'What about building 7'?

[jaydeehess]

Collapses are often sudden. When one column fails, the weight is redistributed among the remaining columns. That process is very quick, in the tenths or hundredths of second. When the remaining columns are not enough to hold the building, they fail in rapid sequence as the load redistributes and columns get overloaded in turn, so everything fails at virtually the same time.

Example:




.

I do note that the metal legged desk was destroyed by the dynamic load of the weights falling, what is that, 16 inches?

 

[jaydeehess]

Like any building, if you somehow stack an ever increasing balanced load on the roof, sooner or later the crushing gravitational force created will overwhelm the building's engineered vertical support.

But this is not what WTC7 experienced,,,,,,,,,

True, instead WTC7 had a progressive loss of supporting structure meaning the load on remaining structure would behave in similar fashion as simply increasing the load.

Meanwhile in the real world of concrete and structural steel, buildings behave as expected.

I welcome you to provide real world examples of "often" sudden building collapses that were not CDs.

Delft University. Video has been posted several times in these threads.

All because of a stupid coffee machine that had an electrical fault. yeah,,, right more likely soopernanothermite cutters.

Do you have any idea what would qualify as a symmetrical collapse in engineering terms or are you hung up on "perfect"?

Well Realts used the term "perfect" take it up with him.

Any delay in one side failing before the other, and that building will start tilting. There is no significant tilt until late in the collapse.[/color]

Other than all visible floors tilting inwards towards the "kink" (in the symmetric 1/3 of the way accross the north side), which occured prior to your precious six second time period.

 

[pgimeno]

Like any building, if you somehow stack an ever increasing balanced load on the roof, sooner or later the crushing gravitational force created will overwhelm the building's engineered vertical support.

Or, in other words, the load will eventually exceed the column capacity.

But this is not what WTC7 experienced, making your pathetic example absolutely worthless as comparison.

Wrong. It's exactly what the WTC7 outer frame experienced: the load exceeded the capacity of the frame. The falling core probably overloaded it and caused a failure. You don't see the weight on top because it's not on top, it's on the inside. The process is the same, though.

And best of all, it explains the faster-than-free-fall period. How do you explain it? Oh right, you don't, you just hand-wave it.

Meanwhile in the real world of concrete and structural steel, buildings behave as expected.

I welcome you to provide real world examples of "often" sudden building collapses that were not CDs.

Here's a few:









And here's a bunch from a Spanish documentary:

http://www.metacafe.com/watch/339311/building_collapse/

ETA: And what do you think vérinage demolitions exploit?

 

[JayUtah]

Collapses are often sudden. When one column fails, the weight is redistributed among the remaining columns. That process is very quick, in the tenths or hundredths of second.

Collapses can be sudden or they can be protracted. Loads indeed transfer at a speed commensurate with the failure of some candidate member. If a column takes 0.03 second to buckle to the point of plastic deformation, the load it carried transfers to remaining structural elements at roughly the same speed.

The response of the structural remainder to the transfered loads depends entirely upon the particulars of the structure. Factors such as redundancy, geometry, remaining reserve strength, overload factor, the eccentricity of the load, the strain rate associated with the transfer, and other hard-to-predict factors affect whether the subsequent response is instantaneous or lengthy.

Hence you will find examples of both abrupt and prolonged global failures. High-rise steel structures tend not to have as much reserve strength or structural redundancy than short, squat structures made of concrete etc. -- and several orders of magnitude less redundancy than a child's Lego structure. Different framing strategies (e.g., the aforementioned "moment-resisting frames" and others) create different properties along the elasticity-plasticity spectrum in the whole structure or regions of the structure. Hence in some cases excessive loads may result in elastic response while in other cases plastic deformation occurs.

Non-engineers typically want to reason strictly by analogy and example, generally unaware of the significant differences that exist between their toy examples, or even between apparently similar real-world constructions.

You have so far offered no explanation for the building exceeding g and you keep dismissing the explanations that you are given.

This is a prominent feature of conspiracy-style reasoning. The line of reasoning goes that if the "official" story can be shown not to explain an observation, then it must be set aside and the conspiracy theory then holds by default. In other words, "Your theory doesn't explain the evidence, therefore my theory is correct."

Here and elsewhere, this fails for two reasons. First, the "official" theory is usually given in straw-man form. That is, it's oversimplified or otherwise crippled in order to ensure it does not explain the outcome. Here the actual work of Newton is being replaced with a cartoonish, kid-with-Legos formulation. The OP wants a "simple answer," unimpressed that the correct answer is not simple -- but it is correct.

Second, as you've identified, the conspiracy theory doesn't explain the outcome either. In holding up their theories by default -- "It's the only way to explain it" -- they never actually test those theories. That's not how useful investigation works. If failure to explain the outcome is enough to doom the official story, it's enough to doom the conspiracy theory as well.

The fluctuation of spot-checked accelerations above and below the free-fall line do indeed spell out that something more complicated is going on here. Controlled demolition doesn't explain that. Oversimplified Newtonian dynamics doesn't either, but thankfully the official explanation doesn't limit itself to the wrong, misrepresented simplifications of Newton. And since it doesn't, Newton in his full complexity can explain the observations.

 

[000063]

...I welcome you to provide real world examples of "often" sudden building collapses that were not CDs.

Sure. Just as soon as you provide examples of CDs that occurred in buildings that were on fire, or that made the buildings collapse several hours after detonation. Or both!

Do you have any idea what would qualify as a symmetrical collapse in engineering terms or are you hung up on "perfect"?

Oh, look, moving the goalposts and the burden of proof!

[qimg]http://i1265.photobucket.com/albums/jj515/Miragememories/WTC7Comp-7302014_zpscb34b8b8.png[/qimg]

Any delay in one side failing before the other, and that building will start tilting. There is no significant tilt until late in the collapse.

I love how hard you're ignoring the fact that the penthouse collapsed asymmetrically in the very video you're using as the source of that image.

 

[JayUtah]

Oh, look, moving the goalposts and the burden of proof!

Indeed, he is the one claiming a symmetrical collapse. It's his burden to define what symmetry means in this case, to establish that it's the definition that would be used by the appropriate qualified professionals, and that the data fairly show accordant symmetry.

It's a separate burden of proof to show that symmetry (by that definition) would be anomalous in such a structural failure, and that this is the learned opinion of appropriately knowledgeable experts.

As you note, all we're seeing is burden-of-proof shifting and goalpost shifting. None of that is appropriate to an argument seeking to overturn the near-unanimous opinion of the relevant experts.

I love how hard you're ignoring the fact that the penthouse collapsed asymmetrically in the very video you're using as the source of that image.

As we've all mentioned, conspiracists here have to selectively present the evidence so that it appears to display the behavior they claim is anomalous. Examining all the pertinent evidence reveals behavior that does not violate their expectations, whether or not those expectations are in turn valid.

Again, withholding pertinent data is not appropriate to an argument that purports to present the truth in the face of allegations of cover-up and malfeasance in the prevailing view.

 

[Miragememories]

Well, you've shown that if the WTC7 had been constructed of balsa wood, it could not only have rapidly burned to the ground, it could have been crushable.

Your example is that of a structure initially supporting its own weight as load.

Like any building, if you somehow stack an ever increasing balanced load on the roof, sooner or later the crushing gravitational force created will overwhelm the building's engineered vertical support.

But this is not what WTC7 experienced, making your pathetic example absolutely worthless as comparison.

Wrong.

It's exactly what the WTC7 outer frame experienced:

the load exceeded the capacity of the frame.

The falling core probably overloaded it and caused a failure.

You don't see the weight on top because it's not on top, it's on the inside.

The process is the same, though.

And best of all, it explains the faster-than-free-fall period.

How do you explain it?

Oh right, you don't, you just hand-wave it.

Same responses, same wrong conclusions.

Both sides are effectively arguing that WTC7 suffered an implosion.

The primary difference is the causation.

It makes little difference if video measurements fluctuate sufficiently to produce data points appearing faster than g or slightly less than g.

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

No where has it been shown that fire activity in WTC7 could possibly enable the visible NE, NW and SE corners to fail in unison.

Unlike the amateur anonymous engineering sleuths here, the NIST, with all its resources and years of investigation, was stymied in their quest to find an implosion explanation that precluded controlled demolition.

The totally flawed column 79 scenario was the best they could come up with.

What occurred was a controlled demolition implosion including the classic "kink" before global collapse.

Edited by LashL: 

Removed breach. Cut out the name-calling please.

 

[JayUtah]

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

"Virtually zero opposition" according to whom? What should have the "opposition" looked like and how do you know that?

No where has it been shown that fire activity in WTC7 could possibly enable the visible NE, NW and SE corners to fail in unison.

Actually it has, but you simply refuse to consider it.

Unlike the amateur anonymous engineering sleuths here...

And your relevant qualifications are ... ?

NIST ... was stymied in their quest to find an implosion explanation that precluded controlled demolition.

Red herring. NIST wasn't trying to "preclude[] controlled demoltion" in its investigation of WTC 7. In contrast, you haven't shown any evidence for controlled demolition, and you can't explain how the vast body of data singularly fail to show any markers.

The totally flawed column 79 scenario was the best they could come up with.

They consider it the most likely scenario, yes. Your attempts to show it is "flawed" aren't convincing. You're simply applying your layman's understanding of it.

What occurred was a controlled demolition implosion including the classic "kink" before global collapse.

You give no proof that the "kink" was due to "controlled demolition," as you claim. You have simply substituted that as the default because you think you've eliminated any sort of damage or fire explanation.

Edited by LashL: 

Removed quote of moderated content.

Name-calling is inappropriate. Personal attacks are inappropriate. Your representation of NIST's evaluation of its efforts is in error. Your representation of your critics as overstepping any belief based on NIST's findings is similarly in error. If a group of people say that's the most likely sort of explanation, and some other people agree, there's nothing nefarious in that.

 

[beachnut]

Edited by LashL: 

Removed quote of moderated content.

Name calling, the 911 truth substitution for evidence.

Edited by LashL: 

Removed reply citing moderated content.

You fail to realize the interior of the WTC fell before the exterior, thus any momentum transfer would show up as a speed which fools you and 911 truth into claiming free-fall/CD/BS, etc,. You are fooled by physics.

The entire system of WTC 7 fell below g, but that is physics, and 911 truth don't do physics. 911 truth does paranoid conspiracy theories of secret thermite, and silent explosives.

13th year of complete failure, what will the 14th year bring? Let me answer that, more complete failure. See, real engineers answer questions, 911 truth engineers make up lies. When is the next big smoking gun claims coming? 13th year... lol

 

[jaydeehess]

Both sides are effectively arguing that WTC7 suffered an implosion.

The primary difference is the causation.

Ok,,,,,,,,

It makes little difference if video measurements fluctuate sufficiently to produce data points appearing faster than g or slightly less than g.

OK,,,,,,,,,

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

With the core gone and that causing a huge increase in load to columns under the cantilever trusses with the consequent movement of those trusses, and the moment frame, why is this important?

No where has it been shown that fire activity in WTC7 could possibly enable the visible NE, NW and SE corners to fail in unison.

Actually what is not in evidence is you accepting that it has.

Unlike the amateur anonymous engineering sleuths here, the NIST, with all its resources and years of investigation, was stymied in their quest to find an implosion explanation that precluded controlled demolition.

Why would anyone have to work to preclude something for which there is no evidence of it ever having occurred?

The totally flawed column 79 scenario was the best they could come up with.

What occurred was a controlled demolition implosion including the classic "kink" before global collapse.

So you are changing your scenario to one in which the CD involved only taking out col 79, or col 79 plus core columns?

Good to know

 

[pgimeno]

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

No, the important point is that the "opposition" was less than zero: it was negative.

How can it be negative? It can't, and therefore that proves that there were more forces into play that you aren't acknowledging.

 

[Miragememories]

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

Virtually zero opposition" according to whom?

What should have the "opposition" looked like and how do you know that?

The opposition was represented by 24 core columns and 57 perimeter columns, interlocked.

From the Aug.26, 2008 NIST Technical Briefing re:WTC7 Collapse Report;

"...a *free fall time would be an object that has no...uh... structural components below it..."

From the NIST is summary in Section 3.6 of the final summary report, NCSTAR 1A (released Nov. 20, 2008; available at http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR 1A.pdf) and detailed in Section 12.5.3 of NIST NCSTAR 1-9 (available at http://wtc.nist.gov/NCSTAR1/PDF/NCST... Vol 2.pdf).

* Stage 2 (1.75 to 4.0 seconds): gravitational acceleration (free fall)

No where has it been shown that fire activity in WTC7 could possibly enable the visible NE, NW and SE corners to fail in unison.

Actually it has, but you simply refuse to consider it.

If you want to re-open the steel expansion and fire temperature timeline debate go for it.

And your relevant qualifications are ... ?

My highest grades were in my structural engineering courses at college but I majored in electronics.

Unlike the amateur anonymous engineering sleuths here, the NIST, with all its resources and years of investigation, was stymied in their quest to find an implosion explanation that precluded controlled demolition.

The totally flawed column 79 scenario was the best they could come up with.

Red herring.

NIST wasn't trying to "preclude[] controlled demoltion" in its investigation of WTC 7.

In contrast, you haven't shown any evidence for controlled demolition, and you can't explain how the vast body of data singularly fail to show any markers.

Column 79 is now a red herring?

If you actually read the NIST WTC7 Report (and I have little doubt you will claim an intimate knowledge of its contents), you will see they never tested for thermite (see the 2009 Bentham paper) and they based their conclusion of no explosives pretty much on the lack of audio evidence.

The vast body of data does show the markers;

-collapse symmetry
-roofline kink
-freefall
-total high speed collapse
-lower floor core implosion

The totally flawed column 79 scenario was the best they could come up with.

They consider it the most likely scenario, yes.

Your attempts to show it is "flawed" aren't convincing.

You're simply applying your layman's understanding of it.

I haven't attempted to show the flaws in the NIST 'column 79 hypothesis' in this thread.

You might want to visit this thread if the subject interests you;

http://www.internationalskeptics.com/forums/showthread.php?t=242773

What occurred was a controlled demolition implosion including the classic "kink" before global collapse.

You give no proof that the "kink" was due to "controlled demolition," as you claim.

You have simply substituted that as the default because you think you've eliminated any sort of damage or fire explanation.

The roofline kink is a classic 'tell' for the start of an implosive building collapse. Look into it for yourself if you think it reveals something different.

I stand by controlled demolition as the cause because it is the only engineering explanation that 'holds water'.

If you can logically explain how the evidence supports a fire induced a 47 storey implosion, I'll be quite interested.

 

[Miragememories]

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

No, the important point is that the "opposition" was less than zero:

it was negative.

How can it be negative?

It can't.

Therefore that proves that there were more forces into play that you aren't acknowledging.

It can, but it can't?

What are you smoking?

Given the method of determination (video analysis) and the amount of deviation involved, I would chalk it up
to % error.

Another possibility is that objects moving through air create a 'draft'. If propelled by means other than gravity (explosives), it would seem possible that such forces as you suggest might be observed.

 

[JayUtah]

The opposition was represented by 24 core columns and 57 perimeter columns, interlocked.

Not an answer to my question. You are claiming the speed of the collapse is anomalous. An anomaly is a departure from expectations. I want to know what your quantitative expectations derive from. How fast should have the building fallen down instead, and how do you know that?

Numbers, please.

If you want to re-open the steel expansion and fire temperature timeline debate go for it.

I don't need to.

My highest grades were in my structural engineering courses at college but I majored in electronics.

Most engineering schools don't let you take advanced structural engineering courses (e.g., indeterminate statics, finite structural analysis) unless you are a major. Those are third- and fourth-year classes. So I'll need to know what university, what year, and what your actual declared major was so that I can verify the credibility of your new claim.

Also, are you now claiming to be an engineer trained and experienced in structural mechanics?

If you actually read the NIST WTC7 Report ... you will see they never tested for thermite...

Well, to start with, thermite isn't an explosive. Its inability to have the effect upon the structure that Truthers claim has already been well discussed. In the broader sense do you have any evidence for the use of chemical explosives that doesn't amount to a circular inference?

...they based their conclusion of no explosives pretty much on the lack of audio evidence.

You have no credible competing audio evidence either. You proposed -- from your claimed expertise in audio and audio-recording electronics -- that the absence of any audio evidence was due to some electronic saturation effect. But when challenged by another person with audio recording experience, you would not defend that claim. Nor when challenged could you provide any examples of the effect you claimed, nor any evidence that such an effect was present at the time of the WTC 7 collapse.

Your sole evidence in favor of the use of explosives is a single alleged eyewitness whose testimony is highly problematic.

-collapse symmetry
-roofline kink
-freefall
-total high speed collapse
-lower floor core implosion

No, you simply declare those to be the result of some hitherto unknown controlled demolition scenario. Do you understand the difference between evidence and a claim? Do you understand the difference between inference and evidence?

You just beg the question that this list of claims is true and that it inexorably points to controlled demolition.

You might want to visit this thread if the subject interests you;

I'm familiar with that thread. You should be aware that I refuted Szamboti on those points in a different thread and he has so far failed to respond to it, or even acknowledge that such a refutation was provided. He has turned tail and run.

The roofline kink is a classic 'tell' for the start of an implosive building collapse.

In your newfound expert opinion as a forensic structural engineer and a controlled demolition expert?

Look into it for yourself if you think it reveals something different.

I don't believe it is a "classic tell," as you claim. Since it's your claim, it's your burden of proof. Disputation of your layman's assumptions does not incur a converse burden of proof.

I stand by controlled demolition as the cause because it is the only engineering explanation that 'holds water'.

Not according to any actual engineer. I don't consider your "audio engineer" experience a relevant qualification.

If you can logically explain how the evidence supports a fire induced a 47 storey implosion, I'll be quite interested.

Well, I'm reasonably familiar with nonlinearity in structural responses, so the prevailing explanation accepted by the relevant industry seems more credible than your controlled demolition theory, which doesn't seem to have any traction whatsoever among the relevant qualified experts.

Nice try at shifting the burden of proof, but you're the one claiming your outlying hypothesis better explains the data. Instead you simply cite a selective treatment of the available data and infer from that that there was a controlled demolition according to a hitherto unknown structural response profile.

 

[JayUtah]

What are you smoking?

Not all opposition to your layman's minority claims can be written off as drug intoxication. Try not to insult your critics with every post.

Given the method of determination (video analysis) and the amount of deviation involved, I would chalk it up to % error.

It is possible to bound measurement error in an appropriate error analysis. Since error analysis would have been possible in your newfound claims to engineering education, please provide the error analysis here that supports this interpretation of the results.

Another possibility is that objects moving through air create a 'draft'. If propelled by means other than gravity (explosives), it would seem possible that such forces as you suggest might be observed.

So no matter what the data appear to show, it has to be explosives? Explain for example how thermite would "propel" a structural element weighing many thousands of pounds.

 

[Grizzly Bear]

A child who makes Lego buildings or Meccano structures can tell you it's impossible for the whole structure to fail at once to provide zero resistance. Maybe it's time to wake up guys and face reality.

Kids building legos do it for fun. You're arguing with the big leagues who design and build life sized structures for a living. Snark aside, I'm not invested in writing long rebuttals of people who want to rationalize why their peers won't agree with them. I'll only state the obvious, that when we design buildings we don't consider the raw number of columns a building needs to stand up, we consider how the loads have to be carried efficiently in order for it to be economically feasible and safe. When buildings collapse, we are not concerned with how many columns are holding it up, we are concerned about how the loads are redistributed and the progression of failure. You're arguing "fancy math" AKA "BS" math I guess to prop up your "knowledge" and "expertise". I'm not sure which it is, nor do I care; the essential point is that you're basically arguing things that have no engineering or design relevance with respect to this discussion, and I would say the same of MM's points referring to the number of "interlocking parts". I have yet to see you or MM mention anything that is relevant to the specific design criteria that would justify a "CD" abnd I'll reiterate my straight forward response that neither of you can produce the evidence required in order to make "CD" even a consideration.

 

[ProBonoShill]

Well, you've shown that if the WTC7 had been constructed of balsa wood, it could not only have rapidly burned to the ground, it could have been crushable.

Your example is that of a structure initially supporting its own weight as load.

Like any building, if you somehow stack an ever increasing balanced load on the roof, sooner or later the crushing gravitational force created will overwhelm the building's engineered vertical support.

But this is not what WTC7 experienced, making your pathetic example absolutely worthless as comparison.

Meanwhile in the real world of concrete and structural steel, buildings behave as expected.

I welcome you to provide real world examples of "often" sudden building collapses that were not CDs.



Do you have any idea what would qualify as a symmetrical collapse in engineering terms or are you hung up on "perfect"?

[qimg]http://i1265.photobucket.com/albums/jj515/Miragememories/WTC7Comp-7302014_zpscb34b8b8.png[/qimg]

Any delay in one side failing before the other, and that building will start tilting. There is no significant tilt until late in the collapse.

Another physics fail for the twoof.

 

[Animal]

Most engineering schools don't let you take advanced structural engineering courses (e.g., indeterminate statics, finite structural analysis) unless you are a major. Those are third- and fourth-year classes. So I'll need to know what university, what year, and what your actual declared major was so that I can verify the credibility of your new claim.

Also, are you now claiming to be an engineer trained and experienced in structural mechanics?

As an architect....my highest grades were in in a Chemical Engineering course and a Textile Engineering course.......guess that makes me a double engineer

 

[Miragememories]

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

Virtually zero opposition" according to whom?

What should have the "opposition" looked like and how do you know that?

The opposition was represented by 24 core columns and 57 perimeter columns, interlocked.

From the Aug.26, 2008 NIST Technical Briefing re:WTC7 Collapse Report;

"...a *free fall time would be an object that has no...uh... structural components below it..."

From the NIST is summary in Section 3.6 of the final summary report, NCSTAR 1A (released Nov. 20, 2008; available at http://wtc.nist.gov/NCSTAR1/PDF/NCSTAR 1A.pdf) and detailed in Section 12.5.3 of NIST NCSTAR 1-9 (available at http://wtc.nist.gov/NCSTAR1/PDF/NCST... Vol 2.pdf).

* Stage 2 (1.75 to 4.0 seconds): gravitational acceleration (free fall)

. . . . . . . . . . . . . . . . . . . .

Interesting how you bypass that answer to YOUR question.

No where has it been shown that fire activity in WTC7 could possibly enable the visible NE, NW and SE corners to fail in unison.

Actually it has, but you simply refuse to consider it.

If you want to re-open the steel expansion and fire temperature timeline debate go for it.

I don't need to.

Yes you do.

Until you become God, your opines are only meaningful if they debunk the arguments that show the serious flaws in the NIST fire-induced steel expansion hypothesis.

Also, are you now claiming to be an engineer trained and experienced in structural mechanics?

No.

If you actually read the NIST WTC7 Report, you will see they never tested for thermite (see the 2009 Bentham paper)...

Well, to start with, thermite isn't an explosive.

Its inability to have the effect upon the structure that Truthers claim has already been well discussed.

In the broader sense do you have any evidence for the use of chemical explosives that doesn't amount to a circular inference?

Read much?

I never said thermite 'is' an explosive.

Nano-thermite in combination with sol-gel chemistry can create an explosive formulation.

Thermite would be found in the residue.

https://e-reports-ext.llnl.gov/pdf/307362.pdf
Synthesis and Characterization of Mixed Metal Oxide Nanocomposite Energetic Materials

It begins: “We have developed a new method of making nanostructured energetic materials, specifically explosives...using sol-gel chemistry.”

I can link you to many more papers if you require additional proof.

You have no credible competing audio evidence either.

You proposed -- from your claimed expertise in audio and audio-recording electronics -- that the absence of any audio evidence was due to some electronic saturation effect.

But when challenged by another person with audio recording experience, you would not defend that claim.

Nor when challenged could you provide any examples of the effect you claimed, nor any evidence that such an effect was present at the time of the WTC 7 collapse.

Your sole evidence in favor of the use of explosives is a single alleged eyewitness whose testimony is highly problematic.

I stand by my claims regarding my work experience as a professional audio/video editor and recording engineer.

The person you cite apparently bamboozled you with his text book recitations.

In 2001, audio digital recordings of News events were not commonly made in the field. Digital recordings made with too high an input level are totally contentless and produce a distinctive screeching sound.

Analog recordings made with too high an input level, become over-modulated and their content is degraded proportionally to the amount of signal received.

Because of the high sound levels at the WTC on 9/11, over modulation was common in many of the recordings which resulted in audio that was either useless or lacking in conclusive detail.

There were a number of witnesses to explosions at the WTC.

Barry Jennings was a good choice because he was inside WTC7 when WTC1 and WTC2 collapsed. As well, he insisted that he heard repeated explosions throughout his time trapped inside.

Additionally, he was trapped because his escape route via the 6th floor stairwell was blown away (as was the only other stairwell). This is particularly interesting because the stairwells were well away from the known debris zone damage (see NIST) and well protected by core columns and elevator banks.

The totally flawed column 79 scenario was the best they could come up with.

They consider it the most likely scenario, yes.

Your attempts to show it is "flawed" aren't convincing.

You're simply applying your layman's understanding of it.

I haven't attempted to show the flaws in the NIST 'column 79 hypothesis' in this thread.

You might want to visit this thread if the subject interests you;

http://www.internationalskeptics.com/forums/showthread.php?t=242773

I'm familiar with that thread.

You should be aware that I refuted Szamboti on those points in a different thread and he has so far failed to respond to it, or even acknowledge that such a refutation was provided.

He has turned tail and run.

Being "familiar" is just another way of saying you don't know much.

I suspect Tony gave up on arguing with a narcissist. Your blustery tirades are awfully tiresome.

The roofline kink is a classic 'tell' for the start of an implosive building collapse. Look into it for yourself if you think it reveals something different.

I stand by controlled demolition as the cause because it is the only engineering explanation that 'holds water'.

If you can logically explain how the evidence supports a fire induced a 47 storey implosion, I'll be quite interested.

Well, I'm reasonably familiar with nonlinearity in structural responses, so the prevailing explanation accepted by the relevant industry seems more credible than your controlled demolition theory, which doesn't seem to have any traction whatsoever among the relevant qualified experts.

Nice try at shifting the burden of proof, but you're the one claiming your outlying hypothesis better explains the data. Instead you simply cite a selective treatment of the available data and infer from that that there was a controlled demolition according to a hitherto unknown structural response profile.

I see. Now you are "reasonably familiar."

Followed by more of your bafflegab.

The important point is that 8 storeys of WTC7's collapse was falling at an acceleration that showed virtually zero opposition.

No, the important point is that the "opposition" was less than zero:

it was negative.

How can it be negative?

It can't.

Therefore that proves that there were more forces into play that you aren't acknowledging.

It can, but it can't?

What are you smoking?

Given the method of determination (video analysis) and the amount of deviation involved, I would chalk it up
to % error.

Another possibility is that objects moving through air create a 'draft'. If propelled by means other than gravity (explosives), it would seem possible that such forces as you suggest might be observed.

Not all opposition to your layman's minority claims can be written off as drug intoxication.

It seemed like a logical explanation given the absurdity of his response.

So no matter what the data appear to show, it has to be explosives? Explain for example how thermite would "propel" a structural element weighing many thousands of pounds.

Somewhat off topic, this thread is specifically about WTC7. Again, I suggest you look into;

https://e-reports-ext.llnl.gov/pdf/307362.pdf
Synthesis and Characterization of Mixed Metal Oxide Nanocomposite Energetic Materials

It begins: “We have developed a new method of making nanostructured energetic materials, specifically explosives...using sol-gel chemistry.”

Please note that once global collapse is initiated, the generated sound volume would make it very difficult to identify sound sources.

 

[carlitos]

MM, if you were trying to get people to skip your posts, throwing in umpteen seeded quotes and bright blue text would be a good way to go.