"1. Jet fuel doesn't burn hot enough to melt structural steel."
It didn't. It weakened the steel. No one claims otherwise.

I was under the impression that the temperature in the WTC was about 1100 to 1500F.

Steel at room temperature: 100% Strength

Steel at -50F: 111% Strength

Steel at 500F: 91% Strength

Steel at 900F: 76% Strength

Steel at 1100F: 69% Strength

Steel at 1350F: 44% Strength

Steel at >1700F: <10% Strength.

... by the "truth movement," and furthermore that you appear to have put no effort whatsoever into finding out what's seriously wrong with the "scientific" claims it makes. Since I would have expected a truly rational and objective person to have already done that research before posting this nonsense on a public board, I predict that you will resist any effort to change your mind now and that this thread will follow the same pattern we've seen dozens of times. But, hey, nothing else going on around here, so....

> 1. Jet fuel doesn't burn hot enough to melt structural steel. Especially when encased by fireproofing. Proven by NIST doing gov. tests.

Answered by zappaman; no "melting" required. Structural steel loses approximately half its strength at 600 degrees C, and when it's under load it's subject to "plastic creep," slowly deforming at even lower temperatures, which is apparently the main story in the collapses. That was a particularly bad place to start your "scientific" discussion.

> 2. Timing does show some free fall throughout collapse of towers. And in fact the upper block of tower one accelerated during collapse.

Contrary to imaginary "truther physics" which seems to expect failing structures to just slowly slump down, "some free fall throughout the collapse" is exactly what should be expected. A steel column can only be compressed a few inches before it starts to buckle and rapidly lose strength. By the time it's buckled just a couple of feet, it is not capable of offering any significant resistance, so the debris that crushed it will proceed to fall at "near freefall acceleration" to the next floor. If, instead of the column buckling, the floor structure is simply ripped away from the column, then that debris is immediately free to fall down to the next floor. When we watch the towers fall, the accelerating collapse front we see is simply the average of thousands of individual events of local failure followed by local freefall. Instead of falling victim to imaginary physics and hand-waving, think about it: What could realistically slow the collapse down, regardless of what initiated the collapse?

> 3.Tower one's upper block shows effect of having fallen due to lack of support underneath it. Not the tower falling because of upper block collapse onto the lower block. Physics suggest it could have supported the upper collapse, and arrested the further collapse of the tower.

The collapse initiation obviously "shows effect of having fallen due to lack of support underneath it," but after that the collapse shows no such thing; it shows the effects of transfer of momentum. Your statement that "physics suggest it could have supported the upper collapse, and arrested the further collapse of the tower" is exactly 180-degrees out of phase with reality. Every independent analysis done by competent structural experts shows that the collapse could not have been halted after it started, whereas every attempt by pretend-expert "truthers" to prove what you claim has been found to be laughably flawed. Don't expect "truther" sites to tell you this.

> 4. No steel skyscraper has ever collapsed due to an airplane strike. One day we have three. Oops two. WTC 7 never hit.

If the subject is science, this one is too irrelevant to even comment on, but I will anyway: Since no structures like the towers have ever been hit by 767s before and then suffered unfought fires, it's absurd to claim mere surprise at the unique results as "evidence" of foul play.

> 5. Floor pancaking postulation slows collapse much more than evidenced.
> 6. FP theory doesn't explain core structure failure. As admitted by NIST (gov. lab). NIST investigation proves FP theory impossible.

Many "truthers" are very confused about the "floor pancaking postulation." What the NIST study concluded was that the collapse was not initiated by "floor pancaking" -- i.e. it did not start with a floor falling away from the perimeter columns and crashing on floors below -- it was initiated by perimeter column buckling when sagging floors pulled them inward. After the collapse started, however, there was considerable "pancaking," and in fact that seems to be the dominant failure mode, with the floors being striped away from the columns and then the columns either being pushed aside immediately or collapsing somewhat later due to lack of lateral support. The evidence for that is the abundance of failed joist and beam seats and the fact that most columns were not buckled. But anyway, your statement that "floor pancaking postulation slows collapse much more than evidenced" makes no sense at all. As mentioned above, once floors were stripped away from their supporting columns, which would happen within a few milliseconds if struck with sufficient force, they were completely free to fall.

> 7. WTC 7 so close to free fall that physics suggest support severing.

Again, another completely empty claim that "physics suggest" something which has never been demonstrated with valid physics. When examined in detail, the NIST collapse hypothesis completely explains what we see, whereas the controlled demolition hypothesis not only requires magical silent explosives, it still leaves unexplained details such as the slow initiation and the fact that the freefall was not seen until after the building was already irrevocably headed down. There is no contest between the the two hypotheses, really.

If I thought it would make a difference, I can point you to references for everything I've said. Would it make a difference? Seems to me, you would have already found them if you were really interested in having your beliefs challenged rather than reinforced.

50 stories of debris with the columns in the middle of the debris standing there. 10 stories a second at free fall speed with huge beams being thrown about says to me it's more than a "melt down". And WTC 7 had small fires on a few floors. If you've ever watched the collapse, you can see the Penthouse on the roof collapse first. And there were explosions heard too. And the Commission never explained how or why WTC 7 fell. But you will never change your mind like we will never change ours.

By idiomatic definition, "conspiracy theorist" has come to mean someone who believes highly implausible theories without good reason. They have complete trust in their paranoid intuitions, so they allow paranoid speculations to grow, unrestrained by any requirement for evidence-based substantiation, into paranoid delusions of "truth." Since they start by assuming a conspiracy, they seek only to confirm that belief, not to challenge it. If that weren't bad enough, conspiracism has a special built-in excuse for eschewing evidence-based reasoning: Any evidence that proves their speculations to be false is dismissed as being fake, and the lack of evidence to prove them right is assumed to be because of a massive cover-up.

That approach sets no limits on what kind of nonsense you will believe. That is simply not how rational people attempt to understand the world, and I'm quite sure I haven't given you any reason to accuse me of thinking the same way from the other side of the fence. I believe in objective reality, and if buildings were brought down by controlled demolition, then it should be possible to prove it with actual evidence. If you could actually do that, it wouldn't matter what William Seger thinks, anyway, but instead of sound evidence-based argument, we get "stuff" like this:

> Pancake theory leaves 50 stories of debris with the columns in the middle of the debris standing there.

In fact, in both tower collapses, there was a "spire" of core columns that remained standing for a short while after the main collapses, but then they fell too because they were not designed to be free-standing. They buckled because they needed the floors for lateral stability. Trust me on this: You'll do far better to assert that demolition charges started the collapses rather than the causes hypothesized by NIST, but then gravity did the rest. You will get exactly nowhere by continuing to assert that demolition charges were necessary for the collapses to continue, because that simply isn't true. Trying to make that case leads to silly stuff like this:

> 10 stories a second at free fall speed with huge beams being thrown about says to me it's more than a "melt down".

But people who actually understand structural mechanics (and who have used actual science-based quantitative analysis instead of naked assertions and hand-waving) disagree with you. Since I think I understand the collapses fairly well, your inability to understand them is not particularly interesting, much less a rational reason for believing the ridiculously implausible controlled demolition theory. To change my mind, you need to explain to me what's wrong with my understanding, and the above quote falls far short. NIST has proposed plausible explanations for what initiated the collapses, and once they started, they could not be stopped because the dynamic forces were simply too large to be absorbed by those structures.

> And WTC 7 had small fires on a few floors.

False, according to the people who were actually there, and not particularly meaningful. anyway, since the NIST simulation shows that there was enough fire to cause the postulated collapse.

> If you've ever watched the collapse, you can see the Penthouse on the roof collapse first.

Which is completely explained by the progressive collapse starting under the penthouse in NIST's theory, and not really explained at all in controlled demolition theories (i.e. why wait for 6 seconds to blow up the rest of the building).

> And there were explosions heard too.

Apparently, you've never heard a real controlled demolition, so I suggest some YouTube research. High-explosive cutter charges have a very sharp, distinctive sound that would have easily been picked up in all the videos. A controlled demolition of a building the size of WTC7 would easily have been heard in New Jersey. But there was absolutely no sound in any of the videos (or any seismic activity recorded, either) that remotely resembles high-explosive cutter charges. That's precisely why the ridiculous, unfounded, and unnecessary thermite theory was invented.

> And the Commission never explained how or why WTC 7 fell.

The 9/11 Commission was not tasked with explaining why WTC 7 or any of the other WTC buildings fell. And obviously it would have made no difference whatsoever to paranoid conspiracy theorists if they had: The NIST reports DO explain them but "truthers" respond with predictable knee-jerk rejection.

I see you've bombarded the board with this kind of nonsense. I'm not much inclined at the moment to respond to all of them, since it's the same recycled nonsense that we've been wading through for years around here.

Leave all the other stuff aside.

"1. Jet fuel doesn't burn hot enough to melt structural steel."

Why do you believe that is at all a relevant observation?

Do you understand this graph:

But the observation is relevant because structural collapse depends on core failure among other factors. Please explain what strain is inverse to temperature rise. And also how that nullifies or supercedes other data. Have you even considered other data? Conflicting data is the major subject I'm trying to sort out. Despite earlier post of being "bamboozled".

Like what? Rereading your post full of unsubstantiated claims, I don't see any evidence that you're really trying to sort out anything. You appear to have uncritically accepted a lot of nonsense which you now represent as "scientific/forensic type stuff." Are you really interested in what's wrong with those claims or not?

However, I have been looking at this research for a while now. Please list what makes your information valid. I don't claim to have final answers. I also do not believe something just because someone puts PHD behind their name. This skepticism works both ways. The true intent of this thread is as stated.

Conflicting data as in conclusions on opposite ends of the spectrum from seemingly "legitimate" research from the same evidence. These people are not idiots. However they could easily be working an agenda. But again, as far as I'm concerned, BOTH sides are in that boat.

I appreciate your information, with sources. I am not prepared to "automatically" believe anything. If something makes sense to me, with my limited scientific knowledge, it becomes plausible. I do not have the background to wade through the equations used. I give not 2 shits about who was involved, or any of the political intrigue behind the events.

Also, it's very easy to be labeled a crackpot, and have your views shit canned. If you read some of the information at the link I provided, you will have a clearer understanding of where I'm coming from. All sides of this issue should be prepared to defend their conclusions. And have their theories shot down if shown to be defective. Period.

Doesn't the science behind those events (any events) put wrong theories to rest?

why are we having this discussion? Without an appropriate technical skill set, how do you expect to tell the legitimate arguments from the fraudulent ones? It seems a bit premature to ask people to defend their conclusions when you haven't yet done your homework and learned how to interpret them.

I'm asking for information.

Even the most studied and decorated math major admits incomplete knowledge.

There's more to a factual explanation than equations.

I'm currently trying to address my ignorance. And I can read the laws of physics and apply them to the tragedy of 9-11

I can understand words, and explanations when explained by individuals capable of explaining technical data to a lay person.

I have read enough scientifically based contradictory information to have questions.

would not have posted the silly OP, and/or you would have thanked those that took the time to provide some explanation.

It's right there in post #7, where you said "All sides of this issue should be prepared to defend their conclusions." That's asking for a defense.

Not all explanations are accessible to laypeople. Claiming that the fault lies with the person making the argument rather than the person who doesn't possess the background to understand the argument reminds me of the burden of proof fallacy.

If I lack the capability to understand, surely the fault lies with me. Would you be kind enough to post credible sources for me to attempt to wade through?

Summaries NIST NCSTAR 1 and 1A (along with the supporting sections) can be found at wtc.nist.gov. I'm not claiming they are without flaws, but reading them should give you some basis for discussion.

... on what basis do you accept the analysis by a high school physics teacher but reject the analysis by a university professor who writes textbooks and peer-reviewed journal papers about structural mechanics?

I'm trying to figure out what kind of reference you would find persuasive, and my best guess is that it depends on their conclusions rather than their credentials.

Of the strength reduction curve of steel under various conditions.

Do you understand that it is not necessarily for steel to "melt" in order to substantially reduce its ability to bear a load?

Goes through stages before turning into a liquid. Those stages can be described as parts of the melting process. Do you understand that?

At the link I listed, there are equations describing the attributes of steel during this process. Written by a guy with a BA in Physics and a MA in Math.

Here: http://www.journalof911studies.com/volume/2010/ChandlerDownwardAccelerationOfWTC1.pdf

I'm sure he's just a kook.

I'm beginning to wonder about the viability of this thread, due to the negative reaction towards my questions, and the (somewhat telling) fact that the people who usually fill a thread up about 9-11 are seemingly staying away from a FACTUAL discussion.

WTF? It seems like everyone else is convinced, one way or the other. Boy! I'm dealing with a bunch of geniuses! I guess I should just trust the government, and STFU!

Questions?? We don't need no stinkin' questions!

But if you want to throw degrees around, I happen to have spent too many years of my life studying molten metal solutions and how they behave, on the way to earning a doctorate in engineering. So I'm not going to say "Wow, a BA in physics!"

There is no model of the failure of the WTC towers which requires or assumes that any piece of steel "melted." And if you are going to define the word "melt" in some way other than as a solid to liquid phase transition, then it would be helpful for you to identify the fact that your words don't mean what everyone else defines them as.

Common office fires burn hot enough to reduce the strength of steel to the point of failure. It is why fire proofing insulation is applied to steel ever since the 1910 Reliable Insurance building fire, which was the first, and quite surprising, collapse of a steel framed building from fire.

Your objection, that these fires cannot burn hot enough to melt steel is totally irrelevant to what happened. And that is not some reflexive STFU - it is the result of the fact that you are spouting a canard which has been repeated here for the better part of a decade, and indicates that your "open minded inquiry" most apparently does not extend to developing a basic understanding of what it is you are attempting to criticize.

But, please, let's not throw around academic degrees.

STFU was joke.

Not throwing around degrees either. I was addressing the fact that analyses have been performed by some credible (to me) sources. I DO respect learning, and the fact that you're educated raises your credibility. I am going to research the Reliable fire too. Do you disagreee with the notion that a time factor is involved with steel melting, and that various stages of strength are reached during that process? Not challenging. Asking.

Even with weakened steel, educated sources claim that collapse should have been arrested under the claimed series of events/failures. Citing design specifications and (again) failure analysis. Have you visited the link I suggested? Can you give a link with a comprehensive analysis that fits the description provided by NIST?

I hope that I can somehow convince you that

A: Lots of conflicting information by credible sources exists.
B: My role in this is "seeking information before closing mind".

I'm not arguing, rebutting, or diminishing your words in any way. I appreciate your answers. If I throw up a canard, please feel free to blast the shit out of it. Believe me, my feelings are disconnected from this, having run up against these reactions before. However, that doesn't mean I don't have questions, and feel that questions are not wrong. Especially from a source seeking learning, and currently (partially) ignorant.

Couldn't find the relevant piece when I searched "Reliable Insurance steel building collapse in 1910". Do you have a link?

Could be local censorship, although it seems unlikely. I'm out of country. Our internet must go through a military server that has in the past, been shown to be incomplete.

Equitable, not reliable...

http://en.m.wikipedia.org/wiki/Equitable_Life_Building_(New_York_City)

But the fact you haven't yet run across it again suggests that your "research" has been pretty limited, since it, the Meridien Building fire, and several others are usually brought up along the way of these shopworn debates.

Let's start really simple with you. Can you tell me why fireproofing materials are applied to steel in office buildings? (Hint: we started doing it after the Equitable fire)

Despite the contempt I hear in your words, I'm gaining information, and hope to continue this path. Again I appreciate true expertise.

You're right in saying that my research as of now, has been limited. Wrong about which conclusions I've drawn, and how & why.

The only references I could find about high rise fires stated that of the six massive building fires studied, all suffered fires more severe than WTC 1&2, and building 7. None collapsed, although some significant design differences existed in some of the buildings. Concrete framing in one, full length atrium in another.
Three major building collapses were mentioned in additional articles. The only one that was attributed to fire was a roof collapse, and didn't destroy the structure. The other 2 cases mentioned suffered failure from inferior construction.
If the conclusions reached in these articles bears a closer look, please explain.
Heat is generally blamed as the cause for WTC collapse. Structural damage from aircraft impact is generally listed as within design parameters of load carrying capability. Yet heat more severe than WTC event occurred in other high rise fires.
So may I surmise the next issue to rebutt is the unique susceptibility of WTC 1&2 that led to collapse?

How was it that molten steel laid in the lower levels for over a month I think. Maybe longer, maybe less, but still, a hell of a long time?

... and the paper you linked to doesn't contain anything about any "stages before turning into liquid." Instead, it's an argument that starts by assuming that the downward acceleration of the upper block was constant and concludes that it couldn't act as a "pile driver." Do you see any potential problems with that logic?

"The roof line of the North Tower of the World Trade Center is shown to
have been in constant downward acceleration until it disappeared. A
downward acceleration of the falling upper block implies a downward net
force, which requires that the upward resistive force was less than the
weight of the block."

Is there not a constant effect? That would rule the whole theory suspect.

Do you think that is really "shown" in his paper or merely claimed? Do you understand enough about his argument to understand why it matters?

Bonus question: How could a controlled demolition possibly cause a "constant" downward acceleration of 0.64% g? (I'm asking you because Chandler doesn't say.)

And finally, if you accept Chandler's conclusion that additional energy was necessary to cause what we see in the WTC videos, how do you explain what we see in this video:

And again, I believe I have a rudimentary understanding of the issue. It seems that his evidence of constant acceleration means that there was nothing there to slow them down when they collided. If that's true, a whole lot of matter had to have been moved out of the way quickly. Or else impact between the upper and lower blocks would have produced a reduction in acceleration.

Is a constant acceleration AKA "free fall"?

I can't watch the video. My location has a crap connection. Demolition with no explosives? Sounds intriguing. What gives?

Has Chandler demonstrated either in the paper or the video that the acceleration was really constant? And why does it matter?

> And again, I believe I have a rudimentary understanding of the issue.

Apparently not, judging by this:

> It seems that his evidence of constant acceleration means that there was nothing there to slow them down when they collided.

No, he claims there was a "constant" downward acceleration of 0.64% of gravity, which means there was something slowing it down, but he claims not as much as should be expected.

> Is a constant acceleration AKA "free fall"?

No, free fall on Earth is a constant 32 feet per second per second, whereas Chandler is claiming a "constant" acceleration a little over 20 feet per second per second for the collapse.

Imagine a frozen pond with a brick sitting on the surface. When frozen, the water easily supports the brick. Now imagine that the ice suddenly melted, allowing the brick to fall to the bottom of the pond. It would fall smoothly through the water at a constant acceleration, but it would be something less than the acceleration it would have if falling through a vacuum because it has to push water out of the way -- agreed?

Chandler's "constant acceleration" claim amounts to saying that the tower collapses showed something like that kind of behavior, and he claims that means some "extra energy" must have come from somewhere to reduce the load capacity of the structure to only 36% of the upper block's weight.

The aforementioned university professor who writes structural mechanics textbooks and peer-reviewed journal papers (Bazant, in case you were wondering) claims that in order to halt a collapse after it begins, the structure below must somehow absorb the gravitational energy released in that initial fall, and he provides calculations to show that even with conservative estimates, there was much more energy released than the structure could absorb.

Right from the outset, the professor's claim sounds reasonable to me, while Chandler's sounds very dubious -- he appears to be ignoring any dynamic behavior -- but is there any empirical way to tell who is right? Well, Chandler would seem to predict that a progressive vertical failure is impossible without something weakening the structure, but the video is a demonstration of a European demolition technique called Verinage. It uses a system of cables and jacks to cause pairs of load-bearing walls to collapse, simply dropping the top of a building onto the bottom and letting gravity do the rest, with no "extra energy" (e.g. explosives) required. It's impossible not to notice the similarity to the tower collapses.

A Verinage demolition doesn't fall with a constant acceleration, however. It's an initial free fall followed by a collision in which velocity is lost but the impulse force causes a structural failure at that level, so the accumulating mass falls freely again to a collision with the next floor. Very careful measurements would show that the acceleration of the collapse varies because of that alternating sequence of collision jolts and free falls. But since the velocity is always increasing, if you only took position measurements with low resolution or at widely spaced points (or both), you wouldn't see those variations: It would look like a fairly constant acceleration and furthermore it would be in the ballpark of 0.64% g, more or less.

That's why it's critical that Chandler doesn't really demonstrate that the acceleration was constant. All he does is plot some points on a graph, draw a line through them, and then claim that the straight line means a constant acceleration. No, it does not; not if you don't know what's happening between the points. Furthermore, for that matter, Chandler doesn't justify that any impulse jolts could be measured at the roof line, even with better measurements, given that the tower collapses involved a tilted fall rather than the straight-down fall of a Verinage demolition. (That tilt would mean that collisions were happening in different places at different times, so instead of a single massive jolt that could easily be observed at one point in time, there would be much smaller jolts distributed in time.) In a previous post, I described a couple of failure modes that would result in local failure followed by local free fall, and I noted that what we really see is the average result of thousands of such events. I claim that what we see in the towers is simply that the average acceleration was 0.64% of gravity, although it was not really constant.

But that isn't the only problem with Chandler's hypothesis: He wants to conclude that his analysis means there must have been a controlled demolition but he fails to describe any demolition technique involving explosives that would produce a constant, like-a-brick-through-water smooth acceleration of 0.64% g. I don't believe that's possible, but feel free to give it a try. So not only does Chandler assume constant acceleration without justification, he also assumes an unjustified reason for it.

This is a lot to chew on. To me it seems like we're getting to where I wanted this to go. Let the chips fall...

after things started to go where you wanted.

Humm?

There are so many things wrong with that weak shit that it scarcely bears replying to. But rather than have anyone think that I was scared off or dumbfounded with evidence, here it is.

1. I don't want anything but discussion. Conclusions not preformed. I don't care what you think.

2. I'm in Kabul Afghanistan with a weak intermittent connection. Regular responses not possible. AND there was way to much information put out for me to analyze in "X" days. Especially at my level of background in math. And these points/issues have been debated for over a decade now. Or are you seriously suggesting that your views are the sole reasonable rational set of facts?

3. Absolute certainty is a priviledge of uneducated minds and fanatics. Not my words.

4. We waste a lot of time during these discussions because of weak shit like your reply that has the trappings of preconcieved certainty.

5. Honest debate and examination seem to be an unreasonable requests. Even if you've gone over this stuff 500 times, either add something useful to this or have the human decency to shut up.

1. You have in fact made conclusions. This has been amply shown in other posts

2. You admit you lack the proper background in math and science. This means you are capable at best of a superficial understanding of the VAST work performed on the SCIENCE behind the collapse by credible engineers and scientists. Evidence of this lack on your part is your reliance on the laughable work by Chandler.

3. My views, while in line with the rational scientific view, is meaningless. Fortunately as a Mechanical Engineer I have the background to understand the work, but I am not an expert in structural engineering or materials science, so I leave it up to those with expertise. There is abundant rational, sensible, scientific views published by credible, reviewed professionals that tell us the how's and whys of the collapse.

3/a It would be pretty foolish of me to question the analysis of a highly credible biologist when I have no background in biology.

4. The notion that anything other than planes impacting, fires, and hundreds of variables that influenced the failure as seen, as the only cause of the collapse is beyond doubt. No matter how many Google trained engineers think otherwise.

5 An open mind is a wonderful thing, just don't leave it so open your brains fall out. Not my words.

6. Honest debate is indeed a wonderful thing. I just don't see it in this thread on your part.

Indeed. Reviewing these posts makes me see I did draw conclusions. Even with the questioning nature of my posts, certain conclusions had to be fore-drawn in order to pose the questions. Backing up as far as I've had to has created much re examination. The evidence at this point, is for me, enlightening. This post started as an inquiry, it remains that for me. I appreciate your responses.

*start*

None of the conspiracy "scholars" have passed a peer reviewed paper in a respected scientific journal saying the collapse of the towers was impossible.
Many peer reviewed papers have been passed in respected scientific journals saying the towers collapsed from impact and fire alone.
The few scholars who say they are structural engineers and are conspiracy theorists are not working in the field.
Dr. Fetzer wrote books on JFK and moon landing conspiracies.
Prof. Jones was a physicist who worked on cold fusion and not structural or civil engineering.
Prof. Judy Woods was a dental engineer and did not have a job in structural engineering.
Gordon Ross is not a structural engineer. None of his so called "papers" have passed peer review by a respected scientific journal. He hasn't made a single attempt in a respected journal.
The scholars for 9/11 truth created their own journal which has no impact to the scientific community and is created by and for the conspiracy theorist community.
Conspiracy theorists haven't tried to pass a peer reviewed paper in a respected scientific journal. This proves they have little faith in their own work.

*stop*

How's that for honest?
Structural engineers in Jones own university call his hypothesis "very unreliable".

I think it came out a bit sideways, but mostly I think it's hard to find words that mean the same things to everyone.

I would be reluctant to say that "beyond doubt" we know all the causes of any event. But I don't mind saying that every controlled demolition hypothesis I've seen makes markedly less sense than the CD-free alternatives. That's not an article of faith for me (or for you) -- it's an observation informed by many people's discussions over many years.

Last edited Sat Mar 10, 2012, 09:34 PM - Edit history (1)

and I agree "beyond doubt" might be a tad too definitive. How about beyond reasonable doubt?

If I were on the "jury," I would certainly vote to "convict" the basic mechanisms identified by NIST, despite the "defense's" attempts to implicate explosives and/or other mysterious agents.

It isn't a matter of trying to suppress "doubt."* It's a matter of observing that the so-called Official Story of the collapses makes a heck of a lot more sense than the conspiracist alternatives.

*ETA: I'm not trying to explain this to you. It's barely possible that it might help some truthily inclined lurker who has been conditioned to think that people like us defend the "Official Story" at all costs.

I'm pretty sure you mean 0.64g = 64% of g, not 0.64% of g, which would be pretty darn slow.

"Therefore the downward force exerted by the falling
block must also have been less than its weight. Since the lower section of
the building was designed to support several times the weight of the upper
block, the reduced force exerted by the falling block was insufficient to
crush the lower section of the building."

Logic failure? At my level of understanding, it seems that the upper block must lose force when impacting lower block. So there would be a diminished effect on the remaining structure. No?

Here's the whole analysis that I'm aware of:

http://www.journalof911studies.com/

I have to claim ignorance. I'm studying the information you gave me now. Reviewing the NIST findings. And deciphering the data as best I can. This is all being done with a bad connection, during lulls in other commitments.

As initially claimed, I'm just looking for factual data. There's mountains of it, and it's going to take me a while. I'll end up with believeable conclusions. Not just someones words.

I do appreciate the information, in spite of your smug superiority.

...to point out that the conclusions you have stated thus far are in disagreement with each other.

That is not "smug superiority". It is basic logic. And you were the one throwing around the fact that Chandler has a BS in physics as if it were some sort of big deal.

to find that inconsistency, where I was not. Logical conclusions require tools as any other analysis.

I wasn't throwing around a damned thing. You made some sort of statement that insinuated I was pulling this data out of my ass, when in fact I was studying computations from a guy with a physics degree. To me, a physics degree IS a big deal. Lends credibility. Never said it was the be all/end all. Not trying to one up anybody. I am obviously unqualified personally to do so.

But all this crap obscures the fact that I'm just seeking information. It seems you have some kind of problem with that. When did seeking information (qualified technical) become such an object of derision? Because I see pausibility in the notion that our government might be telling us the whole truth surrounding those events? Crazy of me I know. So if you can't provide data without ridicule, or talking down to then WTF? This is all so far off the subject, that wading through it obfuscates the objective.

Thank you for your contributions to this point, if you have more data that can help a non-physics qualified layman understand those events better, come on with it. Acting like I'm trying to throw around stuff is baseless, and unproductive.

Let's look at your OP, stating "just facts":

"1. Jet fuel doesn't burn hot enough to melt structural steel. Especially when encased by fireproofing. Proven by NIST doing gov. tests."

That an open jet fuel fire doesn't melt steel is an irrelevant fact. The collapse of the towers does not require anything to melt. "Jet fuel can't melt steel" is a truther talking point and is not relevant to the collapse of the towers. But having digested a laundry list of truther talking points, you assert it as some sort of relevant fact. It sure as heck isn't a "question" seeking an "answer".

Can petroleum fuel fires weaken steel to the point of collapse? Certainly:

http://en.wikinews.org/wiki/Tanker_truck_fire_causes_collapse_on_Oakland_Freeway

So your point about melting is more of red herring than anything else, but listed as your "fact" number 1.

Now let's look at your "fact" number 2:

"2. Timing does show some free fall throughout collapse of towers. And in fact the upper block of tower one accelerated during collapse."

No, the timing does not show any free fall, and you posted a reference which disproves that statement. And, absolutely, the upper block is going to continue to accelerate as long as the kinetic energy gained by dropping even a single floor exceeds the energy required to break what's below it. And nothing in the towers was designed to take that kind of impact. But is it accelerating at "free fall"?

Anyone with eyeballs can see it is not, by simply looking at a single still photograph of the event:



Do you see that big chunk of the outer structure just to the left of the tower?

What does the presence of that piece of debris - broken off from above and falling next to an as-yet uncrushed section of the tower - tell you about whether the collapse front is moving at "free fall"?

Even in the festival of wrong which is the Chandler paper, he did get one thing right - the acceleration of the collapse front was far below free fall.

A 100 story building is a machine that is designed to support a 100 story building. It is not an 80 story building that is designed to have a 20 story building dropped onto it. If you cannot grasp the difference between those two things, then try this experiment:

If you are of reasonable strength, you can probably support a 12 pound bowling ball in the palm of one extended hand. Go ahead and try that. Now, have someone hold that bowling ball just a few inches above your hand, and ask them to drop it onto your hand. What you are going to find is that the dynamic force of impact from that bowling ball falling just a few inches is going to far exceed the static force you exerted to simply hold the bowling ball, and your arm is going to give way like a wet noodle.

Watch what can happen to a building when one floor is compromised:

You say here that you're "just seeking information." But I think most people who read the OP would conclude that you've already made up your mind. Honestly, wouldn't you? I mean, you wrote that you "only consider information from Engineers or Physicists," but the Journal of 9/11 Studies isn't exactly an engineering journal. I'm not saying you have to ignore it, but can you see how this looks to other people? (Suppose someone linked to an article in the Creation Science Quarterly -- assuming there is such a thing -- and said that s/he only considers information from biologists: how would you react?)

Now, just from reading that post, I can't tell whether you're actually interested in learning about this topic or whether you've already decided. From other posts, I'm inclined to give you the benefit of the doubt. There's nothing wrong with reading one side of the story and not seeing the problems with that side. However, it's fairly common for people to post threads in which they try to pose as open-minded, but sooner or later reveal that they aren't. So, if people seem to be jumping to invidious conclusions about you, it's because (1) the OP doesn't seem very open-minded and (2) many have poisoned the well before you.

I don't think anyone here expects "the government" to tell us "the whole truth" about anything in particular. That really isn't the issue here.

And other information I've found, I have to admit that NIST's study seems a lot more plausible. Please read these quotes and comment as to veracity.

It is known that structural steel begins to soften around 425°C and loses about half of its strength at 650°C.4 This is why steel is stress relieved in this temperature range. But even a 50% loss of strength is still insufficient, by itself, to explain the WTC collapse. It was noted above that the wind load controlled the design allowables. The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable, which is roughly one-fifth of the yield strength of the steel. Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.

The additional problem was distortion of the steel in the fire. The temperature of the fire was not uniform everywhere, and the temperature on the outside of the box columns was clearly lower than on the side facing the fire. The temperature along the 18 m long joists was certainly not uniform. Given the thermal expansion of steel, a 150°C temperature difference from one location to another will produce yield-level residual stresses. This produced distortions in the slender structural steel, which resulted in buckling failures. Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire.

**cut**

The perimeter tube design of the WTC was highly redundant. It survived the loss of several exterior columns due to aircraft impact, but the ensuing fire led to other steel failures. Many structural engineers believe that the weak points—the limiting factors on design allowables—were the angle clips that held the floor joists between the columns on the perimeter wall and the core structure (see Figure 5). With a 700 Pa floor design allowable, each floor should have been able to support approximately 1,300 t beyond its own weight. The total weight of each tower was about 500,000 t.


As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell. The floor below (with its 1,300 t design capacity) could not support the roughly 45,000 t of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an estimated speed of 200 km per hour. If it had been free fall, with no restraint, the collapse would have only taken eight seconds and would have impacted at 300 km/h.1 It has been suggested that it was fortunate that the WTC did not tip over onto other buildings surrounding the area. There are several points that should be made. First, the building is not solid; it is 95 percent air and, hence, can implode onto itself. Second, there is no lateral load, even the impact of a speeding aircraft, which is sufficient to move the center of gravity one hundred feet to the side such that it is not within the base footprint of the structure. Third, given the near free-fall collapse, there was insufficient time for portions to attain significant lateral velocity. To summarize all of these points, a 500,000 t structure has too much inertia to fall in any direction other than nearly straight down.

This is from http://www.tms.org/pubs/journals/JOM/0112/Eagar/Eagar-0112.html

I dated a fairly decent man whom I had some things in common with one difference was we were on opposing political sides. I thought I could manage my contempt and he used humor to tease me about birkinstocks and vegans. It was around 2003 and no one had started to theorize, that I knew of. We had a fight.
I speculated that if the Bush administration had mihop or lihop they had used it as such. His reaction as a dyed in the wool supporter, impressed me with how the conservative mind works.

The poor man essentially went wild with fury at the mere speculation that his beloved brand could even be considered in such a light. He had a new Jar of shrimp cocktail sauce in his hand. He was a meticulous house keeper. That that jar went flying, busted all over the ceiling and wall. The room looked like a bloodbath. He screamed at the top of his lungs, THAT'S BLASPHEMY! He wasn't even religious.

Right then I knew, how the whole thing went down. And he got dumped.

Because the conservative guy you were dating refused to believe MIHOP or LIHOP, then that means that MIHOP or LIHOP must be true?
Or does the jar of shrimp cocktail sauce somehow play into this?

But no one else had even talked about it being a conspiracy. Maybe it was 2002. He was mortally shocked that anyone could conceive such a thought. He went on about nobody thinks that. Where did you get that. I just hated Cheney enough to believe he could have set the thing in motion.

I know I completely upset this man's sense of decorum. Offended his sensibilities to the core.

Odd as this sounds I had an epiphany. I knew Bush and co could do anything and get away with it because of the psychological mind set of their followers.


I figured I was the only person on the planet that had doubts that a bunch of nomads and a camel didn't put this whole thing together. I realize it is not actual proof this was an antidote.

You understand!

if someone had mentioned the "shrimp cocktail" theory.

... If that's not the most compelling piece of evidence proving that BushCo was behind it, I don't know what is.

Over ten years later and it all comes down to cocktail sauce.

Yes, it's true. Get your tickets here. I really went through hell for my creative speculation, that night. I don't know why I pushed my theory back then. I thought it up and said it and he went out of his rabid ass mind. I was terrorized although not physically touched.

Believe me I never brought it up with him again. Although I think about it now and wonder if he hears real things like what are posted at the top of the thread.

Please don't let my goofy antidote derail an awesome discussion.

But windows closer to crash site intact.
Janitor who worked at the WTC for 20 years feels an explosion in the basement seconds before plane strikes tower. His testimony was taken out of the commission report.
ALL passengers DNA were ID'd, but plane itself just melted. No seats out of 4 planes 800 seats unaccounted for. Plane engines are 9 feet tall and made of Titanium. Not one of those around either.
Watching the first impact on WTC watch how fast smoke rises to the roof. It takes about minute for smoke 30 stories away from crash site to come billowing OUT of building.
ALL 4 planes crossed over heavy military bases, but none of the planes were caught.
And with EVERY crash the FAA reconstructs planes. All 4 planes were NEVER reconstructed. Not one of them. Flight 800 fell to the bottom floor of the Atlantic, and they retrieved it.
Pentagon only shows us a 10 second video of the crash there. The Pentagon must have hundreds if not thousands of camera's, but we only get that little bit of video. Why ask for more right. Just believe that our government spends billions of dollars on DEFENSE, and our DEFENSE building gets hit. LOL! Laughable at best. Oh and our Secretary of defense is helping victims ain't that sweet. The same man who announced just the day before that the Pentagon "misplaced" 2.3 TRILLION dollars.
If it were truly a terrorist attack, why didn't the Pentagon arm the Pentagon? They knew of other planes being hijacked. They had 35 minutes since the second tower was hit. All that defense money for what? They didn't even protect the White House. The military should have been set to shoot down whatever was in the sky. The Washington airport should have been shut down sooner. But go on and believe we spend all this time and money on defense, and not only did we get hit, it was our DEFENSE building. Which by the way groundbreaking ceremony for the Pentagon 09/11/41. Laughable.

But enough of facts. Everybody knows that fire can bring down steel and concrete at free fall speed. That is what they told us. To believe otherwise is to be laughed at. Even though they have NO facts. If there were facts to the governments story, there would have been a trial by now. The reason for no trial, is they need proof that the "terrorist" did 9/11, and they have NONE. Defense attorneys with witnesses in physics will prove the plane and fire didn't do what they told us. And we can't have that kind of talk going on can we. And just imagine if one of the "dead" terrorist testified. LOL! Which I'm sure would have happened. How would our government explain that. Or that Muslim's don't drink and have sex with prostitutes. It took Bush over 400 days to start the investigation. It's obvious, they didn't want to investigate 9/11.

Is abundant. That's why it seems to me to be even more important to perform honest scientific analysis. But evidence has been altered, and destroyed. There are facts that lend credibility to the NIST study. However the situations you just pointed out, the ignored testimony, and the omissions from the NIST report all speak to a conspiracy. To ignore these realities is to preconceive a conclusion. And the scientific method goes out the window. But after a decade plus, it seems like if there was something to get away with, it has effectively happened. MIHOP/LIHOP scenarios jump the gun, in the face of the lack of a smoking gun.

Nr. 1 It is implausible to believe that the hijackers coincidentally chose the same day to attack as all the exercises - or that the exercises across so many agencies and airspace 'coincidently' reached an unprecedented density that day-after all, this sort of thing is not public information before hand-easily available in official channels though

Nr. 2. The only cogent target on that side of the pentagon was the Office of Naval Intelligence where 38 of 40 were killed. The plane could have more easily hit anywhere or even Rumsfeld's office but flies 3/4 of the way around and just 'concidently' takes out the ONI.

On #1: You haven't demonstrated that exercises on 9/11 reached an "unprecedented density," nor have you demonstrated that the number of exercises on 9/11 has any bearing on the events of the day.

On #2: It's certainly nonsense to say that the plane "could have more easily hit anywhere." In #1 I can at least guess at the argument you intended to make, but I have no idea why you think hitting ONI evinces an inside job. A pun on "navel-gazing," perhaps?

...the plane passes up on hitting the white house, then passes up on hitting the capitol, than passes up on hitting the SecDef office to go around and hit the only newly blast-hardened wing that was relatively empty? You're joking right? You can't ask anyone to believe that someone would pass on those targets.

I see two alternatives - either someone knew the wing was relatively empty and steered there to reduce casualties & deliver more of a symbolic hit or the ONI was targeted. But why ONI? Why not hit that sprawling CIA complex at Langley that's only a minute or two away by air if you want to kill spies? ONI was Jonathan Pollard's old haunt - that give us some idea of the level of material and activity they're involved in - far above and beyond what some terrorist might be after.

So back to Nr. 1 - Don't gloss over the main point - do you believe the terrorists just happened to pick the same day as the exercises-that that was just a coincidence?

Approaching from the west, the plane did not "pass up" either the White House or the Capital in D.C.; the Pentagon is west of D.C. in Virginia. Hanjour approached at about 7000 feet until he had visual identification of the Pentagon, then did a slow, wobbly spiral to lose altitude without gaining too much speed, then plowed into the Pentagon from the south-west. Rumsfield's office was on the east side.

> So back to Nr. 1 - Don't gloss over the main point - do you believe the terrorists just happened to pick the same day as the exercises-that that was just a coincidence?

Lots of issues with this one. First, the primary exercise that the others were coordinated with, Global Guardian, was a two-week exercise into its second week, so the attack wasn't "the same day" as the exercises. Second, the military has exercises throughout the year, so it's not nearly as much coincidence as you seem to think. Third, the exercises are NOT secret -- e.g. Air National Guard participants need to schedule time off from work -- so it's possible that it wasn't a coincidence; that the terrorists knew about the exercises and independently decided to schedule the attack at that time. But fourth, that would be a rather stupid thing to do, simply hoping that the exercises interfered with a response rather than aided a response, since lots of people were already on-station and active. In fact, the 9/11 Commission found that if anything, the military response was faster because the exercise were underway. So, the fundamental premise behind this "reason" is seriously flawed.

But there's another problem when both of your points are considered together: They don't tell a consistent story on their own, and you haven't offered one. The point about the exercises would seem to imply LIHOP while the point about where the plane hit the Pentagon would seem to imply MIHOP. (I admit to guessing what you meant to imply, since you didn't really say.) If both of these points are so convincing to you, which is it -- LIHOP or MIHOP? Or can you fit both of your points into a plausible narrative?

That'll teach me not to eat lunch while replying.

I didn't mention one other detail: The Global Guardian exercise was apparently originally scheduled for October, according to one National Guard newsletter earlier in the year, so some conspiracists (not necessarily Mr. Skeptik) claim it was rescheduled for September when "they" learned of the planned attack. That's why I typically think of it as supporting LIHOP, and I don't see how it could really be used to support MIHOP unless you believe the exercises were secret, which is not the case. But as I said, I'm just guessing at what Mr. Skeptik was getting at.

Most of the time, we could do better.

What are you saying? That it was somehow objectively ridiculous to target the Pentagon instead of the White House or the Capitol? If you actually believe that, surely no one will change your mind. But it isn't very hard to understand why the Pentagon would be an appealing target. (There is also the matter of the fourth plane.)

The plane came from the west and hit the western side of the Pentagon. Dunno how this counts as passing up the White House, passing up the Capitol, and passing up the SecDef office to "go around and hit" a particular side. Also dunno what you think the point would have been of killing 'only' 125 people at the Pentagon when it would have been easier to kill no one at the Pentagon.

I think my favorite is this:

Jet fuel only burns hot in a CONTAINED environment. The towers couldn't keep the heat of the fuel, and the towers were air tight. The towers were like 3 building stacked on top of each other, so jet fuel down the elevator shaft won't work either.

No buildings are airtight, with the exception of specially constructed clean room type facilities. There were huge elevator shafts through out the WTC tower cores, in addition to the emergency stairwells.

As to, the "3 building stacked on top of each other", utter nonsense. The core and perimeter columns construction was maintained all the way up. Yes, the two mechanical floors made it look like there were three buildings, but that was an optical effect.

[img][/img]

I seriously appreciate the entertainment.

That our "resident" physicists and engineers would chime in more, and that motive, and suspects could be more clearly considered in an independent thread. But that's the way this cookie usually crumbles. The 2 are aspects of the same events, and share scientific considerations. There are thousands of analyses, as well as tens of millions of words on those events. It's damned hard for someone with my upper math/physics/engineering background (practically nil) to understand the formulae and conclusions. Not that those are the definitive answer to all the questions that arise, but if one doesn't understand the answers, how is one to eliminate false ones? So I try to keep an open mind, and create threads that explore the possibilities.

Seriously, for the education, your grammar and spelling is flawed.

One can always understand the answers. We can determine agreement or disagreement.

It was a nice response however. I appreciate it.

I grant that the post is a bit hard to follow, but what is your objection to the spelling?

I thought the points in the OP had been addressed pretty well.

One can keep rattling off questions that Truth Movement folks have raised indefinitely, but for sanity's sake, it helps to be selective. Are some issues particularly on your mind?

For confusion. I appreciate solid answers to my question. I'm still trying to visualize all the significant features that caused those buildings to fall despite modern architecture, and engineering. There are so many issues attached to that basic question that the OP gets diluted. There's a mountain of data to get through, and it seems like a pretty narrow set of circumstances had to occur on all 3 buildings in order for the trio of collapses to occur. All plausible and logically explained...

So to acccurately reword my post, I should have said "I need to arrange that data in my own mind". You've chimed in quite well.

I don't know how narrow the circumstances were, especially with respect to the towers. The efforts to reconstruct the specifics are very intricate, but the broad outline is consonant with common sense: structural damage at the time(s) of impact; extended fires causing observable further degradation; ultimately, the inability of the structure at the impact zone to bear the mass above; gravity does the rest. WTC 7 is an odder case because we can't really see a lot of what happens, but it's not too surprising that when a penthouse on one side of the building collapses, the structure is fatally compromised. Regardless, the consequences are so shocking that it's hard to wrap one's head around the events. That's one of the reasons I started posting in this forum (back when it was a forum) -- for a while, I was learning interesting things about engineering and various other topics, as well as about how people argue. Honestly, it may have been more fun for you if you had started back when I did, or even earlier -- but there's still room for excellent discussion.

This week, on another board, I saw someone argue that NIST had contradicted itself because one of its models showed a particular girder moving off its seat in one direction, while another model showed it eventually rocking off its seat in the opposite direction. Now, that might be relevant, or it might be more like questioning whether the tide destroyed a sand castle because of ambiguities in the forensic reconstruction. The spooky thing is that this fellow doesn't even seem to ask himself whether it's relevant. When we're out of field -- and even when we're in field -- we can't always tell what is and isn't relevant, but at least we know that some things are more important than others. But when refuting an "official story" becomes an end in itself, that perspective is lost. (That works both ways in principle, although honestly, I don't remember anyone trying to defend the NIST study as infallible, whereas I see lots of people reaching for excuses to discredit it.)