Creative Speculation
Related: About this forumThey shall be known as Bush's Laws of Motion
from now on.
the events of 9/11 prove one thing: the known laws of physics are out of date and require immediate updating, in light of the official reports. because the laws of gravity are so 17th century. and Isaac Newton was obviously a conspiracy nut trufer.
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zappaman
(20,618 posts)You have amply demonstrated you know nothing about physics and even less about gravity.
Would be funny if it wasn't so sad.
I know nothing about the new fangled post-9/11 physics.
care to explain them to me?
William Seger
(11,082 posts)... is exactly the same as pre-9/11 physics, despite the "truth movement" attacks. For example, you can find an actual-physics-based explanation for the "near free fall" acceleration of the collapse in this paper by Dr. Frank Greening. If you don't like that one, there are plenty of others that take completely different approaches and arrive at the same general conclusions.
The mere fact that you're baffled by the collapses doesn't mean any new physics are required to explain them. Maybe you're a little too willing to be baffled...
zappaman
(20,618 posts)Care to link?
gyroscope
(1,443 posts)only problem is, I have a hard time understanding Bushspeak.
would you (or anyone else) care to translate? thanks in advance.
Bolo Boffin
(23,872 posts)For one, making it seem that the upper section could have been supported by a crane. It totally throws your mind's perception of the event off.
For two, debris that fell out and was free to fall did indeed accelerate faster than the upper section.
There is nothing that violates the law of gravity about this event.
gyroscope
(1,443 posts)what difference does it make?
the debris was propelled outward and downward by the force of the explosions.
it wasn't just gravity.
OnTheOtherHand
(7,621 posts)Obviously your opinions don't have a lot to do with the laws of motion.
gyroscope
(1,443 posts)the explosions that were reported by hundreds of firefighters, journalists, and others on the scene. just the people who were there. that's all.
nothing to see here, move along.
because you know, the NIST people were not on the scene.
yet they somehow know better than all the witnesses who were?
yeah, that makes sense.
zappaman
(20,618 posts)Good to know.
How many people are we up to now that were in on this?
gyroscope
(1,443 posts)A) NIST?
or
B) Innumerable on-scene witnesses who corroborate each other?
One of them is lying. Guess which one?
OnTheOtherHand
(7,621 posts)I guess we could quibble about the definition of "explosions" -- that's been done extensively over the last decade.
But if you really believe (not that you said this) that many eyewitnesses share your opinion that the Twin Towers were demolished by explosives, then NIST is the least of your problems. The people who believe that generally aren't eyewitnesses; they seem disproportionately to be people who spend lots of time staring at videos. If eyewitnesses tended spontaneously to form the impression that the towers were demolished by explosives, then the movement wouldn't have to seine for a handful of people to say so at its events; people would have been saying so all over New York City.
It's logically possible that the eyewitness testimony could support an explosive demolition scenario. But it's remarkably hard to get folks to try to lay out such a scenario -- and I can't think of anyone who has tried to develop such a scenario around eyewitness statements. There must be someone, somewhere, but it rarely if ever happens here. I've interacted with a bunch of people who believe in CD, and I can't think of any who seemed to have formed their view based on eyewitness evidence.
Bolo Boffin
(23,872 posts)Ace Acme
(1,464 posts)Bolo Boffin
(23,872 posts)Since both Democrats and Republicans accept the common understanding of how these buildings fell, framing this as "Bush Laws of Motion" is needlessly political.
zappaman
(20,618 posts)but the poster who claims this can't point us to it...
jesters
(108 posts)The "common understanding" of how the buildings fell is still based on FEMA's pancaking model, which NIST declared non-viable. NIST never provided a collapse progression model of its own, and few "common folk" have bothered to read Bazant.
So there really is no "common understanding" of the WTC destruction that's based on any kind of realistic or credible model.
Ace Acme
(1,464 posts)For three years, FEMA's zipper/pancake theory was conventional engineering wisdom. Then in 2005 NIST overturned the zipper/pancake theory--and with no debate, discussion, hand-wringing, or defenses, the column-failure theory becomes
conventional engineering wisdom.
gyroscope
(1,443 posts)of Dubya's well known general distaste for science and facts.
and that the official reports were produced under his administration.
I'm not accusing you or anyone else of being a Bush supporter.
William Seger
(11,082 posts)"Truth movement science" is an oxymoron.
gyroscope
(1,443 posts)I'm flattered but I think the term 'common sense' would suffice.
what do you think happens when the two blocks are dropped?
do they reach the ground at the same time?
or should only one of them reach the ground at all?
what do you think Sir Newton's answer would be?
William Seger
(11,082 posts)> do they reach the ground at the same time?
No.
> or should only one of them reach the ground at all?
No.
> what do you think Sir Newton's answer would be?
No.
That was easy.
> I'm flattered but I think the term 'common sense' would suffice.
You're flattering yourself, but the term is "nonsense."
gyroscope
(1,443 posts)between a cartoon and an illustration?
or should only one of them reach the ground at all?
No.
Upon being dropped from the crane, you're saying the left upper block reaches the ground after smashing through the entire length of the much more massive lower block? Going through the path of most resistance? How in the world does that work? By applying Bushonian laws of physics? Or should I say Nistonian? Magic? David Copperfield? Wow.
That can happen in a cartoon maybe not in the real world.
AZCat
(8,345 posts)What kind of a bizarre argument is that? Anywhere but down is unlikely, considering the objects involved are all exposed to a (quasi)uniform gravitational field.
gyroscope
(1,443 posts)it isn't going anywhere.
the upper block isn't going anywhere (beyond the distance of the gap between it and the lower block). once dropped from the crane, it drops onto the top of the lower block and it rests there. period.
considering the objects involved are all exposed to a (quasi)uniform gravitational field.
the object involved is also exposed to a more massive object resting between it and the ground. did you forget to mention that little detail?
AZCat
(8,345 posts)Happens pretty often, actually. The mass of the object isn't that important (except when considering momentum transfer).
cpwm17
(3,829 posts)The towers when intact and static can support a few times their own weight. How then can the same tower withstand a force many times that after failure has already occurred and not collapse further. You are imagining some new type of physics.
OnTheOtherHand
(7,621 posts)To put AZCat's point about local failure more vividly, you might as well argue that a brick can't smash through a car windshield because, after all, the car has so much more mass than the brick.
Let me attempt to anticipate a likely defense mechanism: yes, yes, of course that is not a good model of the tower collapses. It isn't intended to model the tower collapses; it's intended to illustrate the gaping hole in your reasoning. That "more massive object" isn't just an object; the "lower block" isn't just a block. Your model neglects a really basic fact about a building: it's, y'know, built. It isn't a point mass; it has components and structure.
Of course, the "upper block" isn't just a block, either. Damage is occurring to both the upper floors and the lower floors; ever more mass is falling, some of it within the footprint of the tower, some of it outside. The upper floors don't have to remain intact all the way to the ground (or the pile), nor do they have to smash everything in their path.
If you can't even wrap your head around this possibility -- if you can only imagine that the upper floors drop onto the top of the lower floors and rest there, because there are more lower floors than there are upper floors -- then I guess you'll be pretty puzzled by the professional literature.
cpwm17
(3,829 posts)They might as well claim that the towers couldn't have collapsed because the towers were attached to the earth; and the earth is far more massive than the top sections of the buildings. It's essentially the same argument they are apparently already making taken to its logical extreme.
OnTheOtherHand
(7,621 posts)I decided that it is more appealing (in general) to argue that the windshield is part of the car than that the towers are part of the "built earth." Either way, you have a model that would be fine for some problems, and fails miserably in others.
People who trash the various Bazant models, but seem oblivious to the holes in their own models, don't really seem to understand what models are for. I think that is unfortunate quite apart from any particular debate.
Ace Acme
(1,464 posts)The persistence of 40 stories of the lower core structure after the outer floors had fallen down shows that Bazant's piledriver is a myth.
Had the piledriver remained intact, it would have impaled itself on the intact lower core.
gyroscope
(1,443 posts)Here you go:
1) so how do you explain the total destruction of the core columns, which this NOVA documentary ignores in their ridiculous pancake model?
2) how do you explain that the core columns are very massive at their base getting progressively thinner as they rise toward the top? the 'components and structure' are much more robust at their base then they are at the upper block. how is it possible for the latter to destroy the former? do you have a model that can illustrate this phenomena?
3) how does the upper block remain intact all the way to the bottom without destroying itself on the way down and violating the third law of motion?
for every action, there is an equal and opposite reaction. remember?
OnTheOtherHand
(7,621 posts)Is there any point at which you take it upon yourself to respond to my points? Or is that for the little people?
I couldn't care less about the PBS animation, except as an apparent tacit concession that your previous argument is a smoking ruin.
gyroscope: 3) how does the upper block remain intact all the way to the bottom....
gyroscope: 2) ... the 'components and structure' are much more robust at their base then they are at the upper block. how is it possible for the latter to destroy the former?...
It's true: no one ever said that you had to read my messages before replying to them.
gyroscope
(1,443 posts)How about Bazant's model?
You like that one better?
In Bazant's drawing, the little block looks pretty intact to me.
How is that possible?
OTOH: ...The upper floors don't have to remain intact all the way to the ground (or the pile).
And what about the big block? Why does it disintegrate while the little block remains relatively pristine?
Nuclear Unicorn
(19,497 posts)--erm--
OnTheOtherHand
(7,621 posts)How is that possible?...
And what about the big block? Why does it disintegrate while the little block remains relatively pristine, until it doesn't?
FIFY.
Those questions are answered in the paper. Should I assume that they aren't serious questions, or that you haven't read the paper?
Against my better judgment, I'll try to answer in simple words. In that model, between the "top" and the "bottom" is a compacted zone of rubble, which increases in mass and is accelerated by gravity. As long as it is falling, that rubble is crushing the "bottom," not the "top." That is perfectly consistent with Newton's laws -- and if you can understand that the "top" isn't the only thing that falls, you'll be closer to understanding the professional literature, not to mention the video evidence.
It's not nearly enough to denounce the model as unrealistic. To justify your apparent concern with the timing of crush-up vis-a-vis crush-down, you'll not only have to make your case -- ideally with at least as much formal analysis as Bazant and Verdure -- but you'll also need to make a rigorous case that the timing matters to the fate of the towers. I am not holding my breath.
Ace Acme
(1,464 posts)There's only the fact that NIST does not explain the collapses, and obviously Bazant doesn't either.
William Seger
(11,082 posts)... to a paper that explains that, using nothing but "old-school" physics, analyzed by someone who isn't even a U.S. citizen (Canadian) much less part of the Bush administration, and you completely ignored it. It seem not to occur to you that there are a LOT of people in the world who can understand that paper, and could also recognize a valid, science-based criticism of it if one were offered. Your personal incredulity, however, is not evidence of anything but itself.
gyroscope
(1,443 posts)Oh I remember him now. Isn't he the guy who said the laws of physics were suspended on 9/11!?
Greening: "Newton's 3rd Law applies to bouncing billiard balls, not the interiors of collapsing buildings ........"
Where'd this guy get his degree? Bob Jones University?
To see more of Greening's brilliant mind at work, go here:
http://journalof911studies.com/volume/2009/FGvsNewton.pdf
Jaw-dropping stuff.
OnTheOtherHand
(7,621 posts)Chandler had said, "Moving downward without deceleration while crushing columns designed to support several times the weight...now that's a problem" -- and Legge adds a bracketed gloss that "it would violate Newton's third law."
But it doesn't violate Newton's third law. As several of us have tried to explain, the acceleration of the falling mass will remain positive upon collision unless the reaction force of collision actually equals or exceeds the gravitational force upon the falling mass.
Greening could have said something like this: In high school physics classes, collisions between a moving object and a stationary object almost always cause the moving object to slow down -- because, generally, no other force is accelerating the moving object. (If it's a billiard ball, then gravity is trying to accelerate it right through the table, but the table is pushing back.) But if the object is falling, then the gravitational force does have to be taken into account. Newton's Third Law still applies to the collision, but contrary to Truth Physics, it doesn't dictate that a falling object has to decelerate when it collides with something.
jesters
(108 posts)whether gravity is producing it or some other force. Newton's third law is not changed by the fact that gravity is creating the collision.
I can't believe you're trying to suggest this.
This is absurdity.
cpwm17
(3,829 posts)What's the property of collisions that causes a change of velocity of the colliding bodies? Could it be force?
What is the property of gravity that causes a change in velocity of bodies in a gravitational field? Is it also force?
So what happens when the force of gravity on a body is greater than the opposing force from the colliding object? Well that's easy. The body accelerates through the collision in the direction of gravity - only the acceleration during the collision is not as great.
Bolo Boffin
(23,872 posts)jesters
(108 posts)He's the one who's having problems with this concept.
Nothing you have said here contradicts what I said. Do you understand this?
But then you're trying to take these everyday common sense principles and stretch them to imply that gravity can pull the top portion of a building through itself at a rate just a little bit under free fall. It cannot. There is no theory or model existing today that shows this can happen. It cannot.
AZCat
(8,345 posts)that directly contradict the SECOND law (and then got hostile when I pointed this out).
Your ignorance of physics fundamentals is going to constantly interfere with your understanding of the various models of the collapse. I suggest rectifying this, otherwise you're continually going to be a laughing-stock here.
AZCat
(8,345 posts)He tried to call it a force the other day.
OnTheOtherHand
(7,621 posts)I didn't say a damn thing about changing Newton's third law, based on the cause of the collision or anything else.
If you can't manage to respond to arguments I actually make in short, simple posts, why would you expect to be taken seriously when you attempt to critique JEM articles?
jesters
(108 posts)Ace Acme
(1,464 posts)by the gravitational force transmitted by the falling mass.
But neither NIST nor Bazant even tried to show us how they got a falling mass. They simply assumed it.
It fell because it was falling. Grandma died because death overwhelmed her fading vitality.
That's not good enough. Democracy demands a higher standard than circular arguments.
AZCat
(8,345 posts)By calculating DCRs in excess of 1 (based on their analysis of impact damage and subsequent fires) and examining the sequence of failures that likely resulted, the NIST demonstrated a probable collapse initiation (i.e. a falling mass).
Ace Acme
(1,464 posts)AZCat
(8,345 posts)If you did, you'd find a lot of your arguments to be incorrect. Like this one. I suggest you do more than read the summary as well, since that may summarize topics that get much more detail elsewhere in the supporting documents.
William Seger
(11,082 posts)Last edited Thu Jan 5, 2012, 12:41 PM - Edit history (1)
Newton's third law does not apply to collapsing buildings the way that Chandler is applying it. The irrefutable proof of that is that Chandler's analysis would predict that Verinage demolitions are impossible without weakening all the floors.
In fact, they proceed very much like the Greening energy transfer analysis that you would like to avoid discussing. I personally find it jaw-dropping that anyone could watch a Verinage demolition and still not see that Chandler's analysis cannot possibly be correct. In all the "third law" blather the "truthers" dumped on Greening in its frantic effort to find an excuse to dismiss his other arguments, I can't find much understanding at all of what he was really getting at, which was Chandler's obviously improper handling of the dynamic, gravity-driven scenario. "Truthers" seem to think that attacking Greening's attempt to explain what was wrong with it not only somehow validated Chandler's analysis, it also discredited Greening's collaboration with Bazant, Le, and Benson on a paper that "truthers" apparently can't refute and so resort to personal attacks on all of those authors. But when the smoke cleared, Chandler's interpretation of the collapses was just as idiotic as it always had been, whereas Greening's analysis explains both the WTC collapses and Verinage demolitions in a way that agrees with observation.
And, I see you would also like to ignore my point that Bazant and Greening aren't the only people who have analyzed the collapse and came to the same conclusion: There is no need to resort to bizarre explanations involving imaginary causes for which there is not a shred of credible evidence. On the other hand, you expect us to be impressed with YouTube videos that conclude that Verinage demolitions must be impossible because they violate laws of physics? No thanks.
OnTheOtherHand
(7,621 posts)I think he would say that the Balzac-Vitry verinage proves his point, because the upper block decelerated after impact. In fact, that's what he seems to be saying in the video that jesters linked to in the NTA thread. Of course, his argument is a mess.
I may have the 'history' wrong, but it seems that Chandler shifted from arguing that impact entails a change in acceleration to arguing that it entails a period of negative acceleration, perhaps not even noticing that his argument had changed.
Yeah, trying to use Chandler vs. Greening to discredit Greening is... odd.
ETA: Forgot to mention that your verinage link seems to be broken.
William Seger
(11,082 posts)... by saying a jolt was present in Balzac-Vitry so we should see it in WTC. What I'm referring to is his North Tower Acceleration video. Following the logic of that video, since the Verinage demolitions also show the buildings collapsing at about 2/3 g acceleration, then the structure below was only resisting 1/3 of the weight of the structure, whereas it had been designed to withstand 3 times the weight, leading to the conclusion that the Verinage people are secretly destroying the structures through some means other than dropping the top on the bottom and letting gravity do the rest. To the best of my knowledge, Chandler has never addressed that aspect of Verinage, but it would certainly be entertaining to see him try.
OnTheOtherHand
(7,621 posts)I think part of the problem is that, as we discussed before, it's hard to tell what he intends to argue. In his Balzac-Vitry analysis, he says that the top is accelerating at -8.5 m/s^2 initially, then at -2.1 m/s^2 for about 0.8 s "as the contact begins," then at +3.3 m/s^2 (deceleration relative to gravity) for about 0.4 s when the two sections "fully engage." Hmmmmm. Wow, that's facially weak. (Just what does Chandler think is happening for all that time between the beginning of contact and full engagement?) But anyway, I mention the numbers because I'm not sure what you have in mind by "about 2/3 g acceleration" -- maybe an average, maybe different demolitions.
I imagine Chandler would say that you completely missed his point: his argument that the structure below is only resisting a fraction of the weight of the falling structure (to paraphrase your paraphrase) applies unless the falling block "actually impacts" the structure below (around 2:05 in the NTA video) -- and we know that it didn't because of the (supposedly) uniform downward acceleration.
Of course, that raises the question what Chandler thinks is happening to provide that resistance. (IIRC, Bolo tried to get at that.) Hell, I'm not sure I can enumerate all the questions it raises.
William Seger
(11,082 posts)... as being about what you get if you consider just the total collapse time and distance, i.e. it's just the average acceleration. But again, I claim that the problem with Chandler's WTC analysis is that that's also just looking at an average acceleration, so if Chandler wants to claim it's fundamentally different from a Verinage, he needs to explain why the averages are so similar. A bigger problem is that apparently more careful measurements have detected decelerations in the WTC collapse, so Chandler's premise is simply disproved.
OnTheOtherHand
(7,621 posts)It's another way of seeing why Chandler ought to be surprised that the towers are falling so slowly, if he thinks that the bases are being sequentially blown away (or whatever he believes). It might even reach someone.
Chandler doesn't think he is "just looking at an average acceleration." But even his own measurements indicate changes in acceleration, which he apparently rationalizes as within measurement error. (And, as I said in the other thread, maybe they are -- but either way, he obviously hasn't demonstrated "uniform downward acceleration."
I've been idly curious how much one could conceivably infer from the closest possible analysis of the videos. Certainly Chandler's 5 Hz results seem compatible with actual deceleration, or not. I'd be wary of calling the finding you describe a "bigger problem," since I wouldn't want to risk helping Chandler move the goalposts the entire length of the field -- but, if it is any good at all, at least it underscores how weak his analysis is.
ETA: OK, I came across a thread where femr2 lays out the evidence for decelerations, and Tony Szamboti dismisses it as measurement error. About what I would expect.
ETA2: Oops, strike that: Szamboti dismisses it as deliberate obfuscation: "Anyone who really wanted to muddy the waters might claim to be MIHOP while offering confusing data and positions, which is all I have really seen you attempt to do." Damn those faux MIHOPers with their confusing data!!!!
jesters
(108 posts)that is posited by Bazant (and needed for collapse progression) there would be a massive jolt measurable instantly by the eye and obvious on a graph. This is the whole point. Tony Szamboti estimates a 45% loss of kinetic energy even if half the columns missed each other. The amount of resistance actually seen was less than what could support the static load. The upper section just fell through it while gaining velocity.
You can't have an amplified load without that impulse. Without an amplified load, you don't have collapse progression.
OnTheOtherHand
(7,621 posts)Can you imagine a scenario in which half the columns missed each other and the other half collided in the manner that Szamboti imagines -- one that in some way resembles the observations?
I've watched people try to explain to Szamboti what's wrong with his reasoning, and I even tried it myself. You may think there is some sinister reason why he hasn't won the debate, but I really don't think there is.
Ace Acme
(1,464 posts)That's just the 1st law of thermodynamics. He's not going to argue otherwise.
He argues that impact involves a negative acceleration in the case of Balzac-Vitry because that's what the data show.
We have no way of knowing if the building in the video was subject to pre-weakening in the lower stories. Assuming there was none is bad science.
AZCat
(8,345 posts)"1st law of thermodynamics"? Maybe you should stay out of discussions where you're not conversant with the lingo.
Ace Acme
(1,464 posts)the law of conservation of energy.
It's hard to believe that you guys have been able to convince anyone that you know what you're talking about when you so clearly don't.
AZCat
(8,345 posts)It's a special case of the law of conservation of energy, and it's used for thermodynamic systems (that'd be heat and work).
Besides, you're looking for the first law of motion, which is not the same thing at all. Again, maybe you should stay out of discussions where you're not qualified to participate.
Ace Acme
(1,464 posts)Don't tell me what I'm looking for. Clearly you don't even know what you're looking for.
AZCat
(8,345 posts)Keep digging the hole deeper - you're only hurting yourself.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)So nice of you to double down on your mistake - it makes your ignorance all the more obvious.
Ace Acme
(1,464 posts)I bet you say that to all the guys.
AZCat
(8,345 posts)I'm not the one confusing basic physics principles. I'm quite comfortable with my grasp of them. You, on the other hand, need to put in some work. Have you considered tutors? I've tutored a number of people and I find sometimes a one-on-one approach can be successful for those who don't have as much luck in a classroom environment.
Ace Acme
(1,464 posts)Last edited Fri Dec 6, 2013, 12:51 PM - Edit history (1)
Besides bullying, pedantry, and your comfort with your illusions (otherwise known as solipsism), I mean.
AZCat
(8,345 posts)A competent grasp of the principles of physics. If somehow that equates to bullying and pedantry, I don't get the connection.
Ace Acme
(1,464 posts)Anonymous internet posters make grandiose claims all the time. Only fools think we should believe those claims.
AZCat
(8,345 posts)and an indication of your lack of familiarity with the subject matter. There's nothing grandiose about me pointing out the difference between the first law of thermodynamics and the first law of motion. There is, however, something grandiose about your repeated, heated defense of an obvious mistake.
Ace Acme
(1,464 posts)I never said there was no difference between the first law of motion and the first law of thermodynamics.
You are constantly criticizing your own inventions.
AZCat
(8,345 posts)Instead you demonstrated you couldn't tell the difference, which is just as illuminating.
Ace Acme
(1,464 posts)It's "you can't win" no matter what livery it's dressed up in.
AZCat
(8,345 posts)To qualified professionals it's a relevant, and interesting difference. Your inability to distinguish (and your lack of concern) demonstrates your lack of qualifications.
Ace Acme
(1,464 posts)would expect us to be dumb enough to mistake a cat for a qualified professional. Toonces can't drive very well, can he?
In the current context there is no need to distinguish between the law of conservation of energy and the
first law of thermodynamics.
AZCat
(8,345 posts)Initially you were just wrong, now you're incoherent. Is this strategy intended to distract from your inability to differentiate between basic physics concepts? It is obvious to those with sufficient knowledge that the first law of motion (which you should have referenced) is substantially different from either the first law of thermodynamics or conservation of energy. You, on the other hand, continue to confuse them.
This difference between you (who can't tell the difference) and me (who can) means that we can't have an interesting conversation about the subject at hand, because you lack the foundational knowledge necessary to have a relevant opinion. Instead this subthread has degenerated into you becoming defensive and incoherent when challenged. That's not very worthwhile, unfortunately, and this subthread probably deserves to die a quiet death.
zappaman
(20,618 posts)But I think we passed that point some time ago.
Are you enjoying this latest stay here?
Ace Acme
(1,464 posts)can not also pretend to be a qualified professional who has all the answers but just can't be bothered to share them because they're oh so complicated.
That posture may have been very effective over the years in intimidating honest people with honest questions (and certainly it requires little energy of you--you can simply recycle the same vague grumbling as always), but it won't work on me.
AZCat
(8,345 posts)That is a very strange claim, and doesn't appear to have anything to do with the topic of this sub-thread. What is of interest, however, is your apparent inability to understand the difference between a couple of basic physics concepts, and how that interferes with a productive conversation about the collapses of September 11th. Care to comment on that, or do you find a discussion of cats to be more your style? If so, I suggest you seek other areas of this forum - we're not particularly cat dense here.
Ace Acme
(1,464 posts)The issue was changes in acceleration due to the absorbtion of kinetic energy in doing work processes on the buildings' structure, and the fact that energy can be neither created nor destroyed, and the need for an accounting of the energy budget of the collapses.
And you want us to run off after a pedantic red herring.
It seems that you are blind to the fact that anonymous internet posters have no professional credentials, and only a fool would believe that they do.
AZCat
(8,345 posts)However, I'm willing to move on if you concede you were wrong. Is that so hard for you?
Ace Acme
(1,464 posts)The first law of thermodynamics says energy can neither be created nor destroyed.
The law of conservation of energy says energy can neither be created nor destroyed.
For our purposes here, they are synonymous--unless our purpose is distraction and pedantry and a failed effort to intimidate.
AZCat
(8,345 posts)Shall I quote your original statement? You said (in post #67):
That's just the 1st law of thermodynamics.
Please explain how the first law of thermodynamics relates to changes in acceleration.
Ace Acme
(1,464 posts)Thus impact necessarily takes energy away from the kinetic budget.
AZCat
(8,345 posts)Impacts don't necessarily reduce the kinetic energy. If you draw a free body diagram it should become obvious to you.
Ace Acme
(1,464 posts)That's the first law of thermodynamics.
That's the law of conservation of energy.
Maybe Tony Szamboti had a "problem" with a bunch of jeering clowns at JREF, but the laws of physics are on his side and mine.
AZCat
(8,345 posts)Do you know what a "free body diagram" is? Maybe you should look up some examples, and then try drawing one for the situation you're trying to understand. Then maybe(!) you'll understand why you're wrong. You should probably write out the equation form of the law of conservation of energy while you're at it, and take a close look at the variables included.
Tony has a similar problem to yours, that his opinion of his technical skillset is far higher than actually warranted. Too bad for you guys that it is immediately obvious to qualified people who aren't afraid to correct your mistakes.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)The fundamental equations are quite simple, and your mistakes become apparent once you compare the equations to your claims, or if you draw a simple free body diagram.
A supplemental point is that your grasp of physics is so poor that you can't even work out why you're wrong, even with hints from me. That point doesn't need extra evidence from me - you're doing a fine job supporting it on your own.
Of course, the one thing I can't overcome is your (rather ironic) certainty that you're right, no matter how obvious your wrong-ness is to those who are more capable.
Ace Acme
(1,464 posts)The equations are simple, and the laws themselves are even simpler.
Energy can be neither created nor destroyed. Your attempts to drag equations and diagrams into the issue are red herrings.
I sense that this kind of bullying has served you well in the past.
AZCat
(8,345 posts)then why don't you show your work?
C'mon, you claim to be familiar enough with the laws of physics to make sense of them - this should be easy. What's the equation that you think supports your claim that "impacts necessarily reduce the kinetic energy"? Please write it out, so we can point out where you went wrong. Or you could draw a free body diagram - that should work just as well.
Or you could just admit you're unqualified to engage in the discussion and save a little face.
Ace Acme
(1,464 posts)Impacts necessarily reduce the kinetic energy.
1. impacts absorb kinetic energy
2. energy can neither be created nor destroyed
and thus
3. impacts convert some portion of the kinetic energy to the effects of the impacts: the work of breaking and twisting and pulverizing the structure
You are playing dumb.
AZCat
(8,345 posts)You keep talking about kinetic energy, but you are missing something else important. Why don't you think about what comprises the energy system for a falling body, and what concepts might be absent from your model?
Hostile retorts aren't going to improve the quality of your work, unfortunately. You should just relax and try to learn a little.
Ace Acme
(1,464 posts)If the fundamental laws of physics are wrong then publish your paper, collect your Nobel.
AZCat
(8,345 posts)C'mon, all the smart kids are doing it. You could even use Google to help you solve the problem!
Ace Acme
(1,464 posts)Energy can be neither created nor destroyed.
AZCat
(8,345 posts)Your mistake involves physics concepts so incredibly basic that I'm not even sure there's a point in trying to help you understand where you went wrong.
This is why people with less than competent technical skills are irrelevant to the discussion. Thank you for proving my point once again.
Ace Acme
(1,464 posts)based on nothing but your own non-existent authority.
It seems that it worked for you in the past.
AZCat
(8,345 posts)Will no-one think of the children?
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Oh wait, you don't know. That's right - how could I forget? You've left a trail of wrongness leading up to this post that should stand as a stark reminder.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)How would you know that it's not in my posts? You can't even identify the missing piece from your own work!
Ace Acme
(1,464 posts)Toonces don't drive so good, does he!
AZCat
(8,345 posts)Your posts are substantial evidence of your lack of understanding of physics fundamentals. You haven't even demonstrated an interest in exploring the error and possibly learning something in the process, instead choosing to waste time with irrelevant posts about cats. Why is that? Are you that concerned with admitting ignorance that you'd rather maintain an increasingly bizarre defense of your mistake?
Ace Acme
(1,464 posts)There is nothing bizarre about my arguments. Apparently you've been able to function as some kind of Great and Powerful Oz here on this board and frighten everyone away with your vague allusions to your own omniscience, but it won't work with me.
AZCat
(8,345 posts)That's why you won't write out the energy equation - it's repelled by your anti-physics field.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)You're missing some bits, unfortunately for you.
Ace Acme
(1,464 posts)the dynamic loading perpetual motion wheel.
http://www.lhup.edu/~dsimanek/museum/overbal.htm
AZCat
(8,345 posts)Is that really going to be your response? Do you not have any clue what you're missing?
Ace Acme
(1,464 posts)AZCat
(8,345 posts)That's pretty bad - I'm not sure if your situation is recoverable.
AZCat
(8,345 posts)Usually that's when the most amusing content is created. If you try hard enough, you might end up in the category with such greats as spooked911's rabbit cage, petgoat's rake-on-rake, or Richard Gage's cardboard box video. I sincerely feel you have what it takes to succeed.
zappaman
(20,618 posts)Memories...
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=125x56836
and for giggles...
Ace Acme
(1,464 posts)As any competent person knows. Thanks for demonstrating your ignorance.
zappaman
(20,618 posts)now will you demonstrate why a cardboard box and a 1700 foot tower of steel and concrete are the same?
remember to show your work!
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Just so we're clear.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)I'm not sure how many times I need to point you in the direction of a major mistake in your energy equation before you figure it out. It took Tony Szamboti somewhere around a year (IIRC) before he saw the light - are we going to see a similar delay with you?
Ace Acme
(1,464 posts)AZCat
(8,345 posts)He'd just disappear for a few months, then come back for another round. Sometimes he'd have an improved model, which at least showed he was learning from his mistakes.
AZCat
(8,345 posts)That's the difference between architects like Gage and competent professionals - one group understands that you can't just stack a bunch of cardboard boxes and expect dynamic similitude, and the other doesn't.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)I can buy that.
Ace Acme
(1,464 posts)cardboard boxes and buildings are subject regardless of scale.
AZCat
(8,345 posts)Similitude is more than "looks like".
Ace Acme
(1,464 posts)AZCat
(8,345 posts)You can't just expect your boxes to be un-boxes, right?
Ace Acme
(1,464 posts)AZCat
(8,345 posts)There's a reason Gage's presentation has entered into the internet's collection of amusing fails, along with spooked911's bunny cage and petgoat's "fork on fork".
Ace Acme
(1,464 posts)You're not getting it.
AZCat
(8,345 posts)It's only of minor impact, if all you care about is pandering to the uneducated. The rest of us will have to be excused while we obsess about dimensional analysis because we think it's important (which it is, kids - don't let Ace Acme lead you astray).
Ace Acme
(1,464 posts)There is no coefficient of scale to the 1st law of thermodynamics or Newton's 3rd law.
AZCat
(8,345 posts)The boxes fail as an analog for the towers because the physical principles rely on similitude. If you don't have that, then the boxes don't mean anything. This is why Richard Gage is mocked for his video, because he tried to use the boxes to say something that they simply can't.
Ace Acme
(1,464 posts)A rope is not water, but a rope demonstrates principles of waves that apply to water, to ropes, and to sound waves in air.
AZCat
(8,345 posts)The relationship between the relevant aspects of the two objects (building versus cardboard box) is different. Mass and area scale differently (hence the square and cubic relationships), so even if you built your scale model of the same material it wouldn't behave the same as the larger object. Since Gage was trying to show physical similarity, he was relying on dynamic similitude, except he can't. Because his model doesn't have it.
So no, he can't use the cardboard boxes to demonstrate the laws of physics that apply to buildings.
Ace Acme
(1,464 posts)You have spent so many years pontificating on obfuscatory minutiae that you can't see the Big Picture.
Gage was not claiming any physical similarity. It was a joke. He had a dry, two-hour lecture, much of which was over the collective head of his audience, and he injected a moment of levity with a perfectly valid demonstration of physical principles that are applicable equally to cardboard boxes and to buildings.
There was certainly no claim of dynamic similitude. And yes, he can use cardboard boxes to demonstrate the 1st law of thermodynamics and Newton's 3rd law. Do you claim those do not apply to cardboard boxes? Do you claim those do not apply to buildings?
AZCat
(8,345 posts)And I claim that you cannot use cardboard boxes to demonstrate how those principles apply to buildings (at least those buildings that are not constructed of cardboard and are of a similar size). This is because they lack dynamic similitude, a concept of which both you and Gage are (or were - you can at least type it now) apparently unaware.
Ace Acme
(1,464 posts)So no, neither Mr. Gage nor I were ignorant of it.
I'm sorry that you don't understand the principles that Mr. Gage was legitimately demonstrating with cardboard boxes, but that's not my fault. Some guys can't see the forest for the trees--especially if they don't want to.
AZCat
(8,345 posts)indicates either of you is aware of this at all. Thank goodness Gage isn't involved in buildings anymore. One can only hope you are similarly removed from the industry, for all of our sakes.
Ace Acme
(1,464 posts)... of the argument that Dynamic Loading Explains All. The buildings were just so huge, you see, that this huge mass at the top just irresistibly battered down the wimpy mass at the bottom!
AZCat
(8,345 posts)All these professionals are saying it does, so maybe you should consider it rather than poo-poohing the idea. It may come as a shock, but you and Gage aren't the most qualified of people and if a large group of professionals disagrees with you then it's probably because you're wrong.
Ace Acme
(1,464 posts)Or are these more secret people whose secret investigations have resulted in secret statements known only to you?
AZCat
(8,345 posts)It's somewhere in the mess of documentation, a whole list of people who support the report. Then you have the authors of the report itself, who are many in number. One assumes they count as "professionals".
Ace Acme
(1,464 posts)If the people who support the report are named in the report, they are hardly rendering an independent opinion, are they?
You can't name them. You claim they exist, but when you're challenged to name them, you say they're listed somewhere in 10,000 pages. No surprise there.
AZCat
(8,345 posts)whose opinions would normally be worth considering. Pretty convenient, especially when the opinions of those people are contrary to the theories you'd like to promote.
There are plenty of people who have read all the NIST reports. Just because you can't imagine doing it doesn't mean it doesn't (and hasn't) happen. That's an "argument from incredulity" and is pretty common with people of your disposition.
Ace Acme
(1,464 posts)Thanks for playing.
AZCat
(8,345 posts)I'm not sure where the information is listed. You see, this is old news for building professionals. We stopped discussing the interesting stuff years ago, after we worked out the kinks with the implementation of the NIST recommendations in the relevant codes and standards.
Ace Acme
(1,464 posts)And you think that should distract from your inability to name the secret people in the secret group who say the secret things in secret that you want them to say?
AZCat
(8,345 posts)is somehow "secret". This is quite telling about your general philosophy. Is this the same reason you're so bad at physics? Because nobody ever held your hand while explaining the fundamentals?
Ace Acme
(1,464 posts)... this belief?
AZCat
(8,345 posts)One would hope that a person like you who claims to be aware of the NIST's flaws would have come across the list as well. Or have you even bothered to read any of the reports you continue to disparage?
Ace Acme
(1,464 posts)NIST claims they did not analyze the towers' collapses.
That's all that is necessary.
AZCat
(8,345 posts)means that your opinion of the completeness of the NIST reports is irrelevant. Those of us who do have a better understanding do not generally agree with you. The reasons have been gone over multiple times, and just because you refuse to accept them doesn't mean they're any less valid.
Ace Acme
(1,464 posts)Last edited Thu Dec 19, 2013, 01:24 PM - Edit history (1)
... and how two buildings collapsed, but which declined to analyze the collapses, is inadequate.
You may as well argue that unless I'm a firearms expert I have no right to be concerned that a dozen bullets were fired in the RFK killing, though Sirhan's gun only held 8 bullets.
Your argument from your own aggressively-undemonstrated authority has no legitimacy.
AZCat
(8,345 posts)The rest is obvious to experienced professionals. The NIST was not tasked with explaining basic physics to laypeople. I'm sorry if you don't grasp the principles involved, but I don't feel responsible for your incompetence. I'm pretty sure the NIST doesn't either.
Ace Acme
(1,464 posts)across a robust structural core. And they provide no calculations to support this narrative.
That may be good enough for you, but it's not good enough for many of us. 2100 architects and engineers are now calling for new investigations.
Asymmetrical damage must yield asymmetrical collapse--especially when you consider that the antenna drop on WTC1 shows that the hat truss came apart before the collapse began.
AZCat
(8,345 posts)Where do I see this list? Because it isn't from AE911Truth - they don't have nearly those numbers. Otherwise, it's just a bunch of ill-informed laypeople chattering about something that they lack the technical chops to understand adequately.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Interesting, though, that they still haven't removed my late coworker. He's still listed as a supporter.
Ace Acme
(1,464 posts)78 structural engineers, 40 highrise architects, 7 AIA Fellows, 40 PhD engineers, 11 Stanford engineers.
AZCat
(8,345 posts)I wonder if there needs to be some sort of a legacy page, where people like him can be kept separated from those who are still active or alive.
Are those numbers supposed to impress me? I've seen the efforts of some of that group, and it's not the highest quality work I've seen. It would be more impressive if they could come up with something more than an ad campaign after all these years.
Ace Acme
(1,464 posts)And can you name even one who has no professional ties to NIST?
AZCat
(8,345 posts)Does that somehow invalidate their professional opinions? Oh right - you need that because it's convenient to your narrative.
You need to read the report. There are hundreds, if not thousands, of professionals who contributed to the NIST report.
Ace Acme
(1,464 posts)If there were indeed a consensus in the engineering that NIST got it right, you would think that a few independent engineers could be found to say so, publicly.
AZCat
(8,345 posts)Like I told you several posts ago, the comments are full of organizations and individuals who support the NIST work.
Ace Acme
(1,464 posts)... is not endorsing their collapse sequence, though some try to obscure the difference.
AZCat
(8,345 posts)It's in the public comments on the draft versions of the report. There are lots of organizations and individuals who responded during the comment periods, and you can find support for the NIST reports in those comments.
I had gotten rid of all the draft NIST report stuff I had years ago, not realizing that I didn't have a separate copy of the comments. That's why I couldn't find the names initially, because the comments weren't included in the final report.
Ace Acme
(1,464 posts)merely express agreement with NIST's recommendations, such as widening the stairwells?
AZCat
(8,345 posts)But I guess looking up the comments on the NIST website and finding out for yourself is not your intent? Would you rather trust the word of an anonymous internet poster instead of verifying on your own?
Ace Acme
(1,464 posts)I asked you to clarify your claim. You prefer to be cryptic rather than be clear.
AZCat
(8,345 posts)Go read the comments - it's for your own good.
Ace Acme
(1,464 posts)Now there's a bot's talking point if I ever heard one. You sound like the magic 8-ball.
Ace Acme
(1,464 posts)Or so NIST tells us. Of course maybe computers are more powerful now, and maybe modeling software is better, so maybe instead of hiding behind the legend that their computers weren't up to the job, maybe it's time to open up a new investigation.
I would be curious to hear your rationalizations in opposition to trying to model the collapses. Too much money, right? One Chinook helicopter costs $30 million, but we can't afford $15 million for proper investigations of 9/11.
AZCat
(8,345 posts)Why don't you just make a simple free body diagram? It shouldn't take very long. Or it shouldn't, provided you're a competent person. Other people might have to resort to other methods, like obfuscation.
Ace Acme
(1,464 posts)Oh right, there aren't any.
AZCat
(8,345 posts)Oh right, they are more sophisticated, and used complicated software tools that do the same thing (only a million times over). Free body diagrams are a tool more useful for simple problems, like our discussion.
Ace Acme
(1,464 posts)And one needn't be sophisticated to recognize that fail.
AZCat
(8,345 posts)Or what the NIST might have used instead of them?
Ace Acme
(1,464 posts)They did the easy half--they could reverse-engineer all the parameters to make the numbers turn out right.
But for the second half they had to deal with what actually was, and that didn't work out so well for them.
AZCat
(8,345 posts)Unfortunately it's too obvious to ignore, at least for anybody who is competently trained in those principles.
Ace Acme
(1,464 posts)NIST's report is incomplete, and the empty "trust me, I know" assertions of a guy who claims to be a cat are no substitute for a thorough and honest and complete report.
AZCat
(8,345 posts)Nothing big, of course. That's why you keep ignoring it.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Why don't you just write out the energy equation? It should be obvious what you're missing.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Ace Acme
(1,464 posts)Especially a cat that tries to substitute cryptic marsh gas for substance.
AZCat
(8,345 posts)of an energy balance. You might try taking a class or two - it could improve the quality of your posts, then you wouldn't have to rely on strange commentary about cats and gases.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)It's all there in your post history, so denying it only makes it more painful when you eventually have to confront your mistake.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)I am not going to take the blame for your failure to understand what is a rudimentary physics concept. You've repeatedly shown this failure in this thread, and now you're claiming that you didn't say what you said? It's all right there, conveniently placed in the title of your posts multiple times.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)The first law of thermodynamics is an energy balance. Or are you going to reverse course and now claim that wasn't the equation you were thinking of? Regardless, claiming kinetic energy is the only quantity of interest is quite... illuminating.
Ace Acme
(1,464 posts)Maybe you are. It would be your style.
AZCat
(8,345 posts)Nope, you're still not getting it. Oh well, like I said - it Tony Szamboti quite some time to figure this out, and he had the benefit of relevant schooling to rely on. Unfortunately Tony has an attitude similar to yours, and is resistant to correction.
Ace Acme
(1,464 posts)Did he admit that the NIST reports were complete and honest?
When and where?
AZCat
(8,345 posts)He did finally realize the "missing jolt" wasn't, and that's relevant to our discussion (very much so, even if you don't realize it).
Ace Acme
(1,464 posts)And no, the Missing Jolt is not particularly relevant to the discussion.
The missing jolt merely refutes Bazant, who has nothing to do with reality.
It doesn't change the official story's problems with the first law of thermodynamics and Newton's 3rd law.
AZCat
(8,345 posts)It doesn't refute anything, because it's wrong. Just like your argument. And for the same reason, which you can't seem to figure out even though it should be trivial.
Ace Acme
(1,464 posts)NIST claims they didn't analyze the collapses. That right there indicates the need for further investigations. You trying to poke holes in in some guy's theories does not change the fact of NIST's inadequate work even if you're right about the theories. I'm not interested in alternative theories. I'm interested in getting complete and honest government investigations.
AZCat
(8,345 posts)It can be difficult going for someone who is not very familiar with the concepts or terminology.
Ace Acme
(1,464 posts)fact that NIST claims they did not analyze the towers' collapses, and thus they only delivered half an investigation.
AZCat
(8,345 posts)Of course you could continue to bluster about anything other than your obvious error in basic physics, but that's all a distraction, really.
Ace Acme
(1,464 posts)Even if Mr. Szamboti is completely FoS (and your say-so certainly won't convince me) it changes nothing.
The NIST reports are incomplete and dishonest. That is indisputable.
Thanks for playing.
AZCat
(8,345 posts)Your hostility and attempts to change the subject aren't going to make that go away.
Ace Acme
(1,464 posts)Even if you had one, so what? It's immaterial to the fact that the official 9/11 reports are incomplete, dishonest, and even corrupt. You're on the wrong side of history, guy.
AZCat
(8,345 posts)I've seen how poorly received that is by you, and it's just not worth it. I'd prefer you actually figure out the mistake on your own (with perhaps a little guidance) because I think the odds are better that you'll learn something this way. See? With my method, everybody wins!
Your opinion is quite irrelevant on technical matters. Please either address topics where you can demonstrate competency, or perhaps work to increase your competency in the fundamentals of physics.
Ace Acme
(1,464 posts)Thanks for demonstrating the indefensibility of your claims.
AZCat
(8,345 posts)How come the wrong side of history has the right physics, and your side is demonstrably lacking?
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Too bad, because it means you're going to continue propagating this misinformation for years, maybe for the rest of your life.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Someone who doesn't might mistake their misunderstanding of technical arguments for some dark plot to deceive.
AZCat
(8,345 posts)The first law of thermodynamics is going to get you on the wrong path. You really need to use a different relationship in order to see what you're missing. Perhaps now that you're thinking about the problem a bit more this mistake will become apparent.
Ace Acme
(1,464 posts)... we shouldn't run new computer models, taking advantage of advanced computer power.
AZCat
(8,345 posts)The limitations on modelling don't have to do with computing power (much, anyway - there are some recent developments that might help out), they have to do with the nature of the collapses. Or any nonlinear phenomena, really. It's the same reason that the billions (trillions, possibly) of dollars spent to model the weather all have the same crappy failure rate. Minute differences in the initial states of the systems (real versus modelled in our case) can result in rapid differences in the outcome. This is why it's meaningless to dissect the WTC7 simulation, because it's not going to be a very good representation of the collapses no matter how sophisticated the model gets.
Ace Acme
(1,464 posts)And again, the problem is not the complexity, but the simplicity of the collapses.
One approach would be to see how many inputs of sudden structural weakening would be necessary to keep the collapse centered and "essentially in free fall" and then gradually reduce the number of those inputs to try to approach a model of a natural collapse behaving in that way.
As to WTC7, why not construct a model based on the theory that the collapses of the penthouses were achieved by cutting beams at the top of the building, and the building was then brought down by cutting core columns. Why not do it? What are you afraid of?
AZCat
(8,345 posts)The problem is the complexity of the collapses. It's a common modelling problem, and saying differently doesn't change the nature of modelling. It just makes you look like you don't know what you're talking about.
If you want to model the collapses then what's stopping you? As I've said time and time again, do your own work rather than relying on the NIST to do it for you. It's obvious you're going to dismiss any of their results anyway, so why not skip that step and get right to the interesting part?
Ace Acme
(1,464 posts)You might as well suggest that I reconvene the Warren Commission.
It was NIST's job to provide believable reports. Their failure to do so is corrosive to democracy.
What makes you think I'm going to dismiss their results? Let's see them do an investigation that is free of dishonesty and reverse-engineering before we decide how I'm going to react.
AZCat
(8,345 posts)to check the claims of government organizations. Obviously not everyone is going to be qualified for technical tasks, but that doesn't relieve the responsibility to do what we can as active participants in a democracy to keep our elected and career public servants honest.
If you can't model the collapses because of your limitations to your technical skillset, that's understandable. But please don't try to claim it's not your job - that denigrates the whole concept of an active citizenry.
Ace Acme
(1,464 posts)... to demand honest and complete reports, and reject the sophistry of internet bullshitters.
AZCat
(8,345 posts)I like to think I'm doing my part to ensure arguments in this forum meet a certain standard. However, there are some posters who refuse to agree that making arguments that are based on a flawed understanding of physics is not acceptable.
Ace Acme
(1,464 posts)A lot of people who read the nonsense posted at JREF by anonymous internet poster then consider themselves qualified to pass on the same nonsense (anonymously) to others.
Your claims are not just empty, they are also immaterial. There is no need to argue the laws of physics when the 9/11 Commission Report and the NIST Twin Towers report and the WTC7 report are demonstrably incomplete and dishonest.
AZCat
(8,345 posts)Do I need to remind you of your repeated posts where you claimed the definition of kinetic energy was the energy equation?
Your incompetence regarding physics pretty much negates any opinion you might have about the technical information included in the NIST works. Why don't you find something where you have some competency? Then you might have a relevant opinion.
Ace Acme
(1,464 posts)I never claimed that the definition of kinetic energy was the energy equation. I don't even know what that means--if anything.
You asked me for an equation and I gave it to you.
AZCat
(8,345 posts)Too bad it's just upthread a-ways, where anybody who cares can go see exactly where that happened.
And now we're just continuing in the same vein, when you could have spent all this time learning how to correct your mistakes! Why, if you'd only taken the time you've likely spent arguing about physics without a clue, you could probably have earned at least a bachelor's degree in engineering. Then you would at least be marginally less irrelevant!
Ace Acme
(1,464 posts)I'm so pretend impressed! It would seem that bluff and bullying has been working for you.
Well it won't work with me. Where I went to school we didn't grovel. We demanded that
our instructors earn our respect.
AZCat
(8,345 posts)You could have really used a little humility. It would serve you well here, especially since your knowledge is demonstrably lacking.
Ace Acme
(1,464 posts)AZCat
(8,345 posts)Have you figured out what's missing yet?
gyroscope
(1,443 posts)....it doesn't work on steel-framed buildings.
William Seger
(11,082 posts)Vérinage is a technique suitable for any building with parallel load-bearing walls, but is not suitable for buildings with columns, because the basic technique is to use cables and jacks to cause pairs of parallel walls to fold and collapse simultaneously. It doesn't have anything to do with the material, e.g. it can be used on buildings with reinforced concrete load-bearing walls, but isn't suitable for buildings with reinforced concrete columns. So Vérinage isn't used on steel-framed buildings simply because those buildings have columns instead of load-bearing walls, not because steel is indestructible.
None of which has anything to do with what we've been discussing here. The relevance of Verinage to this discussion is that it's an actual example of the kinetic energy of the top of a building overcoming the structural strength of the bottom by simply falling on it, just as structural mechanics predict.
But now that you mention it, the fact that Vérinage isn't used on steel-framed buildings IS something of a problem for Chandler and Szamboti: They need to justify why they are comparing fine details of Vérinage collapse accelerations to the WTC towers and drawing conclusions from the differences if we're talking about building materials with different behavior characteristics. (That would be in addition to justifying doing "jolt" comparisons when Vérinage tops always fall squarely on the the bottoms, not tilted like the WTC towers.)
gyroscope
(1,443 posts)Verinage can't be used to bring down steel framed buildings, as you acknowledge,
so whats your point?
William Seger
(11,082 posts)Specifically, you claimed there was some "little problem." I asked you, what problem and for whom is it a problem, and you haven't answered. Are you under the impression that anyone suggested Verinage at the WTC and you are refuting that? Or are you just pretending to have an argument, somewhere?
gyroscope
(1,443 posts)I'm getting dizzy from your spinning.
OnTheOtherHand
(7,621 posts)Seriously, why not answer his question? What was your point in saying, "Just one little problem with the Verinage technique ....it doesn't work on steel-framed buildings"?
krispos42
(49,445 posts)The impact of the planes ripped apart part of the load-bearing structure in the building. The load was re-distributed to the remains of the structure, creating localized areas of stress that were at or near the ultimate strength of the materials, the concrete and steel.
As the building swayed in wind, as the fire heated the concrete and steel, the structure progressively weakened as more and more joints deformed or failed. The affected area was in the immediate vicinity of the impact site, naturally.
Eventually, the structure in the affected area weakened enough to cause a very rapid chain-reaction failure of the joints, and the part of the building above the affected area tilted and began falling.
A couple of hundred thousand tons of steel and concrete dropped onto the rest of the building, which was unable to cope with the kinetic energy and momentum transfer. Especially when the dropped load isn't hitting even. The top of the bottom part of the building absorbed the full brunt of the equivalent of a supertanker slamming into it, the jolt shattering concrete, twisting and rending steel, and popping welds and rivets. The upper part of the building continues to fall, with the bottom part of the building crunching steadily downward under the accelerating mass of the upper part.
Every second, the enormous momentum and energy of the upper part is crashing into a structure designed only to hold static loads. The structure is continually overwhelmed all the way down to the bedrock by forces dozens or hundreds of times the design load.
It's like a rope breaking under gradually increasing strain. A few fibers might pop, then all of a sudden... catastrophic failure.
On an episode of "Mythbusters" they were trying to find out if you can rip the transmission of a car out by bolting a cable between the rear axle and, say, a telephone pole.
Despite the fact that the cable was plenty strong enough to pick up the car if it was, say, attached to a crane, the car was able to easily break the cable after getting a few dozen yards of acceleration.
There ya go. When static, the structure of the WTC towers was plenty strong enough to hold the weight. Add motion, and all bets are off.
cpwm17
(3,829 posts)A cable, which was capable of lifting several times the car's weight if done slowly and smoothly, snaps when subjected to a shock load.
Never underestimate momentum and kinetic energy.
Ace Acme
(1,464 posts)Cables are not columns.
And again, saying momentum brought the buildings down is circular reasoning: It fell because it was falling.