Having complained of people posting off topic, it seems a reasonable solution to give an opportunity for people to discuss the topics I am banning from other threads – of which 9/11 seems the most popular.
I do not believe that the US government, or any of its agencies, were responsible for 9/11. It would just need too many people to be involved. Someone would have objected. There are some strange and dangerous people in America, but not in sufficient concentration for this one. They couldn’t even keep Watergate quiet, and that was a small group. Any group I can think of – even Blackwater – would contain operatives with scruples about blowing up New York. They may be sadly ready to kill people in poor countries, but Americans en masse? Somebody would say it wasn’t a good idea.
I asked a friend in the construction industry what it would take to demolish the twin towers. He replied nine months, 80 men, and 12 miles of cabling. The notion that a small team at night could plant sufficient explosives embedded at key points, is laughable.
The forces of the aircraft impacts must have been amazingly high. I have no difficulty imagining they would bring down the building. As for WTC 7, again the kinetic energy of the collapse of the twin towers must be immense.
I admit to a private speculation about WTC7. Unfortunately in construction it is extremely common for contractors not to fix or install properly all the expensive girders, ties and rebar that are supposed to be enclosed in the concrete. Supervising contractors and municipal inspectors can be corrupt. I recall vividly that in London some years ago a tragedy occurred when a simple gas oven explosion brought down the whole side of a tower block.
The inquiry found that the building contractor had simply omitted the ties that bound the girders at the corners, all encased in concrete. If a gas oven had not blown up, nobody would have found out. Buildings I strongly suspect are very often not as strong as they are supposed to be, with contractors skimping on apparently redundant protection. The sort of sordid thing you might not want too deeply investigated in the event of a national tragedy.
Precisely what happened at the Pentagon I am less sure. There is not the conclusive film and photographic evidence that there is for New York. I am particularly puzzled by the much more skilled feat of flying that would be required to hit a building virtually at ground level, in an urban area, after a lamppost clipping route – very hard to see how a non-professional pilot did that. But I can think of a number of possible scenarios where the official explanation is not quite the whole truth on the Pentagon, but which do not necessitate a belief that the US government or Dick Cheney was behind the attack.
In my view the real scandal of 9/11 was that it was blowback – the product of a malignant terrorist agency whose origins lay in CIA funding and provision. Also blowback in a more general sense that it was spawned in the nasty theocratic dictatorship of Saudi Arabia which is so close to the US and to the Bush dynasty in particular. As with almost all terrorist activity, I do not rule out any point on the whole spectrum of surveillance, penetration and agent provocateur activity by any number of possible actors.
But was 9/11 false flag and controlled demolition? No, I think not.
(Now I have given full opportunity to discuss 9/11 here, any further references on other threads will be instantly deleted).
Glenn,
it doesn’t matter why, just butter him up a bit so he’ll answers me!
Vronsky,
thanks. I’ve stopped gnashing my teeth now.
ok, Clark, if you insist.
Tom : Sorry teach’, I shouldn’t have been insulting towards your pet stooge. Although, I do wish we could get past this topic of falling rods, if you read carefully, you’ll find I had not actually disputed the point at all. I often found in school that teachers would use the red pen at the start of a sentence, because they hadn’t bothered reading the whole thing. Then because they’d bust up the structure of the sentence, the end would now be incorrect, and even more red pen was applied. If they’d just left it alone there would be no red pen needed, it was fine in the first place, just not quite meeting their preconception of what was being said.
For instance, I didn’t say a longer rod would be needed (for the first experiment), I said it could _more easily_ be visualised with one. You turn around and say, No, NO! A longer rod is NOT necessary because… . etc..
I mentioned the friction & air resistance just for the sake of completeness, just in case you jumped on that, and you think that was an objection I was raising! And so on throughout your entire reply.
The point stands, though, that free-falling objects do not fall faster than, err, free-fall. Which is what Vronsky was saying all along. These demonstrations are not about free-falling objects.
Why doesn’t Obama blow the lid on 911? Why doesn’t Wikileaks blow the lid on 911?
Nano-thermite took down the WTC?
http://www.youtube.com/watch?v=4RNyaoYR3y0
The demo with the glass and ball demonstrates nothing about g – you have been hoodwinked by the caption on the video.
The glass is fixed to the bar, while the ball is not. The rotation of the bar carries the glass out beneath the ball, which simply falls vertically from its initial position. It is perched just high enough (on what looks like a golf tee) to give the glass time to rotate underneath it. The glass describes an arc down to the bench, the ball falls vertically down into it. No mystery, nothing ‘falling faster than g’.
Here is a diagram to show what happens – it’s quite unexciting. You’re right about one thing, though – a strobe photo would reveal the simple mechanics of the trick.
tinyurl.com/2vy6bj4
Vronsky,
I’ll leap in here, hopefully faster than Tom, and point out that the diagram doesn’t quite match the video, in that the diagramatic ball is a bit higher with respect to the glass than the video shows, and that the glass does accelerate faster than g, but the center of mass of the glass/board system does not. If you agree fast enough, we may skip another lecture and get onto :
1) the relevance of buckingham-pi
2) why demolition is impossible from the WTC7 videos, and
3) has Tom read Gravity’s Rainbow?
I think ‘Larry’ has developed a fault.
Agreed. I exaggerated the placing of the ball to show that it was adjusted so that the trick would work – it is calibrated to take the same time to fall as the glass takes to be rotated to the horizontal by the falling bar. The glass is being moved by the lever mechanism of the falling bar: it is not falling freely.
1) I can’t see the relevance of Buckingham Pi either;
2) I don’t know how something can be impossible when we’ve all seen it several times; and
3) No, I haven’t read Gravity’s Rainbow. Should I?
But it’s bedtime.
Vronsky,
I’ve read Gravity’s Rainbow twice. Weird book, highly recommended. It’s about causality reversal, the development of the V2 rocket, and the pavlovian conditioning of an octopus. Sort of.
LOX = liquid oxygen…
“There was a technician named Slater
Who slept with the LOX generator
His balls and his prick
Froze solid real quick
And his asshole a little bit later”
http://zork.net/fortunes/rocket-limericks
Goodnight.
You guys are quite the team of comedians, ain’tcha?
Clark: “Glenn, Vronsky, would you two please apologise to Tomk and be more careful not to upset him in future? … it seems that I’m not going to get any [answers] unless you’re both mega polite!”
tomk: You won’t get any answers with thinly veiled suggestions of petulance. Sorry, I’ve got a business to operate. I’ll get to your stuff as I can.
I’ve already got several posts to Glenn that I couldn’t get to post (when I didn’t understand about the url limit.) Each of them has several urls to engineering sites in them, so that you can check what I assert for yourself.
Clark, your question (on WTC7) is next.
___
@ Glenn: at July 30, 2010 4:26 PM
Glenn: Nowhere did I dispute that this demonstration with a ruler shows that a part of an object can indeed fall with an acceleration greater than g, I’m saying (in far fewer words) that it’s very obvious that it can.
tom: Great. You understand.
But wait…
at July 30, 2010 6:44 PM
Glenn: The point stands, though, that free-falling objects do not fall faster than, err, free-fall. Which is what Vronsky was saying all along. These demonstrations are not about free-falling objects.
tomk: Back to the beginning. PARTS of a free falling object can fall faster than “g”. The CG of a free falling object falls at, or below, “g”.
And, no, it’s not what V was saying. V STILL doesn’t get it. His last post, that I’ll reply to momentarily, proves it.
___
@ V
V: “The demo with the glass and ball demonstrates nothing about g – you have been hoodwinked by the caption on the video.
The glass is fixed to the bar, while the ball is not. The rotation of the bar carries the glass out beneath the ball, which simply falls vertically from its initial position. It is perched just high enough (on what looks like a golf tee) to give the glass time to rotate underneath it. The glass describes an arc down to the bench, the ball falls vertically down into it. No mystery, nothing ‘falling faster than g’.
tomk: Wrong. Wrong, completely utterly laughably, incompetently Wrong.
[See, Glenn. Told you so. V doesn’t get it at all.]
[Clark, I just saw your comment too. Good. At least you have the ability to open your eyes & learn. That appears to be a talent beyond V’s capabilities.]
The entire purpose of that demo is to show EXACTLY the point that I made.
The ball does NOT start higher than the glass. It starts slightly below the lip of the glass.
The ruler with the glass attached does EXACTLY what the ruler with the coins
Now, tell me what you really do for a living. C’mon. This ain’t quite as embarrassing as the glaring error you made in your last post. But it does make me think that you “Supersize” things for a living.
Now I’ve got to answer Clark…
tom
Clark,
I lied to you. I’m not going to answer your question…
… in this post. There’s something that I need to say in preface to your answer.
But I promise that my next reply will be to your question.
Before I get to that question, I want to say that, from a mechanical engineering point of view, there is nothing (AT THIS POINT) the bit slightest mysterious, inexplicable or even surprising about the collapse of the towers or WTC7. Or the Pentagon.
IMO, an honest engineer could not have said whether or not he expected them to collapse prior to the collapse of WTC2 on 9/11. I certainly could not. I thought that it was in danger. I had no expectation as to whether or not it might collapse. But when it did, I was not at all shocked by it. (From an engineering, not personal, POV, obviously.)
Once WTC2 collapsed, I then expected that WTC1 would collapse also.
And I was not at all surprised when WTC7 collapsed.
The comment about WTC1 showed my experience. The comment about WTC7 showed my ignorance, because it ultimately surprised everyone.
I did not know, at the time, what were the specific causes for any of the collapses. I had precisely zero doubt that it was directly related to the planes flying into the building for the towers & to the physical damage & fire for WTC7.
But this is a crucial point. ANYBODY who says “I knew as soon as I saw them collapse that the cause was [fill in anything here]” is an incompetent. And most likely a politically motivated fool.
Especially if they are engineers who said it.
The ONLY thing that a competent professional says at that point is “let’s wait to see what the investigation shows”.
Now, there are a bunch of structural engineers, who have worked on skyscrapers, who have thought about this, have looked at several of the various issues, who have a solid “feel” for the magnitudes of causes & effects, who could without question offer very useful insight right off the bat.
Zdenek Bazant, Charles Thornton, Matthys Levy, Gene Corley, and (perhaps most of all) Leslie Robertson.
But even those guys would – and did – say early on that they were speculating. It’s called “educated guesswork”. Well, after a short while, their early guesswork was pretty well confirmed … with some adjustments. No surprise there.
Very few people realized, early on, the damage done to the insulation by the plane, for example. It just didn’t occur to many.
And anyone who tells you that they knew, early on, why WTC7 fell is a liar or a crackpot. NOBODY knew. They had to put that one on hold until they had the manpower to look at it in fine detail.
In the event of a plane crash, a bridge collapse, a building collapse, any complex event, ONLY amateurs guess. All the pros say, let’s wait until the experts have examined the evidence.”
I did not know the sequence of events that led to those collapses. I had precisely zero doubt that the engineers examining the evidence would be able to piece together what went wrong. I’ve seen how they work up, close & personal. I’ve had to perform two of them in my career, one for Boeing/NASA & one for the FDA.
It is VERY instructive to me that the vast majority of the bios of the engineers over at AE911T have the author saying “I knew as soon as I saw those buildings collapse that it was a controlled demolition.”
That demonstrates nothing but their amateurishness (& political axes to grind), IMHO.
But circling around to my original point, now that the studies are done & published, there is not a single SIGNIFICANT point regarding any aspect of the collapse of the buildings, the flying of the planes, etc. that is unreasonable.
Tom
Sorry, Clark, I lied to you. First I had to do this one. Now I’ll wri te you.
Right after I have some dinner.
The only viable way to bring down a building with that synchronicity
No sound.
Clark,
No, I haven’t read Gravity’s Rainbow.
Thomas Pynchon, wasn’t it?
I remember that it was extremely popular when I was in college, but I was way too busy at the time.
What connection does any of this have to that story??
Hello Tom,
please pardon the “petulance” – more like impatience, really, as I did sit through n posts about falling rulers, and thought I wasn’t going to get a reply.
Judging from the time you have dinner, you’re in the US. I’m in the UK, and off to bed now, so I’ll look forward to your post tomorrow.
Goodnight.
Anon,
Gravity’s Rainbow is the parabola, the path taken by an object falling freely in a gravitational field. Like a rocket, after fuel cutoff (gone ballistic). Yes, Pynchon. Oh, and Tom cited a mathematical joke, and there’s a good one in that book.
And shooting stars. They make Gravity’s Rainbows, too. Good time of year for shooting stars, so keep your eyes on the skies.
Goodnight.
Hello Tom,
You said:
—-start quote
@ Glenn: at July 30, 2010 4:26 PM
Glenn: Nowhere did I dispute that this demonstration with a ruler shows that a part of an object can indeed fall with an acceleration greater than g, I’m saying (in far fewer words) that it’s very obvious that it can.
tom: Great. You understand.
But wait…
at July 30, 2010 6:44 PM
Glenn: The point stands, though, that free-falling objects do not fall faster than, err, free-fall. Which is what Vronsky was saying all along. These demonstrations are not about free-falling objects.
tomk: Back to the beginning. PARTS of a free falling object can fall faster than “g”. The CG of a free falling object falls at, or below, “g”.
And, no, it’s not what V was saying. V STILL doesn’t get it. His last post, that I’ll reply to momentarily, proves it.
___end quote
Hmmm. Hmmm. I’ve got a nasty feeling that you deliberately misinterpret, quite egregiously, in order to affect a disappointed air in your correspondent. Whether this is to impress the audience or yourself I couldn’t say. That’s why you always revert to this schoolmaster type role, and pretend your “student” has yet again failed to understand.
It’s actually your good self who STILL doesn’t get it. We’re all very much clued into the difference between a genuinely free-falling object, and what you thought was a very clever display that might well impress a class of 13 year olds. No “But wait… ” about it. We weren’t very impressed, but now you want to believe that’s because we don’t understand. I’ve asked a number of times if we might please move on, but you appear to be stuck here. Probably because this is more comfortable.
*
You go on at length with straw men such as “And anyone who tells you that they knew, early on, why WTC7 fell is a liar or a crackpot.” That’s fine. Anyone here say that? But you go on to say, “I had precisely zero doubt that the engineers examining the evidence would be able to piece together what went wrong.”
Now there, we are in more agreement. But whereas a trusting, wide-eyed child would believe every single word the government or daddy had to say, many grown-ups – myself included – are a lot less gullible. If you don’t understand the process by which governments, and powers that be, get the conclusions or results they want, then you understand very little about how the big system works.
Maybe you don’t understand how credible sources are silenced, undermined, ignored, told to sit down and shut up or be ruined at best if they do not. How do you think so many ‘experts’ got such airtime and government ear-time, when they pontificated on these mighty WMDs that Iraq had, no question about it? These were experienced people, after all, experts in their field. Knew the subject inside out. Only fools and amateurs would doubt them. And any other plaudits you heap upon your fellow true-believers, and contempt upon those who do not immediately agree.
You said:
—start
When you dismiss the knowledge, experience and judgment of real, recognized, proven experts, and instead embrace & advocate the contrary views of a bunch of abject amateurs, even when you have been shown that these amateurs make one blatant, inexcusable, fatal (to their crackpot theories) mistake after another, then you have leaped into the deep end of the ignorant pool.
—end
And how do they become such lauded individuals? Ah yes, by agreeing with the Powers That Be. Just as the experts assured that of course Iraq WMD, and only fools and knaves would say otherwise. By definition.
Oh my! How do we trust you “experts”, when you all pull the same stunt of telling us to always, always, trust the Official Story and self-declared experts, but move on Real Quick when it’s shown to be a total bunch of lies, that just happen to be very convenient at the time?
Terminal velocities
——————-
We all know that there is a terminal velocity for falling objects. That is the point at which maximum speed is reached, when resistance to the object (wind resistance, etc.) becomes equal to the force propelling it. In free-fall in the Earth’s atmosphere, we achieve terminal velocity when the force of gravity equals the upward force of wind resistance.
Likewise, when one drops an object through a fluid there will be a terminal velocity. It is likely to be much lower, because a far smaller speed will generate enough resistance to achieve this equilibrium through a medium vastly more viscous than air.
This leads me to wonder what the terminal velocity would be for a building falling through its own structure. In this rather interesting case, we have not just a viscous medium, but an extensive tethered structure of interconnected steel framework and concrete which will act as a formidable resistance which progressively increases, in the case of the twin towers. This is akin to a medium becoming progressively more dense the further one descends.
One might think – should they be entirely untrained and ignorant – that such a structure would impose a significant restriction when compared with air. But no, experts will assure us that such structures will not arrest a falling body, not reach a steady speed at best, and in fact the integrated effect of a fall through the structure will not noticeably impede the progress. Not at all. It will not reach terminal velocity, and the acceleration will largely be that of an object dropped from the sky.
What would be the terminal velocity of such an event, given a building of sufficient height to achieve such a thing? Tom – I look forward to your reply. Please bring on plenty of science this time, I don’t want to hear any more appeals to authority.
@ Clark,
Finally… here ya go.
The reason WTC7 (or the towers) could not possibly have been a demolition.
First, THE BIG PICTURE.
Learning to look at The Big Picture is crucial. You guys get all knotted up in details.
Details are also crucial. But details, by themselves, are pretty much useless. They must fit into a bigger picture.
And in any complex event, there will always be a couple of pieces that seem to not fit. The reason for that is not that “they don’t fit”. The reason is “there is some piece of info that you don’t know. And may never know.”
By good analogy, you’ve put together a giant jig-saw puzzle. You’ve got it 99% complete, and it a picture of a beautiful tall ship, sailing into some exquisite blue lagoon around Bora-Bora.
But you’ve got 3 pieces of the puzzle that are flaming pink. And there is no flaming pink anywhere in your big picture.
Now which is more likely:
A. You disassemble the whole puzzle, start over, and end up with an image of OBL in TORA-Bora?
B. Someone at the factory mixed up a couple of pieces.
You may THINK that I’m blowing smoke here. I am not. I am serious as a heart attack.
You MUST look at the big picture. Starting over on the puzzle is not going to get you any other picture than the ship in the lagoon. Finding any anomaly in WTC7 is not going to unravel the encyclopedia that is the rest of the 9/11 investigations.
My Big Picture of why WTC7 could not be a demolition:
1. I SAW what happened. I saw planes fly into buildings. Giant explosions. Huge fires. Buildings collapse. Giant buildings fall on much smaller (but still very fragile) other impossibly tall, narrow building, fires break out, burn for 7 hours without fire fighting efforts, building progressively lean over the course of several hours, then building collapse.
My fundamental problem is that I have a working, functional brain. I can NOT bring myself to suggest that all of the above was unrelated to the collapse, and that it was really demolition charges that dunnit.
Well, I can do it, but I immediately start pointing fingers at myself & making fun of me. And I don’t like that.
2. How WTC7 fits in with the rest of the events of 9/11. On BOTH the official side & the truther side.
If it were only WTC7 that we were discussing, then the evidence (in the detail picture below) is still compelling, but much lighter. But I look at the totality of the 9/11 story and I find:
The “official side” was put together by 10s of thousands of competent professionals who did their respective jobs.
And this point is ABSOLUTELY CRUCIAL: all those professionals who contributed were experts who were working within their respective fields of expertise.
Contrast this with the truther side. Particle physicists, water quality inspectors, naval insurance claims adjusters, professors of philosophy of religion, a couple kids from Orange County … all trying to do structural engineering or controlled demolitions analysis. And failing miserably.
The official story holds together, not perfect but rock solid, from every aspect in my field of expertise. And there’s nothing in the other fields that strikes me as the slightest bit tenuous.
Perhaps you guys would list for me the 3 or 4 MOST compelling arguments that prove to you that (??) whatever. (3 or 4 only please. The scattershot approach proves a lack of substance.)
___
Detailed Picture
Simplest observation: No cut columns. End of story.
3. No cut columns = no demolition.
The columns broke exactly where they were manufactured: at their ends. The connections snapped. Bolts & small welds. The columns didn’t fold in half or snap. (A tiny percent did, of course, by being caught in the crush down.
There is absolutely zero way that they could have hidden the cuts, the charges, all the associated equipment from the bomb sniffing dogs (cross trained rescue dogs), the engineers on the site, and the engineers at Fresh Kills.
4. No sounds = no explosions.
Explosives are the ONLY POSSIBLE WAY to execute a CD on a building like that. You can NOT do it slowly (aka, thermite, which would take about 3 minutes to cut thru one column, even if someone could figure out how to cut a vertical one. Which they have not figured out how to do.)
You have to heat, melt, remove a BUNCH of metal, & you have to do it in milliseconds. That means explosives. Not lasers, not chemicals, not thermite, not termites. Explosives.
And explosives go “Boom”.
5. The “anomalies” are baseless.
Please try to hear, listen & understand what I am saying.
All those videos that you guys love to pour over, that you think show the collapse of WTC7… they do NOT show “the collapse of WTC7”.
They show “the collapse of WTC7 north & west facades”.
They show the collapse of what are essentially a 600′ tall x 300′ wide x (3′ – 15′ thick, depending on local damage) wall, with a whole bunch of really heavy, falling debris hanging off of the side that you can’t see.
For a brief period of time, the EXTERNAL WALL of the building DID come down at NEAR free fall acceleration. Did you catch all of that?
1. Brief period of time. About 2 seconds. Things in free fall experience “g” ALL the time.
2. Exterior wall. NOT “the building”.
3. Near free fall.
If THE BUILDING had really fallen “at free fall”, meaning collapsed in about 6.5 seconds, then that would have been suspicious & called for a detailed explanation.
The building did not take 6.5 seconds to collapse. Or 7 seconds, or 8, or 10, 12, 14, 16 or 18 seconds to collapse.
THE BUILDING took about 20 seconds to collapse.
There is no mystery here.
___
No mystery, except how you guys can piss away the better part of a decade giving each other amateurish, incompetent reach-arounds. And convincing yourselves that you are the only moral, ethical, honorable fart-smellers on the planet.
This pretty much summarizes my “Big Picture”, Clark.
tom
@ Glenn,
Thanks for this post, Glenn. It is enlightening.
It shows the TRUE basis of all of your objections: politics and a scorching case of Angry Young Man Syndrome.
Sorry, kid. None of those things amount to chickenshit in a cow pasture, when it comes to engineering.
Engineers & scientists are NOT politicians, lawyers, political appointees, or sycophants. You got your head firmly placed up your keister on that score.
ALL established engineers would take any political hack or lawyer, who asked them to falsify their results on something as significant the events of 9/11, and 1. beat them about the head & shoulder, 2. call the press & report exactly what happened.
The NIST group were NOT political hacks, or lawyers, or appointees. They were first rate engineers from NIST, academia & industry.
You do NOT attain their stature by kissing up to anybody. You get there by being right, by being competent.
No established engineer is going to put their name on an engineering report that they KNOW is going to be examined by other professional engineers and engineering students for decades with a fine-tooth comb. Your fraud wouldn’t last 30 days.
And the NIST report HAS been examined, in detail, by thousands of competent professional engineers and engineering students. And it has held up just fine.
I’ll ignore the temper-tantrum stuff.
With one comment. I do not deliberately misinterpret. You are sloppy with your choice of words. You write one thing, then say you meant something different.
___
Glenn: “You go on at length with straw men such as “And anyone who tells you that they knew, early on, why WTC7 fell is a liar or a crackpot.” That’s fine. Anyone here say that?”
tom: It was not a straw-man. You are not the only one who gets to bring up topics. MY topic was the issue of “non-experts who jump to conclusions.”
Apparently you missed my point. Almost all of the “engineers” at AE911T DID say exactly that. I invite you to go check for yourself.
___
Glenn: “But whereas a trusting, wide-eyed child would believe every single word the government or daddy had to say, many grown-ups – myself included – are a lot less gullible. If you don’t understand the process by which governments, and powers that be, get the conclusions or results they want, then you understand very little about how the big system works.”
tom: And sophomoric arguments will reduce the world to simplistic Manachaen dualities, including “daddy” metaphors.
Meanwhile revealing far more about your own personality than you should.
NOBODY strong-arms a scientist or engineer into fraud. A tiny percent choose to take that path. Anyone attempting to force anyone, ESPECIALLY on a topic as huge, as signirficant,
We are ALL independent cusses. The wimps fall by the way-side.
Some political flunky tried to tell the earth scientists at NASA what they could say about Global Warming a few years ago. Did you follow that story?
The flunky was gone, the scientist stayed, and the White House issued an apology.
___
Glenn: “Maybe you don’t understand how credible sources are silenced, undermined, ignored, told to sit down and shut up or be ruined at best if they do not. How do you think so many ‘experts’ got such airtime and government ear-time, when they pontificated on these mighty WMDs that Iraq had, no question about it? These were experienced people, after all, experts in their field. Knew the subject inside out. Only fools and amateurs would doubt them. And any other plaudits you heap upon your fellow true-believers, and contempt upon those who do not immediately agree.”
tom: … ahhh, politics again. Silly me. I thought that we were discussing engineering.
___
Glenn: “And how do they become such lauded individuals? Ah yes, by agreeing with the
Powers That Be. Just as the experts assured that of course Iraq WMD, and only
fools and knaves would say otherwise. By definition.”
tom: Yeah, sure, kid. Conservative structural engineering calculations versus Liberal structural engineering calculations. That’s how to get a building to stand up, an airplane to fly or a bridge built.
Sure, kid. That’s how you gain respect & stature in the engineering field. Be a political suck-up…?!! That’s what we all admire….
___
Glenn: “Oh my! How do we trust you “experts”, when you all pull the same stunt of telling us to always, always, trust the Official Story and self-declared experts, but move on Real Quick when it’s shown to be a total bunch of lies, that just happen to be very convenient at the time?”
tom: You seem to be confusing politics with engineering, kid. Best take a step back and try to see the difference.
Can you answer one question for me. How old are you?
Tom
“You seem to be confusing politics with engineering, kid. Best take a step back and try to see the difference. Can you answer one question for me. How old are you?”
You seem to be confusing ageism with engineering, tomk.
Gone again. Busy.
Hello Tom.
I’m rather disappointed that you’re apparently lumping me in with ‘truthers’, and that you have chosen to write to me as if I’m a bit stupid. If you don’t like this sort of discussion, don’t do it – simple! No one is twisting your arm, are they?
A while back you wrote: “And I was not at all surprised when WTC7 collapsed… [which] showed my ignorance, because it ultimately surprised everyone”. I’d be interested to know how WTC7 surprised you.
You also started some tantalizing technical arguments that you haven’t returned to. I’d be interested to read the rest of those, though I’m not a structural engineer, so please explain technical terms – I do math… eventually.
But if you don’t wish to proceed, that’s OK by me too.
dreoilin,
dreoilin: “You seem to be confusing ageism with engineering, tomk.”
It ain’t “ageism”.
I don’t care if he’s 98 years old with great-grandkids. Or 15 years old.
His attitude (everyone in any position of power is evil, a coward or sell-out) is emblematic of a petulant 15 year-old with a stereotypical case of Angry Young Man Syndrome.
And that EARNS one, anyone, any age, the title “kid”.
tom
Tom,
You wrote, “Conservative structural engineering calculations versus Liberal structural engineering calculations…”
Now don’t I seem to remember that Challenger was lost because management applied pressure to accept the lesser of two safety margin estimates for SRB O-rings? I do think you’re being a bit overly black-and-white. Or should I call that ‘spherical cow’?
“One might think – should they be entirely untrained and ignorant – that such a structure would impose a significant restriction when compared with air.”
The calculation is here:
http://www.journalof911studies.com/articles/W7Kuttler.pdf
WTC 7: A short computation
Kenneth L. Kuttler
Professor of Mathematics
Brigham Young University
Provo, Utah 84602
Introduction
I provide a short computation, focused on World Trade Center building 7. Based on very favorable assumptions for achieving a fast fall, including ignoring resistance due to intact steel columns, I could only get the building to fall in about 8.3 seconds, whereas the observed roof-fall time is approximately 6.5 seconds.
The problem is the large number of floors and conservation of momentum in a collision. Some of the “official” explanations about progressive collapse are evocative but they do not explain the difficulty in the rapid fall of the building along with what is evidently taking place when the video of the falling building is observed.
Clark,
I haven’t lumped you in with anyone. I apologize if I gave you that impression.
Everyone is an individual.
WTC7 surprised everyone. Because everyone expected that the collapse was due to the physical damage from WTC1 falling on it.
That was not the cause.
People also expected that the oil stored in the diesel tanks contributed to the fires. They did not. Virtually all the oil was accounted for & removed during the clean up.
WTC7 surprised everyone to such a degree that they had to set the analysis aside. Because it became clear that their original theories just did not hold up to scrutiny.
And you guys (collectively, not you, Clark) are CRAZY if you think that you guys have put in 1/100th the (competent) scrutiny that the NIST engineers put in, before they released their reports, attacking their own conclusions. This is a standard part of any failure analysis. It happens at every single step along the way. And then it happens formally before any report is released to the public.
These guys are professionals. Highly visible, well known professionals. Any engineering error, no matter how trivial, can NOT be hidden. An engineering student finds it, holds it up to the text book references, and the kids a hero, and the professionals all look like idiots. On the biggest, most embarrassing stage in the world.
The way you prevent that is to have hard, vicious, rip each other’s hearts out critiques of each others’ work. It’s a blood bath. I’ve been in those meetings. I’ve run those meetings. It’s a challenge to keep some junk-yard dog personalities away from each others’ throats.
Back to WTC7…
The fact is that few modern buildings have collapsed just due to fire.
This is because engineers understand well what fire does to steel. If you really want to understand, read the “Analysis” portion carefully here:
http://www.mace.manchester.ac.uk/project/research/structures/strucfire/CaseStudy/HistoricFires/BuildingFires/default.htm
If you read it carefully, you will find out that EVERY uninsulated column buckled (and most collapsed). EVERY insulated column did not buckle & survived.
In the very same fire. Do you understand what that means to the (laughable) argument “fire doesn’t harm steel”.
It is a source of constant amusement to me when people bring up the Windsor Towers as “proof” that no building has collapsed from fire alone.
So engineers protect building supports with:
1. Insulation, which just buys you time. Usually about 1-2 hours, to clear the building & bring in some firefighters. See url below. Insulation is NOT a barrier (on its own) to collapse. Necessary. Not sufficient.
2. Sprinklers: The most useful technique: stop the fire before it grows. Useless on 9/11. Little water (just what was in the tanks on the roof. That ran out quickly, and no refilling, because the street mains were severed by the collapse of WTC 1&2. If the water mains had not been broken, the building would likely still be standing.
Look here Fig 2 at what fire temps are (http://www.mace.manchester.ac.uk/project/research/structures/strucfire/CaseStudy/steelComposite/default.htm)
With sprinklers, fire temps barely get above room temp. It’s an astonishing difference.
3. Active fire fighting. Which was unavailable for WTC7 on 9/11.
But the failure mode was NOT obvious. And ultimately they found a serious design flaw in the building. One that would NOT have brought it down if the usual fire fighting efforts were available. But, in their absence, did bring it down.
And, like many of this type of disaster, it wasn’t one thing. It was a combination of things. The extra long horizontal supports. The poorly chosen end plate anchoring. The asymmetric loading on the one lateral beam. And differential thermal expansion between steel & concrete that fractured the concrete around the studs. Leading to loss of stability of the column, which then propagated thru the building.
It is a sad fact of the engineering business that we learn 100x more about the weaknesses in our designs every time a plane crashes than every 100x that it lands safely. You find the weak points in your design. We found a weak point, one that only appears when the water is unavailable to fight the fire, with WTC7. Buildings built from 2005 on (when the weakness was discovered) will not have this weakness.
In fact, it’s far, far faster to build things with safety factors LESS THAN 1, take them out & break them, fix the part that broke and repeat the process, than it is to build it with design factors GREATER THAN 1, and try to start paring back the material that you don’t need.
During WWII, we needed fighter planes fast. We couldn’t afford to run a “safe” program, or the war would have been over before the first one was delivered. The bottom of Long Island Sound & the Channel Islands (off of LA) are littered with the remains of planes & test pilots who contributed to that painful learning curve.
tom
Clark,
tomk wrote: “Conservative structural engineering calculations versus Liberal structural engineering calculations…”
Sorry, sarcasm doesn’t travel well in this medium. There are no “politically based engineering calculations”. There is no toggle bit in your FEA materials database for “Republican administration” or “Democrat administration” that changes the material properties.
___
Clark: Now don’t I seem to remember that Challenger was lost because management applied pressure to accept the lesser of two safety margin estimates for SRB O-rings? I do think you’re being a bit overly black-and-white. Or should I call that ‘spherical cow’?
tomk: The Challenger was lost for 1000 reasons. Only a few of them (but some really, really important ones) appeared on that cold January day.
The principle failure before then were the failure of NASA to listen to the warnings of their own engineers who dismantled the SRBs and found repeated incidents of “blow by”, around the O-rings.
Because several accountants & project managers (NOT engineers) looked at what it would do to budgets & schedules to have to re-engineer the SRBs.
Plus, you had launched many missions before and “gotten away with it”. That makes it hard to convince management.
Like many accidents, it was the confluence of several factors that produced the disaster. If only a few had been different, then it likely would not have happened.
But if it had not happened with Challenger, then it is likely that it would have happened with a later flight. Until the issue got fixed.
There were probably about 100 similar issues with the early shuttles. Issues that all the engineers kept their fingers crossed each flight. When the Challenger happened, a boat load of them got fixed, and a bunch of engineers slept well for the first time in their careers.
The principle cause of the procedural failure that happened that day is that one of the NASA managers massively violated the spirit & letter of NASA operations.
The rule that he turned on its head was one that NASA has had forever (before then, and especially after) that applies to all manned flight hardware: “Prove that it is safe!”
When MT engineers & management would not sign the launch release, the NASA engineer demanded “Prove to me that it is unsafe”.
Think of all possible designs as something the size of a football field. About 3 square feet has been “proven” (as best you can, which is never 100%) to be safe. About 100 square feet you know for certain is unsafe. The other 10,000 square feet fall into the category of “not sure”.
It’s not possible to do at a conference table, 1 hour before launch. When the engineers would still not budge, the MT management asked them to step outside of the meeting. With the engineers out of the picture, the management signed the release & the rest is history.
As a direct result, a bunch of procedures got revised. I pretty sure that it is now a serious violation of NASA procedures to have the engineers excluded from engineering based decisions.
tom
Whose is this? Clark? Glenn?
“One might think – should they be entirely untrained and ignorant –
that such a structure would impose a significant restriction when
compared with air.”
The calculation is here:
http://www.journalof911studies.com/articles/W7Kuttler.pdf
WTC 7: A short computation
Kenneth L. Kuttler
Professor of Mathematics
Brigham Young University
Provo, Utah 84602
tom
Tom,
thank you for at last getting to the crux of this matter. Appreciated. No time now; I’ll read your links later.
Tom,
sorry, not me. Some people insist on posting anonymously. There is no moderation here, no registration required; it’s remarkable that it stays as civilised as it does. That said, some decent posters do get abused; see the latest post, where some idiots are ‘impersonating’ Suhayl Saadi.
Oops,
I didn’t quite finish the “football field shuttle design” analogy.
Under NASA’s rules, if it hasn’t been proven safe, it doesn’t fly. That means that the things in the 10,000 square feet do not get to fly.
The project manager, who said “prove that it is unsafe” decided on his own that anything in the 10,000 square feet (every thing that is not in the 100 square feet of “proven unsafe”) gets to fly.
A very bad decision.
tom