Roves Shill:
I still believe that the NIST Report is incorrect/inconsistent in how it describes the amount of tilt of WTC 1 and 2 BEFORE collapse initiation - the quoted tilt angles are simply too large. I have been over this before on the old thread so I wont go over it again....
And when I first looked at the variation in the angular momentum of the upper section of WTC 2, I reached the conclusion that the rate of tipping was too fast to be gravity driven.
However, I now see that I was incorrect in this conclusion because I did not factor in the loss of rigidity of the upper section. This means that h, the height of the upper section, changes with time. Angular momentum is NOT conserved because the mass of the upper section is not conserved.
Shagster:
I remember reading somewhere that it was not just journalists who were convinced that a chemical rocket could not escape the earth's gravity, but a number of physics PROFESSORS wrote papers claiming to prove this.
I guess we all make mistakes!
NF
David Ray Griffin has written a new book, due out in March I believe, entitled:
"Debunking 9/11 Debunking"
Recently he agreed to answer questions submitted to him from folks interested in specific aspects of 9/11.
Here is one of the questions and DRG's answer (posted on Feb 5th on rinf forum):
"2BFree Asks:
Dr Griffin,
My question concerns the apparent lack of potential energy needed to bring down the twin towers. Do you know of any one who has studied all the energy needed to produce the type of destruction that occurred on 9/11 to the towers? Dr. Judy Wood contends that no available method or process could produce the result that happened i.e. turning the concrete to dust and "dissolve" the huge steel columns as we witnessed except a possible use of "Star Wars" type technology. Do you have any hypothesis to explain this "energy deficiency" that we all saw?
Thank you for your efforts to find the truth."
DRG's response:
"Dear 2Bfree,
There are, of course, various theories, with some scientists proposing thermite or thermate, others proposing mini-nukes, and still others, such as Judy Wood, proposing another kind of technology. I do not have the expertise to enter into these debates. I also suspect it’s a mistake for proponents to become too wedded to any one theory of what really happened. We, of course, want to know, and scientists should not be discouraged from making the case for the theories that seems most probable to them. But we will probably not know for sure until those who orchestrated the destruction of the buildings are forced to reveal how they did it.
We should, therefore, put our emphasis, especially in our public presentations, on the point on which we all agree: that the official story, according to which the buildings were destroyed by the combination of fire and externally caused damage, is false. This is partly, as you say, because of the energy deficiency. But it is also because of all the features of the destruction of WTC 1, 2, and 7 that can be explained, and can only be explained, through the use of some sort of technology that could produce explosions sufficient to slice steel and pulverize virtually all of the concrete.
We can show, accordingly, know that official theory is false without knowing what the true theory is. And that is all we need to show in order to demonstrate that the destruction of the WTC was an inside job."
----------------------------------------------------------------
There are many things I find quite disturbing about this little exchange of views but I will focus on this:
David Ray Griffin is a THEOLOGIAN, not a SCIENTIST. He even admits that "I do not have the expertise to enter into these debates." Nevertheless he proceeds to state that:
".... the destruction of WTC 1, 2, and 7 can be explained, and can only be explained, through the use of some sort of technology that could produce explosions sufficient to slice steel and pulverize virtually all of the concrete...."
To make such a statement is outrageous and irresponsible in the extreme!
I know for a fact that David Ray Griffin is quite familiar with the existence of the NIST Report and the papers by Bazant et al. So why does he choose to completely ignore such peer-reviewed works by acknowledged EXPERTS in science and engineering in favor of very questionable material from the likes of Judy Wood?
In fact, when DRG talks of scientists' theories about the collapse of WTC 1, 2 & 7 he implies that theories involving pre-planted explosives, incendiaries or energy beams, are the ONLY theories on offer!
Apparently Dr. Griffin teaches ETHICS at a College in California.....
SHAME ON YOU DR. GRIFFIN!
NF
"Debunking 9/11 Debunking"
Recently he agreed to answer questions submitted to him from folks interested in specific aspects of 9/11.
Here is one of the questions and DRG's answer (posted on Feb 5th on rinf forum):
"2BFree Asks:
Dr Griffin,
My question concerns the apparent lack of potential energy needed to bring down the twin towers. Do you know of any one who has studied all the energy needed to produce the type of destruction that occurred on 9/11 to the towers? Dr. Judy Wood contends that no available method or process could produce the result that happened i.e. turning the concrete to dust and "dissolve" the huge steel columns as we witnessed except a possible use of "Star Wars" type technology. Do you have any hypothesis to explain this "energy deficiency" that we all saw?
Thank you for your efforts to find the truth."
DRG's response:
"Dear 2Bfree,
There are, of course, various theories, with some scientists proposing thermite or thermate, others proposing mini-nukes, and still others, such as Judy Wood, proposing another kind of technology. I do not have the expertise to enter into these debates. I also suspect it’s a mistake for proponents to become too wedded to any one theory of what really happened. We, of course, want to know, and scientists should not be discouraged from making the case for the theories that seems most probable to them. But we will probably not know for sure until those who orchestrated the destruction of the buildings are forced to reveal how they did it.
We should, therefore, put our emphasis, especially in our public presentations, on the point on which we all agree: that the official story, according to which the buildings were destroyed by the combination of fire and externally caused damage, is false. This is partly, as you say, because of the energy deficiency. But it is also because of all the features of the destruction of WTC 1, 2, and 7 that can be explained, and can only be explained, through the use of some sort of technology that could produce explosions sufficient to slice steel and pulverize virtually all of the concrete.
We can show, accordingly, know that official theory is false without knowing what the true theory is. And that is all we need to show in order to demonstrate that the destruction of the WTC was an inside job."
----------------------------------------------------------------
There are many things I find quite disturbing about this little exchange of views but I will focus on this:
David Ray Griffin is a THEOLOGIAN, not a SCIENTIST. He even admits that "I do not have the expertise to enter into these debates." Nevertheless he proceeds to state that:
".... the destruction of WTC 1, 2, and 7 can be explained, and can only be explained, through the use of some sort of technology that could produce explosions sufficient to slice steel and pulverize virtually all of the concrete...."
To make such a statement is outrageous and irresponsible in the extreme!
I know for a fact that David Ray Griffin is quite familiar with the existence of the NIST Report and the papers by Bazant et al. So why does he choose to completely ignore such peer-reviewed works by acknowledged EXPERTS in science and engineering in favor of very questionable material from the likes of Judy Wood?
In fact, when DRG talks of scientists' theories about the collapse of WTC 1, 2 & 7 he implies that theories involving pre-planted explosives, incendiaries or energy beams, are the ONLY theories on offer!
Apparently Dr. Griffin teaches ETHICS at a College in California.....
SHAME ON YOU DR. GRIFFIN!
NF
How do we post images on this new thread?
QUOTE (roves shill+Feb 7 2007, 10:50 AM)
How do we post images on this new thread?
Why? Do you have some newly discovered, never before seen photos?
Why? Do you have some newly discovered, never before seen photos?
QUOTE (NEU-FONZE+Feb 7 2007, 10:31 AM)
"2BFree Asks:
Dr Griffin,
. . . ."dissolve" the huge steel columns as we witnessed "
OOOH, the columns were disolved. That is a new theory.
So, if the steel was the solute, what exactly was the solvent?
QUOTE (shagster+Feb 7 2007, 09:27 AM)
I was using an average based on the mass of the upper 14 stories. Adding up the NIST numbers at the 95/96 level gives 83282 kips or 3.79E6 kg That's about 2.7E6 kg per story. I've been using an average 3E6 kg per story in my computer models.
Thanks for the reminder to reread ENERGY TRANSFER.
From Table 4-7, NCSTAR1-6D, p 176 (240 ordinal), taking first differences produces the following kip values
3379
3397
3387
3382
3370
--------
16915 / 5 = 3383 kip --> 1534.6 tonnes
so I don't follow your calculation, at all.
The mass of 'the upper 14 stories' actually includes the mass of the PH Roof level, the hat truss, and the upper mechanical floors. This appears to be why your 'average' is too big by a factor of two. Below floor 105 all the floors were ordinary trussed floors down to about floor 81. But averaging first differences from Table 4-8 gives masses per story about 6% larger than the figure above.
Thanks for the reminder to reread ENERGY TRANSFER.
From Table 4-7, NCSTAR1-6D, p 176 (240 ordinal), taking first differences produces the following kip values
3379
3397
3387
3382
3370
--------
16915 / 5 = 3383 kip --> 1534.6 tonnes
so I don't follow your calculation, at all.
The mass of 'the upper 14 stories' actually includes the mass of the PH Roof level, the hat truss, and the upper mechanical floors. This appears to be why your 'average' is too big by a factor of two. Below floor 105 all the floors were ordinary trussed floors down to about floor 81. But averaging first differences from Table 4-8 gives masses per story about 6% larger than the figure above.
QUOTE (Palpatane+Feb 7 2007, 05:00 PM)
Why? Do you have some newly discovered, never before seen photos?
I just thought a man of your integrity and objectivitey would like to make sure the calculations presented matches the behavour observed.
I just thought a man of your integrity and objectivitey would like to make sure the calculations presented matches the behavour observed.
QUOTE (roves shill+Feb 7 2007, 03:05 PM)
I just thought a man of your integrity and objectivitey would like to make sure the calculations presented matches the behavour observed.
You need to make X posts before being allowed to post a link (this is apparently to cut down on bot spam).
I'm not sure what X is but I think its 5, so my guess is you can post those pics now.
If not, make a few more posts and eventually you will be able to post the pics.
Arthur
You need to make X posts before being allowed to post a link (this is apparently to cut down on bot spam).
I'm not sure what X is but I think its 5, so my guess is you can post those pics now.
If not, make a few more posts and eventually you will be able to post the pics.
Arthur
QUOTE (adoucette+Feb 6 2007, 09:08 AM)
Did you notice that 3 of the people have respirators but are NOT using them?
Arthur
The filters need to be changed everyday, sometimes twice a day otherwise they clog.
just providing the respirator is not enough, you have to train the worker in how to maintian it and see that they change the filters regularly.
Arthur
The filters need to be changed everyday, sometimes twice a day otherwise they clog.
just providing the respirator is not enough, you have to train the worker in how to maintian it and see that they change the filters regularly.
QUOTE (Palpatane+Feb 7 2007, 04:23 PM)
The filters need to be changed everyday, sometimes twice a day otherwise they clog.
just providing the respirator is not enough, you have to train the worker in how to maintian it and see that they change the filters regularly.
I think you'll notice that the respirators all appear to be the same type, and most of the people working there appear to be fireman.
http://www.box.net/public/26rjp73slx
I would believe that whoever provided the respirators (most likely FEMA) also knew that they have to be changed and thus its hard to believe that replacement canisters weren't available.
Still, as you can see in the FOREGROUND shot, the air APPEARS to be fairly clear, yet when you look all the way to the back ground its clear that this cleanliness is an illusion.
Still people THINK that air is typically better quality than it is.
Which is why I think they aren't wearing them.
They don't PERCEIVE the danger.
They do PERCEIVE the inconvenience and discomfort from using them however.
Arthur
just providing the respirator is not enough, you have to train the worker in how to maintian it and see that they change the filters regularly.
I think you'll notice that the respirators all appear to be the same type, and most of the people working there appear to be fireman.
http://www.box.net/public/26rjp73slx
I would believe that whoever provided the respirators (most likely FEMA) also knew that they have to be changed and thus its hard to believe that replacement canisters weren't available.
Still, as you can see in the FOREGROUND shot, the air APPEARS to be fairly clear, yet when you look all the way to the back ground its clear that this cleanliness is an illusion.
Still people THINK that air is typically better quality than it is.
Which is why I think they aren't wearing them.
They don't PERCEIVE the danger.
They do PERCEIVE the inconvenience and discomfort from using them however.
Arthur
QUOTE (NEU-FONZE+Feb 7 2007, 04:31 PM)
There are many things I find quite disturbing about this little exchange of views but I will focus on this:
David Ray Griffin is a THEOLOGIAN, not a SCIENTIST. He even admits that "I do not have the expertise to enter into these debates." Nevertheless he proceeds to state that:
".... the destruction of WTC 1, 2, and 7 can be explained, and can only be explained, through the use of some sort of technology that could produce explosions sufficient to slice steel and pulverize virtually all of the concrete...."
To make such a statement is outrageous and irresponsible in the extreme!
I know for a fact that David Ray Griffin is quite familiar with the existence of the NIST Report and the papers by Bazant et al. So why does he choose to completely ignore such peer-reviewed works by acknowledged EXPERTS in science and engineering in favor of very questionable material from the likes of Judy Wood?
Well no, the whole point of his response is that he doesn't think it is important, or necessary, to determine the exact method used for bringing down the twin towers. Judy Wood's "space beam" theory, the nuke theory, the thermate/conventional explosives theory are not important.... Once you recognize that the official NIST theory of a solely gravity-driven collapse cannot explain the observed events, and that therefore the towers were - somehow - deliberately brought down, the exact mechanism used is not that important. Rather, D.R.Griffin is saying that there is enough incriminating information - based on the above fact alone - to launch a criminal investigation and this should be the focus, not bickering over alternate theories.
As to why a theology professor should be writing about this, his book "The 9/11 Commission Report: Omissions And Distortions" for example, is a wide ranging look at many aspects of the 911 official story, not just the twin tower collapse. There is a need for generalists to tie things together in any discipline. For his work on the twin towers, I believe he draws upon the work of people like Jim Hoffmann, Kevin Ryan, Steven Jones who have done a lot of work in this area. But in the end you just need some basic physics and common sense to see that gravity alone cannot explain what happened. For example - for WTC1 & 2, this picture that foxx posted sometime ago:
911blimp.net/graphics/suspendedWTCtop2.gif
(sorry, can't post links/pictures yet - cut and paste it into browser)
the block on the left cannot fall as fast as the one on the right - simple as that.
As for WTC7, I won't even get into it except to say that there isn't even an official NIST theory over 5 years after the events.
My question to you NEU-FONZE is, what would you have said to critics of Colin Powell's now infamous WMD speech at the UN? After all, his information was vetted by the CIA a multi-billion dollar organization with "acknowledged EXPERTS" in intelligence. How many of these "EXPERTS" had the courage to put their job on the line, stand up and call it what it was: complete bunk?
What about the EPA declaring the air safe to breathe at ground zero? Again, an official governmental organization with thousands of "acknowledged EXPERTS" in environmental science - puts out complete nonsense. And no one in the EPA (or the media for that matter) puts out a squeak of protest.
Because a large official organization of "acknowledged EXPERTS" says something doesn't make it automatically true. Governments lie. And because the media has ceased to function in its capacity of watchdog, it is unfortunately all too often left to a somewhat more eclectic group of unaffiliated individuals and concerned citizens to try and pick up the slack. I'm glad D.R.Griffin is among them.
Karl Rove, master of the "creating our own reality," sums up the octs on this board.
"On June 25, 2006, NIST Director of Media Relations, Michael E. Newman" (you don't think he is a neocon Bush shill do you?) "responded:
"The members of the NIST WTC Investigation Team has [sic] respectfully declined your invitation to participate in the National 9/11 Debate. A change in venue or date will not alter that decision."
Debate in an open society is the foundation of modern democracy. Only con men peddling snake oil or Ponzi schemes refuse to discuss the crap they force the public to swallow.
The Bushnik neocon baby killing, war criminals/profiteers, are going to the gallows; no ifs, buts, or maybes about it. This is going to be the reality they created for themselves.
Patriots are going to take this country back.
The Bushnik scum have the guns, but the patriots have the numbers.
I advise all scientists to think of their legacy before taking pieces of silver from the murderers that lied the country into war.
COME ON PHYSICS!
DO THE STUDY AND LET THE CHIPS FALL WHERE THEY MAY!
"On June 25, 2006, NIST Director of Media Relations, Michael E. Newman" (you don't think he is a neocon Bush shill do you?) "responded:
"The members of the NIST WTC Investigation Team has [sic] respectfully declined your invitation to participate in the National 9/11 Debate. A change in venue or date will not alter that decision."
Debate in an open society is the foundation of modern democracy. Only con men peddling snake oil or Ponzi schemes refuse to discuss the crap they force the public to swallow.
The Bushnik neocon baby killing, war criminals/profiteers, are going to the gallows; no ifs, buts, or maybes about it. This is going to be the reality they created for themselves.
Patriots are going to take this country back.
The Bushnik scum have the guns, but the patriots have the numbers.
I advise all scientists to think of their legacy before taking pieces of silver from the murderers that lied the country into war.
COME ON PHYSICS!
DO THE STUDY AND LET THE CHIPS FALL WHERE THEY MAY!
ROTFLMAO
From the latest study that you quoted from:
69% think that the Bush admin is either telling the truth or MOSTLY telling the truth
So clearly CT'ers (who have shown LITTLE EVIDENCE OF BEING PATRIOTS) clearly DON'T have the numbers.
Which is why NO ONE is calling for an investigation except your typical fringe loonies.
As far as the NIST and debate goes, they NIST issued DRAFT reports FOR PUBLIC COMMENT, so they DID allow debate (and in fact PUBLISH the comments) before issuing the FINAL DRAFT. I notice that few CT'ers even bothered to comment.
As far as the study you call for, NIST has already done it and if you had any REAL interest in the truth you'd spend some time READING IT.
Arthur
From the latest study that you quoted from:
69% think that the Bush admin is either telling the truth or MOSTLY telling the truth
So clearly CT'ers (who have shown LITTLE EVIDENCE OF BEING PATRIOTS) clearly DON'T have the numbers.
Which is why NO ONE is calling for an investigation except your typical fringe loonies.
As far as the NIST and debate goes, they NIST issued DRAFT reports FOR PUBLIC COMMENT, so they DID allow debate (and in fact PUBLISH the comments) before issuing the FINAL DRAFT. I notice that few CT'ers even bothered to comment.
As far as the study you call for, NIST has already done it and if you had any REAL interest in the truth you'd spend some time READING IT.
Arthur
Given the Greening model has anyone done any calculations, on the amount or frequency of shock waves building in the core, that could have speed the collapse?
I am not talking about a sudden all encompassing shock wave but a steady building energy transference to the steel structure.
It would seem to me that the structure would actually be oscillating do to the constant impact, and compression forces.
The reason for this let me give a simple analogy is the metal is like a samurai sword, it is light and strong, from heat treating and layering.
However if a mistake was made during the layering, folding, heating process and a small section of harder metal is formed the sword breaks when it is used to strike an object.
I am not suggesting that the building is a samurai sword only that a constantly increasing wave form energy structure in the core beams can reduce the structure as the mass accumulates, causing speed-ed collapse.
If the structure was storing energy in the beams because it could not dissipate that energy quick enough it might provide incite into the weld and metal failure!
I am not talking about a sudden all encompassing shock wave but a steady building energy transference to the steel structure.
It would seem to me that the structure would actually be oscillating do to the constant impact, and compression forces.
The reason for this let me give a simple analogy is the metal is like a samurai sword, it is light and strong, from heat treating and layering.
However if a mistake was made during the layering, folding, heating process and a small section of harder metal is formed the sword breaks when it is used to strike an object.
I am not suggesting that the building is a samurai sword only that a constantly increasing wave form energy structure in the core beams can reduce the structure as the mass accumulates, causing speed-ed collapse.
If the structure was storing energy in the beams because it could not dissipate that energy quick enough it might provide incite into the weld and metal failure!
Lozenge 124:
I'm sorry, I don't think it's at all "obvious" that the collapse of WTC 1 & 2 was a controlled demolition. And Griffin is absolutely incorrect when he says there was insufficient gravitational potential energy to bring down the towers and pulverize the concrete.
Griffin can write all he wants to about the President's behavior on 9/11, or alleged complicity by US officials, etc, etc, but his opinions on physics are worthless.
And as for your question about the alleged lies by the US government over WMD or the air quality at GZ, etc..... This may well be true and is obviously unacceptable, but are you saying Bazant knowingly lied about the physics of the WTC collapse?
And why would you believe Griffin's intuition about the collapse over Bazant's mathematical model?
If a building collapsed in your town, would you ask a theologian or a civil engineer why it happened.....
Griffin should stick to peddling his NWO religion to the faithful at Claremont....
NF
I'm sorry, I don't think it's at all "obvious" that the collapse of WTC 1 & 2 was a controlled demolition. And Griffin is absolutely incorrect when he says there was insufficient gravitational potential energy to bring down the towers and pulverize the concrete.
Griffin can write all he wants to about the President's behavior on 9/11, or alleged complicity by US officials, etc, etc, but his opinions on physics are worthless.
And as for your question about the alleged lies by the US government over WMD or the air quality at GZ, etc..... This may well be true and is obviously unacceptable, but are you saying Bazant knowingly lied about the physics of the WTC collapse?
And why would you believe Griffin's intuition about the collapse over Bazant's mathematical model?
If a building collapsed in your town, would you ask a theologian or a civil engineer why it happened.....
Griffin should stick to peddling his NWO religion to the faithful at Claremont....
NF
Lozenge 124
woops!
NF
woops!
NF
QUOTE (Chainsaw,+Feb 7 2007, 10:31 PM)
Given the Greening model has anyone done any calculations, on the amount or frequency of shock waves building in the core, that could have speed the collapse?
I am not talking about a sudden all encompassing shock wave but a steady building energy transference to the steel structure.
If the structure was storing energy in the beams because it could not dissipate that energy quick enough it might provide incite into the weld and metal failure!
None that I know about, but this is an interesting question, especially as one cannot see the core before Ground Zero.
The general impression of core column members at Ground Zero is that there is little damage to the members and all the welds failed. Indeed, then, some vibrations could have occurred, up to the elastic limit of the mild steel. This could have promoted weld failures.
So! A good question, one which I'll need to read a bit more in a book on dynamic loading.
Thanks.
I am not talking about a sudden all encompassing shock wave but a steady building energy transference to the steel structure.
If the structure was storing energy in the beams because it could not dissipate that energy quick enough it might provide incite into the weld and metal failure!
None that I know about, but this is an interesting question, especially as one cannot see the core before Ground Zero.
The general impression of core column members at Ground Zero is that there is little damage to the members and all the welds failed. Indeed, then, some vibrations could have occurred, up to the elastic limit of the mild steel. This could have promoted weld failures.
So! A good question, one which I'll need to read a bit more in a book on dynamic loading.
Thanks.
QUOTE (David B. Benson+Feb 7 2007, 11:03 PM)
None that I know about, but this is an interesting question, especially as one cannot see the core before Ground Zero.
The general impression of core column members at Ground Zero is that there is little damage to the members and all the welds failed. Indeed, then, some vibrations could have occurred, up to the elastic limit of the mild steel. This could have promoted weld failures.
So! A good question, one which I'll need to read a bit more in a book on dynamic loading.
Thanks.
I was just working on some 1/2 inch by six inch square tubing, banging on it with a hammer, to straiten a bolt when I noticed that the vibrations increase with the rapidity of the pounding and I actually broke the weld that held the lift boom to the stand along the weld eight feet away from where I was hammering.
The part I was hammering on was supported by a big wooden stump.
Just wondered if a similar effect could have happened in the towers?
Some times accidents give you the best incite!
The cters are nuts that is another incite I learned today, I posted this site on an art group, and the people on there blasted it as an American imperialist trash, they did not happen to notice that the artist a friend of mine was German.
Eagle Bike sculpture
Also Dr' Griffin is just covering his hind end, he is beginning to see the science does not back him, so he is trying for a way out, reject the science and say they the Scholars, mislead me but my political assumptions were right!
Old tactic.
The general impression of core column members at Ground Zero is that there is little damage to the members and all the welds failed. Indeed, then, some vibrations could have occurred, up to the elastic limit of the mild steel. This could have promoted weld failures.
So! A good question, one which I'll need to read a bit more in a book on dynamic loading.
Thanks.
I was just working on some 1/2 inch by six inch square tubing, banging on it with a hammer, to straiten a bolt when I noticed that the vibrations increase with the rapidity of the pounding and I actually broke the weld that held the lift boom to the stand along the weld eight feet away from where I was hammering.
The part I was hammering on was supported by a big wooden stump.
Just wondered if a similar effect could have happened in the towers?
Some times accidents give you the best incite!
The cters are nuts that is another incite I learned today, I posted this site on an art group, and the people on there blasted it as an American imperialist trash, they did not happen to notice that the artist a friend of mine was German.
Eagle Bike sculpture
Also Dr' Griffin is just covering his hind end, he is beginning to see the science does not back him, so he is trying for a way out, reject the science and say they the Scholars, mislead me but my political assumptions were right!
Old tactic.
CNN poll: 83% say 9/11 terror was a US Govt 'inside job'!
In a live poll* on Internet, which CNN started last Thursday, March 23, 2006 - the following question was asked:
''Do you agree with Charlie Sheen that the U.S. government covered up the real events of the 9/11 attacks?''
Yes answered 83%
at present 30844 votes
* MSNBC - Live Vote - Concerning the "Project for a Nefarious American Century" (PNAC) - ''Do you believe President Bush's actions justify impeachment?'' - YES: 86% - CNN Poll 83% say 9/11 Terror Was Govt Inside Job
I feel sorry for you Arthur. If you can't interpret a simple poll, how is anyone going to take your take on physics seriously? I will pray for you.
Let me reiterate
May '02 --> Oct. '06
# 08% ----> 28% "Mostly lying"
# 65% ----> 53% "Hiding something"
# 21% ----> 16% "Telling the truth"
# 06% ----> 03% "Not sure"
In a live poll* on Internet, which CNN started last Thursday, March 23, 2006 - the following question was asked:
''Do you agree with Charlie Sheen that the U.S. government covered up the real events of the 9/11 attacks?''
Yes answered 83%
at present 30844 votes
* MSNBC - Live Vote - Concerning the "Project for a Nefarious American Century" (PNAC) - ''Do you believe President Bush's actions justify impeachment?'' - YES: 86% - CNN Poll 83% say 9/11 Terror Was Govt Inside Job
I feel sorry for you Arthur. If you can't interpret a simple poll, how is anyone going to take your take on physics seriously? I will pray for you.
Let me reiterate
QUOTE
Scientific Poll: 84% Reject Official 9/11 Story
A monumental new scientific opinion poll has emerged which declares that only 16% of people in America now believe the official government explanation of the September 11th 2001 terror attacks.
Scientific Poll 84% Reject Official 9/11 StoryA monumental new scientific opinion poll has emerged which declares that only 16% of people in America now believe the official government explanation of the September 11th 2001 terror attacks.
May '02 --> Oct. '06
# 08% ----> 28% "Mostly lying"
# 65% ----> 53% "Hiding something"
# 21% ----> 16% "Telling the truth"
# 06% ----> 03% "Not sure"
QUOTE (->
| QUOTE |
| Scientific Poll: 84% Reject Official 9/11 Story A monumental new scientific opinion poll has emerged which declares that only 16% of people in America now believe the official government explanation of the September 11th 2001 terror attacks. |
Scientific Poll 84% Reject Official 9/11 Story
May '02 --> Oct. '06
# 08% ----> 28% "Mostly lying"
# 65% ----> 53% "Hiding something"
# 21% ----> 16% "Telling the truth"
# 06% ----> 03% "Not sure"
This shift of opinion happened while there was not a single "investigative journalist" that digged into 9/11 contradictions and unanswered questions....
Hail the Internet!
Get a grip Arthur. Take your dollars and go to Europe and see what Bush has done to your savings.
This ain't Physics Arthur, and from now on I will not argue with a "M0R0N."
May '02 --> Oct. '06
# 08% ----> 28% "Mostly lying"
# 65% ----> 53% "Hiding something"
# 21% ----> 16% "Telling the truth"
# 06% ----> 03% "Not sure"
This shift of opinion happened while there was not a single "investigative journalist" that digged into 9/11 contradictions and unanswered questions....
Hail the Internet!
QUOTE
AMERICANS SEE THROUGH THE GRAND FACADE
Even 50% of New Yorkers themselves believe that the Bush Regime orchestrated 9/11 and/or knew the attacks were imminent, yet "consciously failed to act" due to their covert agenda.
Americans See Through the Grand FacadeEven 50% of New Yorkers themselves believe that the Bush Regime orchestrated 9/11 and/or knew the attacks were imminent, yet "consciously failed to act" due to their covert agenda.
Get a grip Arthur. Take your dollars and go to Europe and see what Bush has done to your savings.
This ain't Physics Arthur, and from now on I will not argue with a "M0R0N."
Chainsaw, --- Yes, indeed, as you observed in your backyard!
The simplest case is to consider a perfect elastic column under periodic loading. Then depending upon the ratio of two parameters b/a, the corresponding Matthew-Hill equation may have an unbounded solution!
Well, that didn't happen very often since it implies going into the inelastic regime. But the point of this quick check is that the oscillations can become quite large, stressing the welds. Of course, the core column members in the towers were probably not under periodic loadings, but the general idea for the Matthew-Hill equation ought still to work for members undergoing quasi-periodic loadings as the speed of the descent built up. So it appears there is something to your idea.
Thanks again!
The simplest case is to consider a perfect elastic column under periodic loading. Then depending upon the ratio of two parameters b/a, the corresponding Matthew-Hill equation may have an unbounded solution!
Well, that didn't happen very often since it implies going into the inelastic regime. But the point of this quick check is that the oscillations can become quite large, stressing the welds. Of course, the core column members in the towers were probably not under periodic loadings, but the general idea for the Matthew-Hill equation ought still to work for members undergoing quasi-periodic loadings as the speed of the descent built up. So it appears there is something to your idea.
Thanks again!
QUOTE (NEU-FONZE+Feb 7 2007, 11:00 PM)
Lozenge 124:
I'm sorry, I don't think it's at all "obvious" that the collapse of WTC 1 & 2 was a controlled demolition. And Griffin is absolutely incorrect when he says there was insufficient gravitational potential energy to bring down the towers and pulverize the concrete.
Griffin can write all he wants to about the President's behavior on 9/11, or alleged complicity by US officials, etc, etc, but his opinions on physics are worthless.
And as for your question about the alleged lies by the US government over WMD or the air quality at GZ, etc..... This may well be true and is obviously unacceptable, but are you saying Bazant knowingly lied about the physics of the WTC collapse?
And why would you believe Griffin's intuition about the collapse over Bazant's mathematical model?
If a building collapsed in your town, would you ask a theologian or a civil engineer why it happened.....
Griffin should stick to peddling his NWO religion to the faithful at Claremont....
NF
I wouldn't personally accuse Bazant & Zhou of complicity, but their paper was written in Sept.2001 very soon after the events (for a critique see for example 911research.wtc7.net/disinfo/experts/articles/bazant_jem/bazant_zhou.html ), but most important, like all the official explanations, it doesn't attempt to account for the collapse time.
That's the point of this image (and I'm at a disadvantage as I still can't post images )
911blimp.net/graphics/suspendedWTCtop2.gif
even if you buy that the conditions were such that collapse had to occur (and I don't), and that there was enough potential energy to pulverize the concrete, break up the core, push the exterior outwards etc... there's no way this could have happened at or near free fall speed. That's the "violation of basic laws of physics" that Griffin is reporting (based on work of Hoffman, Jones, Ryan etc.. not his intuition)
I agree with you that I would like to hear more opinions of architects and civil & structural engineers on this, and it is disappointing that there aren't very many active in the scholars for truth movement. But that's also why I mentioned the WMD and EPA scenarios; a lack of dissenting, vocal experts doesn't necessarily mean that everyone is in agreement. Like I mentioned elsewhere, the NIST hasn't made their computer models and datasets accessible, so how can anyone peer review them? There is also not much incentive for a structural engineer to go against the NIST report as he would be ostracized, if not fired (which is what happened to Steven Jones for example). Actually, in that same interview Griffin had some good points on this very issue:
I guess at this point, I haven't seen any good rebuttals to the critiques of the NIST report by Jim Hoffman ( 911research.wtc7.net/talks/collapse/index.html ), Kevin Ryan ( 911research.wtc7.net/reviews/kevin_ryan/newstandard.html ), Steven Jones ( video.google.com/videoplay?docid=9210704017463126290 ) and what they have to say seems to me pretty convincing.
The NIST report is based on a computer model with flawed assumptions (again, see Ryan, Hoffman) with parameters apparently tweaked until the desired collapse initiation was seen. The models are unavailable, and the key "close to free fall" collapse is not modelled or explained. There are so many more problems, the removal of all the steel evidence, William Rodriguez testimony of explosions in the WTC basement prior to the airplane hit, WTC7, etc etc etc. this is why I don't find the NIST report convincing at all.
Incidentally, one of the NIST engineers, Ronald Hamburger, gave a talk last December "Conspiracy or Science: Why Did the Towers Fall?". Unfortunately there's no transcript available, but there's a critique here: 911research.wtc7.net/essays/green/hamburger.html . I find it interesting that this guy apparently didn't know how many core columns there were! (47)
I'm sorry, I don't think it's at all "obvious" that the collapse of WTC 1 & 2 was a controlled demolition. And Griffin is absolutely incorrect when he says there was insufficient gravitational potential energy to bring down the towers and pulverize the concrete.
Griffin can write all he wants to about the President's behavior on 9/11, or alleged complicity by US officials, etc, etc, but his opinions on physics are worthless.
And as for your question about the alleged lies by the US government over WMD or the air quality at GZ, etc..... This may well be true and is obviously unacceptable, but are you saying Bazant knowingly lied about the physics of the WTC collapse?
And why would you believe Griffin's intuition about the collapse over Bazant's mathematical model?
If a building collapsed in your town, would you ask a theologian or a civil engineer why it happened.....
Griffin should stick to peddling his NWO religion to the faithful at Claremont....
NF
I wouldn't personally accuse Bazant & Zhou of complicity, but their paper was written in Sept.2001 very soon after the events (for a critique see for example 911research.wtc7.net/disinfo/experts/articles/bazant_jem/bazant_zhou.html ), but most important, like all the official explanations, it doesn't attempt to account for the collapse time.
That's the point of this image (and I'm at a disadvantage as I still can't post images
) 911blimp.net/graphics/suspendedWTCtop2.gif
even if you buy that the conditions were such that collapse had to occur (and I don't), and that there was enough potential energy to pulverize the concrete, break up the core, push the exterior outwards etc... there's no way this could have happened at or near free fall speed. That's the "violation of basic laws of physics" that Griffin is reporting (based on work of Hoffman, Jones, Ryan etc.. not his intuition)
I agree with you that I would like to hear more opinions of architects and civil & structural engineers on this, and it is disappointing that there aren't very many active in the scholars for truth movement. But that's also why I mentioned the WMD and EPA scenarios; a lack of dissenting, vocal experts doesn't necessarily mean that everyone is in agreement. Like I mentioned elsewhere, the NIST hasn't made their computer models and datasets accessible, so how can anyone peer review them? There is also not much incentive for a structural engineer to go against the NIST report as he would be ostracized, if not fired (which is what happened to Steven Jones for example). Actually, in that same interview Griffin had some good points on this very issue:
QUOTE
Architect Says:
A major issue for the 911 Truth movement has been the lack of any substantial support from the academic and professional communities best placed to consider the underlying causes of collapse; in particular architects, fire engineers, and structural engineers.
Given the amount of qualified people in these fields, in particular world-wide and hence outwith the US immediate sphere of influence, it seems inconceivable that any serious errors in the NIST/FEMA analysis would not have been highlighted.
In contrast, there are a number of papers by various groups such as Ove Arup, Edinburgh University, and Sheffield University which have confirmed (or largely confirmed) key parts of the "official" analysis.
Why do you consider this situation has arisen, and why has the Truth movement been unable to respond with detailed engineering analyses?
--------
Dear Architect,
Although it may at first glance seem “inconceivable” that errors the analyses by FEMA and NIST would not have been highlighted in the press or academic journals, this becomes less inconceivable after one becomes familiar with various relevant factors.
One factor is that most architects and engineers in countries allied with the USA evidently find it inconceivable that 9/11 could have been an inside job that was then covered up by agencies of the US government. Civilized countries, they believe, simply don’t do such things. And so, since pre-set explosives are ruled out, the buildings “must” have come down through some combination of fire and externally produced damage. So like NIST itself, rather than asking, “Can pigs fly?”, they simply ask: “Granted that these pigs flew, how did they do it?” And once that is the question, then NIST’s answer is about as good as one can do.
A second factor is that architectural and engineering firms can thrive and even survive on the basis of their reputations, and in elite circles---the circles that can pay for their services---any firm that supported a “conspiracy theory” about 9/11 would no longer be considered reliable. Or at least the firms fear that this will be the case.
A third factor is that, even if some individual engineers and architects produced contrary analyses, they would most likely not be published by any scientific journals or mentioned in any mainstream press articles. For example, two engineers at the ETH Swiss Federal Institute of Technology, which is very prestigious, have declared that WTC 7 was with the highest probability brought down by explosives. But you will not find reports of these statements in the mainstream press or academic journals in Europe or (especially) the United States. The moral of this discussion is that we have no idea how many architects and engineers have disputed the conclusions reached by NIST.
Let me also add that architects and engineers are not necessarily, as you suggest, “best placed to consider the underlying causes of the collapse.” They build things; they do not destroy things. Also, to disprove the official theory, we not need a full-blown alternative theory. All we need is sufficient evidence that the official story cannot be true, and if this theory violates fundamental laws of physics, that is sufficient evidence.
A major issue for the 911 Truth movement has been the lack of any substantial support from the academic and professional communities best placed to consider the underlying causes of collapse; in particular architects, fire engineers, and structural engineers.
Given the amount of qualified people in these fields, in particular world-wide and hence outwith the US immediate sphere of influence, it seems inconceivable that any serious errors in the NIST/FEMA analysis would not have been highlighted.
In contrast, there are a number of papers by various groups such as Ove Arup, Edinburgh University, and Sheffield University which have confirmed (or largely confirmed) key parts of the "official" analysis.
Why do you consider this situation has arisen, and why has the Truth movement been unable to respond with detailed engineering analyses?
--------
Dear Architect,
Although it may at first glance seem “inconceivable” that errors the analyses by FEMA and NIST would not have been highlighted in the press or academic journals, this becomes less inconceivable after one becomes familiar with various relevant factors.
One factor is that most architects and engineers in countries allied with the USA evidently find it inconceivable that 9/11 could have been an inside job that was then covered up by agencies of the US government. Civilized countries, they believe, simply don’t do such things. And so, since pre-set explosives are ruled out, the buildings “must” have come down through some combination of fire and externally produced damage. So like NIST itself, rather than asking, “Can pigs fly?”, they simply ask: “Granted that these pigs flew, how did they do it?” And once that is the question, then NIST’s answer is about as good as one can do.
A second factor is that architectural and engineering firms can thrive and even survive on the basis of their reputations, and in elite circles---the circles that can pay for their services---any firm that supported a “conspiracy theory” about 9/11 would no longer be considered reliable. Or at least the firms fear that this will be the case.
A third factor is that, even if some individual engineers and architects produced contrary analyses, they would most likely not be published by any scientific journals or mentioned in any mainstream press articles. For example, two engineers at the ETH Swiss Federal Institute of Technology, which is very prestigious, have declared that WTC 7 was with the highest probability brought down by explosives. But you will not find reports of these statements in the mainstream press or academic journals in Europe or (especially) the United States. The moral of this discussion is that we have no idea how many architects and engineers have disputed the conclusions reached by NIST.
Let me also add that architects and engineers are not necessarily, as you suggest, “best placed to consider the underlying causes of the collapse.” They build things; they do not destroy things. Also, to disprove the official theory, we not need a full-blown alternative theory. All we need is sufficient evidence that the official story cannot be true, and if this theory violates fundamental laws of physics, that is sufficient evidence.
I guess at this point, I haven't seen any good rebuttals to the critiques of the NIST report by Jim Hoffman ( 911research.wtc7.net/talks/collapse/index.html ), Kevin Ryan ( 911research.wtc7.net/reviews/kevin_ryan/newstandard.html ), Steven Jones ( video.google.com/videoplay?docid=9210704017463126290 ) and what they have to say seems to me pretty convincing.
The NIST report is based on a computer model with flawed assumptions (again, see Ryan, Hoffman) with parameters apparently tweaked until the desired collapse initiation was seen. The models are unavailable, and the key "close to free fall" collapse is not modelled or explained. There are so many more problems, the removal of all the steel evidence, William Rodriguez testimony of explosions in the WTC basement prior to the airplane hit, WTC7, etc etc etc. this is why I don't find the NIST report convincing at all.
Incidentally, one of the NIST engineers, Ronald Hamburger, gave a talk last December "Conspiracy or Science: Why Did the Towers Fall?". Unfortunately there's no transcript available, but there's a critique here: 911research.wtc7.net/essays/green/hamburger.html . I find it interesting that this guy apparently didn't know how many core columns there were! (47)
I can tell by the amount of hits I got over a few months that the amount of people who believe the conspiracy story is dwindling.
You guys should read the stupid E-mails I get from conspiracy theorists. One guy asked "Why did the commander have time to call Silverstien?" Well gee, maybe because he just gave up on the rescue operations? What do they expect him to do? Direct traffic?!? Heh!
As if building 7 was a trailer. If that was my 47 story billion dollar building I would think a call by a commander of the fire department would be the least they could do after they gave up on it. Especially after all they did was tell people to back away from it. The job of telling someone to get on the radio and tell everyone to pull back takes all of 2 minutes. How stupid can they be...
You guys should read the stupid E-mails I get from conspiracy theorists. One guy asked "Why did the commander have time to call Silverstien?" Well gee, maybe because he just gave up on the rescue operations? What do they expect him to do? Direct traffic?!? Heh!
As if building 7 was a trailer. If that was my 47 story billion dollar building I would think a call by a commander of the fire department would be the least they could do after they gave up on it. Especially after all they did was tell people to back away from it. The job of telling someone to get on the radio and tell everyone to pull back takes all of 2 minutes. How stupid can they be...
Once again BeijingWanker posts the same poll numbers and once again leaves off the qualifier of the second selection. MOSTLY TELLING THE TRUTH.
So once again BeijingWanker posts a poll that shows that 69% of Americans believe the Bush Admin is TELLING THE TRUTH OR MOSTLY TELLING THE TRUTH about 9/11
Since Mostly Telling the Truth would not include blowing up the towers Beijing has proven ONCE AGAIN, that the vast majority of the American people do not believe his BS.
No wonder he has given up debating me.
If I had shiit for facts I'd give up too.
Arthur
So once again BeijingWanker posts a poll that shows that 69% of Americans believe the Bush Admin is TELLING THE TRUTH OR MOSTLY TELLING THE TRUTH about 9/11
Since Mostly Telling the Truth would not include blowing up the towers Beijing has proven ONCE AGAIN, that the vast majority of the American people do not believe his BS.
No wonder he has given up debating me.
If I had shiit for facts I'd give up too.
Arthur
QUOTE (lozenge124+Feb 8 2007, 02:19 AM)
I wouldn't personally accuse Bazant & Zhou of complicity, but their paper was written in Sept.2001 very soon after the events (for a critique see for example 911research.wtc7.net/disinfo/experts/articles/bazant_jem/bazant_zhou.html ), but most important, like all the official explanations, it doesn't attempt to account for the collapse time.
That's the point of this image (and I'm at a disadvantage as I still can't post images )
911blimp.net/graphics/suspendedWTCtop2.gif
even if you buy that the conditions were such that collapse had to occur (and I don't), and that there was enough potential energy to pulverize the concrete, break up the core, push the exterior outwards etc... there's no way this could have happened at or near free fall speed. That's the "violation of basic laws of physics" that Griffin is reporting (based on work of Hoffman, Jones, Ryan etc.. not his intuition)
I agree with you that I would like to hear more opinions of architects and civil & structural engineers on this, and it is disappointing that there aren't very many active in the scholars for truth movement. But that's also why I mentioned the WMD and EPA scenarios; a lack of dissenting, vocal experts doesn't necessarily mean that everyone is in agreement. Like I mentioned elsewhere, the NIST hasn't made their computer models and datasets accessible, so how can anyone peer review them? There is also not much incentive for a structural engineer to go against the NIST report as he would be ostracized, if not fired (which is what happened to Steven Jones for example). Actually, in that same interview Griffin had some good points on this very issue:
I guess at this point, I haven't seen any good rebuttals to the critiques of the NIST report by Jim Hoffman ( 911research.wtc7.net/talks/collapse/index.html ), Kevin Ryan ( 911research.wtc7.net/reviews/kevin_ryan/newstandard.html ), Steven Jones ( video.google.com/videoplay?docid=9210704017463126290 ) and what they have to say seems to me pretty convincing.
The NIST report is based on a computer model with flawed assumptions (again, see Ryan, Hoffman) with parameters apparently tweaked until the desired collapse initiation was seen. The models are unavailable, and the key "close to free fall" collapse is not modelled or explained. There are so many more problems, the removal of all the steel evidence, William Rodriguez testimony of explosions in the WTC basement prior to the airplane hit, WTC7, etc etc etc. this is why I don't find the NIST report convincing at all.
Incidentally, one of the NIST engineers, Ronald Hamburger, gave a talk last December "Conspiracy or Science: Why Did the Towers Fall?". Unfortunately there's no transcript available, but there's a critique here: 911research.wtc7.net/essays/green/hamburger.html . I find it interesting that this guy apparently didn't know how many core columns there were! (47)
Dr. Joneses work is garbage, he is lying or does not understand his own work, Kevin Ryan lied and Dr Griffin says the mechanics of the collapse do not matter fine then there is a god and he is responsible.
That kinda lets Bush off he hook do you not think!
Is there any logical thought going though your skull?
Dr. Jones doe not understand his own work, please fill free to prove that he does, because he has stated that aluminum is not a good black body radiation source, that it can not flow and glow, do to not emitting black body radiation!
That is just bunk sloppy work!
Please if you want to post science do so if you want to just grumble about politics then this is not the place!
No Cter who has ever come here while I have looked in on this site has been able to come up with anything other than what some one else told them!
99% of the Cters that come here are laughable.
If you can prove the towers collapse was an un natural occurance than do so if not there is no reason for you to try! DA
That's the point of this image (and I'm at a disadvantage as I still can't post images
) 911blimp.net/graphics/suspendedWTCtop2.gif
even if you buy that the conditions were such that collapse had to occur (and I don't), and that there was enough potential energy to pulverize the concrete, break up the core, push the exterior outwards etc... there's no way this could have happened at or near free fall speed. That's the "violation of basic laws of physics" that Griffin is reporting (based on work of Hoffman, Jones, Ryan etc.. not his intuition)
I agree with you that I would like to hear more opinions of architects and civil & structural engineers on this, and it is disappointing that there aren't very many active in the scholars for truth movement. But that's also why I mentioned the WMD and EPA scenarios; a lack of dissenting, vocal experts doesn't necessarily mean that everyone is in agreement. Like I mentioned elsewhere, the NIST hasn't made their computer models and datasets accessible, so how can anyone peer review them? There is also not much incentive for a structural engineer to go against the NIST report as he would be ostracized, if not fired (which is what happened to Steven Jones for example). Actually, in that same interview Griffin had some good points on this very issue:
I guess at this point, I haven't seen any good rebuttals to the critiques of the NIST report by Jim Hoffman ( 911research.wtc7.net/talks/collapse/index.html ), Kevin Ryan ( 911research.wtc7.net/reviews/kevin_ryan/newstandard.html ), Steven Jones ( video.google.com/videoplay?docid=9210704017463126290 ) and what they have to say seems to me pretty convincing.
The NIST report is based on a computer model with flawed assumptions (again, see Ryan, Hoffman) with parameters apparently tweaked until the desired collapse initiation was seen. The models are unavailable, and the key "close to free fall" collapse is not modelled or explained. There are so many more problems, the removal of all the steel evidence, William Rodriguez testimony of explosions in the WTC basement prior to the airplane hit, WTC7, etc etc etc. this is why I don't find the NIST report convincing at all.
Incidentally, one of the NIST engineers, Ronald Hamburger, gave a talk last December "Conspiracy or Science: Why Did the Towers Fall?". Unfortunately there's no transcript available, but there's a critique here: 911research.wtc7.net/essays/green/hamburger.html . I find it interesting that this guy apparently didn't know how many core columns there were! (47)
Dr. Joneses work is garbage, he is lying or does not understand his own work, Kevin Ryan lied and Dr Griffin says the mechanics of the collapse do not matter fine then there is a god and he is responsible.
That kinda lets Bush off he hook do you not think!
Is there any logical thought going though your skull?
Dr. Jones doe not understand his own work, please fill free to prove that he does, because he has stated that aluminum is not a good black body radiation source, that it can not flow and glow, do to not emitting black body radiation!
That is just bunk sloppy work!
Please if you want to post science do so if you want to just grumble about politics then this is not the place!
No Cter who has ever come here while I have looked in on this site has been able to come up with anything other than what some one else told them!
99% of the Cters that come here are laughable.
If you can prove the towers collapse was an un natural occurance than do so if not there is no reason for you to try! DA
Maybe this article by Eduardo Kausel, Professor of Civil & Environmental Engineering
Massachusetts Institute of Technology, will help some CTs understand why the upper floor blocks did not tilt of the tops of the towers.
I know many have posted in their own words, the same explanation, but maybe coming from an identifiable authority will make it more respectable.
Massachusetts Institute of Technology, will help some CTs understand why the upper floor blocks did not tilt of the tops of the towers.
I know many have posted in their own words, the same explanation, but maybe coming from an identifiable authority will make it more respectable.
QUOTE
Why did they not fall like a tree?
Some observers have wondered why the buildings telescoped down, instead of overturning and rolling to their side like a tree. Unlike trees which are solid, rigid structures, buildings such as the WTC towers are mostly open space (offices, staircases, elevator shafts, etc.). Indeed, a typical building is 90% air, and only 10% solid material. Thus, it is not surprising that a 110- story structure should collapse into 11 stories of rubble (actually less, because the rubble spreads out laterally, and parts are compressed into the foundation).
In addition, the towers did not fail from the bottom up, but from the top down. For a portion of the tower to roll to either side, it must first acquire angular momentum, which can only occur if the structure can pivot long enough about a stable plane (e.g. the stump in a tree). However, the forces concentrated near the pivoting area would have been so large that the columns and beams in the vicinity of that area would simply have crushed and offered no serious support permitting rolling. Also, both building sections above the crash site were not tall enough to significantly activate an inverted pendulum effect. Thus, the upper part could do nothing but simply fall down onto the lower part, crushing it. While photographic evidence shows the upper part of the South Tower to be inclined just as it began to collapse, it may not necessarily have rolled to the side, but instead fallen down onto the lower floors in a tilted position. (A careful review of collapse videos and additional photos should help clarify this contention.) Indirect evidence points to minimal vertical resistance to telescoping or pancaking of either tower: the duration of the collapses was nearly the same as that of an object in free fall, while any serious resistance would have slowed down the collapse. In essence then, the towers did not collapse like trees because the structures, despite their strength, were too fragile to sustain such motions.
Some observers have wondered why the buildings telescoped down, instead of overturning and rolling to their side like a tree. Unlike trees which are solid, rigid structures, buildings such as the WTC towers are mostly open space (offices, staircases, elevator shafts, etc.). Indeed, a typical building is 90% air, and only 10% solid material. Thus, it is not surprising that a 110- story structure should collapse into 11 stories of rubble (actually less, because the rubble spreads out laterally, and parts are compressed into the foundation).
In addition, the towers did not fail from the bottom up, but from the top down. For a portion of the tower to roll to either side, it must first acquire angular momentum, which can only occur if the structure can pivot long enough about a stable plane (e.g. the stump in a tree). However, the forces concentrated near the pivoting area would have been so large that the columns and beams in the vicinity of that area would simply have crushed and offered no serious support permitting rolling. Also, both building sections above the crash site were not tall enough to significantly activate an inverted pendulum effect. Thus, the upper part could do nothing but simply fall down onto the lower part, crushing it. While photographic evidence shows the upper part of the South Tower to be inclined just as it began to collapse, it may not necessarily have rolled to the side, but instead fallen down onto the lower floors in a tilted position. (A careful review of collapse videos and additional photos should help clarify this contention.) Indirect evidence points to minimal vertical resistance to telescoping or pancaking of either tower: the duration of the collapses was nearly the same as that of an object in free fall, while any serious resistance would have slowed down the collapse. In essence then, the towers did not collapse like trees because the structures, despite their strength, were too fragile to sustain such motions.
QUOTE (David B. Benson+Feb 7 2007, 06:50 PM)
Thanks for the reminder to reread ENERGY TRANSFER.
From Table 4-7, NCSTAR1-6D, p 176 (240 ordinal), taking first differences produces the following kip values
3379
3397
3387
3382
3370
--------
16915 / 5 = 3383 kip --> 1534.6 tonnes
so I don't follow your calculation, at all.
The mass of 'the upper 14 stories' actually includes the mass of the PH Roof level, the hat truss, and the upper mechanical floors. This appears to be why your 'average' is too big by a factor of two. Below floor 105 all the floors were ordinary trussed floors down to about floor 81. But averaging first differences from Table 4-8 gives masses per story about 6% larger than the figure above.
I'm getting the same figures you posted for the actual story masses. My average story mass was higher because I included the entire upper block, as you mentioned.
I can change story masses on a floor by floor basis. I will try this. To this point I've been looking at general trends with the model as a function of E1 and mass shedding using an average mass per story.
From Table 4-7, NCSTAR1-6D, p 176 (240 ordinal), taking first differences produces the following kip values
3379
3397
3387
3382
3370
--------
16915 / 5 = 3383 kip --> 1534.6 tonnes
so I don't follow your calculation, at all.
The mass of 'the upper 14 stories' actually includes the mass of the PH Roof level, the hat truss, and the upper mechanical floors. This appears to be why your 'average' is too big by a factor of two. Below floor 105 all the floors were ordinary trussed floors down to about floor 81. But averaging first differences from Table 4-8 gives masses per story about 6% larger than the figure above.
I'm getting the same figures you posted for the actual story masses. My average story mass was higher because I included the entire upper block, as you mentioned.
I can change story masses on a floor by floor basis. I will try this. To this point I've been looking at general trends with the model as a function of E1 and mass shedding using an average mass per story.
QUOTE (Chainsaw+,Feb 7 2007, 10:31 PM)
If the structure was storing energy in the beams because it could not dissipate that energy quick enough it might provide incite into the weld and metal failure!
The remnant of the core of the north tower (the spire) is seen oscillating laterally for a few seconds before it falls. The entire unit appears to fall at once, so the splices near the ground probably broke. If the splices had little strength, a transverse wave might be able to literally push a length of column laterally out of the splice. Someone would need to model it mathematically. The bare core didn't have anything else to give it stiffness laterally so it isn't surprising that it oscillated laterally. When it was still a part of the main floors and perimeter, it was still restrained. There's the energy associated with the impacts by the front and also the stored strain energy that was in the core before collapse that had to go somewhere as the core was unloaded during collapse.
The larger box columns at the bottom appear to be literally butted up against each other with perhaps a weld between them. A through-thickness weld would be next to impossible on columns that thick. If there were any plates welded to them, they must have been thin compared with the thickness of the box plate. I haven't seen any signs of thick splice plates. There doesn't appear to be much information on how the larger box columns on the core were spliced together.
The remnant of the core of the north tower (the spire) is seen oscillating laterally for a few seconds before it falls. The entire unit appears to fall at once, so the splices near the ground probably broke. If the splices had little strength, a transverse wave might be able to literally push a length of column laterally out of the splice. Someone would need to model it mathematically. The bare core didn't have anything else to give it stiffness laterally so it isn't surprising that it oscillated laterally. When it was still a part of the main floors and perimeter, it was still restrained. There's the energy associated with the impacts by the front and also the stored strain energy that was in the core before collapse that had to go somewhere as the core was unloaded during collapse.
The larger box columns at the bottom appear to be literally butted up against each other with perhaps a weld between them. A through-thickness weld would be next to impossible on columns that thick. If there were any plates welded to them, they must have been thin compared with the thickness of the box plate. I haven't seen any signs of thick splice plates. There doesn't appear to be much information on how the larger box columns on the core were spliced together.
QUOTE (Chainsaw,+Feb 7 2007, 11:21 PM)
I was just working on some 1/2 inch by six inch square tubing, banging on it with a hammer, to straiten a bolt when I noticed that the vibrations increase with the rapidity of the pounding and I actually broke the weld that held the lift boom to the stand along the weld eight feet away from where I was hammering.
Watch some videos of the spire carefully just before it falls.
Watch some videos of the spire carefully just before it falls.
DBB,
I assume you are using the average mean crushing force for E1 in your continuum model. In my discrete model I've tried both the mean crushing force and Greening's method of using a brief dynamic load and found that both give the same collapse duration. A mean crushing force seems easier to use.
I assume you are using the average mean crushing force for E1 in your continuum model. In my discrete model I've tried both the mean crushing force and Greening's method of using a brief dynamic load and found that both give the same collapse duration. A mean crushing force seems easier to use.
If wtc1 is able to absorb a complete plane with a kinetic energy of 3.5 GJ then this implies the columns can absorb a lot of energy, even in a high speed situation. If you assume this energy is relatively independent on orientation then when the upper 14 floors fall a maximum kinetic energy of 2.4 GJ can be obtained, in a real situation it will be lower because it cannot fall 3.8 meter in vacuum, if floors have a thickness then that will maybe be about 2.2GJ. But now only a few columns are damaged, there is still energy needed to crush the remaining columns and that must be a lot.
I understand that collapse initiation is a possibility after an hour of fire, but I don't understand how so much kinetic energy is gathered especially not if the plane's kinetic energy is easily absorbed. If there is fire and there is buckling I don't understand how you physically can prove that this kinetic energy is gathered within a second. The upper block is not hanging on a wire that is on fire but is on top of an extremely strong grid structure of steel. The fuel doesn't really warm up the steel because of conduction. IMO collapse initiation is a small movement, if there is a small movement there is not much potential energy converted into kinetic energy and this is easily absorbed and then we have a new balance and the process repeats itself. We have a continuous physical process, this is also the experience we have with al other situations in which fire is involved. I cannot think of a physical kind of process 9or thought experiment) that is an analogy of the collapse initiation (not taking into account artificial situations as a block hanging on a wire on fire) as happened in the twin towers. It is at least strange.
I understand that collapse initiation is a possibility after an hour of fire, but I don't understand how so much kinetic energy is gathered especially not if the plane's kinetic energy is easily absorbed. If there is fire and there is buckling I don't understand how you physically can prove that this kinetic energy is gathered within a second. The upper block is not hanging on a wire that is on fire but is on top of an extremely strong grid structure of steel. The fuel doesn't really warm up the steel because of conduction. IMO collapse initiation is a small movement, if there is a small movement there is not much potential energy converted into kinetic energy and this is easily absorbed and then we have a new balance and the process repeats itself. We have a continuous physical process, this is also the experience we have with al other situations in which fire is involved. I cannot think of a physical kind of process 9or thought experiment) that is an analogy of the collapse initiation (not taking into account artificial situations as a block hanging on a wire on fire) as happened in the twin towers. It is at least strange.
Einsteen:
I don't think it is very meaningful to compare the kinetic energy of the aircraft impacts to the kinetic energy of a falling block of floors. In the case of the aircraft impacts the energy was absorbed by the swaying of the entire structure. The Twin Towers were designed to accommodate this type of stress, especially with the help of the viscoelastic dampers that were installed throughout the buildings.
By comparison, the ability to absorb the near-vertical impact of 15 to 30 upper floors was NOT designed into the Twin Towers (why would it be?).
NF
I don't think it is very meaningful to compare the kinetic energy of the aircraft impacts to the kinetic energy of a falling block of floors. In the case of the aircraft impacts the energy was absorbed by the swaying of the entire structure. The Twin Towers were designed to accommodate this type of stress, especially with the help of the viscoelastic dampers that were installed throughout the buildings.
By comparison, the ability to absorb the near-vertical impact of 15 to 30 upper floors was NOT designed into the Twin Towers (why would it be?).
NF
QUOTE (einsteen+Feb 8 2007, 12:44 PM)
If wtc1 is able to absorb a complete plane with a kinetic energy of 3.5 GJ then this implies the columns can absorb a lot of energy, even in a high speed situation. If you assume this energy is relatively independent on orientation then when the upper 14 floors fall a maximum kinetic energy of 2.4 GJ can be obtained, in a real situation it will be lower because it cannot fall 3.8 meter in vacuum, if floors have a thickness then that will maybe be about 2.2GJ. But now only a few columns are damaged, there is still energy needed to crush the remaining columns and that must be a lot.
I understand that collapse initiation is a possibility after an hour of fire, but I don't understand how so much kinetic energy is gathered especially not if the plane's kinetic energy is easily absorbed. If there is fire and there is buckling I don't understand how you physically can prove that this kinetic energy is gathered within a second. The upper block is not hanging on a wire that is on fire but is on top of an extremely strong grid structure of steel. The fuel doesn't really warm up the steel because of conduction. IMO collapse initiation is a small movement, if there is a small movement there is not much potential energy converted into kinetic energy and this is easily absorbed and then we have a new balance and the process repeats itself. We have a continuous physical process, this is also the experience we have with al other situations in which fire is involved. I cannot think of a physical kind of process 9or thought experiment) that is an analogy of the collapse initiation (not taking into account artificial situations as a block hanging on a wire on fire) as happened in the twin towers. It is at least strange.
The planes energy is easily absorbed by the unified structure moving in unison to the planes impact, rapid quick buildings Oscillations in individual members destroy the unity in the structure allowing beams to work independently, and fail.
That is why fracture waves constantly building would allow for a rapid destruction of the structure.
I understand that collapse initiation is a possibility after an hour of fire, but I don't understand how so much kinetic energy is gathered especially not if the plane's kinetic energy is easily absorbed. If there is fire and there is buckling I don't understand how you physically can prove that this kinetic energy is gathered within a second. The upper block is not hanging on a wire that is on fire but is on top of an extremely strong grid structure of steel. The fuel doesn't really warm up the steel because of conduction. IMO collapse initiation is a small movement, if there is a small movement there is not much potential energy converted into kinetic energy and this is easily absorbed and then we have a new balance and the process repeats itself. We have a continuous physical process, this is also the experience we have with al other situations in which fire is involved. I cannot think of a physical kind of process 9or thought experiment) that is an analogy of the collapse initiation (not taking into account artificial situations as a block hanging on a wire on fire) as happened in the twin towers. It is at least strange.
The planes energy is easily absorbed by the unified structure moving in unison to the planes impact, rapid quick buildings Oscillations in individual members destroy the unity in the structure allowing beams to work independently, and fail.
That is why fracture waves constantly building would allow for a rapid destruction of the structure.
QUOTE (shagster+Feb 8 2007, 09:32 AM)
The remnant of the core of the north tower (the spire) is seen oscillating laterally for a few seconds before it falls. The entire unit appears to fall at once, so the splices near the ground probably broke. If the splices had little strength, a transverse wave might be able to literally push a length of column laterally out of the splice. Someone would need to model it mathematically. The bare core didn't have anything else to give it stiffness laterally so it isn't surprising that it oscillated laterally. When it was still a part of the main floors and perimeter, it was still restrained. There's the energy associated with the impacts by the front and also the stored strain energy that was in the core before collapse that had to go somewhere as the core was unloaded during collapse.
The larger box columns at the bottom appear to be literally butted up against each other with perhaps a weld between them. A through-thickness weld would be next to impossible on columns that thick. If there were any plates welded to them, they must have been thin compared with the thickness of the box plate. I haven't seen any signs of thick splice plates. There doesn't appear to be much information on how the larger box columns on the core were spliced together.
The spire is where I first noticed the oscillations, thanks for pointing them out.
The building is an interdependent structure relying on the unity of the connected parts for strength a constantly building Oscillation destroys that unity, by allowing the components to act independently of the Structure.
Destroy the unity of the structure and it collapses like a house of cards.
In fact the only way the buildings can collapse, is though the destruction of the buildings unified strength!
The company in Japan that made the beams might have the data your looking for if they still exist, and no their were no reinforcing plates needed.
The Beams were made to be continuously welded, all that is needed is a tapered structure to the beam to allow access to the other side.
Constantly overlaying the weld onto the material while maintaining a constant temperature of the weld allows for and even and constant weld by keeping the welded part in a plastic liquefied state.
The you simply v out the section to be welded and keep the temperature constant using a Torch to control the temperature of the beam and weld, by the color produced though heating.
It is much harder to weld high carbon tool steels than low carbon structural steels
and I weld tool steel using the process all the time.
The larger box columns at the bottom appear to be literally butted up against each other with perhaps a weld between them. A through-thickness weld would be next to impossible on columns that thick. If there were any plates welded to them, they must have been thin compared with the thickness of the box plate. I haven't seen any signs of thick splice plates. There doesn't appear to be much information on how the larger box columns on the core were spliced together.
The spire is where I first noticed the oscillations, thanks for pointing them out.
The building is an interdependent structure relying on the unity of the connected parts for strength a constantly building Oscillation destroys that unity, by allowing the components to act independently of the Structure.
Destroy the unity of the structure and it collapses like a house of cards.
In fact the only way the buildings can collapse, is though the destruction of the buildings unified strength!
The company in Japan that made the beams might have the data your looking for if they still exist, and no their were no reinforcing plates needed.
The Beams were made to be continuously welded, all that is needed is a tapered structure to the beam to allow access to the other side.
Constantly overlaying the weld onto the material while maintaining a constant temperature of the weld allows for and even and constant weld by keeping the welded part in a plastic liquefied state.
The you simply v out the section to be welded and keep the temperature constant using a Torch to control the temperature of the beam and weld, by the color produced though heating.
It is much harder to weld high carbon tool steels than low carbon structural steels
and I weld tool steel using the process all the time.
Swaying of the entire structure. It was of course designed to withstand extreme wind (and also to withstand the plane at that time, and it did in fact do that mechanically for a slightly different plane). That is of course indeed different than the other directory, but I remember that the two independent values obtained (Bazant et al and Wizibiki?) where almost identical and a kind of conclusion was that there was a kind of orientation independency but that applied to the E1 value for strictly one storey. I think my question is again related with the previous problem of absorption of energy at multiple levels simultaneously because building sway also implies this, not only in the radial directory because a building sway implies that there is also energy transfer in the vertical directory otherwise only the impacted storey will sway.
But the other spontaneous behaviour is another thing difficult to swallow for me...
But the other spontaneous behaviour is another thing difficult to swallow for me...
Lozenge 124:
First of al I would like to point out that nothing can "violate the laws of physics" by definition! Nothing!
The fact that Griffin et al. talk this way means that they are simply purveyors of junk science.
I have studied the writings of Jones, Hoffman and Wood and have found so many errors, distortions and omissions it's not funny!
But I have something for all 9/11 "truthers" to consider:
It is obvious that the 9/11 truth movement is entirely dominated and led by a small group of academics that I would call "professional conspiracy theorists" or PCTs.
Did you ever wonder how these PCTs survive in this role?
How is it that all of these "professors" havn't been fired or "retired" like the estimable Dr. Jones?
Having worked in academic and industrial research for 30 years I know scientific research costs plenty of money.....
Who is paying for all this 9/11 conspiracy research?
How do the PCTs get on so many talk shows and have so many other speaking engagements involving expensive travel and hotels?
Who is paying to publish their articles on the web and in books and magazines?
Who is paying for all the 9/11 conspiracy websites?
Someone is funding these PCTs to engage in anti-government propaganda!
The riddle is WHY!
Do some digging.... follow the money trail..... it will help you understand why Griffin, Fetzer, Reynolds, Hoffman and Wood are supporting junk science and which "side" they are really on!
NF
First of al I would like to point out that nothing can "violate the laws of physics" by definition! Nothing!
The fact that Griffin et al. talk this way means that they are simply purveyors of junk science.
I have studied the writings of Jones, Hoffman and Wood and have found so many errors, distortions and omissions it's not funny!
But I have something for all 9/11 "truthers" to consider:
It is obvious that the 9/11 truth movement is entirely dominated and led by a small group of academics that I would call "professional conspiracy theorists" or PCTs.
Did you ever wonder how these PCTs survive in this role?
How is it that all of these "professors" havn't been fired or "retired" like the estimable Dr. Jones?
Having worked in academic and industrial research for 30 years I know scientific research costs plenty of money.....
Who is paying for all this 9/11 conspiracy research?
How do the PCTs get on so many talk shows and have so many other speaking engagements involving expensive travel and hotels?
Who is paying to publish their articles on the web and in books and magazines?
Who is paying for all the 9/11 conspiracy websites?
Someone is funding these PCTs to engage in anti-government propaganda!
The riddle is WHY!
Do some digging.... follow the money trail..... it will help you understand why Griffin, Fetzer, Reynolds, Hoffman and Wood are supporting junk science and which "side" they are really on!
NF
QUOTE (Chainsaw+,Feb 8 2007, 05:03 AM)
Dr. Joneses work is garbage, he is lying or does not understand his own work, Kevin Ryan lied and Dr Griffin says the mechanics of the collapse do not matter fine then there is a god and he is responsible.
That kinda lets Bush off he hook do you not think!
Is there any logical thought going though your skull?
Dr. Jones doe not understand his own work, please fill free to prove that he does, because he has stated that aluminum is not a good black body radiation source, that it can not flow and glow, do to not emitting black body radiation!
That is just bunk sloppy work!
(...)
Please if you want to post science do so if you want to just grumble about politics then this is not the place!
No Cter who has ever come here while I have looked in on this site has been able to come up with anything other than what some one else told them!
99% of the Cters that come here are laughable.
If you can prove the towers collapse was an un natural occurance than do so if not there is no reason for you to try! DA
I think you have it wrong, it is not not D.R.Griffin who claims "the mechanics of the collapse do not matter", it is the NIST. They are not interested in accounting for what happened after "collapse initiation". Griffin is just saying that a close to free fall speed collapse is not possible through gravity alone which means premeditation - this is enough to launch a criminal investigation without knowing the precise mechanism utilized to bring down the towers.
I'm sorry if I do not have the ability to run aluminum experiments in my backyard, and have to rely on the work of others. If it is your opinion that this disqualifies me from commenting on the matter so be it. But I note that the NIST in their 8/2006 faq weighed on the issue, very likely in response to Steven Jones work:
Steven Jones, then attempted to mix in organic materials to reproduce this effect, but found that organic materials wouldn't mix in with the molten aluminum, much like oil and water do not mix. Note though that the NIST agrees with the premise "Pure liquid aluminum would be expected to appear silvery". If you have a reproducable experiment that demonstrates otherwise, good for you, I am glad that Steven Jones hypothesis has allowed you to set up an experiment that can prove or disprove it.
The complaint made with respect to the NIST theory however, is that their computer model and datasets are unavailable and cannot be subjected to the same kind of scrutiny.
btw. in another post you claimed that all the data had already been released, I am still waiting for you to back up this statement.
That kinda lets Bush off he hook do you not think!
Is there any logical thought going though your skull?
Dr. Jones doe not understand his own work, please fill free to prove that he does, because he has stated that aluminum is not a good black body radiation source, that it can not flow and glow, do to not emitting black body radiation!
That is just bunk sloppy work!
(...)
Please if you want to post science do so if you want to just grumble about politics then this is not the place!
No Cter who has ever come here while I have looked in on this site has been able to come up with anything other than what some one else told them!
99% of the Cters that come here are laughable.
If you can prove the towers collapse was an un natural occurance than do so if not there is no reason for you to try! DA
I think you have it wrong, it is not not D.R.Griffin who claims "the mechanics of the collapse do not matter", it is the NIST. They are not interested in accounting for what happened after "collapse initiation". Griffin is just saying that a close to free fall speed collapse is not possible through gravity alone which means premeditation - this is enough to launch a criminal investigation without knowing the precise mechanism utilized to bring down the towers.
I'm sorry if I do not have the ability to run aluminum experiments in my backyard, and have to rely on the work of others. If it is your opinion that this disqualifies me from commenting on the matter so be it. But I note that the NIST in their 8/2006 faq weighed on the issue, very likely in response to Steven Jones work:
QUOTE
Pure liquid aluminum would be expected to appear silvery. However, the molten metal was very likely mixed with large amounts of hot, partially burned, solid organic materials (e.g., furniture, carpets, partitions and computers) which can display an orange glow, much like logs burning in a fireplace.
Steven Jones, then attempted to mix in organic materials to reproduce this effect, but found that organic materials wouldn't mix in with the molten aluminum, much like oil and water do not mix. Note though that the NIST agrees with the premise "Pure liquid aluminum would be expected to appear silvery". If you have a reproducable experiment that demonstrates otherwise, good for you, I am glad that Steven Jones hypothesis has allowed you to set up an experiment that can prove or disprove it.
The complaint made with respect to the NIST theory however, is that their computer model and datasets are unavailable and cannot be subjected to the same kind of scrutiny.
btw. in another post you claimed that all the data had already been released, I am still waiting for you to back up this statement.
QUOTE (NEU-FONZE+Feb 8 2007, 02:25 PM)
First of al I would like to point out that nothing can "violate the laws of physics" by definition! Nothing!
The fact that Griffin et al. talk this way means that they are simply purveyors of junk science.
A theory can violate the laws of physics. The NIST theory violates the laws of conservation of energy and momentum because it requires the towers to collapse at or near free fall speed under the influence of gravity alone.
I too find the work of Judy Wood flawed, but I'd be very interested to hear your comments on Jones & Hoffman. That's one of the reasons I joined this forum, because I haven't really seen any good critique of their work from a scientific standpoint (I have a degree in Physics).
I don't know if you've seen it, but the best presentation I've seen so far was the "Lifting the Fog" conference of November 2006. If you are interested:
www.archive.org/details/liftingthefog_2006_11_11_session2 (Hoffman)
www.archive.org/details/liftingthefog_2006_11_11_session3 (Jones)
I too find the work of Judy Wood flawed, but I'd be very interested to hear your comments on Jones & Hoffman. That's one of the reasons I joined this forum, because I haven't really seen any good critique of their work from a scientific standpoint (I have a degree in Physics).
I don't know if you've seen it, but the best presentation I've seen so far was the "Lifting the Fog" conference of November 2006. If you are interested:
www.archive.org/details/liftingthefog_2006_11_11_session2 (Hoffman)
www.archive.org/details/liftingthefog_2006_11_11_session3 (Jones)
But I have something for all 9/11 "truthers" to consider:
It is obvious that the 9/11 truth movement is entirely dominated and led by a small group of academics that I would call "professional conspiracy theorists" or PCTs.
Did you ever wonder how these PCTs survive in this role?
How is it that all of these "professors" havn't been fired or "retired" like the estimable Dr. Jones?
Having worked in academic and industrial research for 30 years I know scientific research costs plenty of money.....
Who is paying for all this 9/11 conspiracy research?
How do the PCTs get on so many talk shows and have so many other speaking engagements involving expensive travel and hotels?
Who is paying to publish their articles on the web and in books and magazines?
Who is paying for all the 9/11 conspiracy websites?
Someone is funding these PCTs to engage in anti-government propaganda!
The riddle is WHY!
Do some digging.... follow the money trail..... it will help you understand why Griffin, Fetzer, Reynolds, Hoffman and Wood are supporting junk science and which "side" they are really on!
I don't think anyone is getting rich off of this. Setting up a web site is relatively cheap, and I don't think that such a "movement" would have been possible pre-internet age. The fast & cheap access to information that the internet makes possible is the only reason many people are able to do 'research' in the first place.
I went to see Kevin Ryan give a talk at a university a few weeks ago, and it was stated that he wasn't receiving any fees for his appearance (travel & lodging I don't know). And the TV appearances of any of these guys are few and far between AFAIK.
But you're right, I cannot for sure say that the motives of all these people are benign (especially people like Reynolds and Wood who embrace the no-planes theory) that's why I think it is important to focus on the science rather than ad hominem arguments.
Out of interest, what is your theory on their motives?
I think you have it wrong, it is not not D.R.Griffin who claims "the mechanics of the collapse do not matter", it is the NIST. They are not interested in accounting for what happened after "collapse initiation". Griffin is just saying that a close to free fall speed collapse is not possible through gravity alone which means premeditation - this is enough to launch a criminal investigation without knowing the precise mechanism utilized to bring down the towers.
I'm sorry if I do not have the ability to run aluminum experiments in my backyard, and have to rely on the work of others. If it is your opinion that this disqualifies me from commenting on the matter so be it. But I note that the NIST in their 8/2006 faq weighed on the issue, very likely in response to Steven Jones work:
Steven Jones, then attempted to mix in organic materials to reproduce this effect, but found that organic materials wouldn't mix in with the molten aluminum, much like oil and water do not mix. Note though that the NIST agrees with the premise "Pure liquid aluminum would be expected to appear silvery". If you have a reproducable experiment that demonstrates otherwise, good for you, I am glad that Steven Jones hypothesis has allowed you to set up an experiment that can prove or disprove it.
The complaint made with respect to the NIST theory however, is that their computer model and datasets are unavailable and cannot be subjected to the same kind of scrutiny.
btw. in another post you claimed that all the data had already been released, I am still waiting for you to back up this statement.
Iron is an organic compound, simply firing steel water fowl shot into heat softened aluminum will produce aluminum that will glow yellow as it flows.
Dr. Jones has only tried to melt materials with aluminum he never tried an impact experiment!
The data was released to Purdue who confirmed the computer models, and Purdue I believe is releasing the data.
The data is also in the NIST reports I believe if you check.
If you want to check the previous tread you can find a lot of what I posted previously there!
http://forum.physorg.com/index.php?showtopic=7444
Here is an article that might enlighten you some, though, I have actualy corresponded with a lot of the people who did the investigations.
With and With Dr. Steven Jones.
http://www.mauinews.com/story.aspx?id=22618
Dr. Jones seems to have substancial knowledge in gravity, but little in matrerials sciences or engineering.
I am even able to create metal oxide reactions by just clamping and heating the materials to the bumper on my John Deere diesel tractor, because the sound vibrations of the tractor are transmitted well though the structure of the metals.
There was actually molten Iron produce here along with some melting of the metal container.
Sorry I have problems capturing this stuff, because I can only work on it when I can not work at sculpting because my left hand goes numb and my neck hurts, so usually when I do an experiment I am working with only one hand and have to just quickly grab the camera and try to document what I can.
The only reason I do it anyway is it takes my mind of the physical pain I am always in when I can not sculpt, I have to have a release from the pain or I would go nuts!
The fact that Griffin et al. talk this way means that they are simply purveyors of junk science.
A theory can violate the laws of physics. The NIST theory violates the laws of conservation of energy and momentum because it requires the towers to collapse at or near free fall speed under the influence of gravity alone.
QUOTE
I have studied the writings of Jones, Hoffman and Wood and have found so many errors, distortions and omissions it's not funny!
I too find the work of Judy Wood flawed, but I'd be very interested to hear your comments on Jones & Hoffman. That's one of the reasons I joined this forum, because I haven't really seen any good critique of their work from a scientific standpoint (I have a degree in Physics).
I don't know if you've seen it, but the best presentation I've seen so far was the "Lifting the Fog" conference of November 2006. If you are interested:
www.archive.org/details/liftingthefog_2006_11_11_session2 (Hoffman)
www.archive.org/details/liftingthefog_2006_11_11_session3 (Jones)
QUOTE (->
| QUOTE |
| I have studied the writings of Jones, Hoffman and Wood and have found so many errors, distortions and omissions it's not funny! |
I too find the work of Judy Wood flawed, but I'd be very interested to hear your comments on Jones & Hoffman. That's one of the reasons I joined this forum, because I haven't really seen any good critique of their work from a scientific standpoint (I have a degree in Physics).
I don't know if you've seen it, but the best presentation I've seen so far was the "Lifting the Fog" conference of November 2006. If you are interested:
www.archive.org/details/liftingthefog_2006_11_11_session2 (Hoffman)
www.archive.org/details/liftingthefog_2006_11_11_session3 (Jones)
But I have something for all 9/11 "truthers" to consider:
It is obvious that the 9/11 truth movement is entirely dominated and led by a small group of academics that I would call "professional conspiracy theorists" or PCTs.
Did you ever wonder how these PCTs survive in this role?
How is it that all of these "professors" havn't been fired or "retired" like the estimable Dr. Jones?
Having worked in academic and industrial research for 30 years I know scientific research costs plenty of money.....
Who is paying for all this 9/11 conspiracy research?
How do the PCTs get on so many talk shows and have so many other speaking engagements involving expensive travel and hotels?
Who is paying to publish their articles on the web and in books and magazines?
Who is paying for all the 9/11 conspiracy websites?
Someone is funding these PCTs to engage in anti-government propaganda!
The riddle is WHY!
Do some digging.... follow the money trail..... it will help you understand why Griffin, Fetzer, Reynolds, Hoffman and Wood are supporting junk science and which "side" they are really on!
I don't think anyone is getting rich off of this. Setting up a web site is relatively cheap, and I don't think that such a "movement" would have been possible pre-internet age. The fast & cheap access to information that the internet makes possible is the only reason many people are able to do 'research' in the first place.
I went to see Kevin Ryan give a talk at a university a few weeks ago, and it was stated that he wasn't receiving any fees for his appearance (travel & lodging I don't know). And the TV appearances of any of these guys are few and far between AFAIK.
But you're right, I cannot for sure say that the motives of all these people are benign (especially people like Reynolds and Wood who embrace the no-planes theory) that's why I think it is important to focus on the science rather than ad hominem arguments.
Out of interest, what is your theory on their motives?
QUOTE (einsteen+Feb 8 2007, 02:22 PM)
Swaying of the entire structure. It was of course designed to withstand extreme wind (and also to withstand the plane at that time, and it did in fact do that mechanically for a slightly different plane). That is of course indeed different than the other directory, but I remember that the two independent values obtained (Bazant et al and Wizibiki?) where almost identical and a kind of conclusion was that there was a kind of orientation independency but that applied to the E1 value for strictly one storey. I think my question is again related with the previous problem of absorption of energy at multiple levels simultaneously because building sway also implies this, not only in the radial directory because a building sway implies that there is also energy transfer in the vertical directory otherwise only the impacted storey will sway.
But the other spontaneous behaviour is another thing difficult to swallow for me...
Then you should do some research on the materials and how different energy forms affect them it is not the fault of the people here that you do not understand what is being discussed in regards to energy transference.
Your very good on math einsteen but you do have a lack of knowledge in regards to energy transference in structures and materials.
If you do some research on that I think you will find the answers your looking for! Sound, wave form energy in metals can be a very powerful force because it disrupts the crystalline lactic structure of the bonding of the metallic crystals that compose the materials weakening it at areas of differentiation.
The crystalline structure of iron is in fact similar to crystalline glass only the electron bonding is stronger in the iron.
A fracture wave is merely a wave form that disrupts the electron bonds of the Crystals with in the material allowing formation of fractures.
It is simple disruption of chemical bonds by rapid movement induce by wave actions transiting the beams, causing them to oscillate.
But the other spontaneous behaviour is another thing difficult to swallow for me...
Then you should do some research on the materials and how different energy forms affect them it is not the fault of the people here that you do not understand what is being discussed in regards to energy transference.
Your very good on math einsteen but you do have a lack of knowledge in regards to energy transference in structures and materials.
If you do some research on that I think you will find the answers your looking for! Sound, wave form energy in metals can be a very powerful force because it disrupts the crystalline lactic structure of the bonding of the metallic crystals that compose the materials weakening it at areas of differentiation.
The crystalline structure of iron is in fact similar to crystalline glass only the electron bonding is stronger in the iron.
A fracture wave is merely a wave form that disrupts the electron bonds of the Crystals with in the material allowing formation of fractures.
It is simple disruption of chemical bonds by rapid movement induce by wave actions transiting the beams, causing them to oscillate.
Lozenge,
In fairness, although I also have a lot of problems with the official story (there is certainly CT blood in me, although the term is a little bit an insult imo), the collapse time is of course higher than the free fall collapse time. The more they differ the more energy is of course required to crush a storey or detach floors whatever. Theoretically we could have any collapse time dependent on Greening's E1 value.
In fairness, although I also have a lot of problems with the official story (there is certainly CT blood in me, although the term is a little bit an insult imo), the collapse time is of course higher than the free fall collapse time. The more they differ the more energy is of course required to crush a storey or detach floors whatever. Theoretically we could have any collapse time dependent on Greening's E1 value.
QUOTE (lozenge124+Feb 8 2007, 03:06 PM)
I think you have it wrong, it is not not D.R.Griffin who claims "the mechanics of the collapse do not matter", it is the NIST. They are not interested in accounting for what happened after "collapse initiation". Griffin is just saying that a close to free fall speed collapse is not possible through gravity alone which means premeditation - this is enough to launch a criminal investigation without knowing the precise mechanism utilized to bring down the towers.
I'm sorry if I do not have the ability to run aluminum experiments in my backyard, and have to rely on the work of others. If it is your opinion that this disqualifies me from commenting on the matter so be it. But I note that the NIST in their 8/2006 faq weighed on the issue, very likely in response to Steven Jones work:
Steven Jones, then attempted to mix in organic materials to reproduce this effect, but found that organic materials wouldn't mix in with the molten aluminum, much like oil and water do not mix. Note though that the NIST agrees with the premise "Pure liquid aluminum would be expected to appear silvery". If you have a reproducable experiment that demonstrates otherwise, good for you, I am glad that Steven Jones hypothesis has allowed you to set up an experiment that can prove or disprove it.
The complaint made with respect to the NIST theory however, is that their computer model and datasets are unavailable and cannot be subjected to the same kind of scrutiny.
btw. in another post you claimed that all the data had already been released, I am still waiting for you to back up this statement.
Iron is an organic compound, simply firing steel water fowl shot into heat softened aluminum will produce aluminum that will glow yellow as it flows.
Dr. Jones has only tried to melt materials with aluminum he never tried an impact experiment!
The data was released to Purdue who confirmed the computer models, and Purdue I believe is releasing the data.
The data is also in the NIST reports I believe if you check.
If you want to check the previous tread you can find a lot of what I posted previously there!
http://forum.physorg.com/index.php?showtopic=7444
Here is an article that might enlighten you some, though, I have actualy corresponded with a lot of the people who did the investigations.
With and With Dr. Steven Jones.
http://www.mauinews.com/story.aspx?id=22618
Dr. Jones seems to have substancial knowledge in gravity, but little in matrerials sciences or engineering.
I am even able to create metal oxide reactions by just clamping and heating the materials to the bumper on my John Deere diesel tractor, because the sound vibrations of the tractor are transmitted well though the structure of the metals.
There was actually molten Iron produce here along with some melting of the metal container.
Sorry I have problems capturing this stuff, because I can only work on it when I can not work at sculpting because my left hand goes numb and my neck hurts, so usually when I do an experiment I am working with only one hand and have to just quickly grab the camera and try to document what I can.
The only reason I do it anyway is it takes my mind of the physical pain I am always in when I can not sculpt, I have to have a release from the pain or I would go nuts!
Chainsaw,
I admit I don't have that knowledge about fracture waves etc. that was the reason I used some obtained results. The E1 used for radial impact is used in collapse calculations which is something that doesn't go in that directory. It is of the same order as the one Bazant gave and dr. Greening remarked that it is relatively independent of the orientation which on the one hand is amazing, because the construction of the building is angle dependent.
I admit I don't have that knowledge about fracture waves etc. that was the reason I used some obtained results. The E1 used for radial impact is used in collapse calculations which is something that doesn't go in that directory. It is of the same order as the one Bazant gave and dr. Greening remarked that it is relatively independent of the orientation which on the one hand is amazing, because the construction of the building is angle dependent.
QUOTE (einsteen+Feb 8 2007, 04:49 PM)
Chainsaw,
I admit I don't have that knowledge about fracture waves etc. that was the reason I used some obtained results. The E1 used for radial impact is used in collapse calculations which is something that doesn't go in that directory. It is of the same order as the one Bazant gave and dr. Greening remarked that it is relatively independent of the orientation which on the one hand is amazing, because the construction of the building is angle dependent.
Do you remember the story of William Rodriguez, hearing bombs in the basements?
http://en.wikipedia.org/wiki/William_Rodriguez
I have explained this to several people, sound travels at roughly 5000 meters per second, though steel, the steel beams in the core are contiguously welded steel, so they are naturally perfect sound conduits.
If William Rodriguez had stated he did not hear a big boom in the basement (reflections of impact sounds when they hit the foundations)before the impact sounds reached him from above, I would have to conclude he was lying.
The sound from he impact in air was traveling at about 600 meters per second, the sound from the crash could have rebounded though the metal structure four times before the sound reached William Rodriguez.
What you have in the center of that buildings is a giant tunning fork, all you have to do is free it from the connections. With enough oscillation energy it will do that itself.
If you weaken certain sections, by heating and other sections remain cold, unheated the saturation gets even worse. I do not think all the insulation was stripped off every where. I think that pockets of heated metal and pockets of cooled metal made it impossible for the structure to dissipate fracture waves in a unified manor, making the components work Independently and destroying the structure that way.
I do not believe the Controlled Demolition argument because aluminum in thermites is vulnerable to the same sound energy that Mr. Rodriguez confirms was in the buildings and trinitrotoluene compounds would also not survive fires or the impact sounds and energies.
In theory the oxide coating on one particle of aluminum in a charge of thermite could create a thermite spark, destroying the entire charge!
I have tested this myself and the theory is accurate.
The only thing that makes since to me is a natural extreme chemical reaction, or failure do to a Fracture wave energy build up!
I do not have all the answers and that is why I am here!
I admit I don't have that knowledge about fracture waves etc. that was the reason I used some obtained results. The E1 used for radial impact is used in collapse calculations which is something that doesn't go in that directory. It is of the same order as the one Bazant gave and dr. Greening remarked that it is relatively independent of the orientation which on the one hand is amazing, because the construction of the building is angle dependent.
Do you remember the story of William Rodriguez, hearing bombs in the basements?
http://en.wikipedia.org/wiki/William_Rodriguez
I have explained this to several people, sound travels at roughly 5000 meters per second, though steel, the steel beams in the core are contiguously welded steel, so they are naturally perfect sound conduits.
If William Rodriguez had stated he did not hear a big boom in the basement (reflections of impact sounds when they hit the foundations)before the impact sounds reached him from above, I would have to conclude he was lying.
The sound from he impact in air was traveling at about 600 meters per second, the sound from the crash could have rebounded though the metal structure four times before the sound reached William Rodriguez.
What you have in the center of that buildings is a giant tunning fork, all you have to do is free it from the connections. With enough oscillation energy it will do that itself.
If you weaken certain sections, by heating and other sections remain cold, unheated the saturation gets even worse. I do not think all the insulation was stripped off every where. I think that pockets of heated metal and pockets of cooled metal made it impossible for the structure to dissipate fracture waves in a unified manor, making the components work Independently and destroying the structure that way.
I do not believe the Controlled Demolition argument because aluminum in thermites is vulnerable to the same sound energy that Mr. Rodriguez confirms was in the buildings and trinitrotoluene compounds would also not survive fires or the impact sounds and energies.
In theory the oxide coating on one particle of aluminum in a charge of thermite could create a thermite spark, destroying the entire charge!
I have tested this myself and the theory is accurate.
The only thing that makes since to me is a natural extreme chemical reaction, or failure do to a Fracture wave energy build up!
I do not have all the answers and that is why I am here!
shagster --- For WTC 1 I determine the best fitting value of E1 for the entire 3.0 seconds of data. For WTC 2 there are actually four different values for E1 used. (1) The initial few floors had a low E1, presumably due to damage. (2) The partially beamed floors had a high E1. (3) The totally beamed floors had a very high E1. (4) The floors below floor 75 had an E1 about the same as in WTC 1.
lozenge124 --- Sorry, but Griffin is completely wrong about the collapse times. Judy Wood's physics is wrong as she ignores momentum. Greening has calculated these, I have, shagster has, einsteen has. All are in essential agreement with regard to the principles of physics involved and the resulting collapse times.
Chainsaw, --- The Matthew equation describes the reaction of a perfect, pinned, elastic column to a cosine wave force. The result is an infinite collection of harmonic responses, each depending upon two parameters, a_n and b_n. For b_n = 0 the response is no vibration. As b_n gets larger then for more and more of the a_n values the response is unbounded.
For the towers were cannot actually use the Matthew or Hill equations, since the force impacting the core columns is not periodic. It is, however, quasi-periodic, a chirp rising for about 1/3 Hz to 5 Hz for each three story column member. Furthermore, the column members were welded, not pinned. While it is possible to write down the appropriate ODE for those conditions, and solve it numerically, I don't see any reason to go to that effort. The Matthew equation solutions suffice to see that indeed the core columns could have vibrated and rather seriously so.
However, this would not be a 'fracture wave' in the sense of destroying the actual core columns. It might be a method of destroying welds, if that is what you mean.
lozenge124 --- Sorry, but Griffin is completely wrong about the collapse times. Judy Wood's physics is wrong as she ignores momentum. Greening has calculated these, I have, shagster has, einsteen has. All are in essential agreement with regard to the principles of physics involved and the resulting collapse times.
Chainsaw, --- The Matthew equation describes the reaction of a perfect, pinned, elastic column to a cosine wave force. The result is an infinite collection of harmonic responses, each depending upon two parameters, a_n and b_n. For b_n = 0 the response is no vibration. As b_n gets larger then for more and more of the a_n values the response is unbounded.
For the towers were cannot actually use the Matthew or Hill equations, since the force impacting the core columns is not periodic. It is, however, quasi-periodic, a chirp rising for about 1/3 Hz to 5 Hz for each three story column member. Furthermore, the column members were welded, not pinned. While it is possible to write down the appropriate ODE for those conditions, and solve it numerically, I don't see any reason to go to that effort. The Matthew equation solutions suffice to see that indeed the core columns could have vibrated and rather seriously so.
However, this would not be a 'fracture wave' in the sense of destroying the actual core columns. It might be a method of destroying welds, if that is what you mean.
QUOTE (David B. Benson+Feb 8 2007, 06:23 PM)
shagster --- For WTC 1 I determine the best fitting value of E1 for the entire 3.0 seconds of data. For WTC 2 there are actually four different values for E1 used. (1) The initial few floors had a low E1, presumably due to damage. (2) The partially beamed floors had a high E1. (3) The totally beamed floors had a very high E1. (4) The floors below floor 75 had an E1 about the same as in WTC 1.
lozenge124 --- Sorry, but Griffin is completely wrong about the collapse times. Judy Wood's physics is wrong as she ignores momentum. Greening has calculated these, I have, shagster has, einsteen has. All are in essential agreement with regard to the principles of physics involved and the resulting collapse times.
Chainsaw, --- The Matthew equation describes the reaction of a perfect, pinned, elastic column to a cosine wave force. The result is an infinite collection of harmonic responses, each depending upon two parameters, a_n and b_n. For b_n = 0 the response is no vibration. As b_n gets larger then for more and more of the a_n values the response is unbounded.
For the towers were cannot actually use the Matthew or Hill equations, since the force impacting the core columns is not periodic. It is, however, quasi-periodic, a chirp rising for about 1/3 Hz to 5 Hz for each three story column member. Furthermore, the column members were welded, not pinned. While it is possible to write down the appropriate ODE for those conditions, and solve it numerically, I don't see any reason to go to that effort. The Matthew equation solutions suffice to see that indeed the core columns could have vibrated and rather seriously so.
However, this would not be a 'fracture wave' in the sense of destroying the actual core columns. It might be a method of destroying welds, if that is what you mean.
Exactly the Contiguous welds are the strength of the column and we can see it was the welds that failed.
Destroy the welds and the columns becomes a series of unconnected beams. destroying the strength in the critical core reducing resistance to collapse while mass accumulates.
As we can see in the photos the welds failed, the beams seem to have just snapped at or along the welded joints, in the core beams.
The combinations of the oscillating core and the accumulating mass, would have been totally devastating to any resistance the core structure could have provided.
There is a calculation for the welded columns somewhere, I know that I saw it, and the pin beams would allow for more movement than the welded columns, or am I wrong on that Idea?
I believe the design submission for another tower-tube frame building actually has the calculations for amount of forced oscillation a Continuously welded Column can go though, before its failure.
I know I read about it some where, but can not find the information now, it was in an engineering Journal, in the mid to late 1990s and showed computer modeling of a tube frame structure, and both beam flex do to load, and beam oscillations do to Seismic activity.
I am pretty sure the building was in the Asian pacific maybe Japan, or Indonesia, it was on designing tube frame buildings to survive earth quakes.
They were designing a building with sufficient Oscillation dampers, big rubber cushions, and joints that moved, to actually prevent an earth quake from destroying the structural integrity of the building though oscillations.
Maybe it was not in an engineering journal but in some other science Journal, and I have been looking all this time in the wrong place!
lozenge124 --- Sorry, but Griffin is completely wrong about the collapse times. Judy Wood's physics is wrong as she ignores momentum. Greening has calculated these, I have, shagster has, einsteen has. All are in essential agreement with regard to the principles of physics involved and the resulting collapse times.
Chainsaw, --- The Matthew equation describes the reaction of a perfect, pinned, elastic column to a cosine wave force. The result is an infinite collection of harmonic responses, each depending upon two parameters, a_n and b_n. For b_n = 0 the response is no vibration. As b_n gets larger then for more and more of the a_n values the response is unbounded.
For the towers were cannot actually use the Matthew or Hill equations, since the force impacting the core columns is not periodic. It is, however, quasi-periodic, a chirp rising for about 1/3 Hz to 5 Hz for each three story column member. Furthermore, the column members were welded, not pinned. While it is possible to write down the appropriate ODE for those conditions, and solve it numerically, I don't see any reason to go to that effort. The Matthew equation solutions suffice to see that indeed the core columns could have vibrated and rather seriously so.
However, this would not be a 'fracture wave' in the sense of destroying the actual core columns. It might be a method of destroying welds, if that is what you mean.
Exactly the Contiguous welds are the strength of the column and we can see it was the welds that failed.
Destroy the welds and the columns becomes a series of unconnected beams. destroying the strength in the critical core reducing resistance to collapse while mass accumulates.
As we can see in the photos the welds failed, the beams seem to have just snapped at or along the welded joints, in the core beams.
The combinations of the oscillating core and the accumulating mass, would have been totally devastating to any resistance the core structure could have provided.
There is a calculation for the welded columns somewhere, I know that I saw it, and the pin beams would allow for more movement than the welded columns, or am I wrong on that Idea?
I believe the design submission for another tower-tube frame building actually has the calculations for amount of forced oscillation a Continuously welded Column can go though, before its failure.
I know I read about it some where, but can not find the information now, it was in an engineering Journal, in the mid to late 1990s and showed computer modeling of a tube frame structure, and both beam flex do to load, and beam oscillations do to Seismic activity.
I am pretty sure the building was in the Asian pacific maybe Japan, or Indonesia, it was on designing tube frame buildings to survive earth quakes.
They were designing a building with sufficient Oscillation dampers, big rubber cushions, and joints that moved, to actually prevent an earth quake from destroying the structural integrity of the building though oscillations.
Maybe it was not in an engineering journal but in some other science Journal, and I have been looking all this time in the wrong place!
Chainsaw, --- Pinned columns are easier to analyze. To compute Euler buckling for fixed, i.e., welded columns, one just changes the actual length to 'effective length', about 0.5 to 0.7 of the actual length, depending.
There are other possible ways to fracture the welds. For example, hit the top of the column very hard and slightly off-center, but just the once. In this analysis, as in all the rest, one difficulty is knowing just how to model the strength of the weld.
There are other possible ways to fracture the welds. For example, hit the top of the column very hard and slightly off-center, but just the once. In this analysis, as in all the rest, one difficulty is knowing just how to model the strength of the weld.
@Chainsaw:
thanks for the links. (I was a lurker here for quite a while before I registered and I did read those other threads at least in part)
I appreciate what you are trying to do with your experiments, but to me this is the kind of stuff that should have been done by the NIST on whose shoulders the burden of proof for a gravity driven collapse squarely falls. The stakes are very high in knowing precisely what happened to the towers, and though your ideas like fracture waves destroying welds, oscillations removing fireproofing, etc are interesting they aren't in the NIST report. To me it is troubling in of itself that so many things remain to be explained.
I emailed NIST earlier this week about the computer models, and we'll see what they say if they reply. I know the scholars have a petition for the release of 911 information including "6,899 photographs and 6,977 segments of video footage held by NIST" but not sure about the models/datasets.
About your William Rodriguez comment, I don't think the times add up. Sound travels in air at 344m/s (68F). The towers were roughly 417m tall. As the plane hit below the top we are talking about ~1second for the sound to travel from the crash to Rodriguez.
Here is his testimony:
( bellaciao.org/en/article.php3?id_article=6625 )
In your scenario, even if the basement reaction occurs instantly as soon as the plane hits the tower, the sound will reach there 1 second later. This isn't consistent with "Seconds after the first massive explosion below in the basement still rattled the floor, I hear another explosion from way above". 1 second is too short.
thanks for the links. (I was a lurker here for quite a while before I registered and I did read those other threads at least in part)
I appreciate what you are trying to do with your experiments, but to me this is the kind of stuff that should have been done by the NIST on whose shoulders the burden of proof for a gravity driven collapse squarely falls. The stakes are very high in knowing precisely what happened to the towers, and though your ideas like fracture waves destroying welds, oscillations removing fireproofing, etc are interesting they aren't in the NIST report. To me it is troubling in of itself that so many things remain to be explained.
I emailed NIST earlier this week about the computer models, and we'll see what they say if they reply. I know the scholars have a petition for the release of 911 information including "6,899 photographs and 6,977 segments of video footage held by NIST" but not sure about the models/datasets.
About your William Rodriguez comment, I don't think the times add up. Sound travels in air at 344m/s (68F). The towers were roughly 417m tall. As the plane hit below the top we are talking about ~1second for the sound to travel from the crash to Rodriguez.
Here is his testimony:
QUOTE
"When I heard the sound of the explosion, the floor beneath my feet vibrated, the walls started cracking and it everything started shaking," said Rodriguez, who was huddled together with at least 14 other people in the office.
(...)
"Seconds after the first massive explosion below in the basement still rattled the floor, I hear another explosion from way above," said Rodriguez. "Although I was unaware at the time, this was the airplane hitting the tower, it occurred moments after the first explosion."
(...)
"Seconds after the first massive explosion below in the basement still rattled the floor, I hear another explosion from way above," said Rodriguez. "Although I was unaware at the time, this was the airplane hitting the tower, it occurred moments after the first explosion."
( bellaciao.org/en/article.php3?id_article=6625 )
In your scenario, even if the basement reaction occurs instantly as soon as the plane hits the tower, the sound will reach there 1 second later. This isn't consistent with "Seconds after the first massive explosion below in the basement still rattled the floor, I hear another explosion from way above". 1 second is too short.
Lozenge 124:
I see no violation of energy or angular momentum conservation laws in the collapse of WTC 1 & 2.
First there was ample PE stored in one Tower to accommodate a self-sustained gravitational collapse AND concrete pulverization. Try reading Greening's papers on 911myths and tell me where you see a problem....
Secondly, conservation of energy requires that:
1/2 .I. (Omega)^2 = Mg. L/2. [1 - cos(Theta)]
where I is the moment of inertia of the upper block of floors, M is the mass, Omega the angular velocity, L is the height and Theta the angle of tilt from the vertical.
Now since I = 1/3 M. L^2 we find that:
Omega = Sqrt {3g[1 - cos(theta)]/L}
Also, from the definition of angular momentum,
I. d(Omega)/dt = Torque = Mg. sin(Theta). L/2
From this we find the angular acceleration is:
d(Omega)/dt = 3/2. g/L. sin (theta)
You can apply these equations to the observed rotational motion of the upper section of WTC 2 and prove for yourself that the motion is quite "natural" at least for the first few seconds. Thereafter the crushing of the upper block dominates (i.e. L is no longer constant) and the rotation changes to a VERTICAL motion of the center of mass, again as dictated by the forces involved.
Now Dr. Jones, (and you!), think this is in violation of the laws of physics, but strangely Dr. Jones doesn't offer any real reason or calculation as to what is the problem. In fact, while we are on the subject of Jones' "research" it is very telling that in all his published work on the WTC collapse you do not see a single equation or formula! Pretty odd for a scientist who calls himself a scholar (And please don't accuse me of an ad hominem attack on Jones - the facts is the facts!)
Jones is also way off-base with his so-called "evidence" of thermite/thermate residues from the sulfiding of steel. In truth there were PLENTY of sources of sulfur in the Twin Towers including gypsum wallboard, diesel fuel, sulfuric acid in lead acid batteries, etc. If Jones was any kind of scientist he would acknowledge these additional sources of sulfur; so why does he choose to ignore them?
As for Hoffman's work, his pyroclastic flow calculation is in serious error. As I recall it, Hoffman simply uses the gas laws to show that the temperature in the dust cloud must have been more than 3 times ambient or about 700 deg C. This is nonsense when you know that people survived for several minutes INSIDE Hoffman's alleged volcanic dust cloud!
As for the motives of these purveyors of junk science I can only assume that the intention is to deliberately mislead, confuse and misdirect 9/11 research. If you think about it, the 9-11 truth movement is now in total disarray thanks to Jones, Fetzer and Woods efforts.
But perhaps it's mission accomplished for these miscreants.....
NF
I see no violation of energy or angular momentum conservation laws in the collapse of WTC 1 & 2.
First there was ample PE stored in one Tower to accommodate a self-sustained gravitational collapse AND concrete pulverization. Try reading Greening's papers on 911myths and tell me where you see a problem....
Secondly, conservation of energy requires that:
1/2 .I. (Omega)^2 = Mg. L/2. [1 - cos(Theta)]
where I is the moment of inertia of the upper block of floors, M is the mass, Omega the angular velocity, L is the height and Theta the angle of tilt from the vertical.
Now since I = 1/3 M. L^2 we find that:
Omega = Sqrt {3g[1 - cos(theta)]/L}
Also, from the definition of angular momentum,
I. d(Omega)/dt = Torque = Mg. sin(Theta). L/2
From this we find the angular acceleration is:
d(Omega)/dt = 3/2. g/L. sin (theta)
You can apply these equations to the observed rotational motion of the upper section of WTC 2 and prove for yourself that the motion is quite "natural" at least for the first few seconds. Thereafter the crushing of the upper block dominates (i.e. L is no longer constant) and the rotation changes to a VERTICAL motion of the center of mass, again as dictated by the forces involved.
Now Dr. Jones, (and you!), think this is in violation of the laws of physics, but strangely Dr. Jones doesn't offer any real reason or calculation as to what is the problem. In fact, while we are on the subject of Jones' "research" it is very telling that in all his published work on the WTC collapse you do not see a single equation or formula! Pretty odd for a scientist who calls himself a scholar (And please don't accuse me of an ad hominem attack on Jones - the facts is the facts!)
Jones is also way off-base with his so-called "evidence" of thermite/thermate residues from the sulfiding of steel. In truth there were PLENTY of sources of sulfur in the Twin Towers including gypsum wallboard, diesel fuel, sulfuric acid in lead acid batteries, etc. If Jones was any kind of scientist he would acknowledge these additional sources of sulfur; so why does he choose to ignore them?
As for Hoffman's work, his pyroclastic flow calculation is in serious error. As I recall it, Hoffman simply uses the gas laws to show that the temperature in the dust cloud must have been more than 3 times ambient or about 700 deg C. This is nonsense when you know that people survived for several minutes INSIDE Hoffman's alleged volcanic dust cloud!
As for the motives of these purveyors of junk science I can only assume that the intention is to deliberately mislead, confuse and misdirect 9/11 research. If you think about it, the 9-11 truth movement is now in total disarray thanks to Jones, Fetzer and Woods efforts.
But perhaps it's mission accomplished for these miscreants.....
NF
QUOTE (lozenge124+Feb 8 2007, 08:06 PM)
... to me this is the kind of stuff that should have been done by the NIST on whose shoulders the burden of proof for a gravity driven collapse squarely falls. The stakes are very high in knowing precisely what happened to the towers, and though your ideas like fracture waves destroying welds, oscillations removing fireproofing, etc are interesting they aren't in the NIST report. To me it is troubling in of itself that so many things remain to be explained.
NIST found a "probable collapse scenario". The fact that gravity assisted is obvious.
Why are the stakes high? NIST is interested in building safety, not the details of progressive collapse.
Why is it troubling? Life is full of things which remain to be explained. As a trivial example, the LED clock on my coffee maker decided, all on its own, to add an hour to the time...
NIST found a "probable collapse scenario". The fact that gravity assisted is obvious.
Why are the stakes high? NIST is interested in building safety, not the details of progressive collapse.
Why is it troubling? Life is full of things which remain to be explained. As a trivial example, the LED clock on my coffee maker decided, all on its own, to add an hour to the time...
QUOTE (lozenge124+Feb 8 2007, 08:06 PM)
@Chainsaw:
thanks for the links. (I was a lurker here for quite a while before I registered and I did read those other threads at least in part)
I appreciate what you are trying to do with your experiments, but to me this is the kind of stuff that should have been done by the NIST on whose shoulders the burden of proof for a gravity driven collapse squarely falls. The stakes are very high in knowing precisely what happened to the towers, and though your ideas like fracture waves destroying welds, oscillations removing fireproofing, etc are interesting they aren't in the NIST report. To me it is troubling in of itself that so many things remain to be explained.
I emailed NIST earlier this week about the computer models, and we'll see what they say if they reply. I know the scholars have a petition for the release of 911 information including "6,899 photographs and 6,977 segments of video footage held by NIST" but not sure about the models/datasets.
About your William Rodriguez comment, I don't think the times add up. Sound travels in air at 344m/s (68F). The towers were roughly 417m tall. As the plane hit below the top we are talking about ~1second for the sound to travel from the crash to Rodriguez.
Here is his testimony:
( bellaciao.org/en/article.php3?id_article=6625 )
In your scenario, even if the basement reaction occurs instantly as soon as the plane hits the tower, the sound will reach there 1 second later. This isn't consistent with "Seconds after the first massive explosion below in the basement still rattled the floor, I hear another explosion from way above". 1 second is too short.
True I did give the wrong sound in meters per second would have been around 341, I was thinking closer to miles per hour, I was told the temperature that morning was around 15c. however much of the initial impact energy of he plane hitting the buildings would rebound though the steel at over 5960 meters per second almost instantly, so regardless the energy from the impact would still be transmitted up tens of seconds before the fire ball explosion of the plane's fuel tanks in the wings. In other words it would have sounded like there was an explosion below.
Everyone in the building reported a delay between the buildings shaking and the explosion, it took a second for the plane to tunnel in and then the fuel tanks in the wings exploded the shock waves from the plane first hitting the building could would already have been rebounding upward when the fuel air blast took place.
Remember the planes initial impact, is being absorbed by the building before the fuel air blast. It would have taken two or more seconds for the sound energy to reach William Rodriguez.
So no is not to short, also given the amount that stress plays on memory we can not even tell if peoples memories are exactly accurate under those conditions.
The first thing felt would have been the inital shock waves from the impact then the fuel air explosion.
The plane has to cut though steel beams before the wings hit and the fuel tanks explode into the fire ball.
I hope that NIST will repond to you, and give you the data, I also wish they had done more.
However they may only have been acting out of causation.
IF in fact there is only evidence of gravitationally induce collapse then what do you expect NIST to say?
Greening and others point to the possibility that gravitational collapse is possible.
I am just doing what I am to satisfy may own curiosity.
thanks for the links. (I was a lurker here for quite a while before I registered and I did read those other threads at least in part)
I appreciate what you are trying to do with your experiments, but to me this is the kind of stuff that should have been done by the NIST on whose shoulders the burden of proof for a gravity driven collapse squarely falls. The stakes are very high in knowing precisely what happened to the towers, and though your ideas like fracture waves destroying welds, oscillations removing fireproofing, etc are interesting they aren't in the NIST report. To me it is troubling in of itself that so many things remain to be explained.
I emailed NIST earlier this week about the computer models, and we'll see what they say if they reply. I know the scholars have a petition for the release of 911 information including "6,899 photographs and 6,977 segments of video footage held by NIST" but not sure about the models/datasets.
About your William Rodriguez comment, I don't think the times add up. Sound travels in air at 344m/s (68F). The towers were roughly 417m tall. As the plane hit below the top we are talking about ~1second for the sound to travel from the crash to Rodriguez.
Here is his testimony:
( bellaciao.org/en/article.php3?id_article=6625 )
In your scenario, even if the basement reaction occurs instantly as soon as the plane hits the tower, the sound will reach there 1 second later. This isn't consistent with "Seconds after the first massive explosion below in the basement still rattled the floor, I hear another explosion from way above". 1 second is too short.
True I did give the wrong sound in meters per second would have been around 341, I was thinking closer to miles per hour, I was told the temperature that morning was around 15c. however much of the initial impact energy of he plane hitting the buildings would rebound though the steel at over 5960 meters per second almost instantly, so regardless the energy from the impact would still be transmitted up tens of seconds before the fire ball explosion of the plane's fuel tanks in the wings. In other words it would have sounded like there was an explosion below.
Everyone in the building reported a delay between the buildings shaking and the explosion, it took a second for the plane to tunnel in and then the fuel tanks in the wings exploded the shock waves from the plane first hitting the building could would already have been rebounding upward when the fuel air blast took place.
Remember the planes initial impact, is being absorbed by the building before the fuel air blast. It would have taken two or more seconds for the sound energy to reach William Rodriguez.
So no is not to short, also given the amount that stress plays on memory we can not even tell if peoples memories are exactly accurate under those conditions.
The first thing felt would have been the inital shock waves from the impact then the fuel air explosion.
The plane has to cut though steel beams before the wings hit and the fuel tanks explode into the fire ball.
I hope that NIST will repond to you, and give you the data, I also wish they had done more.
However they may only have been acting out of causation.
IF in fact there is only evidence of gravitationally induce collapse then what do you expect NIST to say?
Greening and others point to the possibility that gravitational collapse is possible.
I am just doing what I am to satisfy may own curiosity.
QUOTE (David B. Benson+Feb 8 2007, 10:05 PM)
NIST found a "probable collapse scenario". The fact that gravity assisted is obvious.
Why are the stakes high? NIST is interested in building safety, not the details of progressive collapse.
Why is it troubling? Life is full of things which remain to be explained. As a trivial example, the LED clock on my coffee maker decided, all on its own, to add an hour to the time...
It is most probably condensation in the controls of the clock, had the same thing happen on mine finally figured it out, when it was just a few degrees cooler in the room condensation would cause the time change, by shorting the switch.
We can say things are what we thank they are, or we can rely on the scientific method and prove they are what they are.
When we abandon Science we abandon logic and might as well move back into caves and eat our food raw!
Why are the stakes high? NIST is interested in building safety, not the details of progressive collapse.
Why is it troubling? Life is full of things which remain to be explained. As a trivial example, the LED clock on my coffee maker decided, all on its own, to add an hour to the time...
It is most probably condensation in the controls of the clock, had the same thing happen on mine finally figured it out, when it was just a few degrees cooler in the room condensation would cause the time change, by shorting the switch.
We can say things are what we thank they are, or we can rely on the scientific method and prove they are what they are.
When we abandon Science we abandon logic and might as well move back into caves and eat our food raw!
Oscillations removing fireproofing, etc. --- In general NIST was quite conservative in their approach. They choose to model 'removed fireproofing' only where aircraft pieces were modeled as hitting core columns and so on.
And yes, NIST did, several times, change their hypothesis as to what occurred over the modeled interval of time. The NCSTAR1 report specifically states that they adjusted the model to match the visual evidence. Seems to be a good idea to stick as close as one can to reality.
Despite this, their 'probable collapse scenario' ought to be called an approximate probable collapse scenario. Perhaps that was so obvious to them that they forgot to say it?
Oh, and its Mathieu equation, not 'Matthew'. Apologies.
And yes, NIST did, several times, change their hypothesis as to what occurred over the modeled interval of time. The NCSTAR1 report specifically states that they adjusted the model to match the visual evidence. Seems to be a good idea to stick as close as one can to reality.
Despite this, their 'probable collapse scenario' ought to be called an approximate probable collapse scenario. Perhaps that was so obvious to them that they forgot to say it?
Oh, and its Mathieu equation, not 'Matthew'. Apologies.
Lozenge 124:
You need to think “outside the box”:
Many of the events surrounding 9/11 are questionable, so it’s natural to assume that the “main event” - the collapse of the Twin Towers – is also questionable. And it’s very significant that most truthers such as Griffin, Fetzer and Jones, INSIST on using the collapse of the Twin Towers as “proof” of a pre-planned demolition and a massive government conspiracy….
In truth, the collapse of the Twin Towers, following high-speed aircraft impacts, is “proof” of NOTHING at all!
The truthers are deluded if they believe that their interpretation of how the Towers fell could be used to “nail” the perpetrators. Why? Because in a court of law you will always have some "expert" who will argue that the Towers collapsed in some other way.
This is especially true of the collapse of the Twin Towers because the collapse mechanism, whatever it actually proves to be, is extremely complicated, and involves many variables. Thus it can never be totally quantified or reproduced. But that’s the idea… it’s the perfect topic for an endless debate….. no it isn’t….. yes it is……
Griffin, Fetzer and Jones are on a mission to sow the seeds of doubt and keep the endless debate going. Griffin himself said that we do not need to know how “the deed” was done, only that it was a dirty deed! This is complete BS designed to baffle the masses and prevent serious scientific research. This makes Griffin's thinking reactionary, NOT radical.... That is why I see Griffin, Fetzer, Jones and others of their ilk as “All the King’s Men”.
“Throughout history, governments seeking to perpetuate their control, yet being foresighted enough to channel and contain dissent against their corrupt, repressive policies, use groups called "The King’s Men". Such people get money, power, and benefits from "The King", but he denies knowing them since they pretend to oppose him. At the present time, when the term "truther" is bandied around, it is important to know who some of the alleged "truthers" are, and to consider that some of the "9/11 Truth Movement" are "The King’s Men".
Recent American history has shown that many “revolutionaries” and counter-cultural “heroes” such as Abbie Hoffman, Jerry Rubin, Timothy Leary were in fact undercover government operatives…. The King's Men.....”
Oh and by the way, in the case of 9/11, "The King" is not necessarily "The President"!!!
NF
You need to think “outside the box”:
Many of the events surrounding 9/11 are questionable, so it’s natural to assume that the “main event” - the collapse of the Twin Towers – is also questionable. And it’s very significant that most truthers such as Griffin, Fetzer and Jones, INSIST on using the collapse of the Twin Towers as “proof” of a pre-planned demolition and a massive government conspiracy….
In truth, the collapse of the Twin Towers, following high-speed aircraft impacts, is “proof” of NOTHING at all!
The truthers are deluded if they believe that their interpretation of how the Towers fell could be used to “nail” the perpetrators. Why? Because in a court of law you will always have some "expert" who will argue that the Towers collapsed in some other way.
This is especially true of the collapse of the Twin Towers because the collapse mechanism, whatever it actually proves to be, is extremely complicated, and involves many variables. Thus it can never be totally quantified or reproduced. But that’s the idea… it’s the perfect topic for an endless debate….. no it isn’t….. yes it is……
Griffin, Fetzer and Jones are on a mission to sow the seeds of doubt and keep the endless debate going. Griffin himself said that we do not need to know how “the deed” was done, only that it was a dirty deed! This is complete BS designed to baffle the masses and prevent serious scientific research. This makes Griffin's thinking reactionary, NOT radical.... That is why I see Griffin, Fetzer, Jones and others of their ilk as “All the King’s Men”.
“Throughout history, governments seeking to perpetuate their control, yet being foresighted enough to channel and contain dissent against their corrupt, repressive policies, use groups called "The King’s Men". Such people get money, power, and benefits from "The King", but he denies knowing them since they pretend to oppose him. At the present time, when the term "truther" is bandied around, it is important to know who some of the alleged "truthers" are, and to consider that some of the "9/11 Truth Movement" are "The King’s Men".
Recent American history has shown that many “revolutionaries” and counter-cultural “heroes” such as Abbie Hoffman, Jerry Rubin, Timothy Leary were in fact undercover government operatives…. The King's Men.....”
Oh and by the way, in the case of 9/11, "The King" is not necessarily "The President"!!!
NF
QUOTE (einsteen+Feb 8 2007, 04:49 PM)
Chainsaw,
I admit I don't have that knowledge about fracture waves etc. that was the reason I used some obtained results. The E1 used for radial impact is used in collapse calculations which is something that doesn't go in that directory. It is of the same order as the one Bazant gave and dr. Greening remarked that it is relatively independent of the orientation which on the one hand is amazing, because the construction of the building is angle dependent.
The E1 value used in collapse calculations is the one that gives the observed collapse rate. See DBB's and Greening's work. Greening used the results of Wierzbicki as a way of estimating the amount of energy associated with bending columns to the point of failure. The estimate of E1 based on Wierzbicki, the E1 obtained by BZ theoretically, and the value needed to account for the observed collapse rate agree fairly well. BZ's value was about 0.25 GJ per story, the estimate based on Wierzbicki was about 0.6 GJ, and the value of E1 needed to account for the collapse rate during the first four seconds of a non-shedding model was about 0.8 GJ.
The energy needed to fail columns does have an orientation independence to some extent. It takes a certain amount of energy to plastically deform metal of a certain volume to a particular amount of strain. That energy depends on the product of the yield strength of the metal, the plastic strain, and the volume of metal strained. Yield strength has units of force per area or energy per volume. Strain is unitless but when multiplied by the volume of the metal that is being strained gives units of volume. The product of strain, volume, and yield strength is energy.
When slender to intermediate columns buckle, the load they can support as a function of axial displacement drops quickly. Fig. 5 of the BZ paper shows the relationship. That behavior precludes a cushioning effect.
There were a number of adjacent floors damaged by the aircraft impacts and fire, so the model doesn't have to rely solely on a situation of a drop through only the first story height at near freefall and then through totally undamaged stories. In reality there was probably a drop less than freefall rate through 2 or 3 damaged stories that offered limited resistance compared with undamaged stories and allowed the upper block to accelerate. That drop also involved other failure modes such as tilting, wedging, and lateral strikes which are a more uniform mode of deforming the columns with respect to drop height as opposed to the more all-or-nothing type of failure associated with axial strikes and buckling.
I admit I don't have that knowledge about fracture waves etc. that was the reason I used some obtained results. The E1 used for radial impact is used in collapse calculations which is something that doesn't go in that directory. It is of the same order as the one Bazant gave and dr. Greening remarked that it is relatively independent of the orientation which on the one hand is amazing, because the construction of the building is angle dependent.
The E1 value used in collapse calculations is the one that gives the observed collapse rate. See DBB's and Greening's work. Greening used the results of Wierzbicki as a way of estimating the amount of energy associated with bending columns to the point of failure. The estimate of E1 based on Wierzbicki, the E1 obtained by BZ theoretically, and the value needed to account for the observed collapse rate agree fairly well. BZ's value was about 0.25 GJ per story, the estimate based on Wierzbicki was about 0.6 GJ, and the value of E1 needed to account for the collapse rate during the first four seconds of a non-shedding model was about 0.8 GJ.
The energy needed to fail columns does have an orientation independence to some extent. It takes a certain amount of energy to plastically deform metal of a certain volume to a particular amount of strain. That energy depends on the product of the yield strength of the metal, the plastic strain, and the volume of metal strained. Yield strength has units of force per area or energy per volume. Strain is unitless but when multiplied by the volume of the metal that is being strained gives units of volume. The product of strain, volume, and yield strength is energy.
When slender to intermediate columns buckle, the load they can support as a function of axial displacement drops quickly. Fig. 5 of the BZ paper shows the relationship. That behavior precludes a cushioning effect.
There were a number of adjacent floors damaged by the aircraft impacts and fire, so the model doesn't have to rely solely on a situation of a drop through only the first story height at near freefall and then through totally undamaged stories. In reality there was probably a drop less than freefall rate through 2 or 3 damaged stories that offered limited resistance compared with undamaged stories and allowed the upper block to accelerate. That drop also involved other failure modes such as tilting, wedging, and lateral strikes which are a more uniform mode of deforming the columns with respect to drop height as opposed to the more all-or-nothing type of failure associated with axial strikes and buckling.
I ran across this web page, SOME ARTICLES FROM ENGINEERING NEWS RECORD..
It contains a lot of engineering and construction details of the towers.
It contains a lot of engineering and construction details of the towers.
This Could help NIST with the WTC7 report:
*** A New Jersey Emergency Medical Technician has gone public on how
emergency workers were told that Building 7 was going to be "pulled".
A 20 second demolition countdown was broadcast over emergency workers
radios before its collapse. The ground zero rescue worker who for now
wishes to remain anonymous also witnessed multiple underground support
columns of the WTC towers which were severed before the buildings
imploded.
http://www.innworldreport.net/archives/fro...udio/index.html
*** A New Jersey Emergency Medical Technician has gone public on how
emergency workers were told that Building 7 was going to be "pulled".
A 20 second demolition countdown was broadcast over emergency workers
radios before its collapse. The ground zero rescue worker who for now
wishes to remain anonymous also witnessed multiple underground support
columns of the WTC towers which were severed before the buildings
imploded.
http://www.innworldreport.net/archives/fro...udio/index.html
Reasonwhy:
You have to wonder why this emergency worker has waited more than 5 years to come out with this story.... And he/she still chooses to remain anonymous...
What use could NIST or anyone make of such anecdotal "evidence"?
It's right up there with a UFO sighting isn't it, really!
NF
You have to wonder why this emergency worker has waited more than 5 years to come out with this story.... And he/she still chooses to remain anonymous...
What use could NIST or anyone make of such anecdotal "evidence"?
It's right up there with a UFO sighting isn't it, really!
NF
Only to someone claiming to be a scientist and ignoring anything that is contrary to his beliefs.
Does WTC7 look like a perfect demolition of the largest building in history?
Attacking the messenger is typical OCT BS.
Quite a few people claim that they were told WTC7 was going to collapse.
The only way anyone would know a building was going to collapse is if it was a CD.
According to OCT folklore, all you need to do is remove half the columns in one floor at the top of a building and it will collapse to the ground.
I would compare the Official Conspiracy Theory and your paper to UFO’s. Even though UFO’s are much more likely to be true.
Is the moderator going to remove this (I cant believe I was censored on this forum)?
Does WTC7 look like a perfect demolition of the largest building in history?
Attacking the messenger is typical OCT BS.
Quite a few people claim that they were told WTC7 was going to collapse.
The only way anyone would know a building was going to collapse is if it was a CD.
According to OCT folklore, all you need to do is remove half the columns in one floor at the top of a building and it will collapse to the ground.
I would compare the Official Conspiracy Theory and your paper to UFO’s. Even though UFO’s are much more likely to be true.
Is the moderator going to remove this (I cant believe I was censored on this forum)?
reasonwhy
More likely it is just more BS from the CTer crowd.
Grumpy
QUOTE
This Could help NIST with the WTC7 report:
*** A New Jersey Emergency Medical Technician has gone public on how
emergency workers were told that Building 7 was going to be "pulled".
A 20 second demolition countdown was broadcast over emergency workers
radios before its collapse. The ground zero rescue worker who for now
wishes to remain anonymous also witnessed multiple underground support
columns of the WTC towers which were severed before the buildings
imploded.
http://www.innworldreport.net/archives/fro...udio/index.html
*** A New Jersey Emergency Medical Technician has gone public on how
emergency workers were told that Building 7 was going to be "pulled".
A 20 second demolition countdown was broadcast over emergency workers
radios before its collapse. The ground zero rescue worker who for now
wishes to remain anonymous also witnessed multiple underground support
columns of the WTC towers which were severed before the buildings
imploded.
http://www.innworldreport.net/archives/fro...udio/index.html
More likely it is just more BS from the CTer crowd.
Grumpy
[URL=http://propagandamatrix.com/articles/february2007/080207building7.htm]
Another report with more detail
Another report with more detail
QUOTE (reasonwhy+Feb 9 2007, 11:05 AM)
This Could help NIST with the WTC7 report:
*** A New Jersey Emergency Medical Technician has gone public on how
emergency workers were told that Building 7 was going to be "pulled".
A 20 second demolition countdown was broadcast over emergency workers
radios before its collapse. The ground zero rescue worker who for now
wishes to remain anonymous also witnessed multiple underground support
columns of the WTC towers which were severed before the buildings
imploded.
http://www.innworldreport.net/archives/fro...udio/index.html
What's the POINT of "remaining anonymous" since one can't even determine if the person WAS IN NY at the time or at the WTC buildings?
Well if this countdown was BROADCAST there should be LOTS of corroboration.
Where is it?
If he's a NJ EMT how the heck does he manage to see
And if he SAW them before the buildings "imploded" why didn't he TELL ANYONE????
Did we find corroboration of this in ANY of the thousands of interviews with OTHER NON-ANON people?
NOPE.
So without SOME CORROBORATION, this means NOTHING.
For all we know it could have been you, REASONWHY, who made these bogus claims.
Arthur
*** A New Jersey Emergency Medical Technician has gone public on how
emergency workers were told that Building 7 was going to be "pulled".
A 20 second demolition countdown was broadcast over emergency workers
radios before its collapse. The ground zero rescue worker who for now
wishes to remain anonymous also witnessed multiple underground support
columns of the WTC towers which were severed before the buildings
imploded.
http://www.innworldreport.net/archives/fro...udio/index.html
What's the POINT of "remaining anonymous" since one can't even determine if the person WAS IN NY at the time or at the WTC buildings?
Well if this countdown was BROADCAST there should be LOTS of corroboration.
Where is it?
If he's a NJ EMT how the heck does he manage to see
QUOTE
multiple underground support columns of the WTC towers which were severed before the buildings imploded.
And if he SAW them before the buildings "imploded" why didn't he TELL ANYONE????
Did we find corroboration of this in ANY of the thousands of interviews with OTHER NON-ANON people?
NOPE.
So without SOME CORROBORATION, this means NOTHING.
For all we know it could have been you, REASONWHY, who made these bogus claims.
Arthur
reasonwhy
No, it doesn't. To the experts it appears to be a fire/damage induced progressive collapse.
No, it doesn't. To the experts it appears to be a fire/damage induced progressive collapse.
Attacking the messenger is typical OCT BS.
When the messenger is spouting obvious lies HE/SHE should be attacked. The "20 second countdown" DID NOT OCCUR(except in the fevered imaginations of CTer who were nowhere near the event).
EVERYBODY was told WTC7 was going to collapse. The Fire Department determined that at 2:30 in the afternoon. That is why they "pulled" their personnel away from the building. It didn't fall until 5:20 in the evening. (got to be the longest 20 second countdown ever!!!)
EVERYBODY was told WTC7 was going to collapse. The Fire Department determined that at 2:30 in the afternoon. That is why they "pulled" their personnel away from the building. It didn't fall until 5:20 in the evening. (got to be the longest 20 second countdown ever!!!)
The only way anyone would know a building was going to collapse is if it was a CD.
One of the stupidest statements ever posted on this forum. Obviously false.
You also need the impact damage/fires caused by the aircraft collisions and fuel load. NIST has documented the series of failures this caused. It's analysis stands unchallenged.
You also need the impact damage/fires caused by the aircraft collisions and fuel load. NIST has documented the series of failures this caused. It's analysis stands unchallenged.
I would compare the Official Conspiracy Theory and your paper to UFO’s. Even though UFO’s are much more likely to be true.
Well, as you have shown repeatedly, your opinion is worthless when it comes to reality and real scientific investigation.
Grumpy
All your post shows is you have a POLITICAL AGENDA (repeal of the Patriot Act, get out of Iraq and Afghanistan, impeach the president etc) that you DESPERATELY hope could be advanced by ANOTHER INVESTIGATION into the events of 9/11.
This is absurd on MANY LEVELS.
Arthur
Your post have to be the MOST political of anyone on the forum.
You could be the White House Press Secretary.
Anything the government says is the Bible to Arthurs.
The official conspiracy fairytale is not only unquestioned by Arthurs but supported post after post.
QUOTE
Does WTC7 look like a perfect demolition of the largest building in history?
No, it doesn't. To the experts it appears to be a fire/damage induced progressive collapse.
QUOTE (->
| QUOTE |
| Does WTC7 look like a perfect demolition of the largest building in history? |
No, it doesn't. To the experts it appears to be a fire/damage induced progressive collapse.
Attacking the messenger is typical OCT BS.
When the messenger is spouting obvious lies HE/SHE should be attacked. The "20 second countdown" DID NOT OCCUR(except in the fevered imaginations of CTer who were nowhere near the event).
QUOTE
Quite a few people claim that they were told WTC7 was going to collapse.
EVERYBODY was told WTC7 was going to collapse. The Fire Department determined that at 2:30 in the afternoon. That is why they "pulled" their personnel away from the building. It didn't fall until 5:20 in the evening. (got to be the longest 20 second countdown ever!!!)
QUOTE (->
| QUOTE |
| Quite a few people claim that they were told WTC7 was going to collapse. |
EVERYBODY was told WTC7 was going to collapse. The Fire Department determined that at 2:30 in the afternoon. That is why they "pulled" their personnel away from the building. It didn't fall until 5:20 in the evening. (got to be the longest 20 second countdown ever!!!)
The only way anyone would know a building was going to collapse is if it was a CD.
One of the stupidest statements ever posted on this forum. Obviously false.
QUOTE
According to OCT folklore, all you need to do is remove half the columns in one floor at the top of a building and it will collapse to the ground.
You also need the impact damage/fires caused by the aircraft collisions and fuel load. NIST has documented the series of failures this caused. It's analysis stands unchallenged.
QUOTE (->
| QUOTE |
| According to OCT folklore, all you need to do is remove half the columns in one floor at the top of a building and it will collapse to the ground. |
You also need the impact damage/fires caused by the aircraft collisions and fuel load. NIST has documented the series of failures this caused. It's analysis stands unchallenged.
I would compare the Official Conspiracy Theory and your paper to UFO’s. Even though UFO’s are much more likely to be true.
Well, as you have shown repeatedly, your opinion is worthless when it comes to reality and real scientific investigation.
Grumpy
QUOTE (reasonwhy+Feb 9 2007, 11:59 AM)
Quite a few people claim that they were told WTC7 was going to collapse.
The only way anyone would know a building was going to collapse is if it was a CD.
Nope.
I wasn't there but I don't believe they KNEW it was going to collapse, but that they THOUGHT it was going to collapse.
Why?
Well it would seem logical that they would consider that TWO buildings had already collapsed that day and thus along with the observed damage to the building, that the stability of the building (leaning determined by transit) was in doubt and the fact that it was a steel building and they weren't fighting the fires in the building and thus they would know that if critical beams failed that the structure could collapse which could be reinforced by the sounds coming out of the building.
So no, I think that if you weren't fighting the fires in the damaged building then it would be prudent to pull your people back and it would probably become evident that the building was likely to collapse before it actually did.
Arthur
The only way anyone would know a building was going to collapse is if it was a CD.
Nope.
I wasn't there but I don't believe they KNEW it was going to collapse, but that they THOUGHT it was going to collapse.
Why?
Well it would seem logical that they would consider that TWO buildings had already collapsed that day and thus along with the observed damage to the building, that the stability of the building (leaning determined by transit) was in doubt and the fact that it was a steel building and they weren't fighting the fires in the building and thus they would know that if critical beams failed that the structure could collapse which could be reinforced by the sounds coming out of the building.
So no, I think that if you weren't fighting the fires in the damaged building then it would be prudent to pull your people back and it would probably become evident that the building was likely to collapse before it actually did.
Arthur
QUOTE (NEU-FONZE+Feb 8 2007, 09:38 PM)
Lozenge 124:
I see no violation of energy or angular momentum conservation laws in the collapse of WTC 1 & 2.
First there was ample PE stored in one Tower to accommodate a self-sustained gravitational collapse AND concrete pulverization. Try reading Greening's papers on 911myths and tell me where you see a problem....
I haven't looked into the angular momentum aspect, it's the linear momentum that I find more interesting. I'll give you my take below. But first Greening's paper:
I think his analysis in section 3.0 (where he considers the momentum transfer floor by floor with pure inelastic collisions) is a good one. Even though such a pancaking collapse of "unsupported (or weakly supported!)" floors does not correspond to the real situation, it's a mathematically simple and fairly uncontroversial method of finding a lower bound on the possible time of collapse.
Where I find his analysis deeply flawed though is in his conception and discussion of his variable E1 the energy "needed to bring about the collapse of one floor" (section 4.2). His modus operandi is to estimate E1, compare this to Ti - the kinetic energy of the block of floors that is about to impact the floor in question - and compare the two to see if there is enough Ti to provide E1. "If Ti is found to be significantly larger than E1, a self-sustaining total building collapse is possible."
Now to me this is a seriously flawed assumption. When the incoming falling block impacts the stable floor, you cannot just substract E1 from Ti and continue on down. The floor is connected to all the floors beneath it and the earth by the central interconnected core of the tower and the perimeter walls. The energy at impact will be transferred to this whole system through the steel structure, there is no way the block will somehow neatly transfer E1 energy to one floor, collapse it, and continue on down.
To illustrate: take a 2x4 steel bar say 3ft long, and place it vertically. Now take a sledgehammer and hit the top. The energy imparted by the hammer to the 2x4 is going to travel through the bar to the floor, will cause the bar to vibrate some, and will be dissipated in heat. You cannot get the energy to concentrate itself say 1 inch below the top of the bar.
Greening's is carrying over his "unsupported (or weakly supported!)" floors assumption (that is useful in section 3.0 for a rough time estimate), to his energy discussion of section 4.2 and beyond. Doing so is not justifiable. His graphs showing collapse time as a function of E1 are therefore invalid.
The E1 assumption is the biggest problem I have with the paper.
Now to the linear momentum discussion:
As I said, I agree with Greening's calculation in 3.0. I tried something similar in excel and got similar numbers. Jim Hoffmann took this model a little further by making a more generalized model that models the progressive increase of weight of the floors towards the bottom (he does this linearly), and allows for a fraction of the mass of falling block to be lost/ejected at each floor collision (which is more in line with observations).
He runs the model with some different initial parameters, and I urge you to take a look at the results ( 911research.wtc7.net/wtc/models/ ), but I think you will agree that the collapse times are already at or close to the maximum range of the observed collapse times.
Now, mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse) and you have an excellent qualitative case for why the observed time of collapse was impossible under gravity alone.
I see no violation of energy or angular momentum conservation laws in the collapse of WTC 1 & 2.
First there was ample PE stored in one Tower to accommodate a self-sustained gravitational collapse AND concrete pulverization. Try reading Greening's papers on 911myths and tell me where you see a problem....
I haven't looked into the angular momentum aspect, it's the linear momentum that I find more interesting. I'll give you my take below. But first Greening's paper:
I think his analysis in section 3.0 (where he considers the momentum transfer floor by floor with pure inelastic collisions) is a good one. Even though such a pancaking collapse of "unsupported (or weakly supported!)" floors does not correspond to the real situation, it's a mathematically simple and fairly uncontroversial method of finding a lower bound on the possible time of collapse.
Where I find his analysis deeply flawed though is in his conception and discussion of his variable E1 the energy "needed to bring about the collapse of one floor" (section 4.2). His modus operandi is to estimate E1, compare this to Ti - the kinetic energy of the block of floors that is about to impact the floor in question - and compare the two to see if there is enough Ti to provide E1. "If Ti is found to be significantly larger than E1, a self-sustaining total building collapse is possible."
Now to me this is a seriously flawed assumption. When the incoming falling block impacts the stable floor, you cannot just substract E1 from Ti and continue on down. The floor is connected to all the floors beneath it and the earth by the central interconnected core of the tower and the perimeter walls. The energy at impact will be transferred to this whole system through the steel structure, there is no way the block will somehow neatly transfer E1 energy to one floor, collapse it, and continue on down.
To illustrate: take a 2x4 steel bar say 3ft long, and place it vertically. Now take a sledgehammer and hit the top. The energy imparted by the hammer to the 2x4 is going to travel through the bar to the floor, will cause the bar to vibrate some, and will be dissipated in heat. You cannot get the energy to concentrate itself say 1 inch below the top of the bar.
Greening's is carrying over his "unsupported (or weakly supported!)" floors assumption (that is useful in section 3.0 for a rough time estimate), to his energy discussion of section 4.2 and beyond. Doing so is not justifiable. His graphs showing collapse time as a function of E1 are therefore invalid.
The E1 assumption is the biggest problem I have with the paper.
Now to the linear momentum discussion:
As I said, I agree with Greening's calculation in 3.0. I tried something similar in excel and got similar numbers. Jim Hoffmann took this model a little further by making a more generalized model that models the progressive increase of weight of the floors towards the bottom (he does this linearly), and allows for a fraction of the mass of falling block to be lost/ejected at each floor collision (which is more in line with observations).
He runs the model with some different initial parameters, and I urge you to take a look at the results ( 911research.wtc7.net/wtc/models/ ), but I think you will agree that the collapse times are already at or close to the maximum range of the observed collapse times.
Now, mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse) and you have an excellent qualitative case for why the observed time of collapse was impossible under gravity alone.
lozenge124
And this points to the central error of most of the CT crowd. When E1 is applied to the floors the energy is transferred to the rest of the structure BUT ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN, THE ATTACHMENT POINTS BETWEEN THE FLOOR DIAPHRAMS AND THE FRAME AND CORE. Once these limits are reached the floor connections FAIL and can therefore not transfer any more of E1 and the floor joins the mass hitting the next floor down, whose connections are even more easily overcome(more mass/higher velocity) in a continuous process that completely bypasses the theoretical strength of the frames and core. Each floor of that building(except mech floors(3/110)) had exactly the same connections to the frame and core, and therefore the same vulnerability to failure.
Once the floors were gone the top block only had to push the unbraced exterior frame(not crush it) and it fell over, breaking it's bolted connections as it did so. The core, unbraced, was not able to support it's own weight stabily, much less the weight of a 10-20 floor block and snapped much like spagetti does, mostly at the welds.
Thus E1 was ORDERS OF MAGNITUDE larger than the energy required to cause one floor's connections to fail, the rest is gravity.
Grumpy
QUOTE
I think his analysis in section 3.0 (where he considers the momentum transfer floor by floor with pure inelastic collisions) is a good one. Even though such a pancaking collapse of "unsupported (or weakly supported!)" floors does not correspond to the real situation, it's a mathematically simple and fairly uncontroversial method of finding a lower bound on the possible time of collapse.
Where I find his analysis deeply flawed though is in his conception and discussion of his variable E1 the energy "needed to bring about the collapse of one floor" (section 4.2). His modus operandi is to estimate E1, compare this to Ti - the kinetic energy of the block of floors that is about to impact the floor in question - and compare the two to see if there is enough Ti to provide E1. "If Ti is found to be significantly larger than E1, a self-sustaining total building collapse is possible."
Now to me this is a seriously flawed assumption. When the incoming falling block impacts the stable floor, you cannot just substract E1 from Ti and continue on down. The floor is connected to all the floors beneath it and the earth by the central interconnected core of the tower and the perimeter walls. The energy at impact will be transferred to this whole system through the steel structure, there is no way the block will somehow neatly transfer E1 energy to one floor, collapse it, and continue on down.
Where I find his analysis deeply flawed though is in his conception and discussion of his variable E1 the energy "needed to bring about the collapse of one floor" (section 4.2). His modus operandi is to estimate E1, compare this to Ti - the kinetic energy of the block of floors that is about to impact the floor in question - and compare the two to see if there is enough Ti to provide E1. "If Ti is found to be significantly larger than E1, a self-sustaining total building collapse is possible."
Now to me this is a seriously flawed assumption. When the incoming falling block impacts the stable floor, you cannot just substract E1 from Ti and continue on down. The floor is connected to all the floors beneath it and the earth by the central interconnected core of the tower and the perimeter walls. The energy at impact will be transferred to this whole system through the steel structure, there is no way the block will somehow neatly transfer E1 energy to one floor, collapse it, and continue on down.
And this points to the central error of most of the CT crowd. When E1 is applied to the floors the energy is transferred to the rest of the structure BUT ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN, THE ATTACHMENT POINTS BETWEEN THE FLOOR DIAPHRAMS AND THE FRAME AND CORE. Once these limits are reached the floor connections FAIL and can therefore not transfer any more of E1 and the floor joins the mass hitting the next floor down, whose connections are even more easily overcome(more mass/higher velocity) in a continuous process that completely bypasses the theoretical strength of the frames and core. Each floor of that building(except mech floors(3/110)) had exactly the same connections to the frame and core, and therefore the same vulnerability to failure.
Once the floors were gone the top block only had to push the unbraced exterior frame(not crush it) and it fell over, breaking it's bolted connections as it did so. The core, unbraced, was not able to support it's own weight stabily, much less the weight of a 10-20 floor block and snapped much like spagetti does, mostly at the welds.
Thus E1 was ORDERS OF MAGNITUDE larger than the energy required to cause one floor's connections to fail, the rest is gravity.
Grumpy
lozenge124 --- I used the measured drops posted much earlier by NEU-FONZE to obtain a best fit to the Bazant & Verdure 'crush-down' differential equation. The fit is very good. In this way it is possible to determine the energy consumed in the collapse,
330-340 J/kg
for ordinary, trussed, office stories. A typical weight per ordinary story in the upper part of the towers was about 1530 tonnes. This gives
E1 = 0.5+ GJ
when I use a stretch (compaction ratio) of 0.14.
This value of E1 is then empirical. It remains to determine just how much resistance the towers could have. First, shagster determined that destroying the truss seats, thus disconnecting the floors from the exterior wall and also the core, required but 0.01 GJ. I did this independently, and agree. So far not much of the 0.5+ GJ has been consumed.
Second is breaking the welds of core columns. It is clear that this actually requires little energy, although I do not currently know how to estimate it.
Third is sending sections of the exterior wall to considerable distances. Again shagster worked this out and not much of the available energy was consumed this way, although I don't remember the figures.
Fourth is crushing concrete, comminution. NEU-FONZE has worked this out. Uses up lots of energy.
Fifth is simple friction. Anything that wasn't used in comminuting concrete (and other materials) could well have gone directly to heat via friction, although some very tiny portion of the 0.5+ GJ has to go into blowing the air out of the towers.
So I see no way that the towers could possibly survive once collapse is initiated. Furthermore, there is no evidence, of any kind, for the use of explosives or intensional use of chemical reactions.
Anyway, in an earlier post I asked you some questions. Care to answer?
330-340 J/kg
for ordinary, trussed, office stories. A typical weight per ordinary story in the upper part of the towers was about 1530 tonnes. This gives
E1 = 0.5+ GJ
when I use a stretch (compaction ratio) of 0.14.
This value of E1 is then empirical. It remains to determine just how much resistance the towers could have. First, shagster determined that destroying the truss seats, thus disconnecting the floors from the exterior wall and also the core, required but 0.01 GJ. I did this independently, and agree. So far not much of the 0.5+ GJ has been consumed.
Second is breaking the welds of core columns. It is clear that this actually requires little energy, although I do not currently know how to estimate it.
Third is sending sections of the exterior wall to considerable distances. Again shagster worked this out and not much of the available energy was consumed this way, although I don't remember the figures.
Fourth is crushing concrete, comminution. NEU-FONZE has worked this out. Uses up lots of energy.
Fifth is simple friction. Anything that wasn't used in comminuting concrete (and other materials) could well have gone directly to heat via friction, although some very tiny portion of the 0.5+ GJ has to go into blowing the air out of the towers.
So I see no way that the towers could possibly survive once collapse is initiated. Furthermore, there is no evidence, of any kind, for the use of explosives or intensional use of chemical reactions.
Anyway, in an earlier post I asked you some questions. Care to answer?
QUOTE (Grumpy+Feb 9 2007, 05:54 PM)
lozenge124
And this points to the central error of most of the CT crowd. When E1 is applied to the floors the energy is transferred to the rest of the structure BUT ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN, THE ATTACHMENT POINTS BETWEEN THE FLOOR DIAPHRAMS AND THE FRAME AND CORE. Once these limits are reached the floor connections FAIL and can therefore not transfer any more of E1 and the floor joins the mass hitting the next floor down, whose connections are even more easily overcome(more mass/higher velocity) in a continuous process that completely bypasses the theoretical strength of the frames and core. Each floor of that building(except mech floors(3/110)) had exactly the same connections to the frame and core, and therefore the same vulnerability to failure.
Once the floors were gone the top block only had to push the unbraced exterior frame(not crush it) and it fell over, breaking it's bolted connections as it did so. The core, unbraced, was not able to support it's own weight stabily, much less the weight of a 10-20 floor block and snapped much like spagetti does, mostly at the welds.
Thus E1 was ORDERS OF MAGNITUDE larger than the energy required to cause one floor's connections to fail, the rest is gravity.
Grumpy
The problem here is that the pancaking floors scenario that Greening is using is just an abstract model used to try to get a handle on theoretical collapse times. As I mentioned, I think his section 3.0 calculation - using the inertial mass of each floor - is valuable, but it is a simplified model. The assumption that a block of n floors fell perfectly straight down one floor length to start the collapse is also a simplified assumption, as obviously no such gap could have been created across the whole cross section of the tower to initiate things.
As I'm sure has been posted before, the NIST themselves do not hold that a pancaking collapse happened:
Why then look at this simplified model? For the same reason people calculate the freefall time of an object from the top of the towers, to get a lower bound on a purely gravitational collapse time. As I mentioned in my previous post, I think Jim Hoffman does a good job of taking this mathematical analysis further.
I'm having trouble visualizing what you are saying, because you appear to be describing a pancake collapse - "the floor joins the mass hitting the next floor down" - but a pancake collapse with the continuous core of the WTC in the middle. Because of the core, both the initation of the collapse and its progression are far more complex then floors falling one on top of another.
I would like to comment though on your "ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN" remark. Imagine one of the twin towers up to the 80th floor say: remove the top 20 floors or so. Now remove all the floors. That's right, remove all the floors to leave only the steel core and the perimeter.
Now take a giant sledge hammer and bring it down onto this structure hard enough to do some damage... In your scenario, all the weld pops, bending, steel failure etc... would apparently only occur at or around a neat horizontal section centered around where the 79th floor used to be... how likely is that really?
I agree with you that vulnerable, "weakest links" will show damage, but in the real world, where statistical laws apply, the impact of the sledge hammer will travel through the core and perimeter down to the bottom of the tower, damaging "weakest links" at random points in the structure.
And this points to the central error of most of the CT crowd. When E1 is applied to the floors the energy is transferred to the rest of the structure BUT ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN, THE ATTACHMENT POINTS BETWEEN THE FLOOR DIAPHRAMS AND THE FRAME AND CORE. Once these limits are reached the floor connections FAIL and can therefore not transfer any more of E1 and the floor joins the mass hitting the next floor down, whose connections are even more easily overcome(more mass/higher velocity) in a continuous process that completely bypasses the theoretical strength of the frames and core. Each floor of that building(except mech floors(3/110)) had exactly the same connections to the frame and core, and therefore the same vulnerability to failure.
Once the floors were gone the top block only had to push the unbraced exterior frame(not crush it) and it fell over, breaking it's bolted connections as it did so. The core, unbraced, was not able to support it's own weight stabily, much less the weight of a 10-20 floor block and snapped much like spagetti does, mostly at the welds.
Thus E1 was ORDERS OF MAGNITUDE larger than the energy required to cause one floor's connections to fail, the rest is gravity.
Grumpy
The problem here is that the pancaking floors scenario that Greening is using is just an abstract model used to try to get a handle on theoretical collapse times. As I mentioned, I think his section 3.0 calculation - using the inertial mass of each floor - is valuable, but it is a simplified model. The assumption that a block of n floors fell perfectly straight down one floor length to start the collapse is also a simplified assumption, as obviously no such gap could have been created across the whole cross section of the tower to initiate things.
As I'm sure has been posted before, the NIST themselves do not hold that a pancaking collapse happened:
QUOTE
NIST’s findings do not support the “pancake theory” of collapse, which is premised on a progressive failure of the floor systems in the WTC towers (the composite floor system—that connected the core columns and the perimeter columns—consisted of a grid of steel “trusses” integrated with a concrete slab; see diagram below). Instead, the NIST investigation showed conclusively that the failure of the inwardly bowed perimeter columns initiated collapse and that the occurrence of this inward bowing required the sagging floors to remain connected to the columns and pull the columns inwards. Thus, the floors did not fail progressively to cause a pancaking phenomenon.
Why then look at this simplified model? For the same reason people calculate the freefall time of an object from the top of the towers, to get a lower bound on a purely gravitational collapse time. As I mentioned in my previous post, I think Jim Hoffman does a good job of taking this mathematical analysis further.
I'm having trouble visualizing what you are saying, because you appear to be describing a pancake collapse - "the floor joins the mass hitting the next floor down" - but a pancake collapse with the continuous core of the WTC in the middle. Because of the core, both the initation of the collapse and its progression are far more complex then floors falling one on top of another.
I would like to comment though on your "ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN" remark. Imagine one of the twin towers up to the 80th floor say: remove the top 20 floors or so. Now remove all the floors. That's right, remove all the floors to leave only the steel core and the perimeter.
Now take a giant sledge hammer and bring it down onto this structure hard enough to do some damage... In your scenario, all the weld pops, bending, steel failure etc... would apparently only occur at or around a neat horizontal section centered around where the 79th floor used to be... how likely is that really?
I agree with you that vulnerable, "weakest links" will show damage, but in the real world, where statistical laws apply, the impact of the sledge hammer will travel through the core and perimeter down to the bottom of the tower, damaging "weakest links" at random points in the structure.
QUOTE (adoucette+Feb 7 2007, 04:05 PM)
I think you'll notice that the respirators all appear to be the same type, and most of the people working there appear to be fireman.
http://www.box.net/public/26rjp73slx
I would believe that whoever provided the respirators (most likely FEMA) also knew that they have to be changed and thus its hard to believe that replacement canisters weren't available.
Er, no. Not including the two people in the background, the picture shows three firemen watching one iron worker.
The ironworker is wearing a North style half face respirator with a what appears to be a charcoal cartridge and HEPA filter combination.
The one fireman with his back toward the camera is wearing his respirator, of the other two, the one the left appears to be similar to the one with his back to the camera, but you can’t tell for sure, (it appears to be a 3M style) while, the one with the respirator on backwards has a totally different type.
That is at least three different types with three different types of cartridges.
http://www.box.net/public/26rjp73slx
I would believe that whoever provided the respirators (most likely FEMA) also knew that they have to be changed and thus its hard to believe that replacement canisters weren't available.
Er, no. Not including the two people in the background, the picture shows three firemen watching one iron worker.
The ironworker is wearing a North style half face respirator with a what appears to be a charcoal cartridge and HEPA filter combination.
The one fireman with his back toward the camera is wearing his respirator, of the other two, the one the left appears to be similar to the one with his back to the camera, but you can’t tell for sure, (it appears to be a 3M style) while, the one with the respirator on backwards has a totally different type.
That is at least three different types with three different types of cartridges.
David B. Benson -- so you are estimating E1, it is not Greening's E1 estimate I have a problem with, it is the model in which he uses E1.
Are these the questions?
The stakes are high because if 911 is an inside job, elements of the US government have been involved in the murder of ~3000 people. Not to mention all the policies and actions that the current political powers have used 911 for: Patriot Act, invasion of Iraq/Afghanistan etc...
From the NIST faq: one of the "primary objectives of the NIST-led technical investigation of the World Trade Center disaster" is to determine "why and how the World Trade Center buildings 1, 2, and 7 collapsed after the initial impact of the aircraft". Without going beyond collapse initiation (and having a dodgy model to explain collapse initiation) hardly satifsies the how and why part.
For the importance that 911 as had on the political climate of the past 5 years, and because it resulted in so many deaths, I think it is extremely important to understand exactly why and how it happened. If your LED clock had caused the death of thousands of people, I am pretty sure a thorough investigation would have been launched to prevent it from happening again.
Are these the questions?
QUOTE
Why are the stakes high? NIST is interested in building safety, not the details of progressive collapse.
Why is it troubling? Life is full of things which remain to be explained. As a trivial example, the LED clock on my coffee maker decided, all on its own, to add an hour to the time...
Why is it troubling? Life is full of things which remain to be explained. As a trivial example, the LED clock on my coffee maker decided, all on its own, to add an hour to the time...
The stakes are high because if 911 is an inside job, elements of the US government have been involved in the murder of ~3000 people. Not to mention all the policies and actions that the current political powers have used 911 for: Patriot Act, invasion of Iraq/Afghanistan etc...
From the NIST faq: one of the "primary objectives of the NIST-led technical investigation of the World Trade Center disaster" is to determine "why and how the World Trade Center buildings 1, 2, and 7 collapsed after the initial impact of the aircraft". Without going beyond collapse initiation (and having a dodgy model to explain collapse initiation) hardly satifsies the how and why part.
For the importance that 911 as had on the political climate of the past 5 years, and because it resulted in so many deaths, I think it is extremely important to understand exactly why and how it happened. If your LED clock had caused the death of thousands of people, I am pretty sure a thorough investigation would have been launched to prevent it from happening again.
QUOTE (lozenge124+Feb 9 2007, 08:39 PM)
... it is the model in which he uses E1.
The model follows directly from first principles of physics. Making one further simplifying assumption, homogenization of the structure, B & V develop the self-same ideas into a differential equation form. I have looked carefully at both and find nothing wrong. shagster finds nothing wrong. Neither did the referees for the B & V paper, which will appear in ASCE J. Engg. Mechanics. Furthermore, I have shown that there is a very good fit between measured observations for the first few seconds and the form of the solution to the differential equation. That should certainly end the debate on the matter.
So irrespective of the uses to which the tower collapses have been put by politicians, the physics of progressive collapse is reasonably well understood, although one can always wish for more detail, I suppose.
NIST did explain 'why and how' collapse initiated. There was no reason for them to go into the nitty-gritty of the progressive collapse. I don't see anything dodgy in their explanation. In particular, early on they thought that so-called pancaking initiated the collapse. It did not, as their final report makes clear. However, once initiated, the actual trusses of the floors did 'pancake', although I prefer the term 'bagel' for the hole in the middle.
The model follows directly from first principles of physics. Making one further simplifying assumption, homogenization of the structure, B & V develop the self-same ideas into a differential equation form. I have looked carefully at both and find nothing wrong. shagster finds nothing wrong. Neither did the referees for the B & V paper, which will appear in ASCE J. Engg. Mechanics. Furthermore, I have shown that there is a very good fit between measured observations for the first few seconds and the form of the solution to the differential equation. That should certainly end the debate on the matter.
So irrespective of the uses to which the tower collapses have been put by politicians, the physics of progressive collapse is reasonably well understood, although one can always wish for more detail, I suppose.
NIST did explain 'why and how' collapse initiated. There was no reason for them to go into the nitty-gritty of the progressive collapse. I don't see anything dodgy in their explanation. In particular, early on they thought that so-called pancaking initiated the collapse. It did not, as their final report makes clear. However, once initiated, the actual trusses of the floors did 'pancake', although I prefer the term 'bagel' for the hole in the middle.
QUOTE (lozenge124+Feb 9 2007, 01:34 PM)
Jim Hoffmann took this model a little further by making a more generalized model that models the progressive increase of weight of the floors towards the bottom (he does this linearly), and allows for a fraction of the mass of falling block to be lost/ejected at each floor collision (which is more in line with observations).
He runs the model with some different initial parameters, and I urge you to take a look at the results ( 911research.wtc7.net/wtc/models/ ), but I think you will agree that the collapse times are already at or close to the maximum range of the observed collapse times.
Now, mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse) and you have an excellent qualitative case for why the observed time of collapse was impossible under gravity alone.
Why is it that only people without the BACKGROUND in structural engineering can come to this conclusion, while NO ONE skilled in the arts of building design supports them?
The answer is SIMPLE.
Your INCOMPETENCE in the field you are arguing about PREVENTS you from realizing you are in fact INCOMPETENT.
Arthur
He runs the model with some different initial parameters, and I urge you to take a look at the results ( 911research.wtc7.net/wtc/models/ ), but I think you will agree that the collapse times are already at or close to the maximum range of the observed collapse times.
Now, mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse) and you have an excellent qualitative case for why the observed time of collapse was impossible under gravity alone.
Why is it that only people without the BACKGROUND in structural engineering can come to this conclusion, while NO ONE skilled in the arts of building design supports them?
The answer is SIMPLE.
Your INCOMPETENCE in the field you are arguing about PREVENTS you from realizing you are in fact INCOMPETENT.
Arthur
QUOTE (David B. Benson+Feb 9 2007, 09:23 PM)
The model follows directly from first principles of physics. Making one further simplifying assumption, homogenization of the structure, B & V develop the self-same ideas into a differential equation form. I have looked carefully at both and find nothing wrong. Neither did the referees for the B & V paper, which will appear in ASCE J. Engg. Mechanics. Furthermore, I have shown that there is a very good fit between measured observations for the first few seconds and the form of the solution to the differential equation. That should certainly end the debate on the matter.
So irrespective of the uses to which the tower collapses have been put by politicians, the physics of progressive collapse is reasonably well understood, although one can always wish for more detail, I suppose.
NIST did explain 'why and how' collapse initiated. There was no reason for them to go into the nitty-gritty of the progressive collapse. I don't see anything dodgy in their explanation. In particular, early on they thought that so-called pancaking initiated the collapse. It did not, as their final report makes clear. However, once initiated, the actual trusses of the floors did 'pancake', although I prefer the term 'bagel' for the hole in the middle.
Do you have a link for the B & V paper? I am not familiar with it.
I won't repeat what I said in my post critiquing the Greening paper, if you have any speciific comments please share. I also agree with much of Gordon Ross's critique ( for example forum.physorg.com/index.php?act=ST&f=10&t=3108&hl=greening&view=findpost&p=82947 )
Are you aware of Greening's comments on the NIST model? ( 911myths.com/NISTREPORT.pdf )
So irrespective of the uses to which the tower collapses have been put by politicians, the physics of progressive collapse is reasonably well understood, although one can always wish for more detail, I suppose.
NIST did explain 'why and how' collapse initiated. There was no reason for them to go into the nitty-gritty of the progressive collapse. I don't see anything dodgy in their explanation. In particular, early on they thought that so-called pancaking initiated the collapse. It did not, as their final report makes clear. However, once initiated, the actual trusses of the floors did 'pancake', although I prefer the term 'bagel' for the hole in the middle.
Do you have a link for the B & V paper? I am not familiar with it.
I won't repeat what I said in my post critiquing the Greening paper, if you have any speciific comments please share. I also agree with much of Gordon Ross's critique ( for example forum.physorg.com/index.php?act=ST&f=10&t=3108&hl=greening&view=findpost&p=82947 )
Are you aware of Greening's comments on the NIST model? ( 911myths.com/NISTREPORT.pdf )
QUOTE
Clearly, if NIST’s computer model is essentially correct, the Twin Towers collapsed (or fell over!) at ridiculously small downward displacements and tilt angles, and were inherently unstable as soon as they were struck by aircraft. This raises serious questions about the design and construction of the Twin Towers. However, a more reasonable assessment would be that NIST’s computer model is highly inaccurate, and therefore of no value in explaining the demise of the Twin Towers.
QUOTE (lozenge124+Feb 9 2007, 04:39 PM)
The stakes are high because if 911 is an inside job, elements of the US government have been involved in the murder of ~3000 people. Not to mention all the policies and actions that the current political powers have used 911 for: Patriot Act, invasion of Iraq/Afghanistan etc...
From the NIST faq: one of the "primary objectives of the NIST-led technical investigation of the World Trade Center disaster" is to determine "why and how the World Trade Center buildings 1, 2, and 7 collapsed after the initial impact of the aircraft". Without going beyond collapse initiation (and having a dodgy model to explain collapse initiation) hardly satifsies the how and why part.
For the importance that 911 as had on the political climate of the past 5 years, and because it resulted in so many deaths, I think it is extremely important to understand exactly why and how it happened. If your LED clock had caused the death of thousands of people, I am pretty sure a thorough investigation would have been launched to prevent it from happening again.
If 9/11 was an inside job?
For 9/11 to have been an INSIDE JOB, then the hijacking of the planes would have had to have been an INSIDE JOB and that is PATENTLY FALSE.
NIST answered how and why the Tower's collapse was initiated.
Because the INITIATING FACTOR of the WTC tower's collapse was so EXTREME of an event, there is little value in going further then collapse initiation, as it is highly unlikely to be extensible to other, more typical, scenarios.
The HOW AND WHY to be answered had to do with the INITIATING EVENT, not the collapse as that was the cause of the majority of the deaths.
All your post shows is you have a POLITICAL AGENDA (repeal of the Patriot Act, get out of Iraq and Afghanistan, impeach the president etc) that you DESPERATELY hope could be advanced by ANOTHER INVESTIGATION into the events of 9/11.
This is absurd on MANY LEVELS.
Arthur
From the NIST faq: one of the "primary objectives of the NIST-led technical investigation of the World Trade Center disaster" is to determine "why and how the World Trade Center buildings 1, 2, and 7 collapsed after the initial impact of the aircraft". Without going beyond collapse initiation (and having a dodgy model to explain collapse initiation) hardly satifsies the how and why part.
For the importance that 911 as had on the political climate of the past 5 years, and because it resulted in so many deaths, I think it is extremely important to understand exactly why and how it happened. If your LED clock had caused the death of thousands of people, I am pretty sure a thorough investigation would have been launched to prevent it from happening again.
If 9/11 was an inside job?
For 9/11 to have been an INSIDE JOB, then the hijacking of the planes would have had to have been an INSIDE JOB and that is PATENTLY FALSE.
NIST answered how and why the Tower's collapse was initiated.
Because the INITIATING FACTOR of the WTC tower's collapse was so EXTREME of an event, there is little value in going further then collapse initiation, as it is highly unlikely to be extensible to other, more typical, scenarios.
The HOW AND WHY to be answered had to do with the INITIATING EVENT, not the collapse as that was the cause of the majority of the deaths.
All your post shows is you have a POLITICAL AGENDA (repeal of the Patriot Act, get out of Iraq and Afghanistan, impeach the president etc) that you DESPERATELY hope could be advanced by ANOTHER INVESTIGATION into the events of 9/11.
This is absurd on MANY LEVELS.
Arthur
QUOTE (lozenge124+Feb 9 2007, 05:34 PM)
Jim Hoffmann took this model a little further by making a more generalized model that models the progressive increase of weight of the floors towards the bottom (he does this linearly), and allows for a fraction of the mass of falling block to be lost/ejected at each floor collision (which is more in line with observations).
He runs the model with some different initial parameters, and I urge you to take a look at the results ( 911research.wtc7.net/wtc/models/ ), but I think you will agree that the collapse times are already at or close to the maximum range of the observed collapse times.
shagster has recently done similar work. The difference is that shagster is very carefully looking at all the evidence.
I did not allow for mass loss since AFAIK no significant mass loss occurred for the first 3.0 seconds in the case of WTC 1 and 4.0 seconds in the case of WTC 2. I also did not allow for weight gain per story since this is insignificant for the first few seconds.
Edited to add: The B & V paper is available from Professor Bazant's web site. Gordon Ross and I had quite an exchange at the beginning of the part 2 thread. It is clear that his basic understanding of physics is lacking. So no matter how cleverly he writes, I ignore him. I believe that in some of my earlier posts I addressed what I thought you found wrong with Greening's work. I assure you there is nothing seriously wrong with it.
He runs the model with some different initial parameters, and I urge you to take a look at the results ( 911research.wtc7.net/wtc/models/ ), but I think you will agree that the collapse times are already at or close to the maximum range of the observed collapse times.
shagster has recently done similar work. The difference is that shagster is very carefully looking at all the evidence.
I did not allow for mass loss since AFAIK no significant mass loss occurred for the first 3.0 seconds in the case of WTC 1 and 4.0 seconds in the case of WTC 2. I also did not allow for weight gain per story since this is insignificant for the first few seconds.
Edited to add: The B & V paper is available from Professor Bazant's web site. Gordon Ross and I had quite an exchange at the beginning of the part 2 thread. It is clear that his basic understanding of physics is lacking. So no matter how cleverly he writes, I ignore him. I believe that in some of my earlier posts I addressed what I thought you found wrong with Greening's work. I assure you there is nothing seriously wrong with it.
QUOTE (adoucette+Feb 9 2007, 01:59 PM)
All your post shows is you have a POLITICAL AGENDA (repeal of the Patriot Act, get out of Iraq and Afghanistan, impeach the president etc) that you DESPERATELY hope could be advanced by ANOTHER INVESTIGATION into the events of 9/11.
This is absurd on MANY LEVELS.
Arthur
Your post have to be the MOST political of anyone on the forum.
You could be the White House Press Secretary.
Anything the government says is the Bible to Arthurs.
The official conspiracy fairytale is not only unquestioned by Arthurs but supported post after post.
QUOTE (lozenge124+Feb 9 2007, 01:53 PM)
Do you have a link for the B & V paper? I am not familiar with it.
I won't repeat what I said in my post critiquing the Greening paper, if you have any speciific comments please share. I also agree with much of Gordon Ross's critique ( for example forum.physorg.com/index.php?act=ST&f=10&t=3108&hl=greening&view=findpost&p=82947 )
Are you aware of Greening's comments on the NIST model? ( 911myths.com/NISTREPORT.pdf )
He is very aware of Greening's comments becouse Nue fonze is Greening.
Nue fonze is not payed enough to support all the OCT BS, just the math and the Arabs did it.
I won't repeat what I said in my post critiquing the Greening paper, if you have any speciific comments please share. I also agree with much of Gordon Ross's critique ( for example forum.physorg.com/index.php?act=ST&f=10&t=3108&hl=greening&view=findpost&p=82947 )
Are you aware of Greening's comments on the NIST model? ( 911myths.com/NISTREPORT.pdf )
He is very aware of Greening's comments becouse Nue fonze is Greening.
Nue fonze is not payed enough to support all the OCT BS, just the math and the Arabs did it.
Mathieu functions --- Rather to my surprise, I have never encountered these previously, despite applications such as loudspeaker design, eddy currents and even wave guides! So I have enjoyed reading portions of
N.W. Lachlan
Theory and Application of Matthieu Functions
Oxford University Press, 1947
not the least for the sixty year old writing style and the reminder of how difficult research was in the days before computers. (But it also helped to read the Wikipedia page as well.)
In the current context, we are considering the Mathieu equation and its solutions, the Mathieu functions, as approximations to periodic pounding on the tops of columns. For that we strictly need the more general form of Hill's equation, but this just adds complexity without further enlightenment.
The amazing fact is that these solutions are not (strictly) periodic, although for small sinusoidally varying loads, they are close. Even more amazing is that the system can respond at 1/2 of the driving frequency.
So to correct what I stated earlier, there are two parameters, traditionally called a and q. The first parameter refers to system constant minus a suddenly applied constant load of infinite duration, a step function. The second parameter gives the amplitude of the sinusoidally varying load of some given frequency. If q = 0 the equation solutions just refer to the step function response of the linear system, a sum of sinusoids at all multiples of the natural system response when a > 0 and the solutions are unbounded (Euler buckling) for a < 0.
But if q > 0 there are some just barely negative values of a for which Euler buckling is avoided! The (small) sinusoidally varying component of the load actually stabilizes the column! (At least in theory). However, for each value of positive q there are many values of a, both positive and negative, for which unbounded motion occurs.
Of course, in actual physical systems, unbounded vibration cannot occur. So we take these as indications that such could contribute to plastic behavior, such as destroying welds. Of course, the Mathieu and Hill equations no longer apply when there is plastic behavior.
N.W. Lachlan
Theory and Application of Matthieu Functions
Oxford University Press, 1947
not the least for the sixty year old writing style and the reminder of how difficult research was in the days before computers. (But it also helped to read the Wikipedia page as well.)
In the current context, we are considering the Mathieu equation and its solutions, the Mathieu functions, as approximations to periodic pounding on the tops of columns. For that we strictly need the more general form of Hill's equation, but this just adds complexity without further enlightenment.
The amazing fact is that these solutions are not (strictly) periodic, although for small sinusoidally varying loads, they are close. Even more amazing is that the system can respond at 1/2 of the driving frequency.
So to correct what I stated earlier, there are two parameters, traditionally called a and q. The first parameter refers to system constant minus a suddenly applied constant load of infinite duration, a step function. The second parameter gives the amplitude of the sinusoidally varying load of some given frequency. If q = 0 the equation solutions just refer to the step function response of the linear system, a sum of sinusoids at all multiples of the natural system response when a > 0 and the solutions are unbounded (Euler buckling) for a < 0.
But if q > 0 there are some just barely negative values of a for which Euler buckling is avoided! The (small) sinusoidally varying component of the load actually stabilizes the column! (At least in theory). However, for each value of positive q there are many values of a, both positive and negative, for which unbounded motion occurs.
Of course, in actual physical systems, unbounded vibration cannot occur. So we take these as indications that such could contribute to plastic behavior, such as destroying welds. Of course, the Mathieu and Hill equations no longer apply when there is plastic behavior.
reasonwhy
Actually supporting the reality is not being political, it just all us true scientist CAN do
lozenge124
Actually supporting the reality is not being political, it just all us true scientist CAN do
lozenge124
As I'm sure has been posted before, the NIST themselves do not hold that a pancaking collapse happened:
NIST simply points out that pancaking did not initiate the collapses, but the floors did in fact pancake.
Actually, if you take off the top ten floors and then suspend a sandbag with ten times the weight of sand necessary to collapse one floor diaphram, one floor height above the first exposed floor(and core and frame). Release all the sand at one time.
The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
Grumpy
QUOTE
Your post have to be the MOST political of anyone on the forum.
You could be the White House Press Secretary.
Anything the government says is the Bible to Arthurs.
The official conspiracy fairytale is not only unquestioned by Arthurs but supported post after post.
You could be the White House Press Secretary.
Anything the government says is the Bible to Arthurs.
The official conspiracy fairytale is not only unquestioned by Arthurs but supported post after post.
Actually supporting the reality is not being political, it just all us true scientist CAN do
lozenge124
QUOTE (->
| QUOTE |
| Your post have to be the MOST political of anyone on the forum. You could be the White House Press Secretary. Anything the government says is the Bible to Arthurs. The official conspiracy fairytale is not only unquestioned by Arthurs but supported post after post. |
Actually supporting the reality is not being political, it just all us true scientist CAN do
lozenge124
As I'm sure has been posted before, the NIST themselves do not hold that a pancaking collapse happened:
NIST simply points out that pancaking did not initiate the collapses, but the floors did in fact pancake.
QUOTE
I'm having trouble visualizing what you are saying, because you appear to be describing a pancake collapse - "the floor joins the mass hitting the next floor down" - but a pancake collapse with the continuous core of the WTC in the middle. Because of the core, both the initation of the collapse and its progression are far more complex then floors falling one on top of another.
I would like to comment though on your "ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN" remark. Imagine one of the twin towers up to the 80th floor say: remove the top 20 floors or so. Now remove all the floors. That's right, remove all the floors to leave only the steel core and the perimeter.
Now take a giant sledge hammer and bring it down onto this structure hard enough to do some damage... In your scenario, all the weld pops, bending, steel failure etc... would apparently only occur at or around a neat horizontal section centered around where the 79th floor used to be... how likely is that really?
I agree with you that vulnerable, "weakest links" will show damage, but in the real world, where statistical laws apply, the impact of the sledge hammer will travel through the core and perimeter down to the bottom of the tower, damaging "weakest links" at random points in the structure.
I would like to comment though on your "ONLY TO THE LIMITS OF THE WEAKEST LINK IN THAT TRANSFER CHAIN" remark. Imagine one of the twin towers up to the 80th floor say: remove the top 20 floors or so. Now remove all the floors. That's right, remove all the floors to leave only the steel core and the perimeter.
Now take a giant sledge hammer and bring it down onto this structure hard enough to do some damage... In your scenario, all the weld pops, bending, steel failure etc... would apparently only occur at or around a neat horizontal section centered around where the 79th floor used to be... how likely is that really?
I agree with you that vulnerable, "weakest links" will show damage, but in the real world, where statistical laws apply, the impact of the sledge hammer will travel through the core and perimeter down to the bottom of the tower, damaging "weakest links" at random points in the structure.
Actually, if you take off the top ten floors and then suspend a sandbag with ten times the weight of sand necessary to collapse one floor diaphram, one floor height above the first exposed floor(and core and frame). Release all the sand at one time.
The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
Grumpy
QUOTE (reasonwhy+Feb 10 2007, 12:34 AM)
He is very aware of Greening's comments becouse[sic] Nue fonze is Greening.
But I am not.
lozenge124 ---
Having been through some sections of NCSTAR1, I opine they did a credible job on an extremely challenging task. That doesn't mean that the report is perfect. However, if you have some particular portion of NCSTAR1-6 or its various supporting documents which you question, I'm willing to share my understanding of what was done and why various criticisms leveled at this portion of the NCSTAR1 report appear to me to be irrelevant.
But I am not.
lozenge124 ---
Having been through some sections of NCSTAR1, I opine they did a credible job on an extremely challenging task. That doesn't mean that the report is perfect. However, if you have some particular portion of NCSTAR1-6 or its various supporting documents which you question, I'm willing to share my understanding of what was done and why various criticisms leveled at this portion of the NCSTAR1 report appear to me to be irrelevant.
QUOTE (reasonwhy+Feb 9 2007, 07:58 PM)
Anything the government says is the Bible to Arthurs.
The official conspiracy fairytale is not only unquestioned by Arthurs but supported post after post.
If by the Government you mean NIST, then simply point out something substantial that is wrong with the report.
I support the NIST report because of the high QUALITY of the overall report, the ATTENTION to detail, the great amount of RESEARCH that went into the report, the level of DOCUMENTATION provided, the data derived via well designed EXPERIMENTS to insure the incredibly detailed FEA models were as ACCURATE as possible and by the CONSERVATIVE nature of their assumtions.
By your own catagorization of the NIST report as a "FAIRYTALE" its quite clear you have a PREDETERMINED view of the report.
Maybe you should try to spend a little time actually studying it before blowing more of your hot air around.
Arthur
The official conspiracy fairytale is not only unquestioned by Arthurs but supported post after post.
If by the Government you mean NIST, then simply point out something substantial that is wrong with the report.
I support the NIST report because of the high QUALITY of the overall report, the ATTENTION to detail, the great amount of RESEARCH that went into the report, the level of DOCUMENTATION provided, the data derived via well designed EXPERIMENTS to insure the incredibly detailed FEA models were as ACCURATE as possible and by the CONSERVATIVE nature of their assumtions.
By your own catagorization of the NIST report as a "FAIRYTALE" its quite clear you have a PREDETERMINED view of the report.
Maybe you should try to spend a little time actually studying it before blowing more of your hot air around.
Arthur
Lozenge 124:
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
Reasonwhy:
You claim: "Nue fonze is not payed enough to support all the OCT BS, just the math and the Arabs did it."
Please show me where in my last 700-plus posts that I even mention "the Arabs", and could you please elaborate on what precisely I said "the Arabs" did.
I would prefer to discuss size effects in reported values of the modulus of toughness of structural steel. Shagster, the modulus of toughness is often expressed in kJ/m^3..... but what is an appropriate volume of steel to use in the case of the WTC?
NF
You claim: "Nue fonze is not payed enough to support all the OCT BS, just the math and the Arabs did it."
Please show me where in my last 700-plus posts that I even mention "the Arabs", and could you please elaborate on what precisely I said "the Arabs" did.
I would prefer to discuss size effects in reported values of the modulus of toughness of structural steel. Shagster, the modulus of toughness is often expressed in kJ/m^3..... but what is an appropriate volume of steel to use in the case of the WTC?
NF
QUOTE (NEU-FONZE+Feb 9 2007, 07:10 PM)
Lozenge 124:
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
One of the problems with this simplistic model is the core floors were not supported with brackets (beams and columns in the core for 1/3 the total area of the floor ). For the top section to continue as one mass it would have to overcome the immense strength of the core beams and columns. I am sure this is a reason NIST does not support the pancake theory.
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
One of the problems with this simplistic model is the core floors were not supported with brackets (beams and columns in the core for 1/3 the total area of the floor ). For the top section to continue as one mass it would have to overcome the immense strength of the core beams and columns. I am sure this is a reason NIST does not support the pancake theory.
QUOTE (adoucette+Feb 9 2007, 07:07 PM)
If by the Government you mean NIST, then simply point out something substantial that is wrong with the report.
I support the NIST report because of the high QUALITY of the overall report, the ATTENTION to detail, the great amount of RESEARCH that went into the report, the level of DOCUMENTATION provided, the data derived via well designed EXPERIMENTS to insure the incredibly detailed FEA models were as ACCURATE as possible and by the CONSERVATIVE nature of their assumtions.
By your own catagorization of the NIST report as a "FAIRYTALE" its quite clear you have a PREDETERMINED view of the report.
Maybe you should try to spend a little time actually studying it before blowing more of your hot air around.
Arthur
The OCT is a FAIRYTALE.
I have read the NIST report and that is why I call it a JOKE .
The impact floor of WTC2 was the elevator motor room and they did not add the 12 massive motors or the reinforced core floors to the impact model.
NIST also left out all the partial beam floors on the impact model.
Then they used the worst case in all situations and the model still would not fail (just becomes unstable) so NIST decides Global Collapse ensued.
I support the NIST report because of the high QUALITY of the overall report, the ATTENTION to detail, the great amount of RESEARCH that went into the report, the level of DOCUMENTATION provided, the data derived via well designed EXPERIMENTS to insure the incredibly detailed FEA models were as ACCURATE as possible and by the CONSERVATIVE nature of their assumtions.
By your own catagorization of the NIST report as a "FAIRYTALE" its quite clear you have a PREDETERMINED view of the report.
Maybe you should try to spend a little time actually studying it before blowing more of your hot air around.
Arthur
The OCT is a FAIRYTALE.
I have read the NIST report and that is why I call it a JOKE .
The impact floor of WTC2 was the elevator motor room and they did not add the 12 massive motors or the reinforced core floors to the impact model.
NIST also left out all the partial beam floors on the impact model.
Then they used the worst case in all situations and the model still would not fail (just becomes unstable) so NIST decides Global Collapse ensued.
Who gives a Shiit what YOU call the NIST report?
You've YET to post ANYTHING which would make any impartial observer think your views on the NIST report mean diddly squat.
As to the issues you raised, I've already explained why that was a moot point.
You simply IGNORE the aircraft TRAJECTORY, which CLEARLY shows the aircraft MISSED the elevator motors and the two beam sections that NIST left out.
So you bring up something which is true but also moot.
But regardless, that quibble is with WTC 2.
There is NO SUCH ISSUE on WTC 1.
So, your argument FAILS anyway.
We already argued about your erroneous take on the cases NIST used in an earlier thread. You clearly LOST that argument, but feel free to repost them and let us review the spanking I gave you. (hard to believe you have forgotten).
As to your final point, nope again, they clearly show that the models were run until the tilt in upper part of the towers had reached the point that the collapse was inevitable.
Arthur
You've YET to post ANYTHING which would make any impartial observer think your views on the NIST report mean diddly squat.
As to the issues you raised, I've already explained why that was a moot point.
You simply IGNORE the aircraft TRAJECTORY, which CLEARLY shows the aircraft MISSED the elevator motors and the two beam sections that NIST left out.
So you bring up something which is true but also moot.
But regardless, that quibble is with WTC 2.
There is NO SUCH ISSUE on WTC 1.
So, your argument FAILS anyway.
We already argued about your erroneous take on the cases NIST used in an earlier thread. You clearly LOST that argument, but feel free to repost them and let us review the spanking I gave you. (hard to believe you have forgotten).
As to your final point, nope again, they clearly show that the models were run until the tilt in upper part of the towers had reached the point that the collapse was inevitable.
Arthur
QUOTE (NEU-FONZE+Feb 9 2007, 07:30 PM)
Reasonwhy:
You claim: "Nue fonze is not payed enough to support all the OCT BS, just the math and the Arabs did it."
Please show me where in my last 700-plus posts that I even mention "the Arabs", and could you please elaborate on what precisely I said "the Arabs" did.
INF
I apologize for claiming you blamed it on the Arabs.
You claim: "Nue fonze is not payed enough to support all the OCT BS, just the math and the Arabs did it."
Please show me where in my last 700-plus posts that I even mention "the Arabs", and could you please elaborate on what precisely I said "the Arabs" did.
INF
I apologize for claiming you blamed it on the Arabs.
But to be clear, it WAS Mohammed Atta and 18 of his buds who hijacked the planes and crashed them into the towers and the Pentagon on 9/11.
Arthur
Arthur
QUOTE (adoucette+Feb 9 2007, 11:27 PM)
Who gives a Shiit what YOU call the NIST report?
You're the JOKE.
Even if you don't know it.
Which is TYPICAL of the CT'ers that have come and gone over the last year and a half.
As to the issues you raised, I've already explained why that was a moot point.
You IGNORE the aircraft TRAJECTORY, which CLEARLY MISSED the elevator motors.
But regardless, that quibble is with WTC 2.
There is NO SUCH ISSUE on WTC 1.
So, your argument FAILS anyway.
We already argued about your erroneous take on the cases NIST used in an earlier thread. You clearly LOST that argument, but feel free to repost them and let us review the spanking I gave you. (hard to believe you have forgotten).
As to your final point, nope again, they clearly show that the models were run until the tilt in upper part of the towers had reached the point that the collapse was inevitable.
Arthur
Working late Arthurs?
Calling the NIST report a Joke really upsets you.
If you want I can show everyone all the misstatements you have made about the NIST report (you were claiming NIST modeled the partial beam floors at the end of the last thread).
It does not matter if the plane hits the beam directly. The beam would still stiffen the floors and transfer the force to the interior columns. Reinforcing the core area for the 12 motors would make a large difference. Just look at were the joints were stressed on the FEA model. It is not all in the planes path.
You're the JOKE.
Even if you don't know it.
Which is TYPICAL of the CT'ers that have come and gone over the last year and a half.
As to the issues you raised, I've already explained why that was a moot point.
You IGNORE the aircraft TRAJECTORY, which CLEARLY MISSED the elevator motors.
But regardless, that quibble is with WTC 2.
There is NO SUCH ISSUE on WTC 1.
So, your argument FAILS anyway.
We already argued about your erroneous take on the cases NIST used in an earlier thread. You clearly LOST that argument, but feel free to repost them and let us review the spanking I gave you. (hard to believe you have forgotten).
As to your final point, nope again, they clearly show that the models were run until the tilt in upper part of the towers had reached the point that the collapse was inevitable.
Arthur
Working late Arthurs?
Calling the NIST report a Joke really upsets you.
If you want I can show everyone all the misstatements you have made about the NIST report (you were claiming NIST modeled the partial beam floors at the end of the last thread).
It does not matter if the plane hits the beam directly. The beam would still stiffen the floors and transfer the force to the interior columns. Reinforcing the core area for the 12 motors would make a large difference. Just look at were the joints were stressed on the FEA model. It is not all in the planes path.
QUOTE (adoucette+Feb 9 2007, 11:31 PM)
But to be clear, it WAS Mohammed Atta and 18 of his buds who hijacked the planes and crashed them into the towers and the Pentagon on 9/11.
Arthur
To be clear nobody has been tried in the global government conspiracy after 5 years and they are not even pursuing the main suspect OBL.
Arthur
To be clear nobody has been tried in the global government conspiracy after 5 years and they are not even pursuing the main suspect OBL.
Regarding Hoffman,
6% of the mass above the collapse front being lost per impact is a large number. That's 0.06*15=0.9 story worth of mass per impact, nearly a story per impact.
If that much mass was shed for all 95 impacts in stage 1, then the total shed mass would be 0.9*95=85.5 stories. That would leave only 24.5 stories to fill the pit. There wouldn't be enough mass to fill the pit. Losing 3% the mass of the upper block each impact means 49 stories would be left. That's not enough to fill the pit either. That's assuming that mass would continue to be shed at the same rate even after the upper block was used up.
If 6% of the mass equivalent to the mass of the upper block was shed for all 110 impacts, then 99 stories would be shed.
There seems to be a discrepancy on the page about Hoffman's model on 911 research. The elapsed time for the front to reach the ground for 0.06 of the top block shed per story is listed as 16.59 s. The roof-to-ground time is stated as 18.34 s. That means there was a stage 2 collapse duration of 1.75 seconds.
Losing 0.9 of a story per impact above the front means that the upper 15 stories would be lost from the upper block in 15/0.9=17 impacts. There wouldn't be a stage 2 collapse because the upper block would be gone by the time the front reached the ground. The collapse duration would be 16.59 s at most. Even if half the shed mass was lost from the upper block and the other half from the front or lower block, the upper block would be gone in 34 impacts.
If the mass is being shed from only the front or lower block, then the upper block would still be there at the end of stage 1. But then mass wouldn't be shed from the upper block in that case. I'd have to look at Hoffman's model in more detail to see from where the mass is being shed exactly.
33% of a story mass lost per stage 1 impact is more reasonable. After 96 impacts, that would shed 32 stories and leave 78 stories to fill the pit. That would be a shedding ratio of 32/110=0.29 or 29%.
Considering the pit to top of the pile to be about 120 ft (9.6 stories) and assuming a compaction factor of 0.875, about 77 stories could fit in the pile. That would give a shedding ratio of about 33/110=0.30 or 30%. More accurate figures are needed for the pile height and compaction factor.
33% of a story mass is 0.33/15=0.022 or about 2% the mass of the upper block for WTC1.
The mass shedding model I wrote gives a stage 1 duration of 13.9 seconds for WTC1 with a tower mass of 330E6 kg, an E1 at story 96 of 0.5 GJ, an E1 that increases to 1.5 GJ at story 1, a constant story mass of 3E6 kg per story, and a shedding from the collapse front of 0.33 of a story mass per stage 1 impact.
6% of the mass above the collapse front being lost per impact is a large number. That's 0.06*15=0.9 story worth of mass per impact, nearly a story per impact.
If that much mass was shed for all 95 impacts in stage 1, then the total shed mass would be 0.9*95=85.5 stories. That would leave only 24.5 stories to fill the pit. There wouldn't be enough mass to fill the pit. Losing 3% the mass of the upper block each impact means 49 stories would be left. That's not enough to fill the pit either. That's assuming that mass would continue to be shed at the same rate even after the upper block was used up.
If 6% of the mass equivalent to the mass of the upper block was shed for all 110 impacts, then 99 stories would be shed.
There seems to be a discrepancy on the page about Hoffman's model on 911 research. The elapsed time for the front to reach the ground for 0.06 of the top block shed per story is listed as 16.59 s. The roof-to-ground time is stated as 18.34 s. That means there was a stage 2 collapse duration of 1.75 seconds.
Losing 0.9 of a story per impact above the front means that the upper 15 stories would be lost from the upper block in 15/0.9=17 impacts. There wouldn't be a stage 2 collapse because the upper block would be gone by the time the front reached the ground. The collapse duration would be 16.59 s at most. Even if half the shed mass was lost from the upper block and the other half from the front or lower block, the upper block would be gone in 34 impacts.
If the mass is being shed from only the front or lower block, then the upper block would still be there at the end of stage 1. But then mass wouldn't be shed from the upper block in that case. I'd have to look at Hoffman's model in more detail to see from where the mass is being shed exactly.
33% of a story mass lost per stage 1 impact is more reasonable. After 96 impacts, that would shed 32 stories and leave 78 stories to fill the pit. That would be a shedding ratio of 32/110=0.29 or 29%.
Considering the pit to top of the pile to be about 120 ft (9.6 stories) and assuming a compaction factor of 0.875, about 77 stories could fit in the pile. That would give a shedding ratio of about 33/110=0.30 or 30%. More accurate figures are needed for the pile height and compaction factor.
33% of a story mass is 0.33/15=0.022 or about 2% the mass of the upper block for WTC1.
The mass shedding model I wrote gives a stage 1 duration of 13.9 seconds for WTC1 with a tower mass of 330E6 kg, an E1 at story 96 of 0.5 GJ, an E1 that increases to 1.5 GJ at story 1, a constant story mass of 3E6 kg per story, and a shedding from the collapse front of 0.33 of a story mass per stage 1 impact.
QUOTE (reasonwhy+Feb 10 2007, 07:46 AM)
To be clear nobody has been tried in the global government conspiracy after 5 years and they are not even pursuing the main suspect OBL.
QUOTE (Capracus+Feb 10 2007, 02:52 AM)
From the FBI most wanted page.
And your point is?
Are you the best researcher the OCT can put forward?
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed.
Nobody will be indicted or tried in a regular court.
You might have military show trials with new rules (no proof required ).
And your point is?
QUOTE
USAMA BIN LADEN IS WANTED IN CONNECTION WITH THE AUGUST 7, 1998, BOMBINGS OF THE UNITED STATES EMBASSIES IN DAR ES SALAAM, TANZANIA, AND NAIROBI, KENYA. THESE ATTACKS KILLED OVER 200 PEOPLE IN ADDITION, BIN LADEN IS A SUSPECT IN OTHER TERRORIST ATTACKS THROUGHOUT THE WORLD.
Are you the best researcher the OCT can put forward?
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed.
Nobody will be indicted or tried in a regular court.
You might have military show trials with new rules (no proof required ).
QUOTE (lozenge124+Feb 9 2007, 05:34 PM)
Now, mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse) and you have an excellent qualitative case for why the observed time of collapse was impossible under gravity alone.
The columns in the upper stories were a small fraction of the story mass. Someone on this board named Blue added up all the cross-sectional areas of the core columns and came up with 3 m2 around the 83rd story. Assuming the perimeter columns were of comparable area, the total column area was 6 m2. For one story height of 3.78 m and steel density of 7850 kg/m3, the total column mass would be 1.78E5 kg per story.
DBB has provided the actual story mass of 1353 tons or 1.4E6 kg for the regular trussed upper stories.
ratio of column to story mass = 1.78E5 / 1.4 E6 = 0.127
The effective ratio at the 96th story is about half that when considering the extra mass in the two mechanical floors and hat truss at the top of the tower, which gives an average story mass of about 2.7E6 kg per story near the 96th story and above. The columns were also of thinner cross-section at the 96th level which would make the ratio even lower.
The columns accounted for only a small fraction of momentum transfer in the upper stories. Many columns didn't participate in column-to-column axial strikes, as the upper block was offset laterally and tilted. The videos of WTC1 show this effect. It took an offset of only 14 inches for the 209 foot wide upper block to disconnect all the perimeter columns from one another through the front.
By the time the front reached thicker columns in the lower half of the tower, the KE was so large that buckling of all the columns, even the thickest ones, wouldn't have been able to stop the front.
The columns in the upper stories were a small fraction of the story mass. Someone on this board named Blue added up all the cross-sectional areas of the core columns and came up with 3 m2 around the 83rd story. Assuming the perimeter columns were of comparable area, the total column area was 6 m2. For one story height of 3.78 m and steel density of 7850 kg/m3, the total column mass would be 1.78E5 kg per story.
DBB has provided the actual story mass of 1353 tons or 1.4E6 kg for the regular trussed upper stories.
ratio of column to story mass = 1.78E5 / 1.4 E6 = 0.127
The effective ratio at the 96th story is about half that when considering the extra mass in the two mechanical floors and hat truss at the top of the tower, which gives an average story mass of about 2.7E6 kg per story near the 96th story and above. The columns were also of thinner cross-section at the 96th level which would make the ratio even lower.
The columns accounted for only a small fraction of momentum transfer in the upper stories. Many columns didn't participate in column-to-column axial strikes, as the upper block was offset laterally and tilted. The videos of WTC1 show this effect. It took an offset of only 14 inches for the 209 foot wide upper block to disconnect all the perimeter columns from one another through the front.
By the time the front reached thicker columns in the lower half of the tower, the KE was so large that buckling of all the columns, even the thickest ones, wouldn't have been able to stop the front.
QUOTE (lozenge124+Feb 9 2007, 05:34 PM)
To illustrate: take a 2x4 steel bar say 3ft long, and place it vertically. Now take a sledgehammer and hit the top. The energy imparted by the hammer to the 2x4 is going to travel through the bar to the floor, will cause the bar to vibrate some, and will be dissipated in heat. You cannot get the energy to concentrate itself say 1 inch below the top of the bar.
True to some extent, but that ignores mechanisms such as buckling, tilting, wedging, off-axis strikes, breaking of floor connections, and splice failure. If all those mechanisms didn't exist, structural engineering would be easy and buildings would never fail.
True to some extent, but that ignores mechanisms such as buckling, tilting, wedging, off-axis strikes, breaking of floor connections, and splice failure. If all those mechanisms didn't exist, structural engineering would be easy and buildings would never fail.
QUOTE (NEU-FONZE+Feb 10 2007, 03:10 AM)
Lozenge 124:
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
The problem that caused the rapid collapse was oscillation, that caused the residual strain that is inherent in all welds to break, you can not have any weld without some residual strain. That racing ahead of the collapse front weakened the beams. Residual stain is caused by the very practice of welding when the heated metal contracts placing some strain energy on the joint.
If you calculate the tensile strength of the steel then subtract the residual strain of the welds you will find the answers your looking for.
Or at least that is where all the information I have found seems to point, although I could be wrong, that is the problem with the Scholars for truth they declare that something is impossible when in fact they can not prove it.
They declare they have all the answers! Honest researchers would definitely not do so!
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://www.appliedultrasonics.com/pdf/pdf1.pdf
http://www.scientific.net/0-87849-978-4/10/
Metals get their strength from their Crystalline structures, destroy the Crystalline structure and you destroy the strength of the metals. Heat and wave energy are know to have powerful effects on the breakup of such crystalline structures.
I have been looking for calculations on the residual strain values in the towers and I have not found any, Has anyone here ran across such information?
Well, I think DBB and Grumpy have pretty much said what I would have said about the energy absorbing capacity of the lower section of a tower.
The column splices were the weak link in the chain of steel supporting the Towers.
The large number of neatly cut column sections in the rubble pile confirms that the columns mostly failed at their splices - the welds for the core columns and the A325 bolts for the perimeter columns.
Impact damage was concentrated in the concrete and steel within a few floors of the collapse front. This means that the impact kinetic energy exceeded the elastic strain energy absorbing capacity of steel in the collapse front/zone by a factor of about 3. Thus, even in the worst case scenario of the WTC 1 collapse, there was sufficient impact energy to entirely destroy 3 floors-worth of column support.
And BTW, the upper block of 14 to 30 floors did not need to drop entirely in free fall through 3.7 meters. It could drop while being simply hinged at one corner or on one side, and the impact damage to the floor below would still be sufficient to initiate a progressive collapse that would bring down the entire structure...
NF
The problem that caused the rapid collapse was oscillation, that caused the residual strain that is inherent in all welds to break, you can not have any weld without some residual strain. That racing ahead of the collapse front weakened the beams. Residual stain is caused by the very practice of welding when the heated metal contracts placing some strain energy on the joint.
If you calculate the tensile strength of the steel then subtract the residual strain of the welds you will find the answers your looking for.
Or at least that is where all the information I have found seems to point, although I could be wrong, that is the problem with the Scholars for truth they declare that something is impossible when in fact they can not prove it.
They declare they have all the answers! Honest researchers would definitely not do so!
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://scitation.aip.org/getabs/servlet/Ge...=cvips&gifs=yes
http://www.appliedultrasonics.com/pdf/pdf1.pdf
http://www.scientific.net/0-87849-978-4/10/
Metals get their strength from their Crystalline structures, destroy the Crystalline structure and you destroy the strength of the metals. Heat and wave energy are know to have powerful effects on the breakup of such crystalline structures.
I have been looking for calculations on the residual strain values in the towers and I have not found any, Has anyone here ran across such information?
QUOTE (reasonwhy+Feb 10 2007, 12:21 PM)
And your point is?
Are you the best researcher the OCT can put forward?
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed.
Nobody will be indicted or tried in a regular court.
You might have military show trials with new rules (no proof required ).
Bin Laden was already tried and convicted for the embassy bombings, that is why they come first DA! PS. his trial was in a regular court as well as in the court of the country where the embassy bombings took place.
He is already a convicted murderer, and your defending him?
Are you the best researcher the OCT can put forward?
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed.
Nobody will be indicted or tried in a regular court.
You might have military show trials with new rules (no proof required ).
Bin Laden was already tried and convicted for the embassy bombings, that is why they come first DA! PS. his trial was in a regular court as well as in the court of the country where the embassy bombings took place.
He is already a convicted murderer, and your defending him?
@Grumpy
QUOTE
Actually, if you take off the top ten floors and then suspend a sandbag with ten times the weight of sand necessary to collapse one floor diaphram, one floor height above the first exposed floor(and core and frame). Release all the sand at one time.
The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
I agree.The frame will still be standing, as will the core, but all of the floors of the building will be in the basement.
QUOTE (->
| QUOTE |
| Actually, if you take off the top ten floors and then suspend a sandbag with ten times the weight of sand necessary to collapse one floor diaphram, one floor height above the first exposed floor(and core and frame). Release all the sand at one time. The frame will still be standing, as will the core, but all of the floors of the building will be in the basement. |
I agree.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
I think this is an excellent way to look at things, without the distraction of the floors. But how do you calculate 2/3G? The models like Greening or Bazant & Verdure that consider a story by story crush are of no use here because there are no more stories!
Basically, we are looking at a one impact event when the top block hits the entire core and perimeter. I would love to see a model for what happens next, with different tilts and drop heights (why the tilt, by the way? to match observations?).
To me, it does not seem very likely that the block would crush the core (pop the welds, shear off all the bolts?) and peel the perimeter away on all 4 sides. Especially at the collapse speed seen. But if there is a model or analysis of this scenario would be interested to see it.
Now drop the ten stories, tilted, so it will wedge into the bottom sections. The outer frame will peel away and the top block will accelerate into the ground at roughly 2/3G.
I think this is an excellent way to look at things, without the distraction of the floors. But how do you calculate 2/3G? The models like Greening or Bazant & Verdure that consider a story by story crush are of no use here because there are no more stories!
Basically, we are looking at a one impact event when the top block hits the entire core and perimeter. I would love to see a model for what happens next, with different tilts and drop heights (why the tilt, by the way? to match observations?).
To me, it does not seem very likely that the block would crush the core (pop the welds, shear off all the bolts?) and peel the perimeter away on all 4 sides. Especially at the collapse speed seen. But if there is a model or analysis of this scenario would be interested to see it.
reasonless
Actually the NIST report has been out there for some time now, though you and your fellow loons have tried desperately no one has yet made a dent or scratch in their findings.
Is that the best you "troothseekers" can do??? Pathetic!!!
Actually the NIST report has been out there for some time now, though you and your fellow loons have tried desperately no one has yet made a dent or scratch in their findings.
Is that the best you "troothseekers" can do??? Pathetic!!!
To be clear nobody has been tried in the global government conspiracy after 5 years and they are not even pursuing the main suspect OBL. biggrin.gif
This is a complete fabrcation and distortion of the truth...
"USAMA BIN LADEN IS WANTED IN CONNECTION WITH THE AUGUST 7, 1998, BOMBINGS OF THE UNITED STATES EMBASSIES IN DAR ES SALAAM, TANZANIA, AND NAIROBI, KENYA. THESE ATTACKS KILLED OVER 200 PEOPLE IN ADDITION, BIN LADEN IS A SUSPECT IN OTHER TERRORIST ATTACKS THROUGHOUT THE WORLD."
He is still being pursued for other bombings and attacks(despite your lies), and when he is in custody will be the time to charge him with 9/11. If the Marines leave enough of him in one piece, that is.
Grumpy
QUOTE
Are you the best researcher the OCT can put forward? biggrin.gif
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed. biggrin.gif
To indict OBL would take a Grand Jury and the OCT fairytale would be exposed. biggrin.gif
Actually the NIST report has been out there for some time now, though you and your fellow loons have tried desperately no one has yet made a dent or scratch in their findings.
Is that the best you "troothseekers" can do??? Pathetic!!!
QUOTE (->
| QUOTE |
| Are you the best researcher the OCT can put forward? biggrin.gif To indict OBL would take a Grand Jury and the OCT fairytale would be exposed. biggrin.gif |
Actually the NIST report has been out there for some time now, though you and your fellow loons have tried desperately no one has yet made a dent or scratch in their findings.
Is that the best you "troothseekers" can do??? Pathetic!!!
To be clear nobody has been tried in the global government conspiracy after 5 years and they are not even pursuing the main suspect OBL. biggrin.gif
This is a complete fabrcation and distortion of the truth...
"USAMA BIN LADEN IS WANTED IN CONNECTION WITH THE AUGUST 7, 1998, BOMBINGS OF THE UNITED STATES EMBASSIES IN DAR ES SALAAM, TANZANIA, AND NAIROBI, KENYA. THESE ATTACKS KILLED OVER 200 PEOPLE IN ADDITION, BIN LADEN IS A SUSPECT IN OTHER TERRORIST ATTACKS THROUGHOUT THE WORLD."
He is still being pursued for other bombings and attacks(despite your lies), and when he is in custody will be the time to charge him with 9/11. If the Marines leave enough of him in one piece, that is.
Grumpy
QUOTE (reasonwhy+Feb 10 2007, 03:42 AM)
If you want I can show everyone all the misstatements you have made about the NIST report (you were claiming NIST modeled the partial beam floors at the end of the last thread).
It does not matter if the plane hits the beam directly. The beam would still stiffen the floors and transfer the force to the interior columns. Reinforcing the core area for the 12 motors would make a large difference. Just look at were the joints were stressed on the FEA model. It is not all in the planes path.
Feel free to show the miss-statements I've made about the report. I didn't write the report and so the fact that I've been wrong on a few MINOR points on occasion is NOT the same as you proving that the NIST model was flawed.
Which is the point.
You have not shown that the NIST report is a "fairytale".
Far from it.
Like in this issue:
The purpose of the high resolution impact model was to determine the extent of core column and floor damage, distribution of debris and fuel.
The NIST model shows NO DAMAGE to the reinforced area you are referring to, so your argument falls apart since NIST didn't project ANY DAMAGE at all to that area.
You also ignore the fact that compared to all other models of the impact the damage shown by the NIST impact model is THE MOST CONSERVATIVE.
You also conveniently ignore the fact that there were TWO towers and your complaint about the modeling of the beam framed floor do not apply to the model of the other tower.
You CAN'T argue that demolition was needed for ONE tower and not the other, that's just silly, so while you harp on this little issue of the IMPACT model as if its a big deal, you totally miss the key points that NIST didn't project damage in the area in question and the issue ONLY applies to one model of one tower.
Arthur
It does not matter if the plane hits the beam directly. The beam would still stiffen the floors and transfer the force to the interior columns. Reinforcing the core area for the 12 motors would make a large difference. Just look at were the joints were stressed on the FEA model. It is not all in the planes path.
Feel free to show the miss-statements I've made about the report. I didn't write the report and so the fact that I've been wrong on a few MINOR points on occasion is NOT the same as you proving that the NIST model was flawed.
Which is the point.
You have not shown that the NIST report is a "fairytale".
Far from it.
Like in this issue:
The purpose of the high resolution impact model was to determine the extent of core column and floor damage, distribution of debris and fuel.
The NIST model shows NO DAMAGE to the reinforced area you are referring to, so your argument falls apart since NIST didn't project ANY DAMAGE at all to that area.
You also ignore the fact that compared to all other models of the impact the damage shown by the NIST impact model is THE MOST CONSERVATIVE.
You also conveniently ignore the fact that there were TWO towers and your complaint about the modeling of the beam framed floor do not apply to the model of the other tower.
You CAN'T argue that demolition was needed for ONE tower and not the other, that's just silly, so while you harp on this little issue of the IMPACT model as if its a big deal, you totally miss the key points that NIST didn't project damage in the area in question and the issue ONLY applies to one model of one tower.
Arthur
QUOTE (reasonwhy+Feb 10 2007, 03:46 AM)
To be clear nobody has been tried in the global government conspiracy after 5 years and they are not even pursuing the main suspect OBL.
False on both counts.
Arthur
False on both counts.
Arthur
@shagster:
thanks for taking a look at Hoffman's model.
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
The columns in the upper stories were a small fraction of the story mass. Someone on this board named Blue added up all the cross-sectional areas of the core columns and came up with 3 m2 around the 83rd story. Assuming the perimeter columns were of comparable area, the total column area was 6 m2. For one story height of 3.78 m and steel density of 7850 kg/m3, the total column mass would be 1.78E5 kg per story.
DBB has provided the actual story mass of 1353 tons or 1.4E6 kg for the regular trussed upper stories.
ratio of column to story mass = 1.78E5 / 1.4 E6 = 0.127
When I said "mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse)". I mean just that, the supporting strength, not the mass.
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
By the time the front reached thicker columns in the lower half of the tower, the KE was so large that buckling of all the columns, even the thickest ones, wouldn't have been able to stop the front.
Again, I think you are comparing upper block kinetic energy with E1 do determine this. (correct me if I'm wrong). The core is a single large structure. I like the model Grumpy proposed where all the floors are removed, and you drop a block onto the remaining steel core and perimeter. I would like to know what you think happens next.
Agreed, and that's why we need a model/analysis of these things after collapse initiation. To me it is not at all self-evident that the collapse would proceed all the way down, let alone at the speed witnessed.
thanks for taking a look at Hoffman's model.
QUOTE
The mass shedding model I wrote gives a stage 1 duration of 13.9 seconds for WTC1 with a tower mass of 330E6 kg, an E1 at story 96 of 0.5 GJ, an E1 that increases to 1.5 GJ at story 1, a constant story mass of 3E6 kg per story, and a shedding from the collapse front of 0.33 of a story mass per stage 1 impact.
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
QUOTE (->
| QUOTE |
| The mass shedding model I wrote gives a stage 1 duration of 13.9 seconds for WTC1 with a tower mass of 330E6 kg, an E1 at story 96 of 0.5 GJ, an E1 that increases to 1.5 GJ at story 1, a constant story mass of 3E6 kg per story, and a shedding from the collapse front of 0.33 of a story mass per stage 1 impact. |
Like I have mentioned in my post about Greening's paper I do not think E1 considerations are valid. The core and perimeters are interconnected you can not look at them on a floor by floor basis. You have to consider them as a whole.
The columns in the upper stories were a small fraction of the story mass. Someone on this board named Blue added up all the cross-sectional areas of the core columns and came up with 3 m2 around the 83rd story. Assuming the perimeter columns were of comparable area, the total column area was 6 m2. For one story height of 3.78 m and steel density of 7850 kg/m3, the total column mass would be 1.78E5 kg per story.
DBB has provided the actual story mass of 1353 tons or 1.4E6 kg for the regular trussed upper stories.
ratio of column to story mass = 1.78E5 / 1.4 E6 = 0.127
When I said "mentally add into the model the supporting strength of 47 core columns and the perimeter walls (again, because up to now we have just considered the inertia of the floor mass in slowing down the collapse)". I mean just that, the supporting strength, not the mass.
QUOTE
Many columns didn't participate in column-to-column axial strikes, as the upper block was offset laterally and tilted. The videos of WTC1 show this effect. It took an offset of only 14 inches for the 209 foot wide upper block to disconnect all the perimeter columns from one another through the front.
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
QUOTE (->
| QUOTE |
| Many columns didn't participate in column-to-column axial strikes, as the upper block was offset laterally and tilted. The videos of WTC1 show this effect. It took an offset of only 14 inches for the 209 foot wide upper block to disconnect all the perimeter columns from one another through the front. |
So what happens to the columns in the lower portion that aren't subject to axial strikes? I don't see how this is favorable to your model.
By the time the front reached thicker columns in the lower half of the tower, the KE was so large that buckling of all the columns, even the thickest ones, wouldn't have been able to stop the front.
Again, I think you are comparing upper block kinetic energy with E1 do determine this. (correct me if I'm wrong). The core is a single large structure. I like the model Grumpy proposed where all the floors are removed, and you drop a block onto the remaining steel core and perimeter. I would like to know what you think happens next.
QUOTE
True to some extent, but that ignores mechanisms such as buckling, tilting, wedging, off-axis strikes, breaking of floor connections, and splice failure. If all those mechanisms didn't exist, structural engineering would be easy and buildings would never fail.
Agreed, and that's why we need a model/analysis of these things after collapse initiation. To me it is not at all self-evident that the collapse would proceed all the way down, let alone at the speed witnessed.
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