Aemilius

It's clear to me now that no one here is either willing or able to directly address the analysis. In view of that, I'll just ban the forum before the forum bans me. You've all had plenty of time and not one of you has said or shown anything that empirically contradicted it.... what a bunch of losers.

Wow! I don't think I've ever seen such an enormously small block of text that so successfully fails to address a simple empiricaly verifiable graphical link removed.... well done (and good luck recovering from that stroke)!

Hah! Right MIgL, nice to (virtually) meet you. Your gift for understatement is already legendery (at least in my mind).... I should mention, though, that the exclusive, really laser like focus of my interest here has to do with the destruction of WTC7, not the Twin Towers, the Pentagon, or Shankesvllle. In view of the empirically verifiably fact that WTC7 was brought down by explosives, the rest of the events that day are really rendered as academic (according to Merriam Webster), provided of course one is willing to adhere to the so called old school scientific method.... that is. Not ignoring you unintentionally swansont, just getting drunk in order to formulate an intelligible response.... shouldn't be long (I'm a lightweight, it's saved me a great deal of money). Alright swansont, I'm fully prepared now (several more shots of extremely low quality whiskey) after cursorily reviewing my old textbook from 1964 entitled "The Fundamentals Of Physics" to respond to your empirically hilarious question.... "How does energy conservation prevent free fall?" Oh God (figuratively speaking)! Hold on a minute,... I've just noticed something else from earlier on. I'll just drink a bit more.... be right back! Edited to add.... Thanks for the "Neg Reps".... still drinking.

The claim that free fall descent is physically impossible? It's not a claim, it's the Law of Conservation of Energy, and in the case of this building (WTC7) it is physically impossible. I've explained why about as thoroughly as humanly possible in the link removed One liner posts are useless and accomplish nothing. Either copy and paste that portion of the analysis you're having trouble with or just continue being befuddled. Another analytically useless one liner. The burden of proof is only on me If it can be shown that the analysis as a whole or some part of it is a bald assertion. You haven't shown that. Copy and paste that part of the link removed you feel is an assertion and not an empirically verifiable fact and show why it's incorrect. Whatever you were going on about there, it didn't show any aspect of the link removed to be incorrect (I hope you enjoyed your bus ride though). Precion timed detonation of charges is routine in demolitions. That's a fact, not an assertion. If you're going to continue trying to misrepresent facts as assertions, I'd say there's little to no point arguing with you. Nothing you said breaks thelink removed No, thelink removed (it's an analysis, not an assertion) hasn't been assailed at all. No audio analysis will alter or change the result of the graphical analysis I did (unless you can empirically show otherwise) or the conclusion it naturally arrives at through process of elimination that indicates some energetic material capable of quickly removing all support from beneath the upper part of the building (WTC7) had to have been physically transported inside the building some time prior to the event. And still.... not one member of this forum has managed to openly criticize it, let alone break it (the analysis) by simply copying and pasting one or more of the animations along with some accompanying text to say something like.... "No, this is wrong and here's why. In reality this animation would play out differently than you have depicted it, it would actually play out like this...." As I said before, if I'm so obviously wrong that everyone looking at the analysis can immediately see I'm wrong or that it's incorrect.... Why hasn't anyone simply pointed that out in the above described manner? Unless and until someone does that the analysis and it's conclusion stand.... the building was brought down by explosives. Happy New Year.

What's really interesting is that, for some reason, coming up on nearly thirty posts now since I posted Post 38, not one member of the forum has just directly addressed it by simply copying and pasting one or more of the animations along with some accompanying text to say something like.... "No, this is wrong and here's why. In reality this animation would play out differently than you have depicted it, it would actually play out like this...." If I'm so wrong and everyone looking at post 38 can immediately see I'm wrong, why can't anyone simply point to what's wrong in Post 38? The only reason I can think of is that none of you can point out anything wrong with it,... that must be it. Post 38 remains empirically unassailed, explosives brought down the building.... that's just the way it is....

Hah! Sorry about the misquote, but in view of the fact that he doesn't even know what building we're talking about, there's no need to resort to any sinister tactics to knock down his argument.... he's done a fine job of it all by himself. As far as addressing his concerns, his "argument" is clearly based on a false premise, namely, that a fuel laden plane flew into WTC 7 and caused the whole thing. What good would it do to address points raised that are obviously based on a false premise? You tell me.... What would be the point of that? No offense but, in view of all that, I'm not terribly interested in talking with him anymore.... you go ahead.

Fascinating. So.... a long, slender, ideal, perfectly straight, homogenous column free from initial stress can become unstable under maximum axial loading.... that's a real game changer! I quote you and respond, you should do the same. Where did I say "the falling is too fast" or "the falling is too slow". Use real quotes, not what your impression is of what I said in quotes. I'm having trouble with the rest there.... Is the cartoon part of your argument? You can say that, but I have an expert who's looked at it and says it would take "very careful calculation" to tell the fall time of the upper part of the building apart from gravitational acceleration. Clearly showing your entire rebuttal to be of no value whatsoever.... you don't even know what building we're talking about. WTC 7 (the subject of this thread) was not hit by a plane. Depends on what building you're talking about. Near free fall is not an expected feature of a building undergoing natural progressive structural failure.... and no building was dropped on WTC 7. You don't know what your talking about. So the building didn't notice the structure under it. I actually had to take a break after I read that.... hilarious! Well, since you don't even know what building we're talking about, I'd say you're hardly in a position to make any value assessments as to my level of understanding. Get away with what? I'm empirically scrutinizing a substantial well defined period of gravitational acceleration that can't be explained by natural progressive structural failure occurring in the building using the analog target system of analysis.... sorry if you don't care for the approach. Who did it? The thread topic is about why WTC 7 came down so quickly, not about who made it come down so quickly. Nothing you've said empirically contradicts any aspect of Post 38, and the fact that your rebbutal revolves around the false starting premise that a fuel laden plane flying into the building caused the whole thing when no plane actually hit the building (WTC 7 was not hit by a plane) really renders everything you've said so far.... meaningless. Not by John Cuthber it hasn't.... Are you talking about someone else, perhaps? Post 38 remains empirically unassailed.... explosives brought down the building.

Right.... the NIST says the observed descent time for the 18 visible stories was 40 percent greater than the computed free fall time for 18 stories.... that's consistent with physical principles. But the observed descent time for 8 stories was 0 percent greater than the computed free fall time for 8 stories.... and that's completely inconsistent with physical principles. There's simply no point during a natural progressive structural failure where the conditions required for free fall can arise. An explosion or other type of event must have occurred that was powerful enough to quickly remove support from beneath the the literally falling upper part of the building (confirmed by both NIST and independent researchers alike), either all at once or incrementally in advance of it's descent, permitting it to descend at gravitational acceleration under and the conditions required for gravitational acceleration to occur. The observed 40 percent greater than computed free fall time for eighteen stories does nothing to explain the observed 0 percent greater than computed free fall time for eight stories.... it's a physical impossibility. No, that's where the NIST looked very carefully at the data for (about) 1.75 seconds to 4 seconds and said "it's in free fall", not me. The NIST conducted the pixel-by-pixel analysis that shows the building descended at gravitational acceleration for 2.25 seconds (eight stories, approximately 105 feet), and says buckling, a natural progressive mode of structural failure, was the cause, when buckling, as empirically shown above, clearly cannot have been the cause of the observed rate of descent in Stage (2). I think I've addressed Stage (1) now and how buckling utterly fails to empirically explain Stage (2). No, I chose to look at an aspect of the NIST analysis that describes a physical impossibility. No cherry picking. Like I said, I chose to look at an aspect of the NIST analysis that describes a physical impossibility, and I've also addressed Stage (1) and how it utterly fails to empirically explain Stage (2). No, that's false, it doesn't have to all happen at once, in fact it rarely does. As anyone who owns an old television set knows, intentional explosive demolition is rarely if ever done by attaching simultaneous high-explosives/cutter charges to the steelwork.... it's done by attaching precision timed high-explosives/cutter charges to the steelwork. The graph isn't mine, it's from the NIST report. Since the detonation sequence of explosives can be and often is precisely timed, the door is thrown wide open for a whole spectrrum of possible outcomes. One could quickly detonate all the charges at once for immediate acceleration to free fall, or one could detonate them slowly over time, including a period of free fall at any point one wished. Sounds more like you than me. Well I don't know about Stalin, but Post 38 remains empirically unassailed.... explosives brought down the building.

That's what they say. Stage (1) is where the NIST report says that.... "a slow descent with acceleration less than that of gravity that corresponded to the buckling of the exterior columns at the lower floors". Actually no, it wouldn't. In Stage (2), the building undergoes free fall for 2.25 seconds (eight stories, approximately 105 feet). But no matter how the columns are buckled in Stage (1), they can't go into free fall because, as we know from fundamental well established and time tested empirically verifiable experiment, even if a giant laser beam suddenly vaporized all but the north face of the building causing the exterior columns to immediately begin buckling, free fall still would not occur.... the strength of buckling columns (whether buckled one at a time or all at once) doesn't just go from 100% to 0% when they fail, it goes from 100% to 0% while they fail, and that's a time consuming process. Whether buckled due to weakening by heat.... Control on the right, details.... http://picasion.com/...8f520c5ad7e.gif ....or buckled due to failure from overloading.... Control on the right, details.... http://picasion.com/...8f520c5ad7e.gif ....buckling columns (a mode of natural progressive structural failure) cannot give rise to the conditions required for gravitational acceleration to occur as they fail because there's no point during the failure of a column where it's resistance to the downward motion of a load will be found equal to that of air.... Control on the right, details.... http://picasion.com/...8f520c5ad7e.gif The scenario playing out below is physically impossible.... Control on the right, details.... http://picasion.com/...8f520c5ad7e.gif There's only one way a load supported by a column can descend at gravitational acceleration, the column supporting it must be quickly removed in order to create the conditions required for free fall to occur.... there's no other way. A column must either be knocked out.... Control on the right, details.... http://picasion.com/...8f520c5ad7e.gif ....pulled out.... Control on the right, details.... http://picasion.com/...8f520c5ad7e.gif ....or blown out.... Control on the right, details.... http://picasion.com/...8f520c5ad7e.gif ....for a load supported by it to descend at gravitational acceleration. In view of the empirically founded explanation above.... you're mistaken. I've shown why some additional force must be introduced to explain observations and also shown why no mode of natural progressive structural failure going on within this building could have given rise to the conditions required for free fall to occur at any point during it's descent Because, as shown above, buckling columns (whether buckled sequentially or all at once) couldn't have given rise to the conditions required for free fall to occur in any part of the building during it's descent. The NIST, in Stage (1), says that.... "a slow descent with acceleration less than that of gravity that corresponded to the buckling of the exterior columns at the lower floors" occurs, and then says that in Stage (2).... "a freefall descent over approximately eight stories at gravitational acceleration for approximately 2.25 seconds" occurs. The buckling columns in Stage (1) cannot explain the 2.25 second period of free fall descent observed in Stage (2). Buckling columns cannot create the conditions required for free fall.... it's physically impossible.

Another one line wonder, that's fine.... one liners won't change the physically consistent basis of Post 38 or refute any of the empirically verifiable information conveyed. Just saying that my "starting premises are false" without even trying to show how or why they're false? That's just hand waving man. Yeah, and it turns out all these multiple people that showed my facts and reasoning was wrong multiple times is just one guy raising the same objection multiple times. Maybe I should have responded earlier.... I'll own that. Anyway, I'll just go ahead and respond to the posts by John Cuthber in order.... I'm sure someone (probably multiple people multiple times) will let me know if I miss anything.

Where, how and by who?

Yeah well you need to back that up.... I say you're just making stuff up and don't know what you're talking about. Post 38 is the product of a two month long exchange I had with a forty year veteran Ph.D research physicist devoted exclusively to this topic. You can make things up and attack me all you want, but it won't change the empirically verifiable information conveyed in Post 38. The only way you or anyone else is going to do that is by empirically showing some aspect of it to be fundamentally incorrect or inconsistent with physical principles.... something tells me, at least in your case, I don't have too much to worry about. More subjective off topic fluff. Just like the rest, nothing you've said empirically contradicts anything in Post 38,... explosives brought down the building.

Saying it is one thing, empirically demonstrating what you're saying is another. You haven't shown that any aspect of post 38 starts from a false premise, nor have you shown how or why the conclusion arrived at is based on a false premise.... unless you can empirically attack post 38 you're just wasting your time. You say you agree with the "general thrust" of andrewcellini's post,,,, What "general thrust"? Since nothing of Post 38 is specifically contradicted empirically by andrewcellini.... What precisely is it you "especially" agree with in this "particular" case? You can all continue talking about false premises and false conclusions, airplanes falling from the sky, bridges collapsing without warning, weeping little children and impacted families, cruelty, misguided stupidity, the phase of the moon and whatever else, but the fact remains (no matter how many times you "Neg Rep" my posts) that no false premise, no false conclusion or any other error has been pointed out in post 38. The simple fundamental physical principles governing this scenario are clear (and have been for several centuries). What's to acknowledge? The building verifiably dropped like a stone at gravitational acceleration for 2.25 seconds (approximately 105 feet).... that's a fact. Trying to sandwich a period of free fall as a "Stage" between two other less than free fall "Stages" to get a fall time that doesn't "exhibit free fall" is the very definition of absurd. Does that mean that starting with Stage One of the complete collapse of a 110 foot tall bulding where it takes 5.71 seconds to descend one inch, followed by Stage Two where it descends at gravitational acceleration for 2.25 seconds (approximately 105 feet), and ending with Stage Three where it descends one inch in 10.28 seconds that it didn't "exhibit free fall" because the total fall time for the 110 foot tall building was 18.24 seconds? Preposterous. Post 38 remains empirically unassailed.... explosives brought down the building.

Planes falling from the sky, old bridges collapsing without warning, the impact on families, weeping little children, cruelty, misguided stupidity.... Was there an on topic comment in there somewhere? Nothing you've said empirically contradicts Post 38,... explosives brought down the building.

Moderator comment acknowledged.

Though the possible composition and placement of the explosives can still be debated, the fact that they were indeed composed and placed cannot. Newtonian physical principles haven't changed. It's physically impossible for the lower part of the asymmetrically damaged building (three core columns and nine perimeter columns) to have progressively/naturally collapsed in any way that could result in the upper part of the building symmetrically descending straight down through itself (starting with column 79, circled below), through the path of greatest resistance, at anything near gravitational acceleration for any period of time.... ....and there is absolutely no mode or combination of modes of progressive/natural structural failure driven solely by gravity that can ever give rise to the conditions required (below) for free fall to have occurred at any point during its descent.... ....and anyone who believes otherwise (below) belongs in a lunatic asylum.... There is simply no point during a natural progressive gravity driven collapse of a steel frame skyscraper like this where one could say.... "Hold it.... right there! That's the point where all the steel columns and structural components that were supporting the building just a moment ago (with an area greater than that of a football field) will undoubtedly be found to be behaving in a manner very much like air (below left).... so much so that it will take very careful calculation to tell the fall times apart during this period of the ongoing progressive structural failure (below right)".... How could anyone who made it through high school really believe that it's not only possible but probable that the lower asymmetrically damaged part of the building progressively/naturally collapsed in a way that resulted in the upper part of the building actually accelerating as it descended symmetrically straight down through itself, through the path of greatest resistance (below right), and also, incredibly, that driven on solely by gravity it actually continued to accelerate so nearly to gravitational acceleration (below left) as to require very careful calculation for any difference between the two to be detected.... So far, the explosion model (below) is still the only one.... ....that can realistically match and empirically be expected to create the conditions (below) that we know must have existed.... ....beneath the literally falling visible upper part of the building (below) during its observed largely symmetrical descent at gravitational acceleration for approximately 105 feet in 2.25 seconds.... The undisputed confirmed observation of a significant period of gravitational acceleration.... ....means an explosion or other type of event must have occurred that was powerful enough to quickly remove the support from beneath the upper part of the building (below right), either all at once or incrementally in advance of its descent, permitting it to descend at gravitational acceleration for the observed period and under the conditions required (below left) for free fall to occur.... After well over a decade, still, no other empirically verifiable explanation has been advanced. The building was brought down by means of explosives.... that's just the way it is. Interesting that another post, firmly based on well known physical principles, immediately gets a "Neg Rep" in a science forum!

So we agree on the conditions required for free fall. And I haven't seen anyone dispute the formal analysis of the event.... ....carried out by the NIST that determined free fall descent occurred for 2.25 seconds, or approximately 105 feet.... ....in "Stage 2" of the graph accompanying the final report.... ....so I'll assume we can also agree on that.

swansont "Actually it's physics, and it's the same argument you make: that you don't get free-fall if you are colliding with material, but you will get free-fall if you don't." I disagree. How can it be the same argument I'm making when I haven't made any argument? In other words, I haven't advanced any theory or made any argument, claim or assertion, I've only written a brief description that echoes the well known conditions under which free fall occurs.... "....gravitational acceleration only occurs when an object falls un-obstructed under the influence of gravity alone. If there's anything beneath the falling object that would tend to impede it's downward progress, then some of its gravitational potential energy will be used in overcoming the resistance and it will not be found falling at gravitational acceleration compared to an identical object falling un-obstructed from the same height at the same time over the same distance...." ....accompanied by an example animation illustrating the required conditions and expected results.... ....along with another example animation that just illustrates why a difference in fall times can be expected between a free falling object (right) and another identical object (left) that encounters resistance, in this case a frangible impedance scenario.... Control on the right, details.... http://picasion.com/pic76/ef2992a1bed34a1ad9d2e8f520c5ad7e.gif I thought I made it pretty clear in post 21 that my goal was to agreeably define free fall before continuing, I don't think I missed anything (open to correction).... Does anyone disagree with the definition* of gravitational acceleration as presented here before we continue? *The Imperial System of measurement used can easily be converted to any system one wishes.... it won't change the outcome.

No, the schematic isn't an argument, it just illustrates free fall. How could a schematic be an argument? I'm just curious really, I don't have an argument/theory per se.... and the imperial system was good enough for the NIST to use in it's analysis and final report. So what's your opinion of the whole thing Ringer? Do you agree with the NIST that the failure of one column caused/triggered the global collapse?

You mean this? Pantaz "When you added "simultaneously" you have indeed proffered a false premise. The report specifically states the measured free fall occurred prior to contacting additional material. Certainly, some portions of nearly any collapsing structure will experience brief periods of "free fall" between the instances of contacting/impacting neighboring debris." That's semantics, not an effective argument. Maybe we should define what we're arguing about before we argue about it. This is a schematic representation of gravitational acceleration.... So, free fall only occurs when an object falls un-obstructed under the influence of gravity alone. If there's anything beneath the falling object that would tend to impede it's downward progress, then some of its gravitational potential energy will be used in overcoming the resistance and it will not be found falling at gravitational acceleration compared to an identical object falling un-obstructed from the same height at the same time over the same distance.... Control on the right, details.... http://picasion.com/pic76/ef2992a1bed34a1ad9d2e8f520c5ad7e.gif The idealised object, or Control (above right), depicted in the animation is for comparison as a constant reminder of what happens to an object in free fall. The scenario (above left) in the animation is depicted on the left."

Right. I haven't seen an effective argument yet.... Do you have an effective argument? Interesting that my opening remark, firmly based on well known physical principles, immediately gets a "Neg Rep" in a science forum!

runlikell "This is astonishing. How could this (free fall) be possible without the use of controlled demolition techniques...." It's not possible. In spite of all the drivel here to the contrary, no natural progressive structural failure or collapse (except for bridges and other structures that pass through air) could have created the conditions required for gravitational acceleration to have occurred at any point during the collapse of the building.

hypervalent_iodine "Hi Aemilius, I've removed the link from your OP as we don't allow blatant attempts at advertisement on SFN (see here ). If you wish to discuss your mechanism, please do so here." Blatant attempts at advertising? Are you nuts? I read the rules before making that post, and your characterization of my referring your members to another science forum topic as being a blatant attempt at advertising (trying to sell something) is simply ridiculous. I'm not selling anything and neither is the science forum I linked to, which leaves me to wonder.... What's your real motivation here hypervalent_iodine?

Interesting forum topic shaping up here. A bit of a bore until it gets to the concept near the bottom of page three.... Link removed