The 9/11 Collapse Theory discussion thread

Very nice...except for the notion that those who disagree with the truthers are "the US Government side".  If George W. Bush, in an unusually lucid moment, said that 4 plus 4 does not equal 9, and I agreed with him, would that make me part of "the US Government side"? Does Noam Chomsky really belong on the "US Government side"?

Edited to add:

This is, I fear, a chronic problem with so many ideologically driven arguments: you simply cannot determine someone's ideological allegiance or the interests they serve solely by looking at their conclusions.  It is a certainty that there are people who are perfectly sincere and ideologically aligned with me whose conclusions are radically different than mine when it comes to any given topic. There are a whole lot of reasons why this may happen, but the most important reason is that the arguments one or both of us is presenting may be flawed: our evidence may be wanting, our inferences may not be sound, etc.  It doesn't help either of find clarity if I simply look at the other person's conclusions and, depending on what they are, label that person as being aligned with the righteous or the nefarious, and thereafter filter my perceptions of the other person's arguments through the lens created by the label. In fact, it's downright dangerous to do so, because it quickly leads to self-destructive groupthink whereby, when considering an argument, we look only at the professed ideological position of the person making the argument, rather than at the quality of the argument itself.  Regardless of the merits of the ideology in question--and there may be many--this simply isn't a good way to make decisions. 

Yeah, the point is that by your reasoning, Noam Chomsky falls on "the US Government side" of the issue.  The fact that he's a linguist is irrelevant: he could be a physicist who was profoundly critical of US imperialism and who still didn't believe that the truther position was at all well-supported. A physicist such as this, by your reasoning, would also fall on "the US Government side" of the issue, and you would consider such a person one of "their" front line scientists.  In other words, the way you have consistently framed the debate necessarily labels any physicist who is politically opposed to the US Government and who also disagrees with truther assertions as being one of "their" front-line scientists. 

Or do you believe it is impossible for a competent, sincere and politically radical physicist to disagree with the truther position?

And I do believe that this is relevant for the thread. I am questioning your assertion, stated in the opening post, that those thinkers and scientists who disagree with truther positions regarding such matters as collapse times are necessarily aligned with the US Government.  I am challenging the way you have framed the opening post.

Jas, you don't seem to understand something. Along with, I suspect, at least a few other people on this board, I have looked at the arguments that you and Fidel have offered and found them terribly wanting--for reasons that Pants-of-Dog has repeatedly made clear.  In my books, at this point neither of you are making arguments that have any credibility. I am offended because I simply do not believe that you and Fidel are arguing in good faith: in your arguments with Pants-of-Dog you have frequently ignored evidence that doesn't agree with your conclusions and you have often dismissed extremely sound arguments because, in your view, they were intellectually wanting. I believe that a new thread title was warranted specifically because the arguments you and Fidel have offered have been thoroughly demolished by Pants-of-Dog, and yet you continue to ridicule his position as being founded upon "faith" and "foggy notions" rather than "logic".  I started a thread with a title that inverted the title you had chosen because I was getting fed up with the insulting subject lines of the previous threads.  I believe that those subject lines expressed an unearned intellectual arrogance.  By inverting them, I was criticizing the arrogance. 

I am very happy with the new thread title, though I did want to draw Fidel's attention to the way he was framing the discussion by labelling people as being on the "US Government's side" or somehow controlled by the US Government (as implied by the use of "their" in the phrase "their front-line scientists"). 

Edited to add: Fidel, I would really like you to answer the question I posed above. Once again: do you believe it is impossible for a competent, sincere and politically radical physicist to disagree with the truther position?

Take your time answering, as I'm off to bed.

.

post 111, pants-fire-etc, previous thread: "..As I have previously mentioned, the rest of the columns had already been substantially weakened by the flames and by being stressed far past their maximum capacity for approximately one hour..."

- a lot of things have been 'mentioned' on all of these threads, but I don't think 'mentioning' something gets your story approved in peer-reviewed physics journals, or becomes 'proof' of anything - and there is a great deal of skepticism about this particular part of the theory (well, about the whole thing, really) - 'mentioning' something is a long, long ways from proof, and this statement needs a lot of proof it does not have. I would note your adjective phrase 'far past' - can you direct me to the place where you or somebody makes any attempt at proving this? i.e. most of we 'truthers' think 'nowhere near' rather than 'far past - where have you or someone else done some calculations along the following line - what kind of energy did the plane have in the first place, how much of that energy was dissipated in the collision with the outer steel columns, how much of the fuel was consumed in the explosion, how much damage the explosion did to the central matrix, how much damage the remaining energy of the plane impact did to the inner matrix and the three other outer wall columns, and so on??

Also, in terms of your 'hinge' and other theories - remember, it's not a flat pancake-like surface on top of another we are talking about, the weight from the upper floors is supported by the outer perimeter and inner matrices of columns, and there is a great amount of redundancy in all of those columns as there would be in any such structure, so even if most of one wall is breached, as is the case in the first tower hit, there are still three walls holding the thing up - and even if 5-10 of the central columns are damaged from the engines after they get through that outer wall (losing considerable energy in so doing), there are still 40 very big, construction-grade steel columns holding the thing up, which are very, very, very resistant to pretty much everything that might try to compromise them - and fires based on office debris, reduced to smoldering after a few minutes, are never, never never going to get hot enough to start to weaken all of that steel. Never. The whole official conspiracy theory steers clear of looking closely at facts like this, and what they mean, for very obvious reasons.

It seems to me that any kind of rational examination of this situation would indicate those outer and inner columns were nowhere near stressed to the point of total collapse - and certainly the lower ~90 stories were hardly stressed at all, so the whole collapse is highly, highly unlikely - impossible, really. I well understand why you want to avoid talking about the huge matrix of construction-steel columns in the middle of these buildings I showed in the picture, or the fact that all available pictures following the plane impacts show pretty clearly that the fires you say are weakening this steel, and the outer columns, to the point of more or less instantaneous collapse according to your theory, are blowing clouds of black smoke, indicating oxygen-starved fires burning at a low temperature. (actually, for others still not convince that 'our' governments and media would en masse participate in this horrendous crime and coverup, I came across this series of pictures I had not seen before - http://www.amanzafar.com/WTC/index.shtm - you just cannot look at these pictures, and believe that the collapse of these towers happened 'naturally' - an hour after the plane impacts, they stand tall and strong, and there is no indication at all that there are fires inside anywhere near strong enough to cause failure at any particular point in the first place, and certainly no fires that are 'weakening steel' throughout the lower 70-90 stories which would allow the kind of total collapse that is about to occur.

An interesting report here on a fire I do not recall hearing about in the Canadian media that makes for a nice comparison of how you would expect a huge concrete-steel building to react to a large fire - http://911research.wtc7.net/wtc/analysis/compare/fires.html - the latest entry on the page, which talks about the The Beijing Mandarin Oriental Hotel Fire - now there is a fire - and yet at the end, the whole cement - steel structure stands, blackened and gutted, but the structure stands. As would have the WTC towers if not brought down by explosives. There can really be no argument about this by intelligent people.

jas wrote:

LOL. Further down, you accuse me of not understanding physics. Pants do you see a difference between an analogy and a comparison?

Well, you used the word analogous, so I used it too.

Quote:

This is also where you frequently confuse the argument by ascribing an opposite quality to a process than is being claimed. You have done this a few times, and no, I'm not going to search out the posts for you. Here you are asking what is so "unique" about the WTC towers that they should have only suffered asymmetrical collapse from asymmetrical damage (the latter descriptors you also mixed up). In fact, one of the big arguments of the anti-science/denier/believer side is that the Twin Towers were so unique that we can't possibly expect them to respond to localized, asymmetrical damage the way other buildings would. You will find jrootham making this argument.

My argument is not that the towers were so "unique" in terms of structural strength and safety. It's that they were designed very much like other buildings of their time, and would respond, and did respond in the past, very much like other buildings would to minor, local and upper-floor damage. Their height does not affect how they deal with local damage.

Fine. Please explain how the most of the buildings built around the time are different from tripods and other structures that do suffer global collpase from local damage (and thank you for pointing out my errors concerning the descriptors).

jas wrote:

LOL. Did I mention that further down you accuse me of not understanding physics?

I have no idea how this is a response to my assertion that two falling objects will fall at the same rate. Do you believe that two objects will fall at different rates if they fall from the same initial velocity at the same time?

jas wrote:

These buildings didn't compact. They were powderized, as you can see by the numerous photographs and videos.

Well, the idea that a 110 storey building would turn into a 110 storey pile of powder is even more ludicrous. Are you finished with your previous argument that the buildings didn't make enough rubble?

Anyhow, I have no idea how much of the building turned into rubble and how much turned into powder. And neither do you. So, I think it would be more correct to say that some of the building compacted and some of the building pulverised, and some came down in great crashing chunks, and some burnt away.

jas wrote:

Pants, the progressive collapse theory requires crushing of floors, not falling. You can't "fall" through 240 perimeter columns and 40 massive core columns. When your alleged upper block of floors crushes through a floor, it is creating the rubble. Further, in order for the upperblock to meet each successive floor of the lower block, it must displace much of the rubble it is creating, kind of like if you build a sandwich too high, the contents start falling out. Much of this rubble is being displaced, as we can also see in the pictures.

I think you need to decide what exactly the process is you're describing.

You are correct that I need to further clarify the process by which the towers collpased.

So, the planes hit, the fire burns, the columns weaken and overload the other columns. Eventually the last few columns fail and the upper block collapses onto the lower block, initiating collapse.

The upper block starts to fall, squeezing the air in the space between the upper and lower blocks out the sides. Light materials such as ash and gypsum dust and paper fly out the holes in the exterior walls of the building. The upper block hits the first floor, demolishing it and turning the structure of the first floor to rubble and powder and large crashing chunks. As the upper block continues to fall after the impact, the rubble under the upper block falls with it. The lighter elements in the rubble get pushed out sideways like the lighter elements that were pushed out, while the heavier elements stay under the falling upper block. The rubble and then the upper block impact the next floor down, one closely following the other. The cycle would continue with the upper block smashing each lower floor and then pushing out some of the lighter elements on every side before impacting the next floor down. The only difference on each floor is that the rubble mass under the upper block gets larger with each impact and the upper block and its rubble mass move faster and faster because they only decelerate slightly with each impact.

jas wrote:

hypothetically.

A mathematical model is hypothetical, pants.

Not necessarily. Mathematical models are no longer simply hypothetical when they make verifiable predictions that end up being consistent with observed data. At that point they are considered accurate descriptions of the phenomena described.

jas wrote:

Bolding to highlight the cartoon premise of your logic.

Did I mention you accuse me of not understanding physics?

Let me put it this way, jas: why don't you show me some math that shows how the upper block would be arrested?

Fidel wrote:

[url=http://the911forum.freeforums.org/demolitions-using-a-falling-upper-bloc... says here[/url], a 20% reduction in velocity. It's a demonstration of Newton's third law.

Fidel, that link takes me to a discussion board similar to this one. The person posting with the name of Szamboti may not actually be named Szamboti, just as you are not really a Cuban revolutionary, and I am not really a pair of trousers made from the skin of canines. Even if we pretend that this is actually Szamboti, there are still no calculations. Also, the thread you linked to does not discuss Newton's third law.

Fidel, please provide a summary of how the 3rd law is violated. I would like some math or at least a force diagram showing your work.

Fidel wrote:

démolition de la tour ABC Balzac à Vitry-sur-Seine (YouTube video)

1. The roofline of ABC building shows deceleration after an 11 metre free-fall and indicating that the lower structure is providing resistance
2. The upper block is destroyed just like the lower block, demonstrating Newton's third law
3. There are no explosives used, so there are no jolts or "bangs" (Popular Mechanics, NIST)

That video does not show any clearly apparent deceleration, nor does it show the destruction of the upper block during collapse.

Fidel wrote:

1. Where's your proof that part C remained rigid? You have none, and neither does Bazant or Greening.

The mathematical evidence for an essentially rigid upper block of storeys begins at the bottom of page 15/29, and ends on the subsequent page. The figure 9 that Bazant mentions during the mathematical discussion is on page 29/29.

http://wtc7lies.googlepages.com/Bazant_WTC_Collapse_What_Did__Did_No.pdf

Fidel wrote:

2. Now think of a hammer that is 64 metres in diameter across the face and cracking a big concrete dinner plate just as long. Now tilt the hammer face just one degree from horizontal. Now imagine dt increasing from 0.01 s all the way to 0.14. right angle triangle calculator

The impact time for the impact between the dinner plate and the hammer do not change due to angle. This is because both are rigid.

Fidel wrote:

Also, remember that Bazant claims there was nil next to no loss of mass as the "rigid upper block" descended. This FEMA debris map shows how absurd Bazant's claim is.

I highly doubt Bazant said anything of the sort. I also highly doubt that you will provide any evidence that Bazant actually said that.

jas wrote:

If you could explain to us in what ways exactly, I would be really appreciative, because I believe both Fidel and myself have been having a hard time following his many twists and reversals. I still can't figure out why it took him three threads to confirm the collapse time which we had already stated. Could you perhaps explain that one to us? Was he purposely trying to waste our time? What, for example, did you get out of that discussion?

I thought of it as taking three threads to get a real asnwer out of you in terms of the collapse times that I presented [url=http://rabble.ca/comment/1149239/jas-wrote-And-then-whatever]halfway through the first thread[/url].

The OP of your very first thread in which I was involved claimed that the towers fall too quickly for gravity to be the only factor. To provide evidence for that claim, you should have given that time in the OP, as well as an explanation as to why these times supported your claim.

The fact that you did not was, in my opinion, one of the reasons why the Burden of Proof thread was started.

jas wrote:

Would you also mind explaining why Pants shouldn't have to complete his calculations on the collapse progression, and why he shouldn't have to account for loss of mass when the visual evidence clearly shows large amounts of matter being ejected in all directions?

I fully intend to as soon as I find some numbers for the amounts of mass and energy involved.

jas wrote:

Can you explain what he means by rubble being added to the invisible upper block to increase its mass, even though it's resting on the lower block?

We have been through this before several times. I will explain it once more, but add a little something that I realised.

Now, anyone who knows anything about physics knows that two objects will fall at the same velocity towards the ground if they start falling at the sameime. We remember that (probably untrue) story of Galileo dropping lead cannonballs off the Tower of Pisa and timing their descent.

Now, where does the rubble come from? It comes from the demolition of the floor above by the descending upper block. And then it falls on the floor below. Just like the upper block. It also falls on the floor below. And we know from Galileo's experiment that they should fall on the lower floor at the same time.

But, you say, isn't the rubble under the upper block, and therefore hitting the lower floor first?

Yes, it is. But let us go back to Galileo and the Tower of Pisa. When he dropped the cannonballs, he dropped them both from a rest position. Is that the case with the WTC towers? No. The upper block is impacting the lower floor at 8.5 meters per second. The lower floor is at rest. So, the upper block is actually going faster than the rubble when the impact occurs.

Now, I've been treating it as an inelastic collision where the two objects (the upper block and the rubble of the impacted floors) basically become one. But let us treat it as two separate masses. How does the rubble behave when it falling down onto the floor below with the upper block also falling on it at even greater velocity?

Let us do a little experiment. Grab something on your desk. Anything with a certain amount of heft, so no paper or dust bunnies or delicate lacy things. Grab your cell phone or something. Now stand facing a bed or couch (you don't have to do this, but if you did grab your cell phone, this is just in case you drop it). Hold your hand palm down with your cellphone in your hand, so that if you uncurled your fingers the cellphone would fall on the bed. Now move your hand down faster than gravity would pull it down and open your fingers at the same time. Does your cell phone fall out of your hand and hit the couch? No, because it is pinned to the underside of your hand by the force of your hand pushing it down.

In this same way, the rubble at the bottom of the upper block would be pinned to the upper block.

jas wrote:

Can you explain how accumulated layers of rubble maintain the same integrity as intact floors until they reach the ground?

They do not. They are rubble. And by definition, do not have the same integrity as intact structures.

jas wrote:

And also wouldn't deflect the downward force of this still invisible but alleged piledriver?

Part of the rubble would absorb a small amount of the kinetic energy, but most would become part of the pile driver itself.

jas wrote:

Could you explain how a building is like a tripod?

Yes. Both are structures that encompass an enclosed volume and rely on more than one structural member to maintain integrity.

jas wrote:

Or how columns not lining up from the upper block will increase, rather than slow a collapse?

Because misaligned columns can't transfer the load to the foundations, which is how buildings stand up.

jas wrote:

Can you find some pictures that show us that these upper blocks still exist halfway through the collapse?

You know full well that the upper block was obscured by the debris cloud.

jas wrote:

...Can you explain how a tilting upper block first of all rotates, but then manages to cause damage on the other side of the floor below it, opposite from where it's tilted? (Hint: apparently it's not because the block rights itself)

I have no idea what you're talking about.

jas wrote:

Can you explain to us why it's utterly natural that a building that experiences localized, asymmetrical, upper floor damage that left intact 85% of the 287 steel columns in those upper floors would experience rapid, global and symmetrical collapse?

Because after those columns were damaged by the initial impact, many columns lost their fireproofing (again, due to impact) and then were weakened in the large fire caused by the impact of the planes. The loss of integrity acompanying the failure of the initially impacted columns and the heat-weakened columns then went on to overstress the remaining columns, which then subsequently failed.

siamdave wrote:

- a lot of things have been 'mentioned' on all of these threads, but I don't think 'mentioning' something gets your story approved in peer-reviewed physics journals, or becomes 'proof' of anything - and there is a great deal of skepticism about this particular part of the theory (well, about the whole thing, really) - 'mentioning' something is a long, long ways from proof, and this statement needs a lot of proof it does not have. I would note your adjective phrase 'far past' - can you direct me to the place where you or somebody makes any attempt at proving this? i.e. most of we 'truthers' think 'nowhere near' rather than 'far past - where have you or someone else done some calculations along the following line - what kind of energy did the plane have in the first place, how much of that energy was dissipated in the collision with the outer steel columns, how much of the fuel was consumed in the explosion, how much damage the explosion did to the central matrix, how much damage the remaining energy of the plane impact did to the inner matrix and the three other outer wall columns, and so on??

Asking a lot of questions in the hope that your opponent is overwhelmed is also not quite as good as providing evidence.

Your questions about fire are easily answered. Any video of the planes impacts will show the large fireball that accompanied the impact. The continued presence of black smoke from the time of impact to the time of collpase show clearly that the fire continued to burn throughout this time. The fireproofing around the structure must surely have been dislodged when the planes impacted, and the weakening of steel under temperatures such as those present in normal fires is well documented.

Quote:

[url=http://www.softwood.org/AITC_eVersion/EN/p3.htm]Unprotected metals quickly lose their strength and collapse suddenly, often with little warning...

Average building fire temperatures range from approximately 700º to 900º Celsius. Steel weakens dramatically as its temperature climbs above 230ºC, retaining only 10% of its strength at about 750ºC.[/url]

After many columns failed from the fire, the load of the upper block would have been concentrated on the few remaining columns which were not designed to hold up so much. This wouldd have overstressed them, causing them to fail.

Feel free to provide any evidence that would disprove my assertions.

siamdave wrote:

Also, in terms of your 'hinge' and other theories - remember, it's not a flat pancake-like surface on top of another we are talking about, the weight from the upper floors is supported by the outer perimeter and inner matrices of columns, and there is a great amount of redundancy in all of those columns as there would be in any such structure, so even if most of one wall is breached, as is the case in the first tower hit, there are still three walls holding the thing up - and even if 5-10 of the central columns are damaged from the engines after they get through that outer wall (losing considerable energy in so doing), there are still 40 very big, construction-grade steel columns holding the thing up, which are very, very, very resistant to pretty much everything that might try to compromise them - and fires based on office debris, reduced to smoldering after a few minutes, are never, never never going to get hot enough to start to weaken all of that steel. Never. The whole official conspiracy theory steers clear of looking closely at facts like this, and what they mean, for very obvious reasons.

The bolded statement is simply wrong. For a detailed understanding of this, please read the appropirate section in this book:

http://www.amazon.com/Fundamentals-Building-Construction-Materials-Metho...

I picked this book because it is the standard textbook for explaining construction methods to architecture students and is easy to read, easily available at Chapters o Indigo or libraries, and has a good index and table of contents for finding material.

As for your other assertions, i would love to see some sort of evidence descibing the number of columns that survived initial impact and the other factors that initiated the collpase.

Pants-of-dog wrote:

The OP of your very first thread in which I was involved claimed that the towers fall too quickly for gravity to be the only factor. To provide evidence for that claim, you should have given that time in the OP, as well as an explanation as to why these times supported your claim.

jas, in <a href="http://rabble.ca/babble/humanities-science/science-fail-nist-physics-tells-us-resistance-only-mental">this</a> OP of <a href="http://rabble.ca/babble/humanities-science/science-fail-nist-physics-tells-us-resistance-only-mental">this</a> thread wrote:

Various arguments that have been presented here at Babble or in official story venues to explain what is not explainable by any known scientific principle include:

1. the speed of collapse was “nowhere near” free fall, being up to four seconds longer than free fall. This argument, in essence, asks us to believe that 91 and 78 floors respectively of the Twin Towers produced only 1- 4 seconds of resistance to the descending upper mass of floors. This argument also cannot explain at what point this descending mass of floors was pulverized in its descent (as there is no visual evidence of any significant pancaking having occurred). Was it on the way down, or did it get “crushed up” at the bottom, as the “crush down, crush up” theory suggests?

If we know free fall to be 9 secs roughly, and I am citing the argument that it was up to four seconds longer, we know that we are talking about 10 - 13 seconds. Your post directly beneath this one was your very first post in these threads, as you point out. There is no way you could have missed this paragraph or misunderstood what collapse time frame I was talking about. You spent three threads arguing that the collapse times were 11.5 and 12.8 seconds according to Bazant's math, and that this was "nowhere near" free fall. An argument that I had already cited in this OP.

Then, after that, you reversed your argument, saying that, in fact, yes, a portion of the building, the upper block, did collapse at free fall speed through the impact zone. A reversal of your argument, and moreover a claim that confirms our point about the obvious contradiction with physical laws, in that it would have had to crush through 85% of the remaining columns in the impact zone.

Pants-of-dog wrote:

Fine. Please explain how the most of the buildings built around the time are different from tripods and other structures that do suffer global collpase from local damage (and thank you for pointing out my errors concerning the descriptors).

This is so blatantly, bizarrely silly I don't even know how to respond. I'm tempted to turn it into some kind of hilarity, but I don't want to hurt your feelings if you really believe that the design of the Twin Towers and the design of a tripod are analogous.

If you're seeking even the remotest analogy to a tripod, I will help you out: Sever all 287 columns of the Twin Towers in the lower third of the buildings, a section approximately 36 storeys high, all at the same time. Then you are removing an essential supporting structure. Then you might have a piledriver effect. But you'd probably still have a large section of upper block, crumpled, but not disintegrated, at ground zero.

jas, I'm curious... what background do you have in the fields of math, physics, and engineering? I am wondering because you were perplexed at PODs use of scientific notation (learned, if I'm not mistaken, in grade 11) and the conversion of gravitational potential energy into kinetic energy (also, I believe, learned in grade 11). So why are you trying to tell POD, who seems to be someone in a technical profession of sorts - likely engineering - that he doesn't know what he's talking about when you can't wrap your head around even basic physical concepts?

Ive never bothered to go through the rigour necessary to calculate the exact figures myself, but yes, I do understand what you are saying. But I read through those posts and you generally did not seem to understand the very basic compnents of the physics. If I am wrong, then I am sorry, its just that you give the impression that you lack in the background knowledge necessary to analyze what is a very complex dynamic at play in the collapse of the towers. To be honest, I'm not entirely interested in getting involved in a debate with a truther about physics.

Fidel wrote:

I'll vouch for Jas. Jas is very knowledgeable of physics and the math behind 9/11 collapse theory. I am impressed with Jas' tenacity for debate  and grasp of the details in general. And, a lot of this stuff can be understood by people who've never taken upper level math and physics courses. The engineering equations using integrals and derivatives of differential equations is a bit much though if we're not familiar with mechanical engineering and architectural principles in general, which I openly admit is the case for me. And thank goodness for the hundreds of A&Es for truth who have written explanatory essays in layman's terms for our benefit. They've used all manner of visual aids as well as debunked Bazant's and Greening's math,  and  blew the whistle when certain liberties have been taken when trying to explain away how Government sponsored theories are at odds with established Newtonian laws of nature.

Thanks Fidel, but I'm really not. As I've made no bones about in the past, I am not a physics whiz; did not take it in university, and am learning much of this - at least the terminology - as we go. You, in fact, seem to have much more experience with that side than I. As you state, though, and so have I in many threads, understanding how buildings collapse does not require advanced physics. Many people looked at those collapses on TV and knew there was something wrong with them. This sense of something being wrong was affirmed by others who do have that physics and engineering knowledge, and they have validated scientifically what we know from common sense can't happen.

This is why I've asked repeatedly in the threads I have started that we keep the discussion in the everyday: plain-language, common sense understandings of everyday physics. Doing this doesn't stop us from being able to look at the structure of a mathematical equation and say, "wait a minute... " Any of us can do this. And it also encourages all parties to restate the arguments in terms we can all understand so we can all look at this in plain view, with eyes open, and with no one trying to intimidate or exclude others or shut down the argument with explanations that few can understand.

The criticisms we have of Bazant's calculations still stand, and you don't need math knowledge to understand them: Bazant's hypothesis relies on a piledriver theory in which the upper block crushes through storey after storey of concrete and structural steel in a few seconds more than it would take to fall through air, AND it accumulates mass (i.e., layers of rubble that somehow serve to crush the lower floors) as it goes - two premises the visual evidence does not support, and also that violate not only real principles of physics but also common sense, everday understandings of how matter moves and interacts in our everyday world.

I think it's really sweet how apparently you don't need to be able to understand the physics in order to know the physics is wrong.

We're just so full of common sense and intuitive knowledge.  Gosh it's beyond me why anyone even bothers studying what is so obvious.

Fidel wrote:

Well I highly doubt it's anyone else but Szamboti. You don't use your real name, and very many non-truthers choose not to use their real names when posting on the internet, and especially not when they attempt to defend Bazant and Greening's unscientific nonsense.

So, no calculations or any evidence at all. Okay.

Fidel wrote:

I've posted a bit of math before, and you had a lot of trouble with it. Remember Garcia's time duration figure? Besides, if I want to read Greening or Bazant, it's there on the web. I don't need you to recopy it here.

So, no calculations or any evidence at all. Okay.

Fidel wrote:

Sure it does. The upper block is destroyed just as the upper blocks of WTC1&2 were destroyed a few seconds into those collapses. That's Newton's third law at work. Of course, and as we know by now, Bazant and Greening are uninterested with explaining how their wacky theories are unsupported by either the video evidence or Newtonian laws of nature.

WTC1 upper block clearly begins disintegrating here as per Newton's third law, from DrJudyWood.com

<snip animated gif>

Yes, both upper blocks were destroyed a few seconds after collpase initiated, just like in the Balzac-Vitry. And like the B-V, the WTC towers had their upper blocks destroyed after the lower blocks. The video you posted is onconclusive as to the exact moment when the upper block began to collapse in the B-V, due to the dust cloud.

And your animated gif shows the upper block descending through the impact zone. What you mistakenly believe is the upper block collapsing is actually the impact zone collapsing. Note the lack of dust cloud on the "first image".

Fidel wrote:

No steel structure was ever annihilated by just 0.15 of itself and gravity alone.

The WTC towers apparntly were.

Fidel wrote:

And, you still haven't explained to us how quantum theory relates to 9/11 collapse theory. Or was that just a brain fart of your's in the last thread? If so, then you're excused.

Actually, I answered that question with another question. I asked you to explain the difference between a rigid body and a deforming one. As soon as you answer that question, I will answer yours.

Fidel wrote:

Baloney.

I see. I hope you understand why I am going to treat this as you conceding this point to me.

Fidel wrote:

Not according to video evidence, no. And so what's the result of dividing 1.11 by 7.7(Garcia's rate of descent)? And you wonder why I don't post much math for you? I think the reason you backed off defending Garcia's essay is that it's not discussed much on the internet. He hasn't replied to Dr. Griscom, and so you're one of his few defenders. That Pythagoras is a tricky guy, isn't he.

He did start his own religion with the help of his "golden thigh".

The way I undestand your math, and correct me if I'm wrong, you are saying that the if the floor was tilted one degree, the difference in height from one end of the floor to the other would be 1.11m. And if the upper block is travelling at 7.7m/s, we should be able to divide the distance by the velocity, we should get the time. This is the time between the moment the upper block touches the topmost part of the slanting floor and the moment when the the upper block touches the lowest part of the upper surface of the slanting floor.

You then go on to assume that this is equivalent to the duration of impact. About 0.15 seconds.

This is wrong.

The math is correct, but the underlying assumption that this is the duration of impact is incorrect. It is the duration of collapse for the upper portion of the floor structure. This is because the upper block must collpase this portion of the lower floor if it is to contact this lowest part of the upper surface of the slanting floor.

We had previously discussed the fact that the duration of impact is not the same as duration of collapse.

Fidel wrote:

So who's arguing the pile driver effect now if it isn't Bazant and Greening? Are they now not saying that rubble accreted on each successive floor and adding to the total mass and causing symetrical collapse of two skyscrapers hit by planes,  and a third building that fell down by fire-induced collapse? Remember, Bazant's IHOP pancake theory is out and pile driver is in. That's what you're trying to defend also. And this latest outsourced theory is not working for very many engineers and scientists for 9/11 truth.

So, no quotes or any evidence at all. Okay.

Fidel wrote:

So, are we just supposed to accept that someone who goes by Pants-of-dog is an authority on mechanical engineering and building collapse analysis, and that POD knows better than 1200 plus certified engineers and architects with a combined 25,000 years of experience? I took a full-year college course in discrete math and logic, and what you're saying doesn't make sense.

I have never offered my credentials for two reasons:

I don't give out personal information on the internet.

My arguments stand on their own merits.

Pants-of-dog wrote:

jas wrote:

Pants thinks very little mass left the building as it descended. Would anyone care to correct him? Video referred from Wood's site:

http://www.youtube.com/watch?gl=GB&hl=en-GB&v=5q7vz3ZEfBw

(Golly, ma, where did the upper block/piledriver go??)

I think I was fairly explicit when I said that neither of us have a good idea as to how much mass was ejected. I would appreciate it if you did not mischaracterise my arguments that way.

I think I have a better idea than you have. Would you agree that this video shows that much more mass is leaving the system than you account for in your calculations? Which, by the way, is zero.

If my memory serves me right the top of the first building to come down started leaning, rotating, and then stopped its rotation and came straight down. In order for the rotation to stop a counter torque had to be applied. That could only come from the structure below the over hang providing more resistance then the structure on the other side. If demolition charges had destroyed the supporting structure below the break so that it would not provide resistance to the top floors from traveling down, then the rotational momentum of the top would have been maintained, but that does not seem to have happened. 

Pants-of-dog, I think we have to give you another name. " The Marathon Runner"

Fidel wrote:

It's a good one. I think you posted it before in another thread, Jas. I think they blew columns on two or three floors?

Not sure, but definitely some height is being lost there.

I have trouble deciding if you and others like you are actually serious about your belief in the official conspiracy theory, or if you are, for some reason, involved with the coverup, and using any tactics you can to try to keep 'agnostics' from understanding that what happened that day was simply impossible in terms of the official theory, and therefore some kind of government involvement is highly indicated, and we seriously need a new investigation by people who actually want to find the truth rather than conceal it. The thing is, 'normal' people without some ulterior motive would not be so dishonest and/or shifty in their approach to the discussion, or so vehement in their denunciations of those of us who question the OCT, as most of the OCT supporters seem regularly to be.

An example or two from your response (14) to my previous post:

1. You say "..Asking a lot of questions in the hope that your opponent is overwhelmed is also not quite as good as providing evidence... Your questions about fire are easily answered. Any video of the planes impacts will show the large fireball that accompanied the impact. The continued presence of black smoke from the time of impact to the time of collpase show clearly that the fire continued to burn throughout this time. The fireproofing around the structure must surely have been dislodged when the planes impacted, and the weakening of steel under temperatures such as those present in normal fires is well documented.."

This is dishonest and misleading in every way. First, regarding your 'overwhelming' comment, I have provided many detailed explanations previously as to what I think happened that day, and the points that I think the supporters of the OCT have failed to address adequately - I mention but a sampling of them here as an example, because they have NOT been addressed, and are the kind of questions I think a real investigation would address, giving the kind of information that would be required for a realistic analysis of what happened that day, but have not.

I wouldn't expect you to be familiar with everything I have written, any more than I am with everything you have, but to pretend this history does not exist is dishonest - but you attempt to dismiss such central, unanswered questions as simply trying to 'overwhelm' you with meaningless distractions - and then move on as if this flippant comment is a sufficient response to these and similar questions, which have not been dealt with but would provide, I suggest, extremely important, even critical, information to such a discussion as this.

The status of the central columns on the impacted and near floors following the plane impact is central to all of the OCT arguments, and to try to subvert serious answers by statements such as "..The fireproofing around the structure must surely have been dislodged when the planes impacted.." is nowhere near the standards of proof or evidence I seem to recall you demanding regularly from others. My mental reconstruction of what would have happened that day after the plane impacts would be very different than this simplistic scenario you present - a great deal, if not most, of the energy of the planes' velocity and mass, it seems to me, would be taken up by the outer steel columns and floor structures, which would have a considerable influence on the degree of damage to the extremely strong inner column matrix. Although the near sides of those inner columns might have suffered some damage, and had some fireproofing dislodged, I would suggest it would be much more likely that most of the fireproofing on most of the columns in the middle and far side would have been intact - your 'must have been dislodged' statement, given with no proof at all, is far from 'evidence' upon which you can base the rest of your theory - but is one of the things that any serious investigation would certainly have to examine, and give credible analysis for whatever answers it came up with. Doing some serious reconstruction of what actually happened when those planes hit, using models and mathematical equations where required, and running simulations of whatever things could be realistically simulated (imagine a 10-floor identical scale model of the WTC, into which was flown one of the 'too old to use' 767s from the aircraft graveyard, and seeing what happened? One can only imagine why they would never do this ...), to honestly assist such modeling, would be, one would think, one of the very first things any serious investigation would do. That no such investigation has been done (it's well known what farces were undertaken by the NIST et al to try to prove their hollywood 'fall down go boom!!!' scenario - this is not the kind of 'real' investigation I am talking about ..) would indicate to me that those officials in charge of the overall 'official' 911 investigation did some preliminary work, and understood that any detailed investigation would show exactly what I and many others believe - that those inner columns would have received very minimal damage from those impacts, and in no way would have failed the way the OCT has them failing. Ergo - no such analysis would officially be undertaken. (This is even more evident when you consider the corner impact of the second plane - it's hard to see how any of the central matrix would have been seriously damaged at all - and in this building additionally you have three again almost completely unaffected corners, and all of the outer perimeter columns between them and extending to the impact corner still holding up this building, and next to no visible fires or smoke - you can scroll down on this website - http://www.amanzafar.com/WTC/ - and see very good pictures of the 'non-fire fire' - to suggest this building failed catastrophically hardly an hour after impact from 'fire-weakened steel' is simply risible (as is the whole OCT of course, when examined with any sense of rationality rather than simplistic Hollywood 'fall down go boom wow!!!' mindsets.)

2. You quote a completely unreferenced or substantiated advertising brochure from a company in the business of selling small wooden buildings as 'proof' of the "weakness" of steel in highrise constructionl !!!!!!!! - which is a good example of the standards of evidence of the OCT in general. (I am not one who uses the LOL acronym, but this really does bring a chuckle ..)

3. "...After many columns failed from the fire, the load of the upper block would have been concentrated on the few remaining columns which were not designed to hold up so much. This wouldd have overstressed them, causing them to fail... Feel free to provide any evidence that would disprove my assertions."

- it is not up to me to explain why your somewhat fantastic hypothesis is 'not' true - it is up to you, and the other OCT supporters still, to provide some credible answers as to how that huge central matrix, and that perimeter of steel columns

all collapsed so mysteriously quickly and so exactly like a controlled demolition (CD), due to those small fires - without (chuckle) being controlled demolition - so obviously so that we do not even have to consider CD. I well understand why you never respond to my comments based on these pictures, there is just no way a rational person could say something like "Yes, that huge central core, and those 250 outer columns, just collapse like a stack of toothpicks from this huge fire in the south tower (left side in pic - and if you want to claim the side we can't see 'really had the big fire!!' - check the great pics on the website I gave eariler, http://www.amanzafar.com/WTC , in which the fires are even less serious looking..) -

- I believe that, and surely any sensible person can see that .."

It is not up to me to provide some kind of mathematical proof that the plane impact and fires could NOT have done that quite unbelievable damage you and others hypothesize, it is up to you to prove they COULD HAVE done that damage - and any time I start asking questions such as this, you people just evade them with smart evasive answers and then move on, or suggest they have already been answered - but they have not. or more commonly, as you have been doing, avoiding them altogether, for reasons I think are clear enough - you cannot win anything here. And repeating things that have already been questioned for their lack of substance is no more 'proof' the second or third or hundredth time than it was the first.

Your argument essentially seems to say that the ~300 construction grade steel columns of the WTC, both inner and outer, were essentially a bunch of sticks standing in the sky, and this huge force came along and smashed them all down like the hammer of god. I say bollocks, to be polite - the 47 central columns and ~250 outer columns represented a matrix of high grade steel, into which a hollow steel tube flew at speed - the spectacle, with the fireball and all, was certainly impressive - but that hollow tube, and the relatively short-lived and small fires had nowhere near the force required to seriously compromise that structure.

Just as a for instance, from the real world - when you want to tell me that those little fires in the WTC weakened that steel to the point of collapse, I need you to give me some rational explanation of why the vastly greater fire in the Oriental Mandarin

 or the Windsor in Madrid

 did not cause these buildings to collapse - a point I regularly raise, which you OCT supporters never respond to. For, I would suggest, obvious reasons - much, much better, from the perspective of supporting the OCT, to get the discussion channelled into completely meaningless, completely unprovable, arguments about what happened AFTER the buildings began their collapse.

It is what happened before that, that will give the truth of this great crime, in the end.

4. You say "..After many columns failed from the fire, the load of the upper block would have been concentrated on the few remaining columns which were not designed to hold up so much. This wouldd have overstressed them, causing them to fail. Feel free to provide any evidence that would disprove my assertions. "

- well, since your 'evidence' that 'many columns failed from the fire' seems to rely on things such as the wooden buildings brochure referenced above, one sees we have a rather low evidential bar to meet here. However, with feet firmly planted on the ground here, as 'truthers' tend to be, let us examine the rest of this statement. You say that the columns would have become overstressed, causing them all to fail at once creating the great piledriver that hammered the remaining lower floors into the ground. This does not seem to stand up to 'eyes open and brain engaged' reason. Were I to accept that many of these columns were severely compromised, either from plane impact or fire, and the remaining columns could not bear the load and actually did fail, I would not expect 'catastrophic instant failure leading to piledriver etc'. Given that the steel is very, very, very strong stuff and not inclined to 'catastrophic failure' in any circumstance, what it seems to me would happen is that as the point of overload approached, the columns - all of them acting together as the load shifted in response to each giving-in of each column, would start to bend and look for a new equilibrium point (and given that there are, in the south tower, still two full outer walls and two half outer walls of columns, all load bearing themselves, these would be part of the dynamic) - and even if a point of general disequilibrium was reached so that the unsupported part would begin to fall, this fall would then not be straight down as in a piledriver, but in a hinged sort of way, as you talk about with the north tower - and once such a hinged fall, started, the upper section would topple - it might be only a partial topple, as the displaced side impacted the lower structure, which would then assume a good part of that weight - but what would certainly NOT happen is the controlled-demolition like collapse we witnessed.

Well, I'll leave it at that - I understand you will again ignore the main points, cherry pick a couple of things to make flippant comments about and move on - but I write mainly for those who are still coming to terms with the fact that a serious crime was committed back on that day in 2001, a crime that, in consideration of the obvious falsity of the official conspiracy theory almost surely involved the very highest levels of the US government which was and is the central promoter of said theory, and because it is not being questioned by other governments or the mainstream media must also, at some very senior levels, involve these people too, and we need to keep talking about this crime and who is responsible until enough people understand this to create some kind of critical mass that will take back our countries and world from the criminals and predators who have taken it. Who are being assisted by those who support the OCT.

jas wrote:

...

Fidel, apparently Pants did not see this photo. I don't believe he's responded to it yet.

Oh, never mind, I see he did respond:

...

So now he's just going to lie about what he sees. So the theory he's defending doesn't in fact support the evidence, It supports a foggy notion he carries in his head.

Pants, why would the upper blocks be destroyed after the lower blocks? And where is your evidence to support this statement? As you claim, the dust clouds obscure everything.

Please do not call me a liar. The animated gif obviously shows the first few moments after collapse initiation. This is obvious from the fact that the dust cloud does not appear in the first image of the animated gif, and is quite small in the second one. The only time when the dust cloud is this size is at the very begining of collpase. Thus, the storeys that collapse in the animated gif can only be the very first storeys collapsed: the storeys where the plane impacted.

jas wrote:

No you weren't. Read your post again.

Do not tell me what I was really thinking. If your argument has descended to the point that you think you can correct me about what I was discussing, I suugest you simply bow out of the discussion. You are not such an expert on my motivations and inner workings that you know better than me what I meant to say.

Quote:

However, you did ask me later, and I replied, on several different occasions, that I believed the 10-13 second timeframe was correct. For different reasons than you, but that wasn't satisfying for you because you had some dead horse you needed to flog.

I don't really need to belabour this point, except I want to point out to others these kinds of instances where you are not being accurate or logical in your arguments. You are often inaccurate in presenting what others have said. And sometimes even in what you have said.

None of this is an argument. At best, it is a criticism of the clarity of my posts.

siamdave wrote:

I have trouble deciding if you and others like you are actually serious about your belief in the official conspiracy theory, or if you are, for some reason, involved with the coverup, and using any tactics you can to try to keep 'agnostics' from understanding that what happened that day was simply impossible in terms of the official theory, and therefore some kind of government involvement is highly indicated, and we seriously need a new investigation by people who actually want to find the truth rather than conceal it. The thing is, 'normal' people without some ulterior motive would not be so dishonest and/or shifty in their approach to the discussion, or so vehement in their denunciations of those of us who question the OCT, as most of the OCT supporters seem regularly to be.

Am I being dishonest, shifty, and vehement?

I was trying to be as clear and as calm as possible.

siamdave wrote:

An example or two from your response (14) to my previous post:

.....I wouldn't expect you to be familiar with everything I have written, any more than I am with everything you have, but to pretend this history does not exist is dishonest - but you attempt to dismiss such central, unanswered questions as simply trying to 'overwhelm' you with meaningless distractions - and then move on as if this flippant comment is a sufficient response to these and similar questions, which have not been dealt with but would provide, I suggest, extremely important, even critical, information to such a discussion as this.

I am not sure how this is a response to my discussion concerning the evidence for a continued fire in the impact zone of the planes.

siamdave wrote:

The status of the central columns on the impacted and near floors following the plane impact is central to all of the OCT arguments,... Although the near sides of those inner columns might have suffered some damage, and had some fireproofing dislodged, I would suggest it would be much more likely that most of the fireproofing on most of the columns in the middle and far side would have been intact...

...those inner columns would have received very minimal damage from those impacts, and in no way would have failed the way the OCT has them failing.

My evidence:

Page 27/34:

Quote:

The derivations of internal damage were taken purely from energy
considerations, and thus, yielded only scalar representations of such damage expressed by the
quantities of damaged floors and columns. For example, the number of damaged core columns,
which bear approximately 60% of the entire gravity load of the building, was determined, in
the previous section, to be 7 to 20 for the South tower. As the total number of core columns
that existed was 44, these quantities represent more than 16% to 45% of the total core strength,
respectively.

Page 24/34:

Quote:

Taking the
each of the factors above into consideration, the predicted number of damaged core
columns in the North Tower will vary between 4 and 12.

http://web.mit.edu/civenv/wtc/PDFfiles/Chapter%20IV%20Aircraft%20Impact.pdf

As we can see, the core columns received far more damage than could reasonably be described as minimal.

siamdave wrote:

Ergo - no such analysis would officially be undertaken. (This is even more evident when you consider the corner impact of the second plane - it's hard to see how any of the central matrix would have been seriously damaged at all - and in this building additionally you have three again almost completely unaffected corners, and all of the outer perimeter columns between them and extending to the impact corner still holding up this building, and next to no visible fires or smoke - you can scroll down on this website - http://www.amanzafar.com/WTC/ - and see very good pictures of the 'non-fire fire' - to suggest this building failed catastrophically hardly an hour after impact from 'fire-weakened steel' is simply risible (as is the whole OCT of course, when examined with any sense of rationality rather than simplistic Hollywood 'fall down go boom wow!!!' mindsets.)

The corner columns of any steel structure are always the weakest ones. This is because they only have to carry one quarter of the floor area that an internal column carries and only half the load of a perimeter column.

siamdave wrote:

2. You quote a completely unreferenced or substantiated advertising brochure from a company in the business of selling small wooden buildings as 'proof' of the "weakness" of steel in highrise constructionl !!!!!!!! - which is a good example of the standards of evidence of the OCT in general. (I am not one who uses the LOL acronym, but this really does bring a chuckle ..)

Assuming that someone is wrong simply because of who they are is a logical fallacy. Unless you have some sort of evidence that softwood salespeople are in on the WTC conspiracy, there is no reason to doubt their claim. Moreover, this claim is easily verifiable from other sources.

See Figure 4 on page 5 of this PDF:

http://www.pwri.go.jp/eng/ujnr/joint/35/paper/71sakumo.pdf

siamdave wrote:

- it is not up to me to explain why your somewhat fantastic hypothesis is 'not' true - it is up to you, and the other OCT supporters still, to provide some credible answers as to how that huge central matrix, and that perimeter of steel columns all collapsed so mysteriously quickly and so exactly like a controlled demolition (CD), due to those small fires - without (chuckle) being controlled demolition - so obviously so that we do not even have to consider CD. I well understand why you never respond to my comments based on these pictures, there is just no way a rational person could say something like "Yes, that huge central core, and those 250 outer columns, just collapse like a stack of toothpicks from this huge fire in the south tower (left side in pic - and if you want to claim the side we can't see 'really had the big fire!!' - check the great pics on the website I gave eariler, http://www.amanzafar.com/WTC , in which the fires are even less serious looking..) -

So, no evidence for your assertions except a photo of the building under construction. Okay. As long as we are clear that you are either unwilling or unable to provide evidence for your claims.

Please note that I am not claiming that the fire was the only factor in the collpase. The damage directly caused by the impact of the planes was another factor. So was the overstressing of the columns due to the failure of those structural members that had been weakened by the impact and the fire.

siamdave wrote:

It is not up to me to provide some kind of mathematical proof that the plane impact and fires could NOT have done that quite unbelievable damage you and others hypothesize, it is up to you to prove they COULD HAVE done that damage - and any time I start asking questions such as this, you people just evade them with smart evasive answers and then move on, or suggest they have already been answered - but they have not. or more commonly, as you have been doing, avoiding them altogether, for reasons I think are clear enough - you cannot win anything here. And repeating things that have already been questioned for their lack of substance is no more 'proof' the second or third or hundredth time than it was the first.

Please see the PDF to which I have already linked for the evidence you require.

siamdave wrote:

Your argument essentially seems to say that the ~300 construction grade steel columns of the WTC, both inner and outer, were essentially a bunch of sticks standing in the sky, and this huge force came along and smashed them all down like the hammer of god. I say bollocks, to be polite - the 47 central columns and ~250 outer columns represented a matrix of high grade steel, into which a hollow steel tube flew at speed - the spectacle, with the fireball and all, was certainly impressive - but that hollow tube, and the relatively short-lived and small fires had nowhere near the force required to seriously compromise that structure.

Now that I have provided evidence for my claims, I would like you to provide evidence for the bolded claim. Thank you.

siamdave wrote:

Just as a for instance, from the real world - when you want to tell me that those little fires in the WTC weakened that steel to the point of collapse, I need you to give me some rational explanation of why the vastly greater fire in the Oriental Mandarin or the Windsor in Madrid did not cause these buildings to collapse - a point I regularly raise, which you OCT supporters never respond to. For, I would suggest, obvious reasons - much, much better, from the perspective of supporting the OCT, to get the discussion channelled into completely meaningless, completely unprovable, arguments about what happened AFTER the buildings began their collapse.

It is what happened before that, that will give the truth of this great crime, in the end.

The reason those buildings didn't fall is because they were not impacted by planes, did not have their fireproofing dislodged, suffered no large asymmetrical destructions of structure, did not have their fire safety systems like sprinklers overwhelmed or knocked out immediately, and had their loads distributed in the way they were designed to be distributed. In those respects, they were unlike the WTC towers.

siamdave wrote:

- well, since your 'evidence' that 'many columns failed from the fire' seems to rely on things such as the wooden buildings brochure referenced above, one sees we have a rather low evidential bar to meet here. However, with feet firmly planted on the ground here, as 'truthers' tend to be, let us examine the rest of this statement. You say that the columns would have become overstressed, causing them all to fail at once creating the great piledriver that hammered the remaining lower floors into the ground. This does not seem to stand up to 'eyes open and brain engaged' reason. Were I to accept that many of these columns were severely compromised, either from plane impact or fire, and the remaining columns could not bear the load and actually did fail, I would not expect 'catastrophic instant failure leading to piledriver etc'. Given that the steel is very, very, very strong stuff and not inclined to 'catastrophic failure' in any circumstance, what it seems to me would happen is that as the point of overload approached, the columns - all of them acting together as the load shifted in response to each giving-in of each column, would start to bend and look for a new equilibrium point (and given that there are, in the south tower, still two full outer walls and two half outer walls of columns, all load bearing themselves, these would be part of the dynamic) - and even if a point of general disequilibrium was reached so that the unsupported part would begin to fall, this fall would then not be straight down as in a piledriver, but in a hinged sort of way, as you talk about with the north tower - and once such a hinged fall, started, the upper section would topple - it might be only a partial topple, as the displaced side impacted the lower structure, which would then assume a good part of that weight - but what would certainly NOT happen is the controlled-demolition like collapse we witnessed.

No. I never said that "the columns would have become overstressed, causing them all to fail at once". That bolded bit is you putting words into my mouth. 

There are several assumptions you make in your collapse model that I am not sure are accurate.

Steel does not look for an equilibrium point. It either falls into a static position where the forces are at an equilibrium or it doesn't.

You assume that the rest of the exterior walls are all perfectly sound. Again, you seem to be ignoring the effects of fire and overstressing due to loads being shifted onto the remaining structure. Now, the structure can hold up even if it overstressed, but not for long.

I agree with your hinge bit, by the way, except I do not believe the lower structure could successfully assume the weight of the upper block. This is due to the fact that the upper block is resting its weight on the weakest part of the floor structure: the composite deck and truss system that spanned the distance between the core and the perimeter.

Fidel wrote:

Tony Szamboti wrote:

"It isn't just reduced acceleration in the abc tower, although that does occur after the first two story fall probably due to the loose debris of the demolished floors, [url=http://911blogger.com/node/20985]there was a real 15 to 20% velocity loss[/url] after the third story of the fall. This would have been when the upper block impacted the intact lower block. In the terms you would like to use, that means there was negative acceleration. It is quite unambiguous also, as it takes time for the velocity to recover and the velocity drop can be detected with more than one data point. Measure it and see for yourself."

"In WTC 1 the energy requirements to buckle the columns on the 97th and 99th floors would have drained 85% of the pre-impact velocity and conservation of momentum in picking up the 98th floor slab would have reduced it further. It would have been a dramatic velocity loss if there was an impulse after a 12 foot drop. There would then have been about a 1000 millisecond window to detect the velocity loss while it was recovering to pre-impact levels. But we don't see this velocity loss in WTC 1, therefore there was no negative acceleration, which means no force amplification and no natural mechanism for collapse. There is no way around that and that is why Dr. Bazant thought there had to be an impact and velocity loss or negative acceleration."

That post of his is actually another post from a forum:

http://the911forum.freeforums.org/post2095.html#p2095

We have already discussed why posts on forums are not good sources. Even if they were, there is still the ongoing problem that Szamboti gives no indication at all how he comes up with these numbers. His numbers for the energy requirements for destroying two floors of the WTC towers are far higher than other people have calculated.

Fidel wrote:

Yes? When you(Bazant and Greening) try to tell us that a "rigid upper block" fell through a lower block nearly six times its own mass, and finally disintegrating after doing all that work, you're talking US Gov.-sponsored conspiracy theory. Where's the video evidence to support these wild claims? You have none.

I assume you are referring to Chandler's erroneous critique, which I have shown to be incorrect.

Fidel wrote:

Do you see a rigid body from video evidence? Because we don't. Not from Judy Woods' video. It looks a lot like the upper block is crumpling from the very beginning as per Newtonian physics.

You are correct that we are not dealing with solely rigid bodies, which is why it makes no sense at all that you keep insisting on discussing it in terms of rigid body mechanics. That is what Newton's thrid law is about: how rigid bodies interact.

Fidel wrote:

Well if you're going to call me a liar, then you should be able to back it up. You can't use calculus to determine delta-t in this instance. There aren't enough known variables. It's a direct observation in the y axis for which no one is able to observe least of all Manuel Garcia. I estimated a value for dt given one degree of tilt using Pythagoras' theorem. Apparently you were dazzled by it. Sad but true. Anyway, let's just conclude that you have nothing further to say in Garcia's defence. No one else has. It's a wacky essay anyway and amounting to so much "proof by intimidation" We know there is a lot of that happening these days. And it's a poor substitute for a proper and transparent investigation.

No, you don't understand.

Garcia is discussing the duration of the impact, which is a specific quantity that can be calculated using momentum and impact force. Or as Garcia puts it, the time interval dt during which the momentum of the upper block is reduced (in magnitude) from m*v(initial) to m*v(final).

You are discussing the time it takes for the upper block to collapse the lower floor if it is lying at a certain angle. Since there is no reason to believe that v(final) occurs at the bottom point of your Pythagorean triangle, you are comparing two unlike things.