Offer to the Truth Movement: Let's Settle It

[Travis]

The mass of a car affects its behavior in accelerating from a standing start but it also affects the behavior in a sharp turn. Inertia is inertia. The height of the center of mass is probably more important in the turn than in the straight line acceleration but mass affects both. Similar things apply to the World Trade Center. The inertia of a large mass is relevant regardless of direction from which force is applied.

I have searched the NCSTAR1 report for "weight distribution", "mass distribution", "distribution of weight" and "distribution of mass". They talk about the distribution of the weight of the airplane more than they do about the building. I have only found two instances discussing the distribution in the building and neither is about the collapse. One is about the impact which I quoted about and the other is about the effect of the wind which is a lateral force like the plane.

It is certainly curious that they do not bring this up in relation to the collapse in a 10,000 page report especially when they claim to be "World renowned experts" on building collapses. ROFLMAO

Such a subject is of academic interest but since the NIST report was only supposed to be about collapse initiation and not about what happened after the collapse started it would have been superfluous to the reports intent to cover it.

 

[Hokulele]

The mass of a car affects its behavior in accelerating from a standing start but it also affects the behavior in a sharp turn. Inertia is inertia. The height of the center of mass is probably more important in the turn than in the straight line acceleration but mass affects both. Similar things apply to the World Trade Center. The inertia of a large mass is relevant regardless of direction from which force is applied.

I have searched the NCSTAR1 report for "weight distribution", "mass distribution", "distribution of weight" and "distribution of mass". They talk about the distribution of the weight of the airplane more than they do about the building. I have only found two instances discussing the distribution in the building and neither is about the collapse. One is about the impact which I quoted about and the other is about the effect of the wind which is a lateral force like the plane.

The NCSTAR discussed collapse initiation, not the collapses after initiation.

(I need to set up a keyboard macro so I don't have to keep typing that.)

ETA: Jinx, Travis! You owe me a coke.

That report on suspended ceilings is the only place I found the use of the term "center of mass". I still don't understand why they bothered researching the ceilings. The only video I have seen of a 9/11 survivor talking about stuff falling from the ceiling was in the basement and that report doesn't contain the word basement.

The ceiling tiles were an integral part of the fire protection system in the towers. If the ceiling tiles were damaged or displaced, the fires would spread more quickly, and the steel would be more likely to heat up faster and to higher temperatures.

Of course, it helps if you actually read that report so you understand these things in context rather than just using the Search tool to look for TONS of STEEL and TONS of CONCRETE.

 

[psikeyhackr]

Such a subject is of academic interest but since the NIST report was only supposed to be about collapse initiation and not about what happened after the collapse started it would have been superfluous to the reports intent to cover it.

The NCSTAR discussed collapse initiation, not the collapses after initiation.

Yes, and it is totally ridiculous that they would only discuss that.

But how can they do a competent job of analyzing that limited portion if they won't even specify the quantity of steel on each level in the impact zone?

Since the kinetic energy of the plane had two effect, punching the hole and producing the deflection which started the oscillation and the energy that produced the deflection cannot be computed without distribution of mass. How can they calculate how much energy went into doing the structural damage without the distribution of mass anyway? So without distribution of mass they could not do a competent job of the stupidly limited task they claimed to be doing.

Guess what, physics is interrelated and interactive and there is no escaping it. LOL You can't go leaving out obviously important information. Even somebody in the NIST admitted it. I guess they aren't all STUPID.

2.4.3 Single Impulse Excitations

Accurate estimation of the tower’s motion during the airplane impact required detailed knowledge of the geometry, weight distribution, and impact velocity of the aircraft, as well as detailed knowledge of the geometry, weight distribution, and structural strength of the tower. At the time of this test series (fall 2003), much of this information was unknown, and the impact motion could only be roughly estimated. To allow this estimate to be made quickly, many simplifying assumptions were made regarding the nature of the impact.

http://wtc.nist.gov/NISTNCSTAR1-5D.pdf page 74

Of course, it helps if you actually read that report so you understand these things in context rather than just using the Search tool to look for TONS of STEEL and TONS of CONCRETE.

So you find a survivor's account of ceiling tiles falling somewhere other than the basement. It was from searching on the word "fall" that I found that comment about "weight distribution" due to that "fall 2003". They seem to have very little evidence of ceilings actually falling due to impact so why create the report though I am glad they did for other reasons. I am wondering if they wanted some unimportant project to assign the competent and conscientious people to so they wouldn't screw up the snow job. But then they go and talk about the need to know the weight distribution. ROFL That should have been obvious on 9/12/01. I also find it very curious that that is the only report that uses the term "center of mass".

psik

 

[Travis]

Guess I owe Hokulele a coke.

Yes, and it is totally ridiculous that they would only discuss that.

If only all government sponsored investigations had their intent & scope dictated by the fantasies of the paranoid imagine how much would be accomplished.

Senator 1: Yes, now um, we have a guy in North Dakota that thinks that the fire in Apollo 1 was caused by time traveling elves that spontaneously combusted upon entry into our world. Please prove that did or didn't happen along with everything else you'll have to do.

Senator 2: Look into miniature fire breathing dragons too!

But how can they do a competent job of analyzing that limited portion if they won't even specify the quantity of steel on each level in the impact zone?

Since the kinetic energy of the plane had two effect, punching the hole and producing the deflection which started the oscillation and the energy that produced the deflection cannot be computed without distribution of mass. How can they calculate how much energy went into doing the structural damage without the distribution of mass anyway? So without distribution of mass they could not do a competent job of the stupidly limited task they claimed to be doing.

Guess what, physics is interrelated and interactive and there is no escaping it. LOL You can't go leaving out obviously important information. Even somebody in the NIST admitted it. I guess they aren't all STUPID.

Simplifying assumptions are standard for complex simulations. Eliminating these assumptions, in this case, would require knowing the exact layout of all furniture, devices, stacks of paper, office plants and human occupants which is simply unknowable.

 

[R.Mackey]

NIST computed the distribution of mass. It's represented in the SAP2000 model.

It's very hard to hold a useful conversation when people butting in only to keep denying simple facts that have already been explained to them numerous times.

Appeals for moderation will follow if this behavior doesn't cease. Thank you for your attention.

 

[Brainache]

I know you are very interested in the distribution of mass Mr Hakr, but don't you think it is generally understood by the engineers etc that the steel was standing in collumns on the outside and in the core of the building, and that the concrete was in the floors in light-weight floor slabs supported by pans and trusses? Those trusses were connected to the collumns at either end and that when the trusses distorted from the heat of the fires it put unusual stresses on the collumns seems pretty easy to understand.

I really don't understand your confusion on this.

 

[Dave Rogers]

You do know there is such a thing as a thermite bomb.

Yes. It's a low velocity explosion, so it's incapable of cutting steel, and it's an explosion rather than a combustion in place, so it will scatter the thermite - and hence the heat source - rather that concentrating it in the area to be melted. So in fact it can't cut steel columns by melting or by explosive action. Is that what was used?

Also you might want to look up oil pipe companies, they have been using chemical and mechanical cutters for years.

That seems a completely irrelevant comment, as neither chemical nor mechanical cutting is under discussion here. Are you suggesting that chemical/mechanical cutters were attached to the support columns of WTC7?

Dave

 

[CliveHill]

I'm in danger of getting into a bad practice here, so let me say up front that this is the last one.
I still have not finished all the reading I need to on the stuff I have been referred to, and I will do that before giving any convinced/not convinced response.
As such I should not keep replying to separate bits and getting taken off on tangents, etc..

No. Think of it like this -- as a structure gets taller, its moment of rotational inertia scales roughly as the square of its height. This means it takes an increasingly high force to get it turning in the first place. A tall structure is simply not designed to rotate, and so it will tend to buckle or crumble in the middle before it can support this force.

I don't that is entirely right.
The force needed to get the same rotational acceleration is larger, but if the structure falls though uneven resistance it will still turn, just it will turn slower.
And the taller the building is, the less rotational movement is needed to put the centre of mass out of line with the resistance so that gravity can keep it turning.
And when a tall structure breaks in the middle as it falls in rotation, this is due to the internal stresses of the upper portion trying to rotate slower than the lower portion, due to the different resulting acceleration from the constant gravitiational force at different heights, and not due to any greater force being applied. You give a reason why it would break if it toppled, not a reason why it could not topple.

See the thread with Gregory Urich's comments. The main reason the Towers collapsed slower was because there was momentum transfer high in the air, between the upper and lower blocks. In other words, the Towers didn't all start falling at once, and the inertia of the lower blocks absorbed a good amount of the velocity. This doesn't happen in WTC 7. It all starts falling more or less at the same time, and as a result, there is no momentum transfer except at the ground. It's perfectly normal given the difference in phenomenology.

Are you saying that the inertia of the lower WTC1 absorbed velocity better than the ground did at WTC7?
Sorry, but it just does not work that way.
If you drop an object so that it starts to fall, it will fall at gravitational acceleration, minus the effect of any braking force that acts on it.
I wish to consider the roofline of the outer wall as this object.
So, there is some body of building structure between this roofline and the point of momentum transfer, that building body in WTC1 applied a braking force, and that building body in WTC7 did not.

And..? Where do we start the clock?

If you want to measure the time taken for an object to travel a certain distance, you start the clock when that object starts to move.

A demolition charge is not like a clap of thunder. What you hear is essentially a shock wave, a very, very sharp CRACK much like a rifle shot or a sonic boom. There is no conceivable way this sound could have been muffled. It would have appeared on virtually all of the recordings near the event, to say nothing of the very sensitive detectors described by Protec that even captured the air motion from the collapses.

It is also extremely unlikely that, had a demolition taken place, there would have been only a single charge. Anything of this complexity should have had redundancy and a good margin of safety built into its design. I would expect to hear many charges go off -- and this noise is unmistakable, multiple shocks in rapid succession.

I think I can safely say that I am not going to be convinced by this argument on the nature of the sound.
There are witnesses who report sounds that maybe fit the bill of explosives, some report a single sound, some report multiple sounds, there are sounds captured on video, both single and multiple. And I think it is way too subjective to argue that just because a witness used the words 'clap of thunder' rather than 'sharp crack' that what they report can be ignored.
If the NIST report claim that there were no sounds was genuine, then it would be convincing, but given that the reality is that we have to qualitatively judge whether the sounds reported fit the bill or not then it's not good enough to deny further investigation.

 

[Dave Rogers]

Are you saying that the inertia of the lower WTC1 absorbed velocity better than the ground did at WTC7?
Sorry, but it just does not work that way.
If you drop an object so that it starts to fall, it will fall at gravitational acceleration, minus the effect of any braking force that acts on it.
I wish to consider the roofline of the outer wall as this object.
So, there is some body of building structure between this roofline and the point of momentum transfer, that building body in WTC1 applied a braking force, and that building body in WTC7 did not.

This clearly needs some additional explanation. The physics of R. Mackey's exxplanation is perfectly sound, and is well understood by all those who've studied the collapses in any detail, but may not be obvious at first look.

Imagine the towers as a series of heavy floors connected by light supports. This isn't an accurate model of the towers, but it illustrates a property of them more clearly than their actual construction. Now assume that zero additional force is needed to break the supports, and that no energy is absorbed by their breaking; in effect, each floor immediately starts falling as any falling mass hits it. This is known as the floating floor model of the towers, and since it neglects any energy loss due to fracture of the supports it will predict a lower bound on the collapse time, rather than an actual collapse time.

Now, for the WTC1/2 case, imagine that the supports break somewhere high up the structure, so that most of the structure is still in place when the top starts falling. The top section accelerates downwards due to gravity until it hits the first undamaged floor. This floor is stationary at the time of impact. Applying the law of conservation of momentum, in order for the first undamaged floor to start moving downwards at the same speed as the rest of the falling block, the speed of the falling block must decrease. Another way of looking at it is that the falling block needs to exert a force on the stationary floor to accelerate it, and from Newton's Third Law this exerts an equal and opposite reaction force on the falling block. The entire falling mass will then accelerate due to gravity until it hits the next stationary floor, where the same thing happens, and so on down to the ground. The result is that, every time the falling block picks up another floor on the way down, it decelerates.

The deceleration at each impact is simple to calculate if the masses of the falling block and the floor are known; it is simply the ratio of the mass of the falling block to the sum of the masses of the falling block and the stationary floor. The calculation has been done by several people, including Gregory Urich who posts on this forum, and gives a result significantly slower than the time expected due to free fall under 1g acceleration. A result of about 0.7g is about right.

Now let's look at WTC7, where the collapse starts low down the structure. The falling block is now very much heavier than the undamaged floor below, simply because there are many more floors falling. The falling block therefore decelerates very much less than in the WTC1/2 case. Also, as soon as the bottom of the falling block reaches the ground, a different collapse mechanism takes over, as there are now no more lower floors to accelerate. The only resistance to collapse is now the energy required to fracture the supports. We've neglected this in our simple model, but done so for both cases, so the comparison is valid.

When a more complex calculation is done that includes the fracture energy of the columns, the result is that it makes only a very small difference to the total collapse time. The momentum transfer is the dominant cause of retardation of collapse once it has started, and the different starting cases of WTC1/2 and WTC7 show up most strongly in the difference in momentum transfer that's predicted.

Dave

 

[Darkhole]

you assume that it was rigged before 9/11.

afaik was Column 79 accesable from the garage.
and according to Danny Jovenko, it would have been possible to rigg even alot more than just one column.
so you could rigg that one column after the tower collapses.

You could point Jowenko to this thread?

Jowenko Explosieve Demolitie B.V.

Tel: +31 118 612735
Fax: +31 118 612779
Mobiel: +31 653 24 21 25
E mail: info@jowenko.com

 

[psikeyhackr]

NIST computed the distribution of mass. It's represented in the SAP2000 model.

It's very hard to hold a useful conversation when people butting in only to keep denying simple facts that have already been explained to them numerous times.

Appeals for moderation will follow if this behavior doesn't cease. Thank you for your attention.

So why does Gregory Urich do an interpolation on the weight distribution of the perimeter columns?

Why can't the NIST tell us the number and weights of each of the 12 different types of perimeter wall panels on each tower?

It is pointless to talk about settling things with such QUESTIONABLE DATA. Oh you have to buy and learn this $2000 program or just shut up and think what you are told.

ROFLMAO

psik

 

[R.Mackey]

I don't that is entirely right.
The force needed to get the same rotational acceleration is larger, but if the structure falls though uneven resistance it will still turn, just it will turn slower.
And the taller the building is, the less rotational movement is needed to put the centre of mass out of line with the resistance so that gravity can keep it turning.
And when a tall structure breaks in the middle as it falls in rotation, this is due to the internal stresses of the upper portion trying to rotate slower than the lower portion, due to the different resulting acceleration from the constant gravitiational force at different heights, and not due to any greater force being applied. You give a reason why it would break if it toppled, not a reason why it could not topple.

But there is no uneven resistance to speak of, particularly in the case of WTC 7. As you yourself noted, the perimeter fell as a unit. The resistance occurs at the ground, and that's completely even. Additionally, the "uneven resistance" has to be really uneven, to the point that the centroid of the descending mass is actually outside of the lower structure. No collapse even approached this.

Are you saying that the inertia of the lower WTC1 absorbed velocity better than the ground did at WTC7?
Sorry, but it just does not work that way.
If you drop an object so that it starts to fall, it will fall at gravitational acceleration, minus the effect of any braking force that acts on it.
I wish to consider the roofline of the outer wall as this object.
So, there is some body of building structure between this roofline and the point of momentum transfer, that building body in WTC1 applied a braking force, and that building body in WTC7 did not.

No, it does work this way. Dave Rogers explained it correctly, but let me try to do it in simpler terms.

In the WTC 7 collapse, as the structure descends, it contacts the ground. That descent breaks the lower structure and transfers the momentum of the stopped bits of structure to the ground.

By comparison, in WTC 1, the descending structure contacts the lower structure. And that descent breaks the structures, and accelerates the lower structure, and eventually transfers momentum to the ground.

That middle step -- transfer of momentum from part of the structure to another part -- doesn't occur in WTC 7 and represents an additional energy sink. As it turns out, this energy sink dominates the collapse time. Dr. Bazant of Northwestern, in particular, has published several journal articles that demonstrate this fact.

Another way to look at it is WTC 7 all began falling at more or less the same time, whereas WTC 1 and 2 didn't. This means WTC 1 and 2 experience a whole bunch of inelastic collisions, and every single one of those dissipates energy. There's nothing like that in WTC 7. As a result, WTC 7 is closer to "free fall." Again, we had this discussion in the thread I linked before, and even the thread starter -- a member of the Truth Movement -- accepts the logic.

If you want to measure the time taken for an object to travel a certain distance, you start the clock when that object starts to move.

What I mean is that you need to be very careful that you and NIST start the clock at the same time. I'm pretty sure you are not, but I need details to verify this.

I think I can safely say that I am not going to be convinced by this argument on the nature of the sound.
There are witnesses who report sounds that maybe fit the bill of explosives, some report a single sound, some report multiple sounds, there are sounds captured on video, both single and multiple. And I think it is way too subjective to argue that just because a witness used the words 'clap of thunder' rather than 'sharp crack' that what they report can be ignored.
If the NIST report claim that there were no sounds was genuine, then it would be convincing, but given that the reality is that we have to qualitatively judge whether the sounds reported fit the bill or not then it's not good enough to deny further investigation.

Fortunately, we don't have to qualititatively judge on the basis of witness statements. We have recordings. Those are not as subjective, and those all unambiguously demonstrate there was no such sound. It would have been absolutely unmistakable, and so loud that no recorder would miss it. But, alas, they all did. Again, that closes the book on demolition via explosives, unless you can provide an alternate hypothesis that takes this fact into account.

 

[R.Mackey]

So why does Gregory Urich do an interpolation on the weight distribution of the perimeter columns?

Why can't the NIST tell us the number and weights of each of the 12 different types of perimeter wall panels on each tower?

It is pointless to talk about settling things with such QUESTIONABLE DATA. Oh you have to buy and learn this $2000 program or just shut up and think what you are told.

ROFLMAO

psik

psik, I need your strict attention.

In your medium-length stay here, you've made 113 posts. 97 of those posts are essentially rephrasings of the exact same question above. Of the remainder, only six have useful content, and ten are basic trolling.

I answered your question, in all of its variants, multiple times, including here. Several others -- many others -- have answered you as well. I even asked the moderators to split you off your own thread, which they did. I've told you that I will not respond to the same question over and over again, months ago. I've also reminded you, five times, that this behavior is a moderatable offense.

I will not answer this question again, since it obviously does no good. Instead, I expect something from you, just one thing, and that is a frank and honest explanation of why you continue to behave in such a fashion. Other people are trying to ask reasonable questions, and you are being disruptive.

I believe you'll find I've been more than tolerant of your abuse, so I ask you this last time to reciprocate. Thanks.

 

[Miragememories]

"If NIST concludes that WTC 7 was brought down by the weakening of one column, Column 79, then that's the only column that would need to be rigged with explosives in the CD scenario.

In other words, if global collapse can occur by the failure of one column, then CD can be accomplished by the demo of this one column, as well."

"Perhaps, but that's gradualism, and it doesn't support your position. Not if you actually try to assemble a hypothesis."

It certainly is representative of the NIST hypothesis.

The NIST even used their belief in a single column (#79) failure as the triggering event to WTC7's collapse when testing the possible use of explosives.

"If your theory is that there was only one explosive charge, a small one, and it was placed at Column 79..."

Again, sorry to interrupt your ramblings but RedIbis is merely re-stating the
the NIST theory. He is not saying this is the theory he finds to be most credible.

He merely confirms that NIST hypothesized that structurally, the failure of a single column in WTC7 could lead to collapse initiation and that the NIST stated that this could be done by an explosive failure of column 79.

"..then whomever placed it must have known the following:

* Exactly how much damage WTC 7 would suffer from the collapse of the Towers"

This is irrelevant, given the NIST determination that debris damage from the collapsing towers was not a factor in the collapse of WTC7.

"Exactly how the fires would progress, leaving their explosive charges intact"

Barry Jennings heard and experienced what appeared to be an early preparatory
explosion that destroyed his stairwell escape route and occurred prior to the collapse of either tower.

It's quite possible that fires did destroy some demolition preparations and it's logical
that there was significant redundancy built into the plan.

"Exactly how the fires would weaken the rest of the structure, such that only a single demo charge would lead to a full collapse."

This assumes that a single column failure was the plan. This ignores the greater likelihood that a single column failure was never part of the plan.

Since fire had never before accomplished what the NIST claimed it did on 9/11,
it's logical to assume that a planned demolition would not have any dependence on fire damage.

"They'd have to know this ahead of time, in 2001. They'd have to know, somehow, that their explosive would not malfunction, or be discovered, or be dislodged.

Ridiculous."

All they had to do was prep with enough redundancy to allow for unforeseen damage.

The core, being the least vulnerable area to fire and debris damage would be the likely area to target.

The failure of column 79 could very well have been an unforeseen consequence of the planned demolition.

There is no credible evidence, or theory, that explains how a 7 second major internal core failure would occur as a result of column 79 buckling, followed by columns 80 & 81 less than a second later.

During this 7 second period, when WTC7 was collapsing internally, little more than a few broken windows were observed across the clearly visible expanse of the north face of WTC7.

Inside WTC7, for this 7 seconds, we supposedly have major column failures occurring. Columns that are joined to trusses which are connected to perimeter columns that miraculously remain stable.

Perimeter columns, none of which on the north face at least, are observed to be pulled inward revealing dramatic damage...well except in the NIST computer model.

The NIST reports a few barely observable broken windows.

"Besides, if you admit the structure can be weakened by fire, such that one charge would do the job, why not admit the structure can be weakened all the way to collapse by fire, and not plant it at all?

I've gone over this before."

Unlike you Ryan, I see him expanding on the the NIST theory but not claiming agreement with that theory.

MM

 

[applecorped]

All they had to do was prep with enough redundancy to allow for unforeseen damage.

Who is "they"?

 

[R.Mackey]

It certainly is representative of the NIST hypothesis.

The NIST even used their belief in a single column (#79) failure as the triggering event to WTC7's collapse when testing the possible use of explosives.

Yes, but the failure of Column 79 in NIST's hypothesis is predicated on multiple failures elsewhere in the structure. If you took an intact WTC 7 -- which you assume, if you claim fire couldn't cause structural damage -- and set off charges to destroy that column (which is impossible, since we would have heard it), we would either not get collapse at all, or a collapse that did not resemble what was seen. The NIST report covers this.

Again, sorry to interrupt your ramblings but RedIbis is merely re-stating the
the NIST theory. He is not saying this is the theory he finds to be most credible.

RedIbis claims to have a superior theory, though he has consistently failed to elaborate. I continue to invite him to explain.

He merely confirms that NIST hypothesized that structurally, the failure of a single column in WTC7 could lead to collapse initiation and that the NIST stated that this could be done by an explosive failure of column 79.

No, it isn't that simple. See above.

This is irrelevant, given the NIST determination that debris damage from the collapsing towers was not a factor in the collapse of WTC7.

This is also not correct. While debris damage did not cause structural damage according to NIST, it did create a specific pattern of fire and ventilation. That has a strong effect on the weakening process, which is critical.

Had someone planted explosives, they would have to know, in advance, that the impacts and fires would create the right amount of weakening, and that it wouldn't interfere with their placed charges, if this is even possible.

In other words, the risk from such an approach would be extreme, and as NIST proves, it isn't necessary. Nor have you explained how it could be done without anyone hearing it. Without addressing these issues, the hypothesis is DOA.

Barry Jennings heard and experienced what appeared to be an early preparatory
explosion that destroyed his stairwell escape route and occurred prior to the collapse of either tower.

Your hypothesis does not appear to require any "preparatory explosives." How do you explain this? It's very hard to respond to your hypothesis if you don't state it.

It's quite possible that fires did destroy some demolition preparations and it's logical
that there was significant redundancy built into the plan.

So... if you accept that some explosives could have been destroyed, how would you rig it to be fail-safe, let alone fail-operable, under a variety of fire situations?

Basically what you've done here is admitted that the fire is a problem for your theory, then stated without any support that it's a solvable problem. And, as before, you have no evidence for explosives, whereas we have sonic evidence that there were no explosives. You're not making progress.

This assumes that a single column failure was the plan. This ignores the greater likelihood that a single column failure was never part of the plan.

OK, now I'm confused. Above you claimed it could be rigged for single column failure. Now you say that might not be the plan at all, i.e. WTC 7 was rigged to collapse but failed by surprise...

What is your hypothesis? You seem to contradict yourself very badly here.

Since fire had never before accomplished what the NIST claimed it did on 9/11,
it's logical to assume that a planned demolition would not have any dependence on fire damage.

I don't follow your logic at all. According to you, the perpetrators planted explosives, and deliberately failed to detonate them until long after WTC 7 started burning. NIST proves that the fire would have significantly weakened the structure, which is inherently obvious. Your comment above suggests they either couldn't anticipate this damage, or they diverged from their original plan on purpose.

Pretty strange.

All they had to do was prep with enough redundancy to allow for unforeseen damage.

I don't believe this was simple. Show me.

The core, being the least vulnerable area to fire and debris damage would be the likely area to target.

The core is the only place to target. The perimeter is too visible, and there aren't any other choices.

The failure of column 79 could very well have been an unforeseen consequence of the planned demolition.

I'm having trouble believing in a demolition approach -- allegedly a stealthy, efficient one -- that accidentally triggered the terminal building mode. Again, you'll have to explain this to me.

There is no credible evidence, or theory, that explains how a 7 second major internal core failure would occur as a result of column 79 buckling, followed by columns 80 & 81 less than a second later.

Yes there is. NCSTAR1A. If you have some valid criticism of the report, please present it. I haven't seen any yet.

During this 7 second period, when WTC7 was collapsing internally, little more than a few broken windows were observed across the clearly visible expanse of the north face of WTC7.

Explainable by building flexure. No explosive sounds. Also, a single explosive on Column 79 wouldn't be expected to cause this pattern of window breakage. If you still think this observable supports your (still unstated) hypothesis, please explain.

Inside WTC7, for this 7 seconds, we supposedly have major column failures occurring. Columns that are joined to trusses which are connected to perimeter columns that miraculously remain stable.

Given the design of WTC 7, there's nothing miraculous about a core failure independent of the perimeter. NCSTAR1A.

Perimeter columns, none of which on the north face at least, are observed to be pulled inward revealing dramatic damage...well except in the NIST computer model.

If you're suggesting you have video of the north face of sufficient resolution to conflict with NIST's findings, that would be worth discussion. I'm guessing, however, you do not.

The NIST reports a few barely observable broken windows.

Is this significant?

Unlike you Ryan, I see him expanding on the the NIST theory but not claiming agreement with that theory.

I can't agree. Both you and he propose a completely different collapse mechanism. If you can come up with one that matches the observed evidence, then it's certainly worth consideration. So far, it doesn't appear to. In particular, I have yet to hear a way around the absence of explosive shockwave sounds.

 

[TjW]

<snippage>
This is also not correct. While debris damage did not cause structural damage according to NIST, it did create a specific pattern of fire and ventilation. That has a strong effect on the weakening process, which is critical.

Had someone planted explosives, they would have to know, in advance, that the impacts and fires would create the right amount of weakening, and that it wouldn't interfere with their placed charges, if this is even possible.

In other words, the risk from such an approach would be extreme, and as NIST proves, it isn't necessary. Nor have you explained how it could be done without anyone hearing it. Without addressing these issues, the hypothesis is DOA.
<snippage>

I think it would be good to watch the phrasing.
What an alternate theory would have to do is explain how the column could be cut without every human being within a kilometer hearing a deafening explosion at the same time.
"Without anyone hearing it" leaves the impression that some people could have NOT heard it.
I'm sure people did hear various explosions before the collapse. Not necessarily explosives, of course, but explosions.

 

[dtugg]

So, RedIbis, why don't you just state what your theory is and why it is better than NIST's? You know the one that you said you have. It would save us all the trouble of trying to guess what you are thinking. Or maybe you have no such theory?

 

[RedIbis]

RedIbis claims to have a superior theory, though he has consistently failed to elaborate. I continue to invite him to explain.

A picture of a fish was apparently offensive to some, so let me just call this the red herring that it is.

 

[leonAzul]

Yes, but the failure of Column 79 in NIST's hypothesis is predicated on multiple failures elsewhere in the structure.

I am quoting this to focus on a very important point.

It has been asserted that the NIST report concerning the collapse of WC7 states that the building came down because of the failure of a single column.

This is false.

The report states that, due to many stresses and failures, column 79 seems to have been the focal point of the first of many subsequent collapses.

The difference is not subtle. The report claims that there were many subordinate failures that contributed to the collapse of the building which, temporally speaking, were expressed in the failure of column 79. Anyone with a third grade level of reading comprehension could appreciate the distinction between that and the claim that the only failure was that of column 79.