9/11

[PolyNewbie]

kimmy:This reminds me of the woman who bills himself as an FDA-recognized expert because she posted her goofy theory in a message on a comments-section of an FDA article.

Ha Ha !! Prooof that the engineers supporting the official version are charlatans !!!

[Riverwind]

You are an idiot. He has a Phd in computer graphics. He used computer graphics to interpret and solve math problems to do with molecular physics & shapes and has published in a lot of prestigious places - especially for his age.

Sorry, you are the idiot: here is his own biography and no mention of a PhD:

http://911research.wtc7.net/re911/hoffman.html

All engineering is applied physics ! Fetzer is a theoretical physicist, well published too. All Phd's are philosophers.

Then what is he doing working in the "Department of Philosophy" http://www.d.umn.edu/~jfetzer/. Read the biography - he only has credentials in philosophy

That fact that you misrepresent the credentials of the 'experts' you use to back up your opinions speaks volumes about your ability (or lack there of) to analyze information.

[White Doors]

All Phd's are philosophers

cool! that's neat how that works!

[Riverwind]

No !!! (again) It doesn't stop rotationg when the structure supporting the rotation fails - that is conservation of mementum. You really have no idea what you are talking about yet talk like you are an expert- this makes you look even more moronic.

Not that simple. You are assuming that the top acquired significant rotational momentum before the pivot collapsed. That implies the pivot must be able to support the weight of the building while that momentum is being acquired. It all comes down to a question of how fast the pivot collapses. If it collapses slowly the building could tip over. However, if it collapses quicky the building will go straight down. How fast the pivot collapses depends on what it is made of and how much excess force is applied. No matter what the material it will collapse in milliseconds if the force is large enough. My example illustrated how even if a structure is overdesigned the weight of the structure could significantly exceed the load bearing capabilities of the remaining supports after even one support is removed.

That is why your claims that buildings can't collapse straight down after asymmetric damage are completely false.

[PolyNewbie]

Riverwind:Sorry, you are the idiot: here is his own biography and no mention of a PhD:

No mention of publishing in Scientific American or Nature or a number of other places as well. In fact no mention of education.

Riverwind:Then what is he doing working in the "Department of Philosophy" http://www.d.umn.edu/~jfetzer/. Read the biography - he only has credentials in philosophy

That fact that you misrepresent the credentials of the 'experts' you use to back up your opinions speaks volumes about your ability (or lack there of) to analyze information.

He regularly publishes in physics journals - 25 so far. See his wiki definition. Also from the page you linked:"He has published more than 100 articles and reviews and 20 books in the philosophy of science"

Riverwind:Not that simple. You are assuming that the top acquired significant rotational momentum before the pivot collapsed. That implies the pivot must be able to support the weight of the building while that momentum is being acquired. It all comes down to a question of how fast the pivot collapses. If it collapses slowly the building could tip over. However, if it collapses quicky the building will go straight down. How fast the pivot collapses depends on what it is made of and how much excess force is applied. No matter what the material it will collapse in milliseconds if the force is large enough.

That is why your claims that buildings can't collapse straight down after asymmetric damage are completely false.

This analysis is not only wrong, its completely rediculous. You have absolutely no idea what you are talking about. Don't tell me what is simple and what isn't because its obvious you have no scientific background at all. Once something starts rotating it needs a force to stop it. This is also irrelevant because we saw the top of the building rotate (tip over).

Why don't you share some of your physics expertise with a physics newsgroup or do a paper showing how Jones,Wood & Hoffman are wrong (amoung others).

So who are the engineers that support the official version ?

[White Doors]

Critics of these alternative theories say they are a form of conspiracism common throughout history after a traumatic event in which conspiracy theories emerge as a mythic form of explanation (Barkun, 2003). A related criticism addresses the form of research on which the theories are based. Thomas W. Eagar, an engineering professor at MIT, suggested they "use the 'reverse scientific method'. They determine what happened, throw out all the data that doesn't fit their conclusion, and then hail their findings as the only possible conclusion."[207] Eagar's criticisms also exemplify a common stance that the theories are best ignored. "I've told people that if [the argument] gets too mainstream, I'll engage in the debate." This, he continues, happened when Steve Jones took up the issue. The basic assumption is that conspiracy theories emerge a set of previously held or quickly assembled beliefs about how society works, which are then legitimized by further "research". Taking such beliefs seriously, even if only to criticize them, it is argued, merely grants them further legitimacy.

Michael Shermer, writing in Scientific American, said: "The mistaken belief that a handful of unexplained anomalies can undermine a well-established theory lies at the heart of all conspiratorial thinking (as well as creationism, Holocaust denial and the various crank theories of physics). All the "evidence" for a 9/11 conspiracy falls under the rubric of this fallacy. Such notions are easily refuted by noting that scientific theories are not built on single facts alone but on a convergence of evidence assembled from multiple lines of inquiry."[208]

There are also behavioristic objections to these conspiracy theories, arguing that the conspiracy theorists behave in an irrational or unscholarly way.[209] One objection is that the conspiracy theorists tend to connect unrelated information. Another is that they will often expand the conspiracy to include those who debunk their original theories, such as Popular Mechanics.[209] There is also the tendency of the conspiracy theorists to quote only other conspiracy theorists and provide little if any expert verification of any of their claims.[210]

Image from "Mystery of the Urinal Deuce", simultaneously parodying the conspiracy theories and the Hardy Boys mystery booksScientific American,[211] Popular Mechanics,[212] and The Skeptic's Dictionary[213] have published articles that challenge and discredit various 9/11 conspiracy theories. Conspiracy theorists have jumped on the contribution to the Popular Mechanics article by "senior researcher" Ben Chertoff, who they claim is cousin of Michael Chertoff - current head of Homeland Security.[214] However, no indication of an actual connection has been revealed and Ben Chertoff has denied the allegation.[215] Popular Mechanics has published a book entitled Debunking 9/11 Myths that expands upon the research first presented in the article.[216] Der Spiegel dismissed 9/11 conspiracy theories as a "panoply of the absurd", stating "as diverse as these theories and their adherents may be, they share a basic thought pattern: great tragedies must have great reasons."[217] 9/11 conspiracy theories were satirized and criticized in "Mystery of the Urinal Deuce", an episode of the animated television series South Park.

This is also from wikipedia. Most of the 'experts' don't respond to 'theories' of the paranoid.

[Canadian Blue]

Ha Ha !! Prooof that the engineers supporting the official version are charlatans !!!

Hold the phone, all engineers are in a psychedelic rock band that influenced the San Francisco music scene!!!

The Charlatans were an influential psychedelic rock band that played a pivotal role in the development of the San Francisco music scene in the 1960s. More akin to earlier jug band and blues influences than the later heavy psychedelia from the same scene, the Charlatans set the stage with their rebellious attitude and appearance. Their recorded output was small, and their first nationally distributed album (The Charlatans) was not released until 1969 (see 1969 in music), long after the band's heyday. This band was the first commercial appearance of Dan Hicks, later of Hot Licks fame.

http://en.wikipedia.org/wiki/The_Charlatans_%28U.S._band%29

So who are the engineers that support the official version ?

Here you go Polynewbie.

http://www.popularmechanics.com/technology...842.html?page=9

Structural Engineering / Building Collapse

Farid Alfawakhiri, Ph.D. senior engineer, American Institute of Steel Construction

David Biggs, P.E. structural engineer, Ryan-Biggs Associates; member, ASCE team for FEMA report

Robert Clarke structural engineer, Controlled Demolitions Group Ltd.

Glenn Corbett technical editor, Fire Engineering; member, NIST advisory committee

Vincent Dunn deputy fire chief (Ret.), FDNY; author, The Collapse Of Burning Buildings: A Guide To Fireground Safety

John Fisher, Ph.D. professor of civil engineering, Lehigh University; professor emeritus, Center for Advanced Technology; member, FEMA Probe Team

Ken Hays executive vice president, Masonry Arts

Christoph Hoffmann, Ph.D. professor of computer science, Purdue University; project director, September 11 Pentagon Attack Simulations Using LS-Dyna, Purdue University

Allyn E. Kilsheimer, P.E.

CEO, KCE Structural Engineers PC; chief structural engineer, Phoenix project; expert in blast recovery, concrete structures, emergency response

Won-Young Kim, Ph.D. seismologist, Lamont-Doherty Earth Observatory, Columbia University

William Koplitz photo desk manager, FEMA

John Labriola freelance photographer, WTC survivor

Arthur Lerner-Lam, Ph.D. seismologist; director,

Earth Institute, Center for Hazards and Risk Research, Columbia University

James Quintiere, Ph.D. professor of engineering, University of Maryland member, NIST advisory committee

Steve Riskus freelance photographer; eyewitness, Pentagon crash

Van Romero, Ph.D. vice president, New Mexico Institute of Mining and Technology

Christine Shaffer spokesperson, Viracon

Mete Sozen, Ph.D., S.E. Kettelhut Distinguished Professor of Structural Engineering, Purdue University; member, Pentagon Building Performance Report; project conception, September 11 Pentagon Attack Simulations Using LS-Dyna, Purdue University

Shyam Sunder, Sc.D.

acting deputy director, lead investigator, Building and Fire Research Laboratory, National Institute of Standards and Technology

Mary Tobin science writer, media relations, Earth Institute, Columbia University

Forman Williams, Ph.D. professor of engineering, physics, combustion, University of California,

San Diego; member, advisory committee, National Institute of Standards and Technology

I'll bet anyone here Polynewbie's response is going to be they were all paid off by the government.

http://www.sciam.com/article.cfm?articleID...E1583414B7F0000

For example, according to www.911research.wtc7.net, steel melts at a temperature of 2,777 degrees Fahrenheit, but jet fuel burns at only 1,517 degrees F. No melted steel, no collapsed towers. "The planes did not bring those towers down; bombs did," says www.abovetopsecret.com. Wrong. In an article in the Journal of the Minerals, Metals, and Materials Society and in subsequent interviews, Thomas Eagar, an engineering professor at the Massachusetts Institute of Technology, explains why: steel loses 50 percent of its strength at 1,200 degrees F; 90,000 liters of jet fuel ignited other combustible materials such as rugs, curtains, furniture and paper, which continued burning after the jet fuel was exhausted, raising temperatures above 1,400 degrees F and spreading the inferno throughout each building. Temperature differentials of hundreds of degrees across single steel horizontal trusses caused them to sag--straining and then breaking the angle clips that held the beams to the vertical columns. Once one truss failed, others followed. When one floor collapsed onto the next floor below, that floor subsequently gave way, creating a pancaking effect that triggered each 500,000-ton structure to crumble. Conspiricists argue that the buildings should have fallen over on their sides, but with 95 percent of each building consisting of air, they could only have collapsed straight down.

All the 9/11 conspiracy claims are this easily refuted. On the Pentagon "missile strike," for example, I queried the would-be filmmaker about what happened to Flight 77, which disappeared at the same time. "The plane was destroyed, and the passengers were murdered by Bush operatives," he solemnly revealed. "Do you mean to tell me that not one of the thousands of conspirators needed to pull all this off," I retorted, "is a whistle-blower who would go on TV or write a tell-all book?" My rejoinder was met with the same grim response I get from UFOlogists when I ask them for concrete evidence: Men in Black silence witnesses, and dead men tell no tales.

[Riverwind]

No mention of publishing in Scientific American or Nature or a number of other places as well. In fact no mention of education.

Your point is? The guy does not have a PhD - if he did he would have said so. Try googling "Jim Hoffman Phd" and you find no reference at all. Face it. You have been caught making up credentials for your "experts".

He regularly publishes in physics journals - 25 so far. See his wiki definition. Also from the page you linked:"He has published more than 100 articles and reviews and 20 books in the philosophy of science"

Why is someone who writes about the "philosophy of science" qualified to talk about why buildings fall down?

Once something starts rotating it needs a force to stop it.

My point is the top cannot _start_ rotating unless the pivot point can support the weight of the building for a period of time. In the example I provided the supports would collapse before any rotation occured so there is no rotational momentum to consider. This is basic physics stuff - I am surprised you got through first year physics.

This is also irrelevant because we saw the top of the building rotate (tip over).

With one of the three towers there was some rotational momentum when the pivot collapsed. However, once the pivot collapses the top will accelerate straight down and gain momemtum in that direction _in addition_ to any rotational momentum. At that point the building collapsed faster than it was tipping so we saw a straight down collapse - the small rotation likely continued but was obsured by the dust.

In other words, there is nothing unusual about the intial rotation and the straight down collapse. Such behavoir is easily explained by the examples I have provided.

[PolyNewbie]

Riverwind:Your point is? The guy does not have a PhD - if he did he would have said so. Try googling "Jim Hoffman Phd" and you find no reference at all. Face it. You have been caught making up credentials for your "experts".

You cannot prove a negative like that.

He doesn't mention any education: From wtc7.net:

"Professional Background

A software engineer by profession, I have developed new algorithms and applications in computational geometry used in both pure mathematics and polymer chemistry. My work in applying scientific visualization to minimal surface geometry was instrumental in the discovery of the first new examples of complete, finite, embedded minimal surfaces in over two hundred years. My visualizations have been featured in articles in Science News, Scientific American, Science Digest, and Nature.

Working with a team of polymer scientists at the Massachusetts Institute for Technology, I discovered new three-dimensional morphologies for modeling block co-polymers, and co-authored papers in Science and Macromolecules.

I have also dabbled in combustion engineering, co-authoring a patent for an internal combustion engine with improved thermal efficiency (US Patent #4,584,972). I created computer simulations to facilitate the development of this and other mechanical engineering inventions.

My experience in software development has proved valuable to my investigation of 9/11/01 in more ways than just teaching me to think outside of the box and to approach problems with scientific rigor: I created the system used to publish the websites I developed. The system creates pages with hierarchical menus that allow navigation to most pages in the site in just two clicks.

"

Why don't you email him and teach him a few things about physics ?

So who is supporting the official version ?

[PolyNewbie]

Riverwind:The guy does not have a PhD - if he did he would have said so.

Not true...who says so....you ?

What are YOUR qualifications ? Where is your list of engineers supporting 911 ?

[Canadian Blue]

Where is your list of engineers supporting 911 ?

Riverwind, just copy my list so Polynewbie will shut up about the list of engineers supporting the theory behind 9/11.

Structural Engineering / Building Collapse

Farid Alfawakhiri, Ph.D. senior engineer, American Institute of Steel Construction

David Biggs, P.E. structural engineer, Ryan-Biggs Associates; member, ASCE team for FEMA report

Robert Clarke structural engineer, Controlled Demolitions Group Ltd.

Glenn Corbett technical editor, Fire Engineering; member, NIST advisory committee

Vincent Dunn deputy fire chief (Ret.), FDNY; author, The Collapse Of Burning Buildings: A Guide To Fireground Safety

John Fisher, Ph.D. professor of civil engineering, Lehigh University; professor emeritus, Center for Advanced Technology; member, FEMA Probe Team

Ken Hays executive vice president, Masonry Arts

Christoph Hoffmann, Ph.D. professor of computer science, Purdue University; project director, September 11 Pentagon Attack Simulations Using LS-Dyna, Purdue University

Allyn E. Kilsheimer, P.E.

CEO, KCE Structural Engineers PC; chief structural engineer, Phoenix project; expert in blast recovery, concrete structures, emergency response

Won-Young Kim, Ph.D. seismologist, Lamont-Doherty Earth Observatory, Columbia University

William Koplitz photo desk manager, FEMA

John Labriola freelance photographer, WTC survivor

Arthur Lerner-Lam, Ph.D. seismologist; director,

Earth Institute, Center for Hazards and Risk Research, Columbia University

James Quintiere, Ph.D. professor of engineering, University of Maryland member, NIST advisory committee

Steve Riskus freelance photographer; eyewitness, Pentagon crash

Van Romero, Ph.D. vice president, New Mexico Institute of Mining and Technology

Christine Shaffer spokesperson, Viracon

Mete Sozen, Ph.D., S.E. Kettelhut Distinguished Professor of Structural Engineering, Purdue University; member, Pentagon Building Performance Report; project conception, September 11 Pentagon Attack Simulations Using LS-Dyna, Purdue University

Shyam Sunder, Sc.D.

acting deputy director, lead investigator, Building and Fire Research Laboratory, National Institute of Standards and Technology

Mary Tobin science writer, media relations, Earth Institute, Columbia University

Forman Williams, Ph.D. professor of engineering, physics, combustion, University of California,

San Diego; member, advisory committee, National Institute of Standards and Technology

[PolyNewbie]

Riverwind,

Stop talking about physics - you discredit yourself.

Start backing upo your arguements with something other than your own expertise and analysis.

[Canadian Blue]

Not true...who says so....you ?

I don't see anything showing the Jim Hoffman has a Phd. All I see is a link saying he is a software engineer.

[PolyNewbie]

Riverwind: If you provide a list of experts I want links to what they are saying. Picking names without providing any of their any explanations around 911 doesn't count. Anyone can go through a phone book and just list engineers.

The NIST report doesn't count because we are talking specifically about the building collapses which are not investigated in NIST. I want to see a link to someone that supports your collapse theories.

[Canadian Blue]

Riverwind,

Stop talking about physics - you discredit yourself.

Start backing upo your arguements with something other than your own expertise and analysis.

Do you have any expertise in structural engineering, I highly doubt it.

[PolyNewbie]

Riverwind:Why is someone who writes about the "philosophy of science" qualified to talk about why buildings fall down?

Because a problem like this has never been seen before - something that looks exactly like CD but claimed to be something else.

[Riverwind]

Start backing upo your arguements with something other than your own expertise and analysis.

I see I have backed you into the corner yet again. I am not surprised. Here is a good paper explaining in detail what happened with the rotational momentum with WTC2.

The collapse of WTC 2 began with a tilting or rotational motion of the upper section of

the Tower about a “hinge” at the 80th floor. This rotational motion, which commenced at

a tilt angle  2, was caused by an almost instantaneous multi-column failure that

eliminated the structural support on one side of WTC 2 near the impact zone. Once set in

motion, the upper block moved with a nearly “free” rotational trajectory of a body

pivoting under the constant force of gravity. This behavior was sustained at tilt angles up

to about 25. Thereafter the motion of the block changed somewhat although the

suggestion that the tilting suddenly stopped is not correct.

What appears to happen is that the tilting upper section was continuously crushed near

the 80th floor by its own momentum so that the rotation was no longer that of a rigid

body. Eventually the "hinge" at the northeast corner failed and the descending block took

on a more vertical motion. Interestingly, once the hinge failed, and the pivot became

frictionless, the motion of the center of gravity is predicted to become vertical, causing a

shift in the rotational axis. Unfortunately, however, details of this stage of the WTC 2

collapse were obscured by smoke, dust and flying debris.

How about that? A real PhD analyzing the problem in detail comes up with same conclusion I did with my static body analysis. Go figure.

Dr. F R Greening has a number of papers that debunk many of the truthie claims.

The best part: he has a track record of making life difficult for gov't as a 'nuclear industry whistle-blower' so this is one guy you cannot dismiss as a stooge of the gov't.

Unfortunately, he is a chemist, not a structural engineer, but he definitely has more qualifications than any of your truthie 'experts'.

However, I found another paper which also confirms my analysis using dynamics instead of static analysis:

The pivoting of the upper part must have started by an asymmetric failure of the columns

on one side of building, but already at this very small angle the dynamic horizontal reaction

at the base of the upper part must have reduced the vertical load capacity of the remaining

columns of the critical floor (even if those were not heated). That must have started the

downward motion of the top part of the South Tower, and afterwards its motion must have

become predominantly vertical. Hence, a vertical impact of the upper part onto the lower

part must have been the dominant mechanism.

This paper was written by a Civil Engineering professor at North Western University which means he is infinitely more qualified than any of your 'philosophers for truth'.

[PolyNewbie]

That paper DOES not explain the collapse.

Riverwind:How about that? A real PhD analyzing the problem in detail comes up with same conclusion I did with my static body analysis. Go figure.

No, he didn't. This paper does not explain the collapse. This paper does not say the same thing you did at all !

Besides, Hoffman rips this work apart in a way that anyone can understand.

[PolyNewbie]

Riverwind:Do you have any expertise in structural engineering, I highly doubt it.

I have taken courses in materials and basic structures, enough to know your physics is all wrong. You do not have a clue about what you are talking about, get elementary concepts wrong and are trying to pass yourself off as an expert.

[Riverwind]

That paper DOES not explain the collapse.

I gave you two papers and I picked out the bits where both papers come to the conclusion that the momentum of the rotating tower was insignificant compared to downward motion once the pivot collapsed. I even highlighted those bits to make it easy. I realize that you have some major denial issues to work through but you going have to do better than make unsupported assertions if you expect people to take you seriously (although it is probably too late for that)

No, he didn't. This paper does not explain the collapse. This paper does not say the same thing you did at all !

Both papers used different approaches but came to the same conclusions. That is the way science works. If you try to solve the problem in 4 different ways and get 4 different answers then you probably don't understand the problem. If you solve the problem in 4 different ways and get the same answer 3 times then you know that is probably the correct answer.

Besides, Hoffman rips this work apart in a way that anyone can understand.

Your mean the computer programmer with no university degree pretending to be a expert on structural engineering? Why should anyone believe what he says? I have given you two links to fairly rigorous scientific papers that come to different conclusions written by real Phds. Plus you have the simplified model I provided that comes to the same conclusions as these papers. The balance of 'evidence' is clearly in favour of my interpretation.

[Riverwind]

Riverwind:Do you have any expertise in structural engineering, I highly doubt it.

I have taken courses in materials and basic structures, enough to know your physics is all wrong. You do not have a clue about what you are talking about, get elementary concepts wrong and are trying to pass yourself off as an expert.

Why should readers bother reading the scientific opinion of someone who can't even figure out how to correctly use the quote feature on this website?

[PolyNewbie]

Riverwind:Your mean the computer programmer with no university degree pretending to be a expert on structural engineering?

Do you mean the guy that works in mathematical research at Berkely and published work for Scientific American ? I guess if he isn't a Phd he must be a genius who never had to go to school.

[PolyNewbie]

From your paper:

That must have started the

downward motion of the top part of the South Tower, and afterwards its motion must have

become predominantly vertical. Hence, a vertical impact of the upper part onto the lower

part must have been the dominant mechanism.

Thats the language of a whitwash. Thats not a proof or explanation of anything.

I gave you two papers and I picked out the bits where both papers come to the conclusion that the momentum of the rotating tower was insignificant compared to downward motion once the pivot collapsed

Oh Yeah ? Apples are better than oranges ! So there !!! Can't you smell BS when you read it ? I'll do a little research on the guy that wrote this and post on him. (since you seem to be so enamoured with him)

[Riverwind]

Do you mean the guy that works in mathematical research at Berkely and published work for Scientific American ? I guess if he isn't a Phd he must be a genius who never had to go to school.

Gawd, you really have no ability to check facts do you. This guy has no connection with the _the_ Berkley. This guy appears to have some association with this outfit: http://www.msri.org/ which happens to be in Berkley, CA. But we don't know what it is. We can assume he was at least a student of mathematics but that does not tell us anything about his credentials.

[PolyNewbie]

Suggestions of the column failure theory were apparent on the day of the attack, amidst the more frequent allusions to the core meltdown theory. Just two days later it was given the support of a technical paper, Why Did the World Trade Center Collapse?-Simple Analysis, written by Zdenek P. Bazant and Yong Zhou.

One of the paper's assumptions it does disclose is that all of the columns of the first story to collapse were heated to 800º C. In that case they would have been glowing red-hot. Perhaps Bazant and Zhou can be forgiven for this oversight and for their wildly innaccurate engineering assumptions, given the short publication deadline they had to meet.

- Hoffman

Hoffmans CritiQue Of Bezant & Zhou

Would you capitulate your position if George Bush said there may have been explosions in the buildings ?

I'm done debating with you because I am noi longer going to entertain a fool