Science fail 3: supporters of NIST physics still relying on faith, foggy notions, over logic

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jas
Science fail 3: supporters of NIST physics still relying on faith, foggy notions, over logic

pants-of-the-dog wrote:
jrootham is apparently suggesting that the kinetic energy would have been transferred along a small surface area if the upper stories were tilted, which could very well result in a more rapid failure where that impact took place.

Oh, a rapid global failure produced by asymmetrical, local damage. Like magic rocks?

Quote:
You are doing two things here: first, you are shifting the burden of proof. As I have already mentioned, the person who makes the claim has the burden of proof. You made the claim, and now you must provide evidence.

Absence of evidence is not evidence of absence. Let's say you and I are in downtown Toronto and I told you I had a magic rock that kept away tigers. You, intelligently enough, ask for proof. Now, when asked for proof, I point out that there are no tigers around. There are no tigers in downtown Toronto. Does that mean my rock is magical? No. Therefore a lack of tigers does not make my rock magic, just like my lack of previous examples of building collapse does not make your false flag hypothesis true.

You don't seem to understand burden of proof. What you're failing to recognize is that the thread that I started is asking for your (or anyone else's) proof that the magic rock does keep away tigers, i.e., that buildings commonly implode into themselves at the rate of near free fall through the force of gravity alone. The entire purpose of this thread, and the six preceding it, is to ask for the scientific evidence, the physical principles upon which this ridiculous claim is based. No one has yet provided it. Moreover, you have no historical evidence to back this claim up, but you're asking me to find it for you. That's not my job, and furthermore, I know there is no such evidence. If you disagree, you're the one who needs to produce it, not me.

Quote:
By the way, I do not think that fire did weakened the lower floors as you claim.

I have never made this claim.

Quote:
Or even the upper floors for that matter. Any fire damage would have been localised to the area where the crashing jets destroyed the fire proofing around the structure.

Yes, that is the first logical thing you've said. Are you aware that the fire is cited as a major causal factor in NIST's explanation? Are you saying that you now agree with the premise of this topic--that the NIST explanation is untenable? If so, then perhaps we're making progress.

jas

Continued, by the way, from here.

Pants-of-dog

jas wrote:
Oh, a rapid global failure produced by asymmetrical, local damage. Like magic rocks?

No, I don't believe that jrootham was saying that. Perhaps you should reread jrootham's posts. (S)he was discussing the fact that if the entire block of upper stories fell in one small spot, the energy from the fall would be concentrated there and cause a lot of damage to that specific area.

It is a logical claim, in my opinion.

 

jas wrote:
You don't seem to understand burden of proof. What you're failing to recognize is that the thread that I started is asking for your (or anyone else's) proof that the magic rock does keep away tigers, i.e., that buildings commonly implode into themselves at the rate of near free fall through the force of gravity alone. The entire purpose of this thread, and the six preceding it, is to ask for the scientific evidence, the physical principles upon which this ridiculous claim is based. No one has yet provided it. Moreover, you have no historical evidence to back this claim up, but you're asking me to find it for you. That's not my job, and furthermore, I know there is no such evidence. If you disagree, you're the one who needs to produce it, not me.

The information has already been provided. The NIST reports for you to look at are already available. We have even done so in the preceding thread. Would you like the links to them again?

Moreover, they did not collapse through gravity alone. There was also substantial fire damage as well as the damage caused directly by the impact of the planes.

 

jas wrote:
I have never made this claim.

I'm sorry, but I though you had. I reread the part that made me think that you had claimed that and I see now that I may have been confused.

 

jas wrote:
Yes, that is the first logical thing you've said. Are you aware that the fire is cited as a major causal factor in NIST's explanation? Are you saying that you now agree with the premise of this topic--that the NIST explanation is untenable? If so, then perhaps we're making progress.

Please quote the relevant text from the NIST report. From what I understand, there is no indication that the NIST claims that all floors would have suffered fire damage. I was under the impression that the claim is that fire damage was partly responsible for the initial collapse, but did not affect the lower floors that were crushed solely by the weight of the falling upper floors.

Fidel

There's one way to clear up ALL of FEMA-NIST's slip-shod investigation of the collapses of WTCs 1,2 & 7, as well as the controversy surrounding Al-CIA'duh.

jas

Quote:
The information has already been provided. The NIST reports for you to look at are already available. We have even done so in the preceding thread. Would you like the links to them again?

Actually, you would need to provide either a specific quote from the NIST report, or be able to reference a specific section of the report where it clearly explains what removed the resistance of 90 and 78 floors of concrete and steel highrise (we'll leave WTC7 out of this for now) so that they would descend within seconds of free fall. Because from what I've read, it's not in there. If you go back through all the other recent threads, this has always been my first and main question. OK? Burden of proof is on you, here.

And while you're at it, you might want to provide the evidence showing that buildings commonly experience rapid and total collapse after having suffered upper floor damage and office fires of 90 minutes or less. Thanks.

jrootham

There aren't that many buildings in the world.  What part of unique, as in, truly unique, never happened before, don't you understand?

 

jrootham

By the way, I'm not really engaging with you.  I'm just laying down a trail of evidence to show that not everyone on this site is fucking stupid.

 

Fidel

We're not saying you're very stupid. A little naive maybe, but not a thundering nit wit or anything like that. And as much as we'd like to, we've never called you a blithering idiot. Never and not once.

Catchfire Catchfire's picture

Alright, cut out the oblique personal attacks jrootham and Fidel.

The word "evidence" in this thread has acquired an almost mystical, divine meaning.

jrootham

Oblique?  Oblique!!  I am shattered.  :)

I thought I was being direct.  But, OK, I think I have made my point.

 

Pants-of-dog

jas wrote:

Actually, you would need to provide either a specific quote from the NIST report, or be able to reference a specific section of the report where it clearly explains what removed the resistance of 90 and 78 floors of concrete and steel highrise (we'll leave WTC7 out of this for now) so that they would descend within seconds of free fall. Because from what I've read, it's not in there. If you go back through all the other recent threads, this has always been my first and main question. OK? Burden of proof is on you, here.

And while you're at it, you might want to provide the evidence showing that buildings commonly experience rapid and total collapse after having suffered upper floor damage and office fires of 90 minutes or less. Thanks.

I have a whole PDF that provides clear equations discussing every aspect of the collapse:

http://www.crono911.net/docs/Bazant2007.pdf

 

I will quote from the conclusion:

Conclusions
Several of the parameters of the present mathematical model have a large range of uncertainty.
However, the solution exhibits small sensitivity to some of them, and the values of others can
be fixed based on observations or physical analysis. One and the same mathematical model,
with one and the same set of parameters, is shown capable of matching all of the observations,
including: (1) the video records of the first few seconds of motion of both towers, (2) the
seismic records for both towers, (3) the mass and size distributions of the comminuted particles
of concrete, (4) the energy requirement for the comminution that occurred, (5) the wide spread
of the fine dust around the tower, (6) the loud booms heard during collapse, (7) the fast
expansion of dust clouds during collapse, and (8) the dust content of cloud implied by its size.
At the same time, the alternative allegations of some kind of controlled demolition are shown to
be totally out of range of the present mathematical model, even if the full range of parameter
uncertainties is considered. These conclusions show the allegations of controlled demolition to
be absurd and leave no doubt that the towers failed due to gravity-driven progressive collapse
triggered by the effects of fire
.

Bolding mine for emphasis.

To answer your specific question about what removed the resistance, I can only answer that no resistance was removed except on the floors where the airplanes impacted. On those floors, the impact of the planes caused extensive structural damage to the core, many of the perimeter columns, and a large part of the floor deck. it also removed a large portion of the fireproofing on the remaining intact structure. The fire caused by the jet fuel weakened the steel dramatically, which then led to the collapse of the remaining structure on the impacted floors. This collapse then led to the subsequent total building collapse.

To summarise, the removal of the fireproofing and the jet-fuel fire weakened the already overloaded structure left intact after the jet impact. This "removed the resistance" of the structure, but only on the floors hit by the planes.

 

As for the demands showing that buildings commonly experience total collapse after having suffered upper floor damage and and office fires, I would like to point out that the WTC buildings would not have collapsed if those were the only two causes of collapse. There are also two other important facts that need to be addressed: the removal of the fire proofing caused by the impact of the planes, and the destruction of the sprinkler system due to the same impact.

E.P.Houle

PoD, Within minutes of watching the "towers" show I was looking at the specs on Bldg. 7 and the 2x600 gal fuel tanks on the 7th floor(14th?). I did not see a 747 parked in the basement. You and Fidel are arguing in two different courts; Fidel proves overwhelming holes in the NIST case, he is in the court trying the credibility of NIST but you are defending NIST in the court of criminal liability. It's interesting that in your approach that the missing steel beams were the first evidence off the property when they could show clearly the cut marks and settle this. I've seen the photo but I cannot email it to you, it seems to be missing.

E.P.Houle

The 9/11 was not the second attack on the WTC. The place had become a case study in civil engineering in 'security hardening'. The fourth attack, an aborted AMFO attack in the basement brought up architectual ablative structures in building defense(attack 4)( lessons that were not applied to the death of hundreds of marines in Africa at an "Embassy'). I, too, actually laughed at first when I saw that creative way to supply that amout of fuel that high in a building that fast BUT those two thousand firemen, cops, janitors, office skeleton staff were all salt of the earth people like me. Thank god #7 went down with less loss of life. But, the planes did not bring the three buildings down. The number of contradictions continues to expand and the profits of KBR keep growing.

jas

pants wrote:

To answer your specific question about what removed the resistance, I can only answer that no resistance was removed except on the floors where the airplanes impacted. On those floors, the impact of the planes caused extensive structural damage to the core, many of the perimeter columns, and a large part of the floor deck. it also removed a large portion of the fireproofing on the remaining intact structure. The fire caused by the jet fuel weakened the steel dramatically, which then led to the collapse of the remaining structure on the impacted floors. This collapse then led to the subsequent total building collapse.

To summarise, the removal of the fireproofing and the jet-fuel fire weakened the already overloaded structure left intact after the jet impact. This "removed the resistance" of the structure, but only on the floors hit by the planes.

Your simplistic outline here demonstrates what I've suspected all along: you don't even understand the issue. For a building's top floors to descend through its lower floors in the time that they did and in the manner that the official theory states it did, resistance has to be removed. It's a law of nature and matter that even NIST accepts. It is false, illogical and idiotic to suggest that the buildings collapsed as they did, with nevertheless all 91 and 78 floors presenting the normal resistive force that one would expect of a steel-frame highrise. This is the whole crux of the argument, which you seem to chronically not understand.

If you were going to suggest that the buildings presented normal resistance in their descent, you might have done it in post #1 so we wouldn't have wasted all this time on you. You truly do not seem to understand what is being argued.

 

As for Bazant, I notice the believers keep bringing up this article, as if it's the only article they have to go on, as if no other reputable scientist in the world would dare touch such nonsense theories. So here we go again with the Bazant debunking:

 

jas

Re-posting some professional observations recorded on this site:

William Rice, BS CE, MS CE, PE – Licensed Professional Engineer, State of Vermont.  Worked on structural steel and concrete buildings in Boston, New York, and Philadelphia for two of the nation’s largest building construction companies; the Austin Company and the George A. Fuller Construction Company.  Former Professor at Vermont Technical College where he taught engineering materials, structures lab, and other building related courses for over 20 years.

Essay Vermont Guardian 3/1/07: "Having worked on structural steel buildings as a civil engineer in the era when the Twin Towers were designed and constructed, I found some disturbing discrepancies and omissions concerning their collapse on 9/11. ...

The interesting fact is that each of these 110-story Twin Towers fell upon itself in about ten seconds at nearly free-fall speed. This violates Newton’s Law of Conservation of Momentum that would require that as the stationary inertia of each floor is overcome by being hit, the mass (weight) increases and the free-fall speed decreases.

Even if Newton’s Law is ignored, the prevailing theory would have us believe that each of the Twin Towers inexplicably collapsed upon itself crushing all 287 massive columns on each floor while maintaining a free-fall speed as if the 100,000, or more, tons of supporting structural-steel framework underneath didn't exist..."

jas

Kerry Lewis McCarthy, B.Arch – Licensed Architect, State of Oregon. Experienced with high-rise steel frame structures, including building-forensic, some steel frame but mostly concrete.  Studied WTC's design, structure and construction at university.  Over 30 years experience. Statement in support of Architects and Engineers petition:

"Very hard to understand the 'complete' lack of concrete rubble in the debris field.  Even had the basements filled with concrete topping slab debris.  There should have been a stack of jumbled building elements about 9 more stories above grade.  The core columns were fully welded yet none were longer than 40 ft (max trucking length).  This event as portrayed by the NIST Report totally messes with my understanding of how buildings behave.  I haven't been able to reconcile the promoted theory of collapse with the way I know buildings to behave."

jas

Brian Brademeyer, MS CE – Former Senior Research Engineer, MIT 1975 - 1987.  Currently Software Engineering Consultant Statement in support of Architects and Engineers petition:

"My first-order analysis of WTC1 collapse suggests insufficient energy for pulverization of concrete slabs in the floor elements. Official story does not explain why weakening by fire resulted in abrupt collapse, rather than a sagging-slumping failure mode."Roland Edward Angle, BS CE, PE – Licensed Professional Civil Engineer, State of California.  Forty years experience in Civil & Military design, analysis & construction, including blast analysis of nuclear hardened facilities. Statement in support of Architects and Engineers petition:

"The official explanation of the building failures defies known scientific methods of analyses and is untenable in the face of logical investigation."

jas

Edward E. Knesl, MS Eng, PE – Licensed Professional Civil and Structural Engineer, State of Arizona.  Thirty five years of domestic and international experience in commercial and transportation projects, including: Structural Design and Analysis, Construction Administration and Management, Plan Review, and Special Inspection. Statement in support of Architects and Engineers petition:

"We design and analyze buildings for the overturning stability to resist the lateral loads with the combination of the gravity loads.  Any tall structure failure mode would be a fall over to its side.  It is impossible that heavy steel columns could collapse at the fraction of the second within each story and subsequently at each floor bellow.

We do not know the phenomenon of the high rise building to disintegrate internally faster than the free fall of the debris coming down from the top.

The engineering science and the law of physics simply doesn't know such possibility.  Only very sophisticated controlled demolition can achieve such result, eliminating the natural dampening effect of the structural framing huge mass that should normally stop the partial collapse.  The pancake theory is a fallacy, telling us that more and more energy would be generated to accelerate the collapse.  Where would such energy would be coming from?"

jas

Jeff King, MD, SB EE (MIT Science Baccalaureate in Biology and Electrical Engineering) – Family Practice Physician (27 years).  Former Electrical Engineer (8 years).

  • Video of presentation Confronting the Evidence Conference 9/11/04:  "When I first saw the [WTC] collapses I was absolutely convinced they were not spontaneous. ...

    [Statement to this website 6/10/07:  "...what we have learned in the years since then (2004) only confirms that initial impression.  At the simplest level there is a gross violation of conservation of energy: for the towers to fall at or near free-fall speed, all the stored gravitational energy would have had to be used to accelerate their own mass downward.  The same energy can’t be  used twice, which is to say that any “work” extracted, for example to pulverize concrete, will slow the collapse by a corresponding amount.

    In the case of the twin towers even a rough calculation of the amount of energy needed to pulverize all the concrete and gypsum to the very fine dust observed (and without including the energy needed to crumple and deform steel) indicates that it would have far exceeded the entire gravitational potential energy of the structures.

    As measurements by Cahill have shown, dust particles were mostly <30 microns, with a sizeable fraction smaller than 0.25 micron.  Not only is an immense amount of energy needed to break most of the chemical bonds holding the concrete together, but there is no mechanism that can be postulated with only a gravitational collapse that might account for such rapid and complete pulverization.  Such a process is almost by definition an explosive event: the almost instantaneous conversion of a slab of concrete into a rapidly expanding cloud of dust.]

    [Continuation of 2004 presentation]  The obvious question is what does it mean that there was a controlled demolition.  At the simplest level, it means that someone had a lot access to the buildings over a long enough period of time to set this up.  It implies, as many other things have tonight, that the people who had effective control of the site had an interest in having it scrubbed and making sure that no information was available; that a forensic reconstruction couldn't be done.

    Even in much smaller catastrophes we typically will reconstruct things as completely as possible.  For example with TWA Flight 800 pieces were dredged off the bottom of the sea.  A complete reconstruction was done to allow a detailed analysis.  In this case, just the opposite was done. ... "

 

Papal Bull

There are two of these threads, jas. You should select one to keep going and then get a mod to close the other one. :P

 

You know babble and thread proliferation, sis/bro.

Pants-of-dog

E.P.Houle wrote:

PoD, Within minutes of watching the "towers" show I was looking at the specs on Bldg. 7 and the 2x600 gal fuel tanks on the 7th floor(14th?). I did not see a 747 parked in the basement. You and Fidel are arguing in two different courts; Fidel proves overwhelming holes in the NIST case, he is in the court trying the credibility of NIST but you are defending NIST in the court of criminal liability. It's interesting that in your approach that the missing steel beams were the first evidence off the property when they could show clearly the cut marks and settle this. I've seen the photo but I cannot email it to you, it seems to be missing.

I'm sorry, but I have no idea what you are trying to say.

 


jas wrote:

Your simplistic outline here demonstrates what I've suspected all along: you don't even understand the issue. For a building's top floors to descend through its lower floors in the time that they did and in the manner that the official theory states it did, resistance has to be removed. It's a law of nature and matter that even NIST accepts. It is false, illogical and idiotic to suggest that the buildings collapsed as they did, with nevertheless all 91 and 78 floors presenting the normal resistive force that one would expect of a steel-frame highrise. This is the whole crux of the argument, which you seem to chronically not understand.

If you were going to suggest that the buildings presented normal resistance in their descent, you might have done it in post #1 so we wouldn't have wasted all this time on you. You truly do not seem to understand what is being argued.

I do understand what you are trying to say. You are claiming that the colllpase of the two WTC towers was so rapid that it could not have been caused solely by the impact of the falling upper block of storeys, and therefore, some other factor (presumably a false flag operation by the US government) was responsible for bringing them down. This factor was responsible for demolishing the structure of the floors in such a way that all resistance was removed, thereby allowing the upper block of storeys to descend at near free fall speeds.

Is that a reasonable summary of your claim?

If not, please explain where I have misunderstood.

If it is a reaonable summary, then I must say that you make several erroneous assumptions that do not seem to correspond with reality, and are simply wrong.

You assume incorrectly that the towers collapsed at near free fall speeds.

You also assume incorrectly that the resistance provided by the structure below was enough to provide support to the descending block of upper storeys.

 

Quote:
As for Bazant, I notice the believers keep bringing up this article, as if it's the only article they have to go on, as if no other reputable scientist in the world would dare touch such nonsense theories. So here we go again with the Bazant debunking:

 

What exactly are the criticisms they have about Bazant's work?

 

Now, I also notice that you have posted several excerpts from several different critics of the NIST report. I will get to them as time allows, but right now my beloved is waiting for me to come to bed.

jas

Hmm, I replied to this last night, but my sketchy wifi access probably lost it.

No, pants, it's not an accurate summary of my claim. I believe I summarize my claim in every thread I start, except perhaps for this one. If you continue to not understand, I can't help you with that.

Moreover, whatever you're claiming is still unknown. Your argument seems to shift frequently and often contradicts itself. You also tend to ask for information and then not read it, or pretend not to have seen it. You also avoid answering questions or, if you do, you do it in an oblique fashion, as if you're having problems finding the real answer. For example, I asked for a reference from the NIST report that explains how it could be that next to no resistance was demonstrated in the remaining 91 and 78 floors of the towers, and you failed to provide it. Then you changed your argument back to disputing the collapse time. You still have not provided any indication as to what you think the collapse time was, nor any evidence that suggests it was outside what is almost unanimously accepted.

You complain about burden of proof but you provide little direct evidence or references yourself, beyond anonymously written amateur debunking sites. And you continue to misunderstand, perhaps deliberately, what is being argued here.

If you dispute the collapse time, tell us what you think it was, and back it up with some facts. If you can't handle a simple task like that, I would ask you to stay out of the discussion.

Fidel

Ya, Pants isn't doing anything but deferring us to whacky theorists like Bazant, who had to change his paper a few times before JEM would finally publish it. And it was due to James Gourley pointing out errors in his work. I think it's time Pants did some explaining in his own words instead of sloughing us off to quacks like Bazant.

Pants-of-dog

jas wrote:
No, pants, it's not an accurate summary of my claim. I believe I summarize my claim in every thread I start, except perhaps for this one. If you continue to not understand, I can't help you with that.

I find it interesting that you can't even bother to explain how I erred in my summation.

jas wrote:
Moreover, whatever you're claiming is still unknown. Your argument seems to shift frequently and often contradicts itself. You also tend to ask for information and then not read it, or pretend not to have seen it. You also avoid answering questions or, if you do, you do it in an oblique fashion, as if you're having problems finding the real answer.

You should show how I actually do this instead of merely accusing me of it, like you did right below.

jas wrote:
For example, I asked for a reference from the NIST report that explains how it could be that next to no resistance was demonstrated in the remaining 91 and 78 floors of the towers, and you failed to provide it.

Actually, I explained quite carefully that there was resistance and it was demonstrated, and that this idea that resistance was removed is an erroneous assumption on your part.

I did that here: http://www.rabble.ca/comment/1154739/jas-wrote-Actually-you

jas wrote:
Then you changed your argument back to disputing the collapse time. You still have not provided any indication as to what you think the collapse time was, nor any evidence that suggests it was outside what is almost unanimously accepted.

I provided that exact information (with evidence) here: http://www.rabble.ca/comment/1149239/jas-wrote-And-then-whatever

 

jas wrote:
You complain about burden of proof but you provide little direct evidence or references yourself, beyond anonymously written amateur debunking sites. And you continue to misunderstand, perhaps deliberately, what is being argued here.

I have at all times endeavoured to provide evidence that actually supports itself with empirical data and sound mathematics, and actualy shows the data and math. If you feel that any specific support I have linked to is somehow faulty in that respect, I would be very grateful if you brought it to my attention.

 

jas wrote:
If you dispute the collapse time, tell us what you think it was, and back it up with some facts. If you can't handle a simple task like that, I would ask you to stay out of the discussion.

I will repeat the content of my previous answer the last time you asked me this question:

http://www.911myths.com/WTCREPORT.pdf (see page 5/32)

WTC 1

tc = (11.6 + 1.0) sec = 12.6 sec

WTC 2

tc = (9.7 + 1.8) sec = 11.5 sec

The facts you asked for may be found in the linked PDF.

Fidel

But that's not what the official conspiracy says, Pants. The Commission's report said the south tower collapsed in ten seconds flat. All of the Commission, Bufo Adada Bazant, FEMA and NISTers should get together and get their official conspiracy theories straight.

"It looked just like one of those controlled demolitions." - Dan Rather

lol

Maysie Maysie's picture

Ok, I'm closing this thread and redirecting everyone to this thread, started 6 days before this one. I will re-open this on, and rename it part 3 when the part 2 is full.

Catchfire Catchfire's picture

Reopening this thread to continue the "discussion"

Fidel

[url=http://www.globalresearch.ca/index.php?context=va&aid=19891]NIST ommitted, falsified, and fabricated evidence[/url] by Prof. David Ray Griffin

Pants-of-dog

jas wrote:
pyroclastic cloud

jas wrote:
Spot the difference.

Pyroclastic clouds do not exist.

When the term is used, it is usually as a synonym for pyroclastic flows. http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry33.html

jas wrote:
As for the crush down theory, common sense tells you that the accreted matter would accumulate between the falling mass and the upright mass, which has to slow the falling mass down.Pulverized material does not accumulate onto the upper block. It's pulverized. It doesn't add to the "crushing power" of the falling block. If anything, it creates an obstruction to its momentum.

The accreted matter would only slow down the falling mass if it is not falling itself. Since it has already been demolished, it can not be held up by the structure anymore. Since it is not held up, it must be falling. Since it is falling, its mass counts as part of the falling mass.

The resulting mass (the original falling mass plus the addition of the accreted matter) would be slower than the velocity of the original mass, at least at the instant after collision, and before it starts accelerating to gravity. To understand the underlying physics, please look up [url=http://en.wikipedia.org/wiki/Inelastic_collision]inelastic collisions[/url].

jas wrote:
Furthermore, there's no logic or any precedent that says that the alleged falling block would have the power to crush down before being crushed itself.

In the video showing the two large towers being demolished using the verinage technique, the upper block clearly was capable of crushing the lower block before the upper block itself was entirely crushed.

jas wrote:
The falling block actually suffered the fire damage, so it's a weaker structure than the standing block.

Neither the upper block nor the lower block suffered fire damage. Fire damage was restricted to the floors that suffered impact from the jets. This is because skyscrapers must have separations between floors capable of resisting a fire for several hours (usually two hours).

jas wrote:
In real life,  all other things being equal, floors would be destroyed on both sides of the interface of the falling mass and the upright mass--as may have been demonstrated in your controlled demolition videos--but in the case of the WTC, with the falling block losing mass before the upright block.

Unfortunately for you, the video showing the two taller towers being destroyed by the verinage technique shows the upper block maintaing cohesion quite well.

This is the video that I am addressing in this post, by the way: http://www.youtube.com/watch?v=EY3nj728WPY

jas wrote:
Finally, simple physics tells you that when something has to crush through something else, energy is lost at each step - much more energy than gravity can make up for.

To crush something takes energy, but that energy is not always higher than the energy due to gravity. For example, I could easily crush an egg by simply lifting a brick above it and letting go. I could just as easily crush an egg by dropping another egg onto it. Sometimes gravity can not make up the energy required to crush something. Sometimes it can.

Pants-of-dog

Fidel wrote:

[url=http://www.globalresearch.ca/index.php?context=va&aid=19891]NIST ommitted, falsified, and fabricated evidence[/url] by Prof. David Ray Griffin

Very little, if any, of that website has anything to do with collapse times.

Pants-of-dog

Here is a summary of the calculations used to figure out the kinetic energy with which the upper block of storeys fell on the lower block of storeys:

Quote:
the mass of one WTC floor [is] assumed to be 1/110 the mass of an entire WTC
tower, namely m = (510,000,000 / 110) kg
...
We consider the initiating event of a WTC tower collapse to be the failure of
crucial steel support structures at the appropriate upper floor level of the building,
followed by the free fall of the entire upper block of n floors through a distance hf = one
floor height = 3.7 meters. It is readily determined using the relation v = the square root of {2gh) that the
descending upper block impacts the floor below at a velocity of 8.5 m/s.

The reason why it is important to know the initial mass and velocity is because we need to know those two numbers in order to calculate the [url=http://en.wikipedia.org/wiki/Kinetic_energy#Newtonian_kinetic_energy]kin... energy.[/url]
[img]http://upload.wikimedia.org/math/4/1/4/4140f53f66a68e92afec2389ba289e25....

Quote:
For one WTC floor collapsing onto a floor below, the kinetic energy immediately
before impact is
Ti = ½{510,000,000/110} x (8.5) to the power of 2 Joules
Ti = 1.67 x 10 to the 8 J
....
Since the WTC 1 collapse consisted of 14 floors
impacting the floor below, and the WTC 2 collapse involved 29 floors impacting the
floor below, we have the kinetic energy before impact,
Ti (WTC 1) = 14 x 1.67 x 10 to the 8 J = 23.4 x 10 to the 8 J
Ti (WTC 2) = 29 x 1.67 x 10 to the 8 J = 48.4 x 10 to the 8 J

Any questions so far?

My quotes come from this paper: http://www.911myths.com/WTCREPORT.pdf

Jacob Two-Two

Thank you for the demolition clips pants. Interesting to see that a building can in fact collapse in such a way without explosives. But I still have some questions about whether the WTC could have done so.

In all those clips we have a set of floors falling on an equal set of floors. Like you say, an egg on an egg and both get squished, but that's not the case in the WTC. It's more like an egg falling on a large upright stack of eggs. Will they all be crushed one by one through to the table? Probably not, and one could say the same about the tower. Wouldn't a section of tower falling through several times its own mass lose more energy on the way down than one falling though the same mass as itself? It makes sense to me that a section crushing itself would happen quite rapidly and not necessarily be indicative of the speed of one crushing several equal sections. Logically, I would expect the latter to move slower and continue to slow as it progressed. Mind you, I freely admit I'm not about to do the math so I'm asking you instead. :) 

Pants-of-dog

Jacob Two-Two wrote:
..... It's more like an egg falling on a large upright stack of eggs. Will they all be crushed one by one through to the table? Probably not, and one could say the same about the tower.

Why not?

 

Jacob Two-Two wrote:
Wouldn't a section of tower falling through several times its own mass lose more energy on the way down than one falling though the same mass as itself? It makes sense to me that a section crushing itself would happen quite rapidly and not necessarily be indicative of the speed of one crushing several equal sections. Logically, I would expect the latter to move slower and continue to slow as it progressed. Mind you, I freely admit I'm not about to do the math so I'm asking you instead. :)

Oh, I understand that it is not intuitive, and I will try to show as clearly as possible how it works.

In a way, you are correct. If a car crashed into a telephone pole it would bend the pole a certain distance. If it crashed into four at the same time, it would go less of a distance. This makes sense.

Now, imagine the car rips the pole out of the ground and keeps going. Obviously, the pole will slow it down.

If it hits four poles one, after the other, it will slow down even more.

But it is important to note that the amount of energy stays the same. Energy is a product of mass and velocity, so if the mass increases, the velocity decreases, but the amount of energy stays the same. In our example, we would add poles (more mass), the car would slow down (less velocity), but the car would still burn the same amount of gas (equal energy).

So, in the WTC collapse, the successive floors would slow down the falling (and ever increasing) mass.

But there is one important difference between our car on the ground and our building falling down: acceleration due to gravity. After each impact, the mass would slow down because of the added mass, but would then accelerate due to gravity. If you want to go back to the car example, imagine it plowing through a series of telephone poles as it drives down a ski slope.

I hope that clarifies things on a non-mathematical level. Later on, I will show the math behind this, but right now, I have to get my beloved to bed.

jas

Pants-of-dog wrote:

The accreted matter would only slow down the falling mass if it is not falling itself. Since it has already been demolished, it can not be held up by the structure anymore. Since it is not held up, it must be falling. Since it is falling, its mass counts as part of the falling mass.

What conveniently circular logic. The accreted material, according to the theory you yourself are defending, is not yet falling. It is resting on the top of the intact block, crushed between your falling block and the top floor of the intact block. It falls when the floor it is resting on collapses (in your theory, by being crushed by the floor above). Unless, of course, you want to admit that indeed the floor is falling before the floor above impacts it, an idea I would support.

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The resulting mass (the original falling mass plus the addition of the accreted matter) would be slower than the velocity of the original mass, at least at the instant after collision, and before it starts accelerating to gravity.

The accreted matter is resting on top of the intact block. Why are you adding its mass to the falling block? In any case, much of this pulverized material has been ejected up and out, as seen in the videos, and as evidenced by the disproportionately small volume of rubble that resulted at the bottom.

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Neither the upper block nor the lower block suffered fire damage. Fire damage was restricted to the floors that suffered impact from the jets. This is because skyscrapers must have separations between floors capable of resisting a fire for several hours (usually two hours).

I mostly agree with you here, except that the videos for one of the buildings show the fire spreading upwards through most of the upper block. In any case, what you are stating here is not what NIST reports. Weakening by fire is a major cause of the floor sagging-collapse sequence that they posit. So, again, you seem to be disagreeing with the NIST report.

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To crush something takes energy, but that energy is not always higher than the energy due to gravity. For example, I could easily crush an egg by simply lifting a brick above it and letting go. I could just as easily crush an egg by dropping another egg onto it. Sometimes gravity can not make up the energy required to crush something. Sometimes it can.

I don't think so in this case. There are too many floors for our fire-weakened block to crush through. It probably wouldn't do it at  all, and could not possibly do it in the timeframe we witnessed. You can show us some math that shows it can do so; we can show you some math that shows it can't. That's the problem with mathematical arguments.

jas

Pants-of-dog wrote:

But it is important to note that the amount of energy stays the same. Energy is a product of mass and velocity, so if the mass increases, the velocity decreases, but the amount of energy stays the same. In our example, we would add poles (more mass), the car would slow down (less velocity), but the car would still burn the same amount of gas (equal energy).

So, in the WTC collapse, the successive floors would slow down the falling (and ever increasing) mass.

But there is one important difference between our car on the ground and our building falling down: acceleration due to gravity. After each impact, the mass would slow down because of the added mass, but would then accelerate due to gravity.

Again, I think you're referring to closed systems here. Energy would be lost not just in the crushing but in expelling of material outward. That is energy lost to the system we are examining. Also, you seem to be giving double credit to gravity. You talk about the impact of the falling block (due to gravity pulling it down) and then about gravity again, as if there are two forces at work here. It's just one. Gravity.

Also, your falling mass does not have much opportunity to regain kinetic energy after crushing through the 284 core and perimeter columns of one floor. For each floor it must crush through, it is only falling 12 feet. It doesn't have time or height to build up that potential energy.

jas

oops. sorry, it's my connection again.

Fidel

Pants-of-dog wrote:

Fidel wrote:

[url=http://www.globalresearch.ca/index.php?context=va&aid=19891]NIST ommitted, falsified, and fabricated evidence[/url] by Prof. David Ray Griffin

Very little, if any, of that website has anything to do with collapse times.

Well you're WRONG again. Because that article mentions that NIST first denied, then admitted WTC7 fell at free fall rate of collapse and in the empirical sense not "qualitative" or any other goofy terms you might decide to splice into the official conspiracy narrative.

 

jas

double post

jas

quadruple post

Pants-of-dog

jas wrote:
What conveniently circular logic. The accreted material, according to the theory you yourself are defending, is not yet falling. It is resting on the top of the intact block, crushed between your falling block and the top floor of the intact block. It falls when the floor it is resting on collapses (in your theory, by being crushed by the floor above). Unless, of course, you want to admit that indeed the floor is falling before the floor above impacts it, an idea I would support.

The accreted matter is resting on top of the intact block. Why are you adding its mass to the falling block?

Where does this "accreted material" come from? How does it come to rest on top of the intact block?

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In any case, much of this pulverized material has been ejected up and out, as seen in the videos, and as evidenced by the disproportionately small volume of rubble that resulted at the bottom.

It is true that a certain proportion of the falling mass is ejected outwards. We shall see how this loss of mass is accounted for in the energy calcualtions as well.

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I mostly agree with you here, except that the videos for one of the buildings show the fire spreading upwards through most of the upper block.

Please provide a link to this video. Thank you.

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In any case, what you are stating here is not what NIST reports. Weakening by fire is a major cause of the floor sagging-collapse sequence that they posit. So, again, you seem to be disagreeing with the NIST report.

I am not really disagrreing iwth the NIST, if they are saying that the fire was partly responsible for the collapse. It was. But as far as I can tell, both NIST and I are discussing the fire on the floors that were impacted by the plane. Neither the NIST nor I are discussing fires anywhere else in the two towers.

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I don't think so in this case. There are too many floors for our fire-weakened block to crush through. It probably wouldn't do it at  all, and could not possibly do it in the timeframe we witnessed. You can show us some math that shows it can do so; we can show you some math that shows it can't. That's the problem with mathematical arguments.

If we both start with the same variables, and use the same equations (i.e. th eapplicable ones), we should arrive at only one objectively verifiable answer. That is the beauty of mathematical arguments.

But you don't trust math for some reason. Which is why I showed you videos that it is indeed possible for the upper storey to crush through the lower blocks in the time we witnessed.

I even repeated that point in bold so that you can't claim I haven't disproven that claim. Here is the link for the post where I did so: http://www.rabble.ca/comment/1156589/jas-wrote-OK-I-watched

By the way, the upper blocks never suffered fire damage.

 


 

 

jas wrote:

Again, I think you're referring to closed systems here. Energy would be lost not just in the crushing but in expelling of material outward. That is energy lost to the system we are examining. Also, you seem to be giving double credit to gravity. You talk about the impact of the falling block (due to gravity pulling it down) and then about gravity again, as if there are two forces at work here. It's just one. Gravity.

Yes, the model I am using to explain inelastic collisions is very simple. There are additional energy expenditures in the collapse of the WTC towers that must be accounted for that are not present in the model. These will be accounted for as I continue the mathematical discussion.

And I am not counting gravity twice. I am talking about how garvity functions in terms of velocity and how it functions in terms of acceleration.

jas wrote:
Also, your falling mass does not have much opportunity to regain kinetic energy after crushing through the 284 core and perimeter columns of one floor. For each floor it must crush through, it is only falling 12 feet. It doesn't have time or height to build up that potential energy.

It has 12 feet to build up that kinetic energy (not potential energy). Are you aware of the difference between potential energy and kinetic energy?

 


 

Fidel wrote:

Well you're WRONG again. Because that article mentions that NIST first denied, then admitted WTC7 fell at free fall rate of collapse and in the empirical sense not "qualitative" or any other goofy terms you might decide to splice into the official conspiracy narrative.

Please note that I said very little of that has to do with collapse times. And that is true. The majority of that website talks about conspiracy theories that are irrelevant to our discussion.

If you feel that the website has pertinent information to our discussion, please quote the relevant text. It is not my job to read long websites to find the applicable information and attempt to piece together your argument from those phrases I think you may wish for me to read.

Fidel

Well it's just that NIST eventually had to admit Sunder's original "qualitative" claim that WTC7 took longer than free fall had to be scrapped because it was at odds with established Newtonian laws of physics as well as video evidence of the collapse. In other words, NIST's original conspiracy theory was revealed to be bullshit thanks to 1200+ architects and engineers for 9/11 Truth, a group which, coincidentally, has 25,000 combined years of professional experience.

Pants-of-dog

Fidel wrote:

Well it's just that NIST eventually had to admit Sunder's original claim that WTC7 took longer than free fall had to be scrapped because it was at odds with established Newtonian laws of physics as well as video evidence of the collapse. In other words, NIST's original conspiracy theory was revealed to be bullshit thanks to 1200+ architects and engineers for 9/11 Truth, a group which, coincidentally, has 25,000 combined years of professional experience.

Fidel, you make a lot of unsupported and irrelevant claims.

If you want people to believe what you are saying, then I strongly suggest you clarify exaclty what your claim is, provide some sort of logical argument for that claim, and provide evidence that your argument is true.

You also keep insisting on your argument from popularity. I do not care how many architects and enginners doubt the NIST report, if none of them can actaullay show any evidence. You have yet to show any evidence of theirs in our discussion, to be honest.

Fidel

Pants-of-dog wrote:

Fidel wrote:

Well it's just that NIST eventually had to admit Sunder's original claim that WTC7 took longer than free fall had to be scrapped because it was at odds with established Newtonian laws of physics as well as video evidence of the collapse. In other words, NIST's original conspiracy theory was revealed to be bullshit thanks to 1200+ architects and engineers for 9/11 Truth, a group which, coincidentally, has 25,000 combined years of professional experience.

Fidel, you make a lot of unsupported and irrelevant claims.

But the claim which you say is unsupported is now stated to be true by NIST themselves. So you're WRONG again. What part of the word WRONG don't you understand?

Pants-of-dog wrote:
If you want people to believe what you are saying, then I strongly suggest you clarify exaclty what your claim is, provide some sort of logical argument for that claim, and provide evidence that your argument is true.

If you can't keep up with the discussion wrt NIST's original lies and deception regarding WTC7 now thoroughly debunked by 1200+ A&Es for truth, then perhaps you should just admit that you don't know and leave it at that. Or get back to us when you do discover what the new and improved official conspiracy says.

[url=http://www.911truth.org/article.php?story=20080829205835711]'Debunking NIST's Conclusions About WTC 7 is as Easy as Shooting Fish in a Barrel' and other Responses to 8/21/08 NIST Briefing on WTC7[/url]

Pants-of-dog

Fidel wrote:
But the claim which you say is unsupported is now stated to be true by NIST themselves. So you're WRONG again. What part of the word WRONG don't you understand?

Putting WRONG in block capitals does not make me wrong. I have no idea which claim you are referring to, nor have you presented evidence that the NIST agrees or disagrees with this claim, whatever it was.

Fidelg wrote:

If you can't keep up with the discussion wrt NIST's original lies and deception regarding WTC7 now thoroughly debunked by 1200+ A&Es for truth, then perhaps you should just admit that you don't know and leave it at that. Or get back to us when you do discover what the new and improved official conspiracy says.

[url=http://www.911truth.org/article.php?story=20080829205835711]'Debunking NIST's Conclusions About WTC 7 is as Easy as Shooting Fish in a Barrel' and other Responses to 8/21/08 NIST Briefing on WTC7[/url]

I admit that I don't know what you are talking about, but that seems to have more to do with the fact that you are apparently incapable of communicating your claims clearly than any problem I seem to be having.

Try this: pretend that I have just started this discussion, and restate your claim in a single paragraph.

Fidel

You seem to be having the same problem with empiricist use of the term free fall that NIST used to experience similarly before their whacky collapse theory was debunked by 1200 plus A&Es for 9/11 truth. If you want to argue against what NIST has since admitted to, then be our guest.

Pants-of-dog

Fidel wrote:

You seem to be having the same problem with empiricist use of the term free fall that NIST used to experience similarly before their whacky collapse theory was debunked by 1200 plus A&Es for 9/11 truth. If you want to argue against what NIST has since admitted to, then be our guest.

Parts of the buildings definitely fell in free fall. Large portions of the buildings fell in free fall for a short while. Overall, the buildings collpased at slower than free fall speeds.

Does that clarify anything or address your concerns?

Fidel

And if you have anymore questions about what NIST has backtracked on over the last several years, just ask.  Jas and I sometimes find it difficult to keep up with your lack of understanding surrounding these issues in general without having to tutor you on each and every detail. You should think about paying us.

Pants-of-dog

Fidel wrote:
And if you have anymore questions about what NIST has backtracked on over the last several years, just ask.  Jas and I sometimes find it difficult to keep up with your lack of understanding surrounding these issues in general without having to tutor you on each and every detail. You should think about paying us.

You are completely correct in your claim that I know next to nothing about the conspiracy theories surrounding the WTC collpase. While I would like to say that you and jas have been very helpful in teaching me about the details of that subject, I must agree that you have not been able to provide sufficient detail or information for me to fully understand your claims. However, it is not through lack of willingness on your parts, as your continued posting speaks for itself as to your determination to make me understand that the conspiracy theories are correct.

I have decided to return the favour of educating me in this subject by extending the same favour to you, but obviously I will help you to understand a different, but related, subject; I have decided to teach you some simple physics.

Let us look at inelastic collisions, which is where we left off last time.

For the purposes of simplicity, let us say that it was a perfectly inelastic collision; i.e. the two masses stuck together after colliding. Or, if you prefer, the upper block and the first floor it struck became fused into one mass at impact.

If that is the case we use this equation:

[img]http://upload.wikimedia.org/math/4/d/f/4df879733089c570fbd48698e428fb34....

which we can use to get this:

[img]http://upload.wikimedia.org/math/7/9/0/7909bbd935e5d7aa3e71b4ea41703c06....

Now, we had previously calculated the mass (m) for the upper blocks:

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the mass of one WTC floor [is] assumed to be 1/110 the mass of an entire WTC
tower, namely m = (510,000,000 / 110) kg

therefore

m1(WTC 1) = 14 x (510,000,000 / 110) kg= 64909091kg

m2 = (510,000,000 / 110) kg= 4636363kg

And v1=8.5m/s (see my last post discussing math for how we arrived at this number.)

v2 is zero, since the lower floor was not moving at the time of impact.

so m1v1(WTC1) is 64909091kg x 8.5 = 551727273.5

and m2v2 is 4636363 x 0 = 0

and m1(WTC1) + m2 = 69545454.

so vf = 7.9 m/s.

This is the velocity of the upper block and the first floor it impacted in WTC1 the instant after collision in our simplified model.

Is everything clear so far?

Pants-of-dog

Fidel wrote:

And which web page have you shamelessly plagiarized now?

Thank you for reminding me.

The equations were taken from here:

http://en.wikipedia.org/wiki/Inelastic_collision#Perfectly_inelastic_col...

The mass and the distance are from the same link as my [url=http://www.rabble.ca/comment/1156932/Here-summary]previous[/url] post.

That information, again, is here:

http://www.911myths.com/WTCREPORT.pdf

Fidel

And which web page have you shamelessly plagiarized now? Because after you claimed to fully understand Manuel Garcia's non-existent calculation for instantaneous time interval for duration of impact, we just don't trust you. Not anymore. Your credibility was somewhat in decline after that.

Pants-of-dog

Fidel wrote:

....Because after you claimed to fully understand Manuel Garcia's non-existent calculation for instantaneous time interval for duration of impact, we just don't trust you. Not really.

Here is where I specifically address the fact that Garcia does not mention how he came to that exact number:

http://www.rabble.ca/comment/1149152/Fidel-wrote-And-there-were

Since I addressed how he did not explain how he came up with that number, I hazarded two guesses. First I assumed that we were dealing with essentially rigid structures, and Bazant's work seems to confirm that, and secondly, I assumed that (s)he posited a relativley short impact time because impacts are, by defintion, very short.

If you feel that any of these two assumptions have been disproven in the course of the debate, please link me to the post.

My comments were in the same post where I point out that Griscom (the person criticisng Garcia) also never showed how (s)he came up with a longer impact time.

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