have you SEEN his analysis? How can you judge it's worth otherwise?

Regardless, there's a difference between a building being designed to behave a certain way, and actually behaving that way. The extreme conditions of an airliner crash is not something that can be easily tested.

Also, the location, type and amount of explosive affects
what we saw externally.
Strangely strategic timing, those smoke emissions.
On both occasions.
Maybe Mr. Roberts can come up with another humdinger of a
disappointing non-explanation.
Or did Charles 'brains' Thornton beat him to it?

The only problem is that the demolition scenario must assume a type of demolition that has never been seen before, pulled from the imagination of the conspiracy theorists to fit the available evidence. This is similar to the sharpshooter fallacy, where one shoots at a wall, draws a target around the hits, and declares himself the winner.

[chek]

Airliners wouldn't do it, that was already established back in 1964.
That's just a Bush science story for the feeble minded - haven't you sussed that much yet?
In any case, I'll believe Skilling's analysis over your neocon-friendly conjecture anyday, thanks.

Have you SEEN his analysis? How can you judge it's worth otherwise?

Regardless, there's a difference between a building being designed to behave a certain way, and actually behaving that way. The extreme conditions of an airliner crash is not something that can be easily tested.

Also, the location, type and amount of explosive affects
what we saw externally.
Strangely strategic timing, those smoke emissions.
On both occasions.
Maybe Mr. Roberts can come up with another humdinger of a
disappointing non-explanation.
Or did Charles 'brains' Thornton beat him to it?

The only problem is that the demolition scenario must assume a type of demolition that has never been seen before, pulled from the imagination of the conspiracy theorists to fit the available evidence. This is similar to the sharpshooter fallacy, where one shoots at a wall, draws a target around the hits, and declares himself the winner.

*yawn*

[Patrick Brown]

Airliners wouldn't do it, that was already established back in 1964.
That's just a Bush science story for the feeble minded - haven't you sussed that much yet?
In any case, I'll believe Skilling's analysis over your neocon-friendly conjecture anyday, thanks.

Have you SEEN his analysis? How can you judge it's worth otherwise?

Regardless, there's a difference between a building being designed to behave a certain way, and actually behaving that way. The extreme conditions of an airliner crash is not something that can be easily tested.

Also, the location, type and amount of explosive affects
what we saw externally.
Strangely strategic timing, those smoke emissions.
On both occasions.
Maybe Mr. Roberts can come up with another humdinger of a
disappointing non-explanation.
Or did Charles 'brains' Thornton beat him to it?

The only problem is that the demolition scenario must assume a type of demolition that has never been seen before, pulled from the imagination of the conspiracy theorists to fit the available evidence. This is similar to the sharpshooter fallacy, where one shoots at a wall, draws a target around the hits, and declares himself the winner.

*yawn*

Indeed,
*yawn*

[Johnny Pixels]

Have you bothered to read the article I gave you? Obviously not since you continue to spout complete rubbish.

Yes I did

Of course driver behaviour is relevant but so is the road type, tyre type, the speed, the object the car hit, the direction of travel, the weather, and so on and so on.

Have you bothered to read what I wrote? I didn't say driver behaviour, I said the way people behave, as in the way their face hits the dashboard.

Of course you don't design a car by crash testing it. I never once designed a building (using AutoCAD) when I was working as an architect by watching it be built then letting it be destroyed. Again you talk nonsense because frankly you don't actually know what you're on about. How the hell can a computer simulate what happens to a car in a crash situation if there is no data to tell the computer what to think? Go read that article again.

You're funny. You need to tell a computer what to think. I can see you don't understand how computer modelling and simulation works.

This is how it works.

Say I am modelling a beam under a compressive load. I would tell the computer the dimensions of the beam, and the properties of the material the beam is made from. I would tell it the magnitude of the load, and its location. I would then create a mesh for this beam. This mesh tells the computer where it should carry out calculations. I could make a mesh that divides the beam into 4 sections. This would mean the calculations would be quick, but not very accurate. I would increase the number of elements in the mesh, so that the computer carries out more calculations, and therefore takes longer, but also gives more accurate results.

When we carry this out on a car, we use more complex elements than simple rectangular beams, and also more complex meshes. This means that computing time is incredibly high, so it is usual practice to model only half the car, along its line of symmetry.

At no point do we tell the computer what to think. The software knows how materials behave from their mechanical properties. That is how we can use the same software to model cars, buildings, aircraft etc.

Why the hell do you think the transport industry bothers to do crash tests at all if a computer can do the job so well? Go think about that one before making anymore stupid remarks!

Because people obviously don't understand. How do you think they designed the A380 airbus? What convinced them that it would fly? How did they design the Eurofighter and other inherently unstable aircraft and have the confidence that they would fly? The windtunnel models only tell them so much, and the majority of wind tunnel testing is carried out on computer simulation.

Why do I bother discussing matters with you and the fluffy owl when the pair of you talk utter nonsense.

If you don't understand what you are reading, then it can appear to be nonsense.

[chipmunk stew]

Airliners wouldn't do it, that was already established back in 1964.
That's just a Bush science story for the feeble minded - haven't you sussed that much yet?
In any case, I'll believe Skilling's analysis over your neocon-friendly conjecture anyday, thanks.

Have you SEEN his analysis? How can you judge it's worth otherwise?

Regardless, there's a difference between a building being designed to behave a certain way, and actually behaving that way. The extreme conditions of an airliner crash is not something that can be easily tested.

chek, you and James C need to get together and decide whether or not it's legitimate to draw a conclusion about a complex, dynamic event based on number-crunching alone. You're each taking the opposite position to argue the same point.

[aggle-rithm]

*yawn*

Indeed,
*yawn*

Yes, the real world can be boring at times. But it does have the advantage of being real.

[Bushwacker]

I've yet to see her physics discredited other than by implying she's somehow 'wrong'.
State what your alternate case is, and I'm sure a way can be found for her to consider them.

1. Wood's model is of a series of balls suspended in space, one over top of the other, that are only set into motion when struck by the ball above.

Ok so far.

2. The first ball drops, accelerating at freefall. It then strikes the ball below it elastically, setting it into motion.

Right

3. At the point of impact, the first ball STOPS momentarily as it imparts its energy to the second ball, then the two balls continue on at freefall FROM REST.

Seems a fair assumption for the first two balls/floors

4. This process continues on down to the bottom.
There are several problems with her model aside from the fact that it's simply a poor representation of the towers.

In step 1, she ignores the fact that gravity is already acting on each of the balls. She simply assumes that gravity kicks in as soon as the balls come into contact with one another. The problem would have made more sense if she had set up a counteracting force that had to be overcome by the collision before the ball could be set into motion. But we'll assume the force to be overcome is just this side of zero (in other words, the counteracting force is capable of resisting the weight of one ball, plus a tiny smidge)

In step 2, she should have been using an inelastic collision. The elastic collision is not realistic. But we'll ignore the fact that this is supposed to model a real-world scenario and just focus on the analysis of the model.

In step 3, this is where she makes her huge error. She fails to factor in that when the first ball strikes the next, it imparts its current velocity to the next by accelerating it in the split second it takes the balls to compress and expand in their elastic collision. This means that the next ball begins freefalling, not AT REST, but at almost the velocity the first ball had reached by the time of the collision.

In step 4, unless she's making the ridiculous assumption that a natural collapse would be perfectly elastic (and therefore that the time can be extended by factoring in a lot of bouncing) the outcome of repeating step 3 on down is a collapse time greater than freefall, but not by much (depends on how much allowance you give to inelastic deformation, heat, etc.)

Firstly, may I thank you for explaining the ineleastic collapse (nee pancake) theory so clearly.

Several problems arise however - the over-engineering of the building is not allowed for - factors of a minimum of 5 times being commonly quoted.
And as can be seen in the attached photos of the South Tower, the building resists the fall of the 30 storey upper portion well, until the explosives -indicated by the line of light coloured smoke - knocks the stuffing out of its support.

Interesting, but a different subject. Dealing with Judy Wood's physics, where she is wrong is, as chipmunk stew identifies, is that she ignores the fact that each ball stikes the ball below with force, it does not just pass it some hypothetical baton, it shoves it in the back, so to speak. As chipmunk stew says, this means that the lower ball starts off with almost the velocity of the ball that has hit it, and accelerates from that speed over its own fall. She treats the collisions as elastic, when in fact they are iinelastic and does not take into account the transfer of momentum. The first error one might say is for the sake of simplicity, but I see no excuse for the second. To put it another way, when a ball is struck by the cue ball on a snooker table, it moves off with almost the speed of the ball that hit it. She ignores that, and treats the struck ball as though no force acts on it apart from gravity.

[Bushwacker]

........And as can be seen in the attached photos of the South Tower, the building resists the fall of the 30 storey upper portion well, until the explosives -indicated by the line of light coloured smoke - knocks the stuffing out of its support.

So what do you say caused the upper portion to fall, prior to the explosives detonating?

[John White]

If you don't understand what you are reading, then it can appear to be nonsense.

Probably why you havnt "clicked" with the case for inside Job then

So.... where are the computer models used by NIST etc so they can be independantly verified? Oh yeah... no-one else can get their mitts on them

Well, thats confidence boosting!

[Anti-sophist]

So.... where are the computer models used by NIST etc so they can be independantly verified? Oh yeah... no-one else can get their mitts on them

Originally I didn't understand why NIST wouldn't release their models, and after dealing with JDX and his merry band of amatuers trying to decipher FDR data, I'm starting to realize why it's a bad idea.

[chek]

........And as can be seen in the attached photos of the South Tower, the building resists the fall of the 30 storey upper portion well, until the explosives -indicated by the line of light coloured smoke - knocks the stuffing out of its support.

So what do you say caused the upper portion to fall, prior to the explosives detonating?

That'd be the upper core being blown (as signified by the antenna drop on the North Tower), followed by the outer columns. You should try critically watching a few videos.

[James C]

Have you bothered to read the article I gave you? Obviously not since you continue to spout complete rubbish.

Yes I did

Of course driver behaviour is relevant but so is the road type, tyre type, the speed, the object the car hit, the direction of travel, the weather, and so on and so on.

Have you bothered to read what I wrote? I didn't say driver behaviour, I said the way people behave, as in the way their face hits the dashboard.

Of course you don't design a car by crash testing it. I never once designed a building (using AutoCAD) when I was working as an architect by watching it be built then letting it be destroyed. Again you talk nonsense because frankly you don't actually know what you're on about. How the hell can a computer simulate what happens to a car in a crash situation if there is no data to tell the computer what to think? Go read that article again.

You're funny. You need to tell a computer what to think. I can see you don't understand how computer modelling and simulation works.

This is how it works.

Say I am modelling a beam under a compressive load. I would tell the computer the dimensions of the beam, and the properties of the material the beam is made from. I would tell it the magnitude of the load, and its location. I would then create a mesh for this beam. This mesh tells the computer where it should carry out calculations. I could make a mesh that divides the beam into 4 sections. This would mean the calculations would be quick, but not very accurate. I would increase the number of elements in the mesh, so that the computer carries out more calculations, and therefore takes longer, but also gives more accurate results.

When we carry this out on a car, we use more complex elements than simple rectangular beams, and also more complex meshes. This means that computing time is incredibly high, so it is usual practice to model only half the car, along its line of symmetry.

At no point do we tell the computer what to think. The software knows how materials behave from their mechanical properties. That is how we can use the same software to model cars, buildings, aircraft etc.

Why the hell do you think the transport industry bothers to do crash tests at all if a computer can do the job so well? Go think about that one before making anymore stupid remarks!

Because people obviously don't understand. How do you think they designed the A380 airbus? What convinced them that it would fly? How did they design the Eurofighter and other inherently unstable aircraft and have the confidence that they would fly? The windtunnel models only tell them so much, and the majority of wind tunnel testing is carried out on computer simulation.

Why do I bother discussing matters with you and the fluffy owl when the pair of you talk utter nonsense.

If you don't understand what you are reading, then it can appear to be nonsense.

You know what, you start to sound clever but then it all goes wrong just after your casual reference to telling the computer about material properties. Where do you get those properties from - the back of a cereal packet, by watching Good Morning TV, by reading The Sun....? Go think about that then come back to me with an answer that might just correct my view that you are not clever enough to understand what is being discussed here.

And if you cannot see the difference between a chaotic event like a crash and what happens to the wind as it passes over a car then you really shouldn't be promoting yourself as an expert.

[Patrick Brown]

Interesting, but a different subject. Dealing with Judy Wood's physics, where she is wrong is, as chipmunk stew identifies, is that she ignores the fact that each ball stikes the ball below with force, it does not just pass it some hypothetical baton, it shoves it in the back, so to speak. As chipmunk stew says, this means that the lower ball starts off with almost the velocity of the ball that has hit it, and accelerates from that speed over its own fall. She treats the collisions as elastic, when in fact they are iinelastic and does not take into account the transfer of momentum. The first error one might say is for the sake of simplicity, but I see no excuse for the second. To put it another way, when a ball is struck by the cue ball on a snooker table, it moves off with almost the speed of the ball that hit it. She ignores that, and treats the struck ball as though no force acts on it apart from gravity.

You seem to have forgotten to account for the lose of kinetic energy due to the pulverization of the concrete floors!

You seem to have forgotten to account for the lose of kinetic energy due to the bending, twisting, shearing and compressing of 47, 36 inch by 12 inch section (2 inch thick) high grade steel core columns!

You seem to have forgotten to account for the lose of kinetic energy due to the 236, 14 inch square section (does anyone no how thick the steel was?) high grade steel external columns which had the ability to support 2000 time their normal load!

And about those floors:

Floor construction typically consisted of 4 inches of lightweight concrete on 1-1/2-inch, 22-gauge
non-composite steel deck. In the core area, slab thickness was 5 inches. Outside the central core, the floor deck was supported by a series of composite floor trusses that spanned between the central core and exterior wall. Composite behavior with the floor slab was achieved by extending the truss diagonals above the top chord so that they would act much like shear studs, as shown in Figure 2-6. Detailing of these trusses was similar to that employed in open-web joist fabrication and, in fact, the trusses were manufactured by a joist fabricator, the LaClede Steel Corporation. However, the floor system design was not typical of open-web-joist floor systems. It was considerably more redundant and was well braced with transverse members. Trusses were placed in pairs, with a spacing of 6 feet 8 inches and spans of approximately 60 feet to the sides and 35 feet at the ends of the central core. Metal deck spanned parallel to the main trusses and was directly supported by continuous transverse bridging trusses spaced at 13 feet 4 inches and intermediate deck support angles spaced at 6 feet 8 inches from the transverse trusses. The combination of main trusses, transverse trusses, and deck support enabled the floor system to act as a grillage to distribute load to the various columns.
[This is another 'must have' PDF]
http://www.house.gov/science/hot/wtc/wt ... TC_ch2.pdf (Page 3)

See images below:

[chek]

In other words, they seem to have forgotten anything relevant to the impossible so-called gravity collapse of these specific buildings.

It's actually quite amazing the lengths NIST go to in their effort to show what they say happened, couldn't have happened.

Moles on the inside, or the 'too much information strategy' working against them?

[aggle-rithm]

You seem to have forgotten to account for the lose of kinetic energy due to the pulverization of the concrete floors!

You seem to have forgotten to account for the lose of kinetic energy due to the bending, twisting, shearing and compressing of 47, 36 inch by 12 inch section (2 inch thick) high grade steel core columns!

I agree that this bending, twisting and shearing of large steel columns would be extremely difficult to achieve by hand, and if it were even possible, there would be very little kinetic energy left over. Here, however, we are dealing with forces far in excess of anything you are likely to experience in your lifetime.

In order to say with confidence that the kinetic energy lost to these events was sufficient to stop the momentum of the moving sections of the buildings, you would have to have some idea of the downward forces relative to the energy required to twist, shear, and compress. You ASSUME that those values are very close to each other. What if the forces were ten times greater than the resistance? A hundred times greater? Would it make any difference how much kinetic energy was lost if it was only 1% of the total available energy?

(I don't know those numbers myself, but judging from the evidence, it appears that the lower floors offered little resistance, and therefore the downward forces were much greater.)