From Kennedy to Roswell to the Illuminati,

Yes, it's all clear now, 9/11 was merely a vehicle to get us in the Middle East ...   

Now if someone can come up with a conspiracy to get us out, 

Shhhhhhhhhhhhh!

you never heard of AQ before 1993

<{POST_SNAPBACK}>

Is there no end to your constant nonsensical mutterings???!!!

Al Quaida is just the latest iteration of arab-wacko and islamo-facist nuttery dating back more than 30 years:

1970 - Munich Airport hostages taken and MURDERED

1972 - Munich Olympics hostages taken and MURDERED

1973 - US Amdassador to Sudan MURDERED

1973 - Rome Airport hostage taking and MURDERS

1974 - US Ambassador to Cyprus MURDERED

1976 - Entebbe aircraft hijacking

1979 - US Ambassador to Afghanistan MURDERED

1979 - US Embassy in Iran invaded and hostages taken

1979 - Grand Mosque in Mecca invaded and hostages taken

1981 - Egyptian President Sadat MURDERED

1983 - US Embassy in Beruit bombed, 63 MURDERED

1983 - US/French barracks in Beruit bombed, 300 MURDERED

1984 - US Embassy diplomat in Beruit MURDERED

1985 - TWA airliner hijacked in Rome, hostages take, US sailor MURDERED

1985 - Beruit, Soviet diplomats kidnapped, one MURDERED

1985 - Achille Lauro ocean liner hijacked, US citizen MURDERED

1985 - Rome/Vienna airports attacked, 13 MURDERED

1986 - Aircraft bombed, Greece, 3 MURDERED

1988 - Lebanon, UN military officer kidnapped and MURDERED

1988 - Naples USO bombed, 1 MUREDERED

1988 - Pan Am 103 bombed, 259 MURDERED

1989 - UTA 102 bombed, 170 MURDERED

It was only at this point, after almost 20 years of attacks and 1000-something murders that Bin Laden and Al Quaida appeared on the screen, and were given an 8-year free pass by the Clinton administration.

How much is enough???

Thank you to Bush for taking the fight to these nutcases, after 8 years of Clintonian namby-pamby pampering and tolerance of these cold blooded killers hiding under the guise of religious fundamentalism.

Libya is a perfect case in point. Reagan held Quadaffi personally responsible for all the terrorist attacks attributed to Libya. He also proactively went in and bombed the living sh*t out of them as an example of what would happen if he didn't get his house in order.

And what to we have 20 years later?? A substantially toned down formerly out of control wacko state, whose leader has smartened up and decided to bring his country into the modern world. He and his people are better off for those decisions.

Iraq will be the same way 10 or 20 years from now, back to it's pre-Saddam state with a solid educational system and prospering non-oil economy.

Iran and Syria are next if they don't shape up and stop exporting terror .... and deservedly so.

There are rules in the modern world. Countries have to play by them or accept the consequences of being outcasts.

Thank you Spee for proving my point exactly !!! your ignorance of AQ that is

Oh yeah, I forgot it's all Clinton fault

you are the living proof that conspiracy nuts are not alone in their "desillusion"

Thank you Spee for proving my point exactly !!! your ignorance of AQ that is 

Oh yeah, I forgot it's all Clinton fault 

you are the living proof that conspiracy nuts are not alone in their "desillusion" 

And you are the laughing stock of this forum, Butterfly.

Major case of Political Relevancy Deprivation Syndrome...

Thank you Spee for proving my point exactly !!! your ignorance of AQ that is 

Oh yeah, I forgot it's all Clinton fault 

you are the living proof that conspiracy nuts are not alone in their "desillusion" 

<{POST_SNAPBACK}>

And you are the laughing stock of this forum, Butterfly.

Major case of Political Relevancy Deprivation Syndrome...

<{POST_SNAPBACK}>

Look who is talking

Liberal Gymnastics

Where Liberals explain why they said what they said isn't really what they said because they were lied to and the dog ate their homework that's why…

you never heard of AQ before 1993

<{POST_SNAPBACK}>

Is there no end to your constant nonsensical mutterings???!!!

Al Quaida is just the latest iteration of arab-wacko and islamo-facist nuttery dating back more than 30 years:

1970 - Munich Airport hostages taken and MURDERED

1972 - Munich Olympics hostages taken and MURDERED

1973 - US Amdassador to Sudan MURDERED

1973 - Rome Airport hostage taking and MURDERS

1974 - US Ambassador to Cyprus MURDERED

1976 - Entebbe aircraft hijacking

1979 - US Ambassador to Afghanistan MURDERED

1979 - US Embassy in Iran invaded and hostages taken

1979 - Grand Mosque in Mecca invaded and hostages taken

1981 - Egyptian President Sadat MURDERED

1983 - US Embassy in Beruit bombed, 63 MURDERED

1983 - US/French barracks in Beruit bombed, 300 MURDERED

1984 - US Embassy diplomat in Beruit MURDERED

1985 - TWA airliner hijacked in Rome, hostages take, US sailor MURDERED

1985 - Beruit, Soviet diplomats kidnapped, one MURDERED

1985 - Achille Lauro ocean liner hijacked, US citizen MURDERED

1985 - Rome/Vienna airports attacked, 13 MURDERED

1986 - Aircraft bombed, Greece, 3 MURDERED

1988 - Lebanon, UN military officer kidnapped and MURDERED

1988 - Naples USO bombed, 1 MUREDERED

1988 - Pan Am 103 bombed, 259 MURDERED

1989 - UTA 102 bombed, 170 MURDERED

It was only at this point, after almost 20 years of attacks and 1000-something murders that Bin Laden and Al Quaida appeared on the screen, and were given an 8-year free pass by the Clinton administration.

How much is enough???

Thank you to Bush for taking the fight to these nutcases, after 8 years of Clintonian namby-pamby pampering and tolerance of these cold blooded killers hiding under the guise of religious fundamentalism.

Libya is a perfect case in point. Reagan held Quadaffi personally responsible for all the terrorist attacks attributed to Libya. He also proactively went in and bombed the living sh*t out of them as an example of what would happen if he didn't get his house in order.

And what to we have 20 years later?? A substantially toned down formerly out of control wacko state, whose leader has smartened up and decided to bring his country into the modern world. He and his people are better off for those decisions.

Iraq will be the same way 10 or 20 years from now, back to it's pre-Saddam state with a solid educational system and prospering non-oil economy.

Iran and Syria are next if they don't shape up and stop exporting terror .... and deservedly so.

There are rules in the modern world. Countries have to play by them or accept the consequences of being outcasts.

<{POST_SNAPBACK}>

Good Post Spee and definatley food for thought

ok - look: I attended lectures at MIT about the structural collapse of the towers. These lectures were given by some of the top engineers, architects, and design professionals in academics and business.

In a nutshell: the heat from the planes melted the *"structural pins" at the point of contact. These "pins" were reinforcements on each floor. As the first "pins" melted, the floor collapsed onto each lower floor, until the excess weight created the unbearable load and momentum to bring each one down in succession, thus, the perfect vertical collapse.

*I say "structural pins because I forgot the technical word; I think they were similar to girders, but were extra reinforcements in the corners of each floor.

** and yes, I have to agree that my questions about the Pentagon are not satisfied by anything I've heard in the media, or by official explanations so far. There are a lot of questions regarding this: timing, political, and crucial evidence at the crash site.

Were the 2 towers destroyed under a controlled demolition ? difficult to say. Maybe a few bombs were set to help the destruction. Who put those bombs ? impossible to say. Were the government involved ? who knows. Maybe the Pentagon is making the shots here, not the Bush administration (who is clueless on about everything anyhow). Bush probably didn't read his Pentagon memo before the attack

Still, your explanation, Kat, doesn't mean shit. Experts can be wrong on about anything. It doesn't mean what they are saying is false, but it's impossible to say in full confidence "this is what happened" because there are thousand possible explanation and what you heard is only one of them. The only thing we can be sure of is "we don't really know"

Now the Pentagon destruction, that's a tougher beast to lie about. The "evidence" are there and it doesn't add up. If they lied about the Pentagon, what else did they lie about ? we know that AQ was invented by the FBI to prosecute Bin Laden. The organization name doesn't exist, that doesn't mean some organization around Bin Laden doesn't exist, but it's not the organization that the US government is painting.

Despite all the surveillance on Iraq, this administration got it wrong with their intelligence. What make you think they could get it right on an organization as obscure and secretive as AQ ?

ok, so what you are saying Butterfly, is that a group of international experts with the blueprints of the Towers in hand, computer simulations, and the expertise to analyze all factors in harmony, doesn't mean shit compared to a conspiracy theory that has no factual basis at all except - "theories".

Add to this the fact that we have videotape of the original hijackers boarding the plane, residents of New York that saw one of the jets flying through the City at very, very low altitude on its way to the Tower, and people at and around the site that heard a huge roaring sound growing progressively louder on approach, which is definitely not the sound of a bomb. Top this off with the fact that once a jet filled with fuel collides into the tower, it is effectively a bomb capable of propelling fuel and flames through the air shafts of elevators ....... and you are saying none of this means shit

YOU are the one who is dogmatically clinging to a theory that can be refuted on the simplest of terms.

I am a licensed engineer and so I must tell you now that what I am about to say I am saying outside of the realm of engineering since I am not technically knowledgeable enough to give engineering advise on structural collapse methods. Having said that, everything I have read about building's collapsing and about what the fireball created inside the twin towers is likely to have done....all of this has led me to believe that the fireball after the impact is all that is necessary to cause the method of collapse as seen on countless videos.

Also, to get a building as tall as either of the twin towers to fall down sideways like a tree is virtually impossible....once the first few floors 'break' all the weight of the building pulls it straight down crushing the floors sequentially as the building moves down....these buildings are really really heavy and the force of gravity is pulling all this weight straight down....and NOT sideways even a little bit!!

ok - look:  I attended lectures at MIT about the structural collapse of the towers.  These lectures were given by some of the top engineers, architects, and design professionals in academics and business.

In a nutshell:  the heat from the planes melted the *"structural pins" at the point of contact.  These "pins" were reinforcements on each floor.  As the first "pins" melted, the floor collapsed onto each lower floor, until the excess weight created the unbearable load and momentum to bring each one down in succession, thus, the perfect vertical collapse.

*I say "structural pins because I forgot the technical word;  I think they were similar to girders, but were extra reinforcements in the corners of each floor.

** and yes, I have to agree that my questions about the Pentagon are not satisfied by anything I've heard in the media, or by official explanations so far.  There are a lot of questions regarding this:  timing, political, and crucial evidence at the crash site.

hi'

I guess that you believed this sh1t ....

an entire tower of this kind if set for a proper demolition would take longer to fall!

technical fact!

the tower began to collapse far fater the hit, there is something not "normal" for such bombed tower, any explosive techy will tell you that it' almost impossible for the tower to fall staight down in one shot without a little help ... not only a plane crash that alone would destroy the top of the hit, but surely not a few hundreds feet of underbuilding that melt too!

no, search for evidences, it was the plane crash/ stop! enough for you poor people!

very fast cleaning of the place, not even an enquiery

and why? ... shortcut to the "terror" threat and some new laws to restrain people!

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

francois

Francois:

Not only "American citizens", but international experts that know what the &lt;deleted&gt; they're talking about. Why is it that sloganeering people like yourself ignore factual and technical information, only to chant your favorite refrain - 'Americans are so stupid'. Without any substantiated information other than second and third hand conspiracy theories to backup your claims, does it ever occur to you, that you may be the stupid one? ......Of course not because you can easily reach for your tired, worn out chants that don't require you to think.

Most structural experts worth their expertise, would gladly tell you that the old explanations about collapsing buildings don't apply, because a "demolition" of this nature - a jet filled with fuel crashing into an enormous tower - is totally unprecedented.

I do not support Bush in the least, and this is so deep I still wouldn't even if I was delerious and insane, but I never sacrafice common sense for political dogma, even if it was extremely convienent for my political beliefs. However, it is apparent that many Bush-haters have about the same quantity of common sense as the Bush-lovers.

I also like your hypocrisy by focusing on Americans although there are many people who have said the same as me who are not American. This simply supports my point.

Francois:

Not only "American citizens", but international experts that know what the &lt;deleted&gt; they're talking about.  Why is it that sloganeering people like yourself ignore factual and technical information, only to chant your favorite refrain - 'Americans are so stupid'.  Without any substantiated information other than second and third hand conspiracy theories to backup your claims, does it ever occur to you, that you may be the stupid one?    ......Of course not because you can easily reach for your tired, worn out chants that don't require you to think. 

Most structural experts worth their expertise, would gladly tell you that the old explanations about collapsing buildings don't apply, because a "demolition" of this nature - a jet filled with fuel crashing into an enormous tower - is totally unprecedented.

I do not support Bush in the least, and this is so deep I still wouldn't even if I was delerious and insane, but I never sacrafice common sense for political dogma, even if it was extremely convienent for my political beliefs.  However, it is apparent that many Bush-haters have about the same quantity of common sense as the Bush-lovers.

I also like your hypocrisy by focusing on Americans although there are many people who have said the same as me who are not American.  This simply supports my point.

<{POST_SNAPBACK}>

This is what Francois said...

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

You deserve to be "American bashed" if you think he is singling your lot out.Some of you yanks should harden up.If I am not mistaken he doubted the honesty of your governing mob as well as his.I would also say the same about the USA and my own government, but I might be labled a yank basher.Christ!

Francois:

Not only "American citizens", but international experts that know what the &lt;deleted&gt; they're talking about.  Why is it that sloganeering people like yourself ignore factual and technical information, only to chant your favorite refrain - 'Americans are so stupid'.  Without any substantiated information other than second and third hand conspiracy theories to backup your claims, does it ever occur to you, that you may be the stupid one?    ......Of course not because you can easily reach for your tired, worn out chants that don't require you to think.  

Most structural experts worth their expertise, would gladly tell you that the old explanations about collapsing buildings don't apply, because a "demolition" of this nature - a jet filled with fuel crashing into an enormous tower - is totally unprecedented.

I do not support Bush in the least, and this is so deep I still wouldn't even if I was delerious and insane, but I never sacrafice common sense for political dogma, even if it was extremely convienent for my political beliefs.  However, it is apparent that many Bush-haters have about the same quantity of common sense as the Bush-lovers.

I also like your hypocrisy by focusing on Americans although there are many people who have said the same as me who are not American.  This simply supports my point.

<{POST_SNAPBACK}>

This is what Francois said...

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

You deserve to be "American bashed" if you think he is singling your lot out.Some of you yanks should harden up.If I am not mistaken he doubted the honesty of your governing mob as well as his.I would also say the same about the USA and my own government, but I might be labled a yank basher.Christ!

<{POST_SNAPBACK}>

And you deserve to be called a hypocrite, if you cannot see how people almost always focus on the American even if the same opinion has been stated by other non-Americans. That was my point - did you miss it

I also expressed my anomosity about Bush in the same manner he expressed about the French Government, but I don't start going on about the poor, disillusioned French people; this is condescending.

You say that some of "my lot" should harden up, but you don't nearly take the same relentless pounding that is meted out to Americans, mostly by people who don't even realize their own hypocrisy. I don't care about criticism or critiques about facts or events, but most of of these types turn this into a rant or a slogan on a regular basis but can't seem to stand it when it is countered with fact.

In fact, many of "your lot" like nothing more than to make all kinds of statements and insults about Americans that you never question, but suddenly say Americans are arrogant or "should be bashed" if we can refute it.

*edit: and this is something else Francois said, but you must of "missed this, too :

" no, search for evidences, it was the plane crash/ stop! enough for you poor people!

very fast cleaning of the place, not even an enquiery"

Francois:

Not only "American citizens", but international experts that know what the &lt;deleted&gt; they're talking about.  Why is it that sloganeering people like yourself ignore factual and technical information, only to chant your favorite refrain - 'Americans are so stupid'.  Without any substantiated information other than second and third hand conspiracy theories to backup your claims, does it ever occur to you, that you may be the stupid one?    ......Of course not because you can easily reach for your tired, worn out chants that don't require you to think.  

Most structural experts worth their expertise, would gladly tell you that the old explanations about collapsing buildings don't apply, because a "demolition" of this nature - a jet filled with fuel crashing into an enormous tower - is totally unprecedented.

I do not support Bush in the least, and this is so deep I still wouldn't even if I was delerious and insane, but I never sacrafice common sense for political dogma, even if it was extremely convienent for my political beliefs.  However, it is apparent that many Bush-haters have about the same quantity of common sense as the Bush-lovers.

I also like your hypocrisy by focusing on Americans although there are many people who have said the same as me who are not American.  This simply supports my point.

<{POST_SNAPBACK}>

This is what Francois said...

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

You deserve to be "American bashed" if you think he is singling your lot out.Some of you yanks should harden up.If I am not mistaken he doubted the honesty of your governing mob as well as his.I would also say the same about the USA and my own government, but I might be labled a yank basher.Christ!

<{POST_SNAPBACK}>

And you deserve to be called a hypocrite, if you cannot see how people almost always focus on the American even if the same opinion has been stated by other non-Americans. That was my point - did you miss it

I also expressed my anomosity about Bush in the same manner he expressed about the French Government, but I don't start going on about the poor, disillusioned French people; this is condescending.

You say that some of "my lot" should harden up, but you don't nearly take the same relentless pounding that is meted out to Americans, mostly by people who don't even realize their own hypocrisy. I don't care about criticism or critiques about facts or events, but most of of these types turn this into a rant or a slogan on a regular basis but can't seem to stand it when it is countered with fact.

In fact, many of "your lot" like nothing more than to make all kinds of statements and insults about Americans that you never question, but suddenly say Americans are arrogant or "should be bashed" if we can refute it.

*edit: and this is something else Francois said, but you must of "missed this, too :

" no, search for evidences, it was the plane crash/ stop! enough for you poor people!

very fast cleaning of the place, not even an enquiery"

<{POST_SNAPBACK}>

Yep, I probably did miss a bit, but also knowing francois previous post etc..he is not a basher.

I don't normally refer to "your lot" in a negative way...now i'd like to chage that...your all a bunch of wallys.

Francois:

Not only "American citizens", but international experts that know what the &lt;deleted&gt; they're talking about.  Why is it that sloganeering people like yourself ignore factual and technical information, only to chant your favorite refrain - 'Americans are so stupid'.  Without any substantiated information other than second and third hand conspiracy theories to backup your claims, does it ever occur to you, that you may be the stupid one?    ......Of course not because you can easily reach for your tired, worn out chants that don't require you to think.  

Most structural experts worth their expertise, would gladly tell you that the old explanations about collapsing buildings don't apply, because a "demolition" of this nature - a jet filled with fuel crashing into an enormous tower - is totally unprecedented.

I do not support Bush in the least, and this is so deep I still wouldn't even if I was delerious and insane, but I never sacrafice common sense for political dogma, even if it was extremely convienent for my political beliefs.  However, it is apparent that many Bush-haters have about the same quantity of common sense as the Bush-lovers.

I also like your hypocrisy by focusing on Americans although there are many people who have said the same as me who are not American.  This simply supports my point.

<{POST_SNAPBACK}>

This is what Francois said...

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

You deserve to be "American bashed" if you think he is singling your lot out.Some of you yanks should harden up.If I am not mistaken he doubted the honesty of your governing mob as well as his.I would also say the same about the USA and my own government, but I might be labled a yank basher.Christ!

<{POST_SNAPBACK}>

And you deserve to be called a hypocrite, if you cannot see how people almost always focus on the American even if the same opinion has been stated by other non-Americans. That was my point - did you miss it

I also expressed my anomosity about Bush in the same manner he expressed about the French Government, but I don't start going on about the poor, disillusioned French people; this is condescending.

You say that some of "my lot" should harden up, but you don't nearly take the same relentless pounding that is meted out to Americans, mostly by people who don't even realize their own hypocrisy. I don't care about criticism or critiques about facts or events, but most of of these types turn this into a rant or a slogan on a regular basis but can't seem to stand it when it is countered with fact.

In fact, many of "your lot" like nothing more than to make all kinds of statements and insults about Americans that you never question, but suddenly say Americans are arrogant or "should be bashed" if we can refute it.

*edit: and this is something else Francois said, but you must of "missed this, too :

" no, search for evidences, it was the plane crash/ stop! enough for you poor people!

very fast cleaning of the place, not even an enquiery"

<{POST_SNAPBACK}>

Yep, I probably did miss a bit, but also knowing francois previous post etc..he is not a basher.

I don't normally refer to "your lot" in a negative way...now i'd like to chage that...your all a bunch of wallys.

<{POST_SNAPBACK}>

I too, don't think of Francois as a basher, but his comment was one-sided, and unfortuantely, focused only on Americans to make the gist of his comment more legitimate, although completely biased.

And I'm sure you've never referred to Americans in a negative way

But, I know defeat must of been hard for the Red Coats, given we were your subjects and infinitely more inferior and all

edit: and Francois - yes, I know the French had a lot to do with that defeat. I drink lots of French wine and am learing French as part of the American Resistance to Fox News

Francois:

Not only "American citizens", but international experts that know what the &lt;deleted&gt; they're talking about.  Why is it that sloganeering people like yourself ignore factual and technical information, only to chant your favorite refrain - 'Americans are so stupid'.  Without any substantiated information other than second and third hand conspiracy theories to backup your claims, does it ever occur to you, that you may be the stupid one?    ......Of course not because you can easily reach for your tired, worn out chants that don't require you to think. 

Most structural experts worth their expertise, would gladly tell you that the old explanations about collapsing buildings don't apply, because a "demolition" of this nature - a jet filled with fuel crashing into an enormous tower - is totally unprecedented.

I do not support Bush in the least, and this is so deep I still wouldn't even if I was delerious and insane, but I never sacrafice common sense for political dogma, even if it was extremely convienent for my political beliefs.  However, it is apparent that many Bush-haters have about the same quantity of common sense as the Bush-lovers.

I also like your hypocrisy by focusing on Americans although there are many people who have said the same as me who are not American.  This simply supports my point.

<{POST_SNAPBACK}>

This is what Francois said...

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

You deserve to be "American bashed" if you think he is singling your lot out.Some of you yanks should harden up.If I am not mistaken he doubted the honesty of your governing mob as well as his.I would also say the same about the USA and my own government, but I might be labled a yank basher.Christ!

<{POST_SNAPBACK}>

And you deserve to be called a hypocrite, if you cannot see how people almost always focus on the American even if the same opinion has been stated by other non-Americans. That was my point - did you miss it

I also expressed my anomosity about Bush in the same manner he expressed about the French Government, but I don't start going on about the poor, disillusioned French people; this is condescending.

You say that some of "my lot" should harden up, but you don't nearly take the same relentless pounding that is meted out to Americans, mostly by people who don't even realize their own hypocrisy. I don't care about criticism or critiques about facts or events, but most of of these types turn this into a rant or a slogan on a regular basis but can't seem to stand it when it is countered with fact.

In fact, many of "your lot" like nothing more than to make all kinds of statements and insults about Americans that you never question, but suddenly say Americans are arrogant or "should be bashed" if we can refute it.

*edit: and this is something else Francois said, but you must of "missed this, too :

" no, search for evidences, it was the plane crash/ stop! enough for you poor people!

very fast cleaning of the place, not even an enquiery"

<{POST_SNAPBACK}>

Yep, I probably did miss a bit, but also knowing francois previous post etc..he is not a basher.

I don't normally refer to "your lot" in a negative way...now i'd like to chage that...your all a bunch of wallys.

<{POST_SNAPBACK}>

I too, don't think of Francois as a basher, but his comment was one-sided, and unfortuantely, focused only on Americans to make the gist of his comment more legitimate, although completely biased.

And I'm sure you've never referred to Americans in a negative way

But, I know defeat must of been hard for the Red Coats, given we were your subjects and infinitely more inferior and all

edit: and Francois - yes, I know the French had a lot to do with that defeat. I drink lots of French wine and am learing French as part of the American Resistance to Fox News

<{POST_SNAPBACK}>

Wrong country for chuchok - Mind you we did send our convicts to Oz.

ok - look:  I attended lectures at MIT about the structural collapse of the towers.  These lectures were given by some of the top engineers, architects, and design professionals in academics and business.

In a nutshell:  the heat from the planes melted the *"structural pins" at the point of contact.  These "pins" were reinforcements on each floor.  As the first "pins" melted, the floor collapsed onto each lower floor, until the excess weight created the unbearable load and momentum to bring each one down in succession, thus, the perfect vertical collapse.

*I say "structural pins because I forgot the technical word;  I think they were similar to girders, but were extra reinforcements in the corners of each floor.

** and yes, I have to agree that my questions about the Pentagon are not satisfied by anything I've heard in the media, or by official explanations so far.  There are a lot of questions regarding this:  timing, political, and crucial evidence at the crash site.

<{POST_SNAPBACK}>

hi'

I guess that you believed this sh1t ....

an entire tower of this kind if set for a proper demolition would take longer to fall!

technical fact!

the tower began to collapse far fater the hit, there is something not "normal" for such bombed tower, any explosive techy will tell you that it' almost impossible for the tower to fall staight down in one shot without a little help ... not only a plane crash that alone would destroy the top of the hit, but surely not a few hundreds feet of underbuilding that melt too!

no, search for evidences, it was the plane crash/ stop! enough for you poor people!

very fast cleaning of the place, not even an enquiery

and why? ... shortcut to the "terror" threat and some new laws to restrain people!

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

francois

<{POST_SNAPBACK}>

'would take longer to fall down'......

'technical fact'........

'any explosive techy'.....

'francois'.....:cheesy:

ok - look:  I attended lectures at MIT about the structural collapse of the towers.  These lectures were given by some of the top engineers, architects, and design professionals in academics and business.

In a nutshell:  the heat from the planes melted the *"structural pins" at the point of contact.  These "pins" were reinforcements on each floor.  As the first "pins" melted, the floor collapsed onto each lower floor, until the excess weight created the unbearable load and momentum to bring each one down in succession, thus, the perfect vertical collapse.

*I say "structural pins because I forgot the technical word;  I think they were similar to girders, but were extra reinforcements in the corners of each floor.

** and yes, I have to agree that my questions about the Pentagon are not satisfied by anything I've heard in the media, or by official explanations so far.  There are a lot of questions regarding this:  timing, political, and crucial evidence at the crash site.

<{POST_SNAPBACK}>

hi'

I guess that you believed this sh1t ....

an entire tower of this kind if set for a proper demolition would take longer to fall!

technical fact!

the tower began to collapse far fater the hit, there is something not "normal" for such bombed tower, any explosive techy will tell you that it' almost impossible for the tower to fall staight down in one shot without a little help ... not only a plane crash that alone would destroy the top of the hit, but surely not a few hundreds feet of underbuilding that melt too!

no, search for evidences, it was the plane crash/ stop! enough for you poor people!

very fast cleaning of the place, not even an enquiery

and why? ... shortcut to the "terror" threat and some new laws to restrain people!

and American citizens accept it like it is

sorry, I still have a lot of doubt about the honnesty of the US gov...

as I do have fro the french one

francois

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'would take longer to fall down'......

'technical fact'........

'any explosive techy'.....

'francois'.....

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Yeah I do admit that is funny - guess Francois never seen a controlled demolition - comes down in seconds.

Wrong country for chuchok - Mind you we did send our convicts to Oz. 

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oh right -the term "Wallys" should have tipped me off. Well, they've come a long way since they were convicts, but they are still subjects of Mother England - who are the Wallys now *However, I'll never refuse a beer from one

*edit: they've

Wrong country for chuchok - Mind you we did send our convicts to Oz. 

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oh right -the term "Wallys" should have tipped me off. Well, they come a long way since they were convicts, but they are still subjects of Mother England - who are the Wallys now

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Kiwi

ok, so what you are saying Butterfly, is that a group of international experts with the blueprints of the Towers in hand, computer simulations, and the expertise to analyze all factors in harmony, doesn't mean shit compared to a conspiracy theory that has no factual basis at all except - "theories".

Add to this the fact that we have videotape of the original hijackers boarding the plane, residents of New York that saw one of the jets flying through the City at very, very low altitude on its way to the Tower, and people at and around the site that heard a huge roaring sound growing progressively louder on approach, which is definitely not the sound of a bomb.  Top this off with the fact that once a jet filled with fuel collides into the tower, it is effectively a bomb capable of propelling fuel and flames through the air shafts of elevators ....... and you are saying none of this means shit 

YOU are the one who is dogmatically clinging to a theory that can be refuted on the simplest of terms.

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You got to be kidding. You are smarter than that. These arguments are borderline rubbish coming from you. They might as well come from Spee or Boon Mee.

Your group of International experts doesn't mean shit, that's the problem. The "evidence" were "disregarded" and there are a thousands of other experts contradicting what "your" experts are saying. It's pointless. For the towers there is no battle possible as it's really "impossible" to prove without doubt eitheir side. The fire inside the tower weren't hot enough to cause a meltdown, that's the problem I have with the "falling floor" theory. You are saying it was hot inside, but there are witness accounts (from firefighters making calls for a water line) that this wasn't the case. Also the timing of the falls is highly suspicious. Again not saying those "theories" are truth but they do bring interesting questions. Anyway the official "collapsing floors" theory doesn't fly with the other "evidence". It doesn't mean it couldn't happen, it just means it didn't happen on 911.

ok, so what you are saying Butterfly, is that a group of international experts with the blueprints of the Towers in hand, computer simulations, and the expertise to analyze all factors in harmony, doesn't mean shit compared to a conspiracy theory that has no factual basis at all except - "theories".

Add to this the fact that we have videotape of the original hijackers boarding the plane, residents of New York that saw one of the jets flying through the City at very, very low altitude on its way to the Tower, and people at and around the site that heard a huge roaring sound growing progressively louder on approach, which is definitely not the sound of a bomb.  Top this off with the fact that once a jet filled with fuel collides into the tower, it is effectively a bomb capable of propelling fuel and flames through the air shafts of elevators ....... and you are saying none of this means shit 

YOU are the one who is dogmatically clinging to a theory that can be refuted on the simplest of terms.

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You got to be kidding. You are smarter than that. These arguments are borderline rubbish coming from you. They might as well come from Spee or Boon Mee.

Your group of International experts doesn't mean shit, that's the problem. The "evidence" were "disregarded" and there are a thousands of other experts contradicting what "your" experts are saying. It's pointless. For the towers there is no battle possible as it's really "impossible" to prove without doubt eitheir side. The fire inside the tower weren't hot enough to cause a meltdown, that's the problem I have with the "falling floor" theory. You are saying it was hot inside, but there are witness accounts (from firefighters making calls for a water line) that this wasn't the case. Also the timing of the falls is highly suspicious. Again not saying those "theories" are truth but they do bring interesting questions. Anyway the official "collapsing floors" theory doesn't fly with the other "evidence". It doesn't mean it couldn't happen, it just means it didn't happen on 911.

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ok, Butterfly, whatever you say. I give up

Bombs in the World Trade Center

The report you're hearing was filed by a news anchor Rick Sanchez on the morning of September 11th 2001.

The details contained therein seem to have slipped under the radar amidst the huge body of evidence proving controlled demolition brought down both the twin towers and Building 7.

Sanchez states,

”Police have found what they believe to be a suspicious device and they fear that it may lead to another explosion."

"I spoke with some police officials moments ago, Chris, and they told me they have reason to believe that one of the explosion at the besides the ones made with the planes, may have been caused by a van that was parked on the building that may have had an explosive device in it.”

It would make sense that police would find at least some of the bombs that tore down the only steel buildings to collapse from fire damage in history at speeds that defied physics. There would have been so many devices involved in the demolition that stumbling across some was inevitable.

This report mirrors those that emerged in the hours following the 1995 Oklahoma City bombing, where bomb squads removed numerous unexploded secondary devices from the Alfred P. Murrah building.

The twin towers were wired to the brim with highly powerful explosives, some of which exploded before the collapse of the buildings and some during.

This is why people like construction worker Philip Morelli, working in the fourth sub-basement of the north tower, were thrown around like rag dolls in an earthquake.

With the sheer volume of evidence and basic straightforward common sense proving controlled demolition, the possibility still remains that the federal government, backed by FEMA, will come forward and announce that another Al-Qaeda cell placed the explosives days before the attack.

This of course is ridiculous, it takes highly trained explosives experts weeks and sometimes months to correctly rig buildings many times smaller than the twin towers, and with varying degrees of success. The towers imploded perfectly and fell down right in their own footsteps, as did Building 7 which wasn't hit by a plane. Any building not owned by Larry Silverstein, despite having closer proximity to the towers, strangely stood its ground.

Larry Silverstein admitted that Building 7 was "pulled," an industry term for demolition, in a September 2002 PBS documentary, but has failed to respond to a firestorm of subsequent questions.

Others argue that the powers that be will simply continue to ignore the evidence now being certified by such credible individuals as Professor Steven Jones and former chief economist for the US Department of Labor under George W. Bush, Morgan Reynolds.

To change such a major element of the official version of events would throw into question all the other pieces of the puzzle and the whole house of cards would come tumbling down.

Nevertheless, the report that police did find explosives in the World Trade Center before the collapse of the towers is another giant smoking gun to add to all the rest proving that the collapse of the buildings and 9/11 was an inside job.

U.S. Unprepared for Attack, 9/11 Panel Says

Associated Press | December 5, 2005

By HOPE YEN

The former Sept. 11 commission is giving Congress and the White House poor marks on protecting the U.S. against an inevitable terror attack because of their failure to enact several strong security measures.

The 10-member panel, equally divided between Republicans and Democrats, prepared to release a report Monday assessing how well their recommendations have been followed. They say the government deserves "more F's than A's" in responding to their 41 suggested changes.

"People are not paying attention," chairman Thomas Kean, a former Republican governor of New Jersey, said Sunday. "God help us if we have another attack."

Since the commission's final report in July 2004, the government has enacted the centerpiece proposal to create a national intelligence director. But it has stalled on other ideas, including improving communication among emergency responders and shifting federal terrorism-fighting money so it goes to states based on risk level.

"There are so many competing priorities," said vice chairman Lee Hamilton, a former Democratic congressman from Indiana. We've got three wars going on: one in Afghanistan, one in Iraq and the war against terror. And it's awfully hard to keep people focused on something like this."

"We believe that another attack will occur. It's not a question of if. We are not as well-prepared as we should be," Hamilton said in a joint appearance with Kean on NBC's "Meet the Press."

National security adviser Stephen Hadley said President Bush is committed to putting in place most of the recommendations.

"We are safer, but not yet safe. There is more to do," Hadley said on "Fox News Sunday."

Some members of the commission, whose recommendations now are promoted through a privately funded group known as the 9/11 Public Discourse Project, contended the government has been remiss by failing to act more quickly.

Kean and Hamilton urged Congress to pass spending bills that would allow police and fire to communicate across radio spectrums and to reallocate money so that Washington and New York, which have more people and symbolic landmarks, could receive more for terrorism defense.

Both bills have stalled in Congress, in part over the level of spending and turf fights over which states should get the most dollars.

Congress established the commission in 2002 to investigate government missteps that led to the attacks of Sept. 11, 2001. Nearly 3,000 people were killed when 19 Arab hijackers organized by al-Qaida flew airliners into New York City's World Trade Center and the Pentagon and caused a crash in the Pennsylvania countryside.

The panel's 567-page final report, which became a national best seller, did not blame Bush or former President Clinton for missteps contributing to the attacks but did say they failed to make anti-terrorism a higher priority.

The commission also concluded that the Sept. 11 attack would not be the nation's last, noting that al-Qaida had tried for at least 10 years to acquire weapons of mass destruction.

Former Democratic commissioner Jamie Gorelick said Sunday she believed the country is "less safe than we were 18 months ago."

"The interest has faded," Gorelick, a Washington lawyer, told ABC's "Good Morning America Weekend." "We assumed that our government would be able to do what it needed to do, and it didn't do it."

I agree with the second article, and, it is cited and dated.

Where did the first article come from?

ok, so what you are saying Butterfly, is that a group of international experts with the blueprints of the Towers in hand, computer simulations, and the expertise to analyze all factors in harmony, doesn't mean shit compared to a conspiracy theory that has no factual basis at all except - "theories".

Add to this the fact that we have videotape of the original hijackers boarding the plane, residents of New York that saw one of the jets flying through the City at very, very low altitude on its way to the Tower, and people at and around the site that heard a huge roaring sound growing progressively louder on approach, which is definitely not the sound of a bomb.  Top this off with the fact that once a jet filled with fuel collides into the tower, it is effectively a bomb capable of propelling fuel and flames through the air shafts of elevators ....... and you are saying none of this means shit 

YOU are the one who is dogmatically clinging to a theory that can be refuted on the simplest of terms.

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You got to be kidding. You are smarter than that. These arguments are borderline rubbish coming from you. They might as well come from Spee or Boon Mee.

Your group of International experts doesn't mean shit, that's the problem. The "evidence" were "disregarded" and there are a thousands of other experts contradicting what "your" experts are saying. It's pointless. For the towers there is no battle possible as it's really "impossible" to prove without doubt eitheir side. The fire inside the tower weren't hot enough to cause a meltdown, that's the problem I have with the "falling floor" theory. You are saying it was hot inside, but there are witness accounts (from firefighters making calls for a water line) that this wasn't the case. Also the timing of the falls is highly suspicious. Again not saying those "theories" are truth but they do bring interesting questions. Anyway the official "collapsing floors" theory doesn't fly with the other "evidence". It doesn't mean it couldn't happen, it just means it didn't happen on 911.

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PLease make a list of "experts" who claim that the collapse of the building is suspect....unless you can do this then everything you are saying does not apply....can you name...say a dozen?.....half a dozen?....four?.....?.....?....one?.....do you think that you have the expertise to be able to tell a structural engineer who is expert in collapse of these types of structures from a wannabe?....

Why Did the World Trade Center Collapse?

Science, Engineering, and Speculation

Thomas W. Eagar and Christopher Musso

News & Update

There have been numerous reports detailing the cause of the World Trade Center Tower collapse on September 11, 2001. Most have provided qualitative explanations; however, simple quantitative analyses show that some common conclusions are incorrect; for example, the steel could not melt in these flames and there was more structural damage than merely softening of the steel at elevated temperatures. Some guidelines for improvements in future structures are presented.

INTRODUCTION

The collapse of the World Trade Center (WTC) towers on September 11, 2001, was as sudden as it was dramatic; the complete destruction of such massive buildings shocked nearly everyone. Immediately afterward and even today, there is widespread speculation that the buildings were structurally deficient, that the steel columns melted, or that the fire suppression equipment failed to operate. In order to separate the fact from the fiction, we have attempted to quantify various details of the collapse.

The major events include the following:

* The airplane impact with damage to the columns.

* The ensuing fire with loss of steel strength and distortion.

* The collapse, which generally occurred inward without significant tipping

Each will be discussed separately, but initially it is useful to review the overall design of the towers.

THE DESIGN

The towers were designed and built in the mid-1960s through the early 1970s. They represented a new approach to skyscrapers in that they were to be very lightweight and involved modular construction methods in order to accelerate the schedule and to reduce the costs.

To a structural engineer, a skyscraper is modeled as a large cantilever vertical column. Each tower was 64 m square, standing 411 m above street level and 21 m below grade. This produces a height-to-width ratio of 6.8. The total weight of the structure was roughly 500,000 t, but wind load, rather than the gravity load, dominated the design. The building is a huge sail that must resist a 225 km/h hurricane. It was designed to resist a wind load of 2 kPa—a total of lateral load of 5,000 t.

In order to make each tower capable of withstanding this wind load, the architects selected a lightweight “perimeter tube” design consisting of 244 exterior columns of 36 cm square steel box section on 100 cm centers (see Figure 3). This permitted windows more than one-half meter wide. Inside this outer tube there was a 27 m × 40 m core, which was designed to support the weight of the tower. It also housed the elevators, the stairwells, and the mechanical risers and utilities. Web joists 80 cm tall connected the core to the perimeter at each story. Concrete slabs were poured over these joists to form the floors. In essence, the building is an egg-crate construction that is about 95 percent air, explaining why the rubble after the collapse was only a few stories high.

The egg-crate construction made a redundant structure (i.e., if one or two columns were lost, the loads would shift into adjacent columns and the building would remain standing). Prior to the World Trade Center with its lightweight perimeter tube design, most tall buildings contained huge columns on 5 m centers and contained massive amounts of masonry carrying some of the structural load. The WTC was primarily a lightweight steel structure; however, its 244 perimeter columns made it “one of the most redundant and one of the most resilient” skyscrapers.

THE AIRLINE IMPACT

The early news reports noted how well the towers withstood the initial impact of the aircraft; however, when one recognizes that the buildings had more than 1,000 times the mass of the aircraft and had been designed to resist steady wind loads of 30 times the weight of the aircraft, this ability to withstand the initial impact is hardly surprising. Furthermore, since there was no significant wind on September 11, the outer perimeter columns were only stressed before the impact to around 1/3 of their 200 MPa design allowable.

The only individual metal component of the aircraft that is comparable in strength to the box perimeter columns of the WTC is the keel beam at the bottom of the aircraft fuselage. While the aircraft impact undoubtedly destroyed several columns in the WTC perimeter wall, the number of columns lost on the initial impact was not large and the loads were shifted to remaining columns in this highly redundant structure. Of equal or even greater significance during this initial impact was the explosion when 90,000 L gallons of jet fuel, comprising nearly 1/3 of the aircraft’s weight, ignited. The ensuing fire was clearly the principal cause of the collapse (Figure 4).

THE FIRE

The fire is the most misunderstood part of the WTC collapse. Even today, the media report (and many scientists believe) that the steel melted. It is argued that the jet fuel burns very hot, especially with so much fuel present. This is not true.

Part of the problem is that people (including engineers) often confuse temperature and heat. While they are related, they are not the same. Thermodynamically, the heat contained in a material is related to the temperature through the heat capacity and the density (or mass). Temperature is defined as an intensive property, meaning that it does not vary with the quantity of material, while the heat is an extensive property, which does vary with the amount of material. One way to distinguish the two is to note that if a second log is added to the fireplace, the temperature does not double; it stays roughly the same, but the size of the fire or the length of time the fire burns, or a combination of the two, doubles. Thus, the fact that there were 90,000 L of jet fuel on a few floors of the WTC does not mean that this was an unusually hot fire. The temperature of the fire at the WTC was not unusual, and it was most definitely not capable of melting steel.

In combustion science, there are three basic types of flames, namely, a jet burner, a pre-mixed flame, and a diffuse flame. A jet burner generally involves mixing the fuel and the oxidant in nearly stoichiometric proportions and igniting the mixture in a constant-volume chamber. Since the combustion products cannot expand in the constant-volume chamber, they exit the chamber as a very high velocity, fully combusted, jet. This is what occurs in a jet engine, and this is the flame type that generates the most intense heat.

In a pre-mixed flame, the same nearly stoichiometric mixture is ignited as it exits a nozzle, under constant pressure conditions. It does not attain the flame velocities of a jet burner. An oxyacetylene torch or a Bunsen burner is a pre-mixed flame.

In a diffuse flame, the fuel and the oxidant are not mixed before ignition, but flow together in an uncontrolled manner and combust when the fuel/oxidant ratios reach values within the flammable range. A fireplace flame is a diffuse flame burning in air, as was the WTC fire.

Diffuse flames generate the lowest heat intensities of the three flame types.

If the fuel and the oxidant start at ambient temperature, a maximum flame temperature can be defined. For carbon burning in pure oxygen, the maximum is 3,200°C; for hydrogen it is 2,750°C. Thus, for virtually any hydrocarbons, the maximum flame temperature, starting at ambient temperature and using pure oxygen, is approximately 3,000°C.

This maximum flame temperature is reduced by two-thirds if air is used rather than pure oxygen. The reason is that every molecule of oxygen releases the heat of formation of a molecule of carbon monoxide and a molecule of water. If pure oxygen is used, this heat only needs to heat two molecules (carbon monoxide and water), while with air, these two molecules must be heated plus four molecules of nitrogen. Thus, burning hydrocarbons in air produces only one-third the temperature increase as burning in pure oxygen because three times as many molecules must be heated when air is used. The maximum flame temperature increase for burning hydrocarbons (jet fuel) in air is, thus, about 1,000°C—hardly sufficient to melt steel at 1,500°C.

But it is very difficult to reach this maximum temperature with a diffuse flame. There is nothing to ensure that the fuel and air in a diffuse flame are mixed in the best ratio. Typically, diffuse flames are fuel rich, meaning that the excess fuel molecules, which are unburned, must also be heated. It is known that most diffuse fires are fuel rich because blowing on a campfire or using a blacksmith’s bellows increases the rate of combustion by adding more oxygen. This fuel-rich diffuse flame can drop the temperature by up to a factor of two again. This is why the temperatures in a residential fire are usually in the 500°C to 650°C range.2,3 It is known that the WTC fire was a fuel-rich, diffuse flame as evidenced by the copious black smoke. Soot is generated by incompletely burned fuel; hence, the WTC fire was fuel rich—hardly surprising with 90,000 L of jet fuel available. Factors such as flame volume and quantity of soot decrease the radiative heat loss in the fire, moving the temperature closer to the maximum of 1,000°C. However, it is highly unlikely that the steel at the WTC experienced temperatures above the 750–800°C range. All reports that the steel melted at 1,500°C are using imprecise terminology at best.

Some reports suggest that the aluminum from the aircraft ignited, creating very high temperatures. While it is possible to ignite aluminum under special conditions, such conditions are not commonly attained in a hydrocarbon-based diffuse flame. In addition, the flame would be white hot, like a giant sparkler. There was no evidence of such aluminum ignition, which would have been visible even through the dense soot.

It is known that structural steel begins to soften around 425°C and loses about half of its strength at 650°C.4 This is why steel is stress relieved in this temperature range. But even a 50% loss of strength is still insufficient, by itself, to explain the WTC collapse. It was noted above that the wind load controlled the design allowables. The WTC, on this low-wind day, was likely not stressed more than a third of the design allowable, which is roughly one-fifth of the yield strength of the steel. Even with its strength halved, the steel could still support two to three times the stresses imposed by a 650°C fire.

The additional problem was distortion of the steel in the fire. The temperature of the fire was not uniform everywhere, and the temperature on the outside of the box columns was clearly lower than on the side facing the fire. The temperature along the 18 m long joists was certainly not uniform. Given the thermal expansion of steel, a 150°C temperature difference from one location to another will produce yield-level residual stresses. This produced distortions in the slender structural steel, which resulted in buckling failures. Thus, the failure of the steel was due to two factors: loss of strength due to the temperature of the fire, and loss of structural integrity due to distortion of the steel from the non-uniform temperatures in the fire.

THE COLLAPSE

Nearly every large building has a redundant design that allows for loss of one primary structural member, such as a column. However, when multiple members fail, the shifting loads eventually overstress the adjacent members and the collapse occurs like a row of dominoes falling down.

The perimeter tube design of the WTC was highly redundant. It survived the loss of several exterior columns due to aircraft impact, but the ensuing fire led to other steel failures. Many structural engineers believe that the weak points—the limiting factors on design allowables—were the angle clips that held the floor joists between the columns on the perimeter wall and the core structure (see Figure 5). With a 700 Pa floor design allowable, each floor should have been able to support approximately 1,300 t beyond its own weight. The total weight of each tower was about 500,000 t.

As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell. The floor below (with its 1,300 t design capacity) could not support the roughly 45,000 t of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an estimated speed of 200 km per hour. If it had been free fall, with no restraint, the collapse would have only taken eight seconds and would have impacted at 300 km/h.1 It has been suggested that it was fortunate that the WTC did not tip over onto other buildings surrounding the area. There are several points that should be made. First, the building is not solid; it is 95 percent air and, hence, can implode onto itself. Second, there is no lateral load, even the impact of a speeding aircraft, which is sufficient to move the center of gravity one hundred feet to the side such that it is not within the base footprint of the structure. Third, given the near free-fall collapse, there was insufficient time for portions to attain significant lateral velocity. To summarize all of these points, a 500,000 t structure has too much inertia to fall in any direction other than nearly straight down.

WAS THE WTC DEFECTIVELY DESIGNED?

The World Trade Center was not defectively designed. No designer of the WTC anticipated, nor should have anticipated, a 90,000 L Molotov cocktail on one of the building floors. Skyscrapers are designed to support themselves for three hours in a fire even if the sprinkler system fails to operate. This time should be long enough to evacuate the occupants. The WTC towers lasted for one to two hours—less than the design life, but only because the fire fuel load was so large. No normal office fires would fill 4,000 square meters of floor space in the seconds in which the WTC fire developed. Usually, the fire would take up to an hour to spread so uniformly across the width and breadth of the building. This was a very large and rapidly progressing fire (very high heat but not unusually high temperature). Further information about the design of the WTC can be found on the World Wide Web.5–8

WHERE DO WE GO FROM HERE

The clean-up of the World Trade Center will take many months. After all, 1,000,000 t of rubble will require 20,000 to 30,000 truckloads to haul away the material. The asbestos fire insulation makes the task hazardous for those working nearby. Interestingly, the approximately 300,000 t of steel is fully recyclable and represents only one day’s production of the U.S. steel industry. Separation of the stone and concrete is a common matter for modern steel shredders. The land-filling of 700,000 t of concrete and stone rubble is more problematic. However, the volume is equivalent to six football fields, 6–9 m deep, so it is manageable.

There will undoubtedly be a number of changes in the building codes as a result of the WTC catastrophe. For example, emergency communication systems need to be upgraded to speed up the notice for evacuation and the safest paths of egress. Emergency illumination systems, separate from the normal building lighting, are already on the drawing boards as a result of lessons learned from the WTC bombing in 1993. There will certainly be better fire protection of structural members. Protection from smoke inhalation, energy-absorbing materials, and redundant means of egress will all be considered.

A basic engineering assessment of the design of the World Trade Center dispels many of the myths about its collapse. First, the perimeter tube design of the towers protected them from failing upon impact. The outer columns were engineered to stiffen the towers in heavy wind, and they protected the inner core, which held the gravity load. Removal of some of the outer columns alone could not bring the building down. Furthermore, because of the stiffness of the perimeter design, it was impossible for the aircraft impact to topple the building.

However, the building was not able to withstand the intense heat of the jet fuel fire. While it was impossible for the fuel-rich, diffuse-flame fire to burn at a temperature high enough to melt the steel, its quick ignition and intense heat caused the steel to lose at least half its strength and to deform, causing buckling or crippling. This weakening and deformation caused a few floors to fall, while the weight of the stories above them crushed the floors below, initiating a domino collapse.

It would be impractical to design buildings to withstand the fuel load induced by a burning commercial airliner. Instead of saving the building, engineers and officials should focus on saving the lives of those inside by designing better safety and evacuation systems.

As scientists and engineers, we must not succumb to speculative thinking when a tragedy such as this occurs. Quantitative reasoning can help sort fact from fiction, and can help us learn from this unfortunate disaster. As Lord Kelvin said,

“I often say . . . that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meager and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.”

We will move forward from the WTC tragedy and we will engineer better and safer buildings in the future based, in part, on the lessons learned at the WTC. The reason the WTC collapse stirs our emotions so deeply is because it was an intentional attack on innocent people. It is easier to accept natural or unintentional tragedies; it is the intentional loss of life that makes us fear that some people have lost their humanity.