The "impossible fire induced collapse" claim

[Carlos]

Statement #1 - Building collapse is the result of multiples and successive structural failures that occur at a certain period of time. The collapse (global or partial) occurs when the structure (or part of it) becomes no longer able to support the loads.

Statement #2 - Fire can cause structural failures on a steel framed structure, i.e. structural elements can fail due to excessive deformations and loss of strength of the steel at high temperatures.

I believe everyone here agree that both statements are true, so would like to ask you truthers a question:

Why fire induced collapse of a steel frame structure building is impossible?

PS. It's not a thread about NIST's analysis and findings, but a thread about the CLAIM, by itself.

 

[thedopefishlives]

I believe the point most argued by Twoofers, as will readily become apparent, is #2. There are two primary arguments against this point:

1) Steel is a good enough heat conductor that the heat should have dissipated through the structure before reaching the point of failure.

2) The temperatures were not high enough to cause enough weakening to bring the structure down. (aka "Fire can't melt steel")

Both of these arguments have been roundly debunked, of course. Against argument #1, steel is, of course, a much better heat conductor than concrete, but that does not mean that it is a superlative conductor of heat. In fact, steel as compared to common heat conducting materials such as aluminum is rather poor. There is no way the steel structure could have distributed the heat energy of those large infernos in the manner truthers describe. Against argument #2, this argument usually takes the form of either incredulity in the temperature of the fire, or incredulity in the rate of steel's strength loss as a function of temperature.

 

[phunk]

The "steel is a good conductor of heat" argument can be debunked in one picture.

http://www.freefoto.com/preview/13-33-2/Traditional-Blacksmith

Note the lack of gloves.

 

[thedopefishlives]

As far as point #1, I see some Truthers on this board argue that nothing short of complete removal of one or more floors could have initiated total collapse. I'm at a loss as for how they arrive at this conclusion, because only a select few have even bothered to provide math, and they do not even claim a need for total core removal.

 

[Edx]

They wont deny that steel can fail in fires thats why they have keep moving the goal posts back to "steel frame high rise" and "complete collapse".

 

[Oystein]

My best rendering of the truther-argument, as perhaps most prominently hinted at by ae911truth, goes something like that:

Fire, working slowly, could at most cause a single concurrent point of failure. Such a single point of failure would be extremely unlikely to cause
a) total collapse
b) symmetric collapse
Instead, for a) and b) to arise, it would be necessary to have multiple and (almost) concurrent initial points of failure.

It isn't totally clear what "symmetric" is supposed to mean, but I think the following comes closest:
All three buildings have a considerable horizantal size, yet it appears that theor entire cross-sections fall almost in unison. I.e. parts of the structures as far as part from each other as 200 feet and more start falling within only a fraction of a section, and this could not come from a single point of failure.


So my best guess is that these truthers contend that the horizontal progression of failure could not go as fast as it did, but they never make that explicit and are perhaps even unaware of what their argument is. I say this because they never get tired to yell from all the roofs how they disbelief the speed of vertical collapse progression. If they understood that their argument about collapse initiation is really an argument about the speed of horizontal collapse progression, they'd make that more explicit.

 

[Miragememories]

"Statement #1 - Building collapse is the result of multiples and successive structural failures that occur at a certain period of time. The collapse (global or partial) occurs when the structure (or part of it) becomes no longer able to support the loads.

Statement #2 - Fire can cause structural failures on a steel framed structure, i.e. structural elements can fail due to excessive deformations and loss of strength of the steel at high temperatures.

I believe everyone here agree that both statements are true, so would like to ask you truthers a question:

Why fire induced collapse of a steel frame structure building is impossible?

PS. It's not a thread about NIST's analysis and findings, but a thread about the CLAIM, by itself."

Simply put, a total steel highrise building collapse can only occur that quickly when its core is rapidly and progressively removed.

The NIST went with a politically-popular conclusion that stood in defiance of the well documented history of fires in steel-structured highrise buildings.

The NIST hypothesis accepts the notion that office-furnishing's fires were able to 'structurally-snap' the damaged, but structurally stabile steel highrise building.

The NIST hypothesis requires nature's fire on that infamous day, to perform this miraculous feat not once, but 3 times (WTC2, WTC1 & WTC7).

Regarding statement #2, there is no question that fire of sufficient intensity, duration and distribution, can and has, seriously weakened and partially collapsed small lateral portions of buildings.

But at no time, was there evidence that the office cubicle fires were sufficiently intense, of long enough duration and well enough distributed to make the intact structural steel, supporting the toppling upper WTC1 and WTC2 sections suddenly snap.

A core snap so fast and widespread, that the initial topplings of the towers' upper sections were supposedly arrested by the rapid failure of the undamaged and intact columns below.

MM

 

[MileHighMadness]

Again...let me be clear

This is very simple and straight forward…if you cook a steel frame building long enough, it’s going to collapse. Architects and Structural Engineers who design and construct multi-story steel building for a living understand this. That’s why they place fireproofing on structural steel beams and columns, and install a sprinkler system throughout the building.

I know hundreds of structural engineers, and everyone one of them understands and accepts the findings of the NIST reports.

I there are structural engineers out there, who buy into the conspiracies of the Truthers, I do not know them, and have never met them.

Well, for the record, the theory that WTC buildings where bought down by controlled demolition is probably one the dumbest ideas in the history of mankind. The chance that any of the controlled demolition theories are true is Absolute Zero

 

[The Big Dog]

But at no time, was there evidence that the office cubicle fires were sufficiently intense, of long enough duration and well enough distributed to make the intact structural steel, supporting the toppling upper WTC1 and WTC2 sections suddenly snap.

A core snap so fast and widespread, that the initial topplings of the towers' upper sections were supposedly arrested by the rapid failure of the undamaged and intact columns below.

MM

I assume you've never heard of the McCormick place collapse in Chicago.

You also don't know how a lever operates, and what can cause its failure. Tip? The failure of its fulcrum.

Another tip: don't ever use the word "supposedly." If you need to just use this instead: "here comes an argument from incredulity." In the long run it saves lots of time.

 

[thedopefishlives]

Simply put, a total steel highrise building collapse can only occur that quickly when its core is rapidly and progressively removed.

The NIST went with a politically-popular conclusion that stood in defiance of the well documented history of fires in steel-structured highrise buildings.

[qimg]http://img377.imageshack.us/img377/7466/nistwtcfloorcubiclesbw9.png[/qimg]

The NIST hypothesis accepts the notion that office-furnishing's fires were able to 'structurally-snap' the damaged, but structurally stabile steel highrise building.

The NIST hypothesis requires nature's fire on that infamous day, to perform this miraculous feat not once, but 3 times (WTC2, WTC1 & WTC7).

Regarding statement #2, there is no question that fire of sufficient intensity, duration and distribution, can and has, seriously weakened and partially collapsed small lateral portions of buildings.

But at no time, was there evidence that the office cubicle fires were sufficiently intense, of long enough duration and well enough distributed to make the intact structural steel, supporting the toppling upper WTC1 and WTC2 sections suddenly snap.

A core snap so fast and widespread, that the initial topplings of the towers' upper sections were supposedly arrested by the rapid failure of the undamaged and intact columns below.

MM

Did I call it or what?

 

[Oystein]

Did I call it or what?

I hope you filed this in time with James Randi

 

[Mark F]

But at no time, was there evidence that the office cubicle fires were sufficiently intense, of long enough duration and well enough distributed to make the intact structural steel, supporting the toppling upper WTC1 and WTC2 sections suddenly snap.

MM

And there you go moving the goal posts yet again with the "office cubicle fires" nonsense. Are you trying to delude yourself or just us?

 

[twinstead]

Are you trying to delude yourself or just us?

False dichotomy. He's trying to do both

 

[000063]

Simply put, a total steel highrise building collapse can only occur that quickly when its core is rapidly and progressively removed.

Except that we have both video and photo evidence that the cores went down last.

The NIST went with a politically-popular conclusion that stood in defiance of the well documented history of fires in steel-structured highrise buildings.

[qimg]http://img377.imageshack.us/img377/7466/nistwtcfloorcubiclesbw9.png[/qimg]

The NIST hypothesis accepts the notion that office-furnishing's fires were able to 'structurally-snap' the damaged, but structurally stabile steel highrise building.

Are you incapable of acknowledging fire and impact? Because unless you can prove WTC 1 was a CD, any theories regarding 7 are irrelevant.

The NIST hypothesis requires nature's fire on that infamous day, to perform this miraculous feat not once, but 3 times (WTC2, WTC1 & WTC7).

Incorrect. Even in 7, fire was only the most dominant cause. 1 and 2 were both fire and impact, your incredulity notwithstanding. Also, why are you bringing NIST into a discussion that was specifically said not to be about NIST? And stop trying to dress up the "first time in history" canard in new clothes; it's still wrong.

Regarding statement #2, there is no question that fire of sufficient intensity, duration and distribution, can and has, seriously weakened and partially collapsed small lateral portions of buildings.

Quit loading with qualifiers so you don't have to admit that the initial statement is right.

But at no time, was there evidence that the office cubicle fires were sufficiently intense, of long enough duration and well enough distributed to make the intact structural steel, supporting the toppling upper WTC1 and WTC2 sections suddenly snap.

Good thing they both got hit by planes, then. Also, office fires, which includes everything else in the joint that would burn. Including people. Much of the steel in question had been damaged by the plane impact, which stripped fireproofing off of it. Heck, some of it was knocked clean out of the building.

A core snap so fast and widespread, that the initial topplings of the towers' upper sections were supposedly arrested by the rapid failure of the undamaged and intact columns below.

MM

Why are you talking about a scenario that's demonstrably wrong? In fact, every sentence in your post is wrong, which is a remarkable achievement.

 

[jaydeehess]

Here's the crux of the matter for me;
while it is known that heat can weaken steel to fail under a load or even buckle while unloaded, that the fuel load in a typical office provides enough heat to do this, and that several thousands gallons of liquid acellerant created a large square footage fire area on several consecutive floors of an already damaged structure.,

the ae911t would instead promote the idea of unknown and unproven explosive devices caused collapse.
Incindiary materials cannot perform the operation MM describes above.

If for no other reason than considering known conditions and mechanisms versus pure conjecture, reason and logic would dictate that one conclude that impact and fire damage led to collapse.

 

[Mikeys]

Statement #1 - Building collapse is the result of multiples and successive structural failures that occur at a certain period of time. The collapse (global or partial) occurs when the structure (or part of it) becomes no longer able to support the loads.

Statement #2 - Fire can cause structural failures on a steel framed structure, i.e. structural elements can fail due to excessive deformations and loss of strength of the steel at high temperatures.

Both statements are irrelevant.The claim has no merit. Where are you going with it? Impact, well, lets call it initial impact, and fire may have severed and collapsed the top, you still have most of the building structurally intact.In reality I doubt it was structurally intact although forces and means used were more calculative than fire.

What happened next is mystify. some kind of progressive collapse from top to bottom would be my guess and one well synchronized and smoothly played out.

 

[jaydeehess]

Both statements are irrelevant.The claim has no merit. Where are you going with it? Impact, well, lets call it initial impact, and fire may have severed and collapsed the top, you still have most of the building structurally intact.In reality I doubt it was structurally intact although forces and means used were more calculative than fire.

What happened next is mystify. some kind of progressive collapse from top to bottom would be my guess and one well synchronized and smoothly played out.

Unfortunately your unsupported contentions just don't carry any weight.

 

[Justin39640]

Both statements are irrelevant.The claim has no merit. Where are you going with it? Impact, well, lets call it initial impact, and fire may have severed and collapsed the top, you still have most of the building structurally intact.In reality I doubt it was structurally intact although forces and means used were more calculative than fire.

What happened next is mystify. some kind of progressive collapse from top to bottom would be my guess and one well synchronized and smoothly played out.

Bowling must amaze you... We all understand that the ball hits the first pin but how the rest fall is just a complete mystery...

 

[twinstead]

Both statements are irrelevant.The claim has no merit. Where are you going with it? Impact, well, lets call it initial impact, and fire may have severed and collapsed the top, you still have most of the building structurally intact.In reality I doubt it was structurally intact although forces and means used were more calculative than fire.

What happened next is mystify. some kind of progressive collapse from top to bottom would be my guess and one well synchronized and smoothly played out.

What happened next has been described in great detail by those greatly more qualified than you to know. Your opinion is noted and rejected.

 

[Oystein]

...
What happened next is mystify.
...

Yes. To you it obviously is all very mystifying.

Any reality sufficiently advanced (relative to the science understanding of the beholder) is indistinguishable from mystery.

You are apparently arguing from a level of understanding that's stuck in some long-gone century, when people were mystified by the work forces greater than that of a couple of oxen.

 

[Kid Eager]

Both statements are irrelevant.The claim has no merit. Where are you going with it? Impact, well, lets call it initial impact, and fire may have severed and collapsed the top, you still have most of the building structurally intact.In reality I doubt it was structurally intact although forces and means used were more calculative than fire.

What happened next is mystify. some kind of progressive collapse from top to bottom would be my guess and one well synchronized and smoothly played out.

Reality disagrees with your doubt, and your guess carries no weight.

 

[Carlos]

Simply put, a total steel highrise building collapse can only occur that quickly when its core is rapidly and progressively removed.

Is there any other circumstance besides controlled demolition in which a skyscraper will collapse, in your opinion?

And why the core would necessarily be removed? What about replace the word "remove" by "fail"?

Regarding statement #2, there is no question that fire of sufficient intensity, duration and distribution, can and has, seriously weakened and partially collapsed small lateral portions of buildings.

Only a small lateral portion? Why? Don't you think a partial collapse may result in a global collapse?

(I'm talking about buildings in general, not specifically the WTC)

But at no time, was there evidence that the office cubicle fires were sufficiently intense, of long enough duration and well enough distributed to make the intact structural steel, supporting the toppling upper WTC1 and WTC2 sections suddenly snap.

The collapse of the lower floors had nothing to do with the fire, they was destroyed by the weight of the upper floors. The towers was not designed to resist the force of this such mass with acceleration different from zero.

 

[Carlos]

My best rendering of the truther-argument, as perhaps most prominently hinted at by ae911truth, goes something like that:

Fire, working slowly, could at most cause a single concurrent point of failure. Such a single point of failure would be extremely unlikely to cause
a) total collapse
b) symmetric collapse
Instead, for a) and b) to arise, it would be necessary to have multiple and (almost) concurrent initial points of failure.

Yes, and WTC5 debunks the truther claim.

A single point of failure can cause several others points of failure. And fire on buildings can cause multiples point of failure and.

By the way, I wonder what would happen if the WTC5 was an 40-story instead 9-story building? Would these columns be able to support the weight of remaining structure?

 

[jaydeehess]

in cases of partial collapse, the collapse usually arrests. horizontally at a column line.
Obviously that cannot occur in the towers where there were no columns between perimeter and core. Column buckling therefore is of greater effect as far as leading to a horizontal progression in these or any long span, large open space floor plan structure.

Thus when collapse began a horizontal progression accross the impact levels was very quick.
MM, and people like him equate the partial collapses of regular post and beam structures with what 'should have' happened in structures that simply do not resemble such type at all.
I can excuse MM, but S Jones, Gage and others should know better

 

[Mikeys]

Yes. To you it obviously is all very mystifying.

Any reality sufficiently advanced (relative to the science understanding of the beholder) is indistinguishable from mystery.

You are apparently arguing from a level of understanding that's stuck in some long-gone century, when people were mystified by the work forces greater than that of a couple of oxen.

I just kindly wanted to point out the global collapse was not induced by impact fire or heat. It was caused by the loose top of rubble that had been broken by the above mentioned factors falling onto undamaged rest of the towers, the mass of the undamaged bottom having been hundreds times heavier. The KE needed would have to be of much much grater scale to advance downward shift. The collapse, even if we assume the force pushing down was a serious contender would have gone sidewise. Under no circumstances a building like that can be squashed to the ground in the real world.

 

[brazenlilraisin]

Under no circumstances a building like that can be squashed to the ground in the real world.

Glad to know it's still standing.

 

[Oystein]

I just kindly wanted to point out the global collapse was not induced by impact fire or heat.

I see no mention of, or reference to, engineering or math in your post. You assert with no evidence, so I can reject with no evidence.

However, I feel nice today, so I'll bite..

It was caused by the loose top of rubble that had been broken by the above mentioned factors falling onto undamaged rest of the towers,

Which loose top of rubble? What evidence do you have that the top 12, 15, 28, 30 or whatever floors were "rubble" by the time "global collapse was ... induced"?

the mass of the undamaged bottom having been hundreds times heavier.

A hundred times? Is that a guess, an exaggeration, or is that supposed to be an actual argument?
What was the mass of "the loose top of rubble" (an upper bound will do)?
What was the mass of "the undamaged bottom" (a lower bound will do)?
I need numbers here.

But anyway, what does it matter? If I hit your head with a 1-kg-hammer that falls from, say, 3 meters down, does it make much of a difference to your head if the undamaged bottom of your body weights 50 kg or 150 kg?

The KE needed would have to be of much much grater scale to advance downward shift.

What was the available KE (an upper bound will do)?
What was the KE necessary "to advance downward shift" (a lower bound will do)?
I need numbers here, so I can check how you figured out that one was "much much grater" than the other? How much is "much much grater", anyway? Factor of 10? Factor of 2? Factor of 1.1?

The collapse, even if we assume the force pushing down was a serious contender would have gone sidewise.

Which force was that?
Which direction does that force usually push?
Oh - you said it: Down! So a force that pushes down goes "sidewise"? You have a strange definition of "down" and "sidewise"

Under no circumstances a building like that can be squashed to the ground in the real world.

Well, it was squashed to the ground, wasn't it? So if plane crashes, fires, gravity and KE weren't sufficient circumstances, can you describe in concrete, verifiably (or better yet: falsifiable) terms, what additional factors you'd need? One bomb? Two bombs? A thousand bombs?
One kg of thermite perhaps? 2 kg? 1000 kg? 1000 tons?
Please provide us with a lower bound of what we would have to add to make the impossible possible! And of course provide us with an engineering reason for that estimate!

 

[DGM]

Well, it was squashed to the ground, wasn't it? So if plane crashes, fires, gravity and KE weren't sufficient circumstances, can you describe in concrete, verifiably (or better yet: falsifiable) terms, what additional factors you'd need? One bomb? Two bombs? A thousand bombs?
One kg of thermite perhaps? 2 kg? 1000 kg? 1000 tons?
Please provide us with a lower bound of what we would have to add to make the impossible possible! And of course provide us with an engineering reason for that estimate!

[truther] I don't know. That's why we need a fully funded, independent investigation with subpoena power. To uncover these details [/truther]

 

[Oystein]

[truther] I don't know. That's why we need a fully funded, independent investigation with subpoena power. To uncover these details [/truther]
...

Of course that is the mode.
But it is an invalid way to (not) reason.

You see, Mikeys claims, rather specifically, that "The KE needed would have to be of much much grater scale to advance downward shift."

Lets denote the energy that would be sufficient "to advance downward shift" as "DSE" ("downward shift energy).

Then, formally, he claims that

KE < DSE​

This is an inequality, which can be true or untrue, depending on the numerical values for both KE and DSE.

Lets consider two other numbers KE and DSE. Let's say, KE is the body weight of Kurt Eisler, and DSE is the body weight of Diana Susan Edelmann.

Then how would we go about evaluating of the inequality

KE < DSE​

is true or false? Could we know if it was true or false if we had no idea of what the numerical values for KE and DSE are? No. At the very least, we should be able to provide an upper and a lower bound. For example, if I knew that Diana is about as tall as I am, but very chubby, then I'd be reasonably sure that she is heavier than I am. My own weight is 70 kg, so I would be reasonbly sure that 71 is a lower bound for Diana's weight.
Would this now suffice to say if she is heavier than Kurt? No, unless I can provide an upper bound for Kurt's weight.
Let's say that I know that Kurt is shorter than I am, and exceptionally skinny, Then I am reasonably sure that he is lighter than myself, an I can safely put an upper bound at 69 kg. I would then have

KE <= 69 kg < 71 kg <= DSE​

and I would be convinced that the above inequality is true.

If however cannot estimate both an upper bound for KE and a lower bound for DSE, or if the upper bound for KE is greater than the lower bound for DSE, then I can't say the inequakity is true.




But Mikeys DID say that the inequality is true. Fron this follows logically that he CAN provide BOTH an upper bound for KE and a lower bound for DSE.



So let's hear it!



Or, alternatively, Mikeys could admit that he really DOESN'T know if the KE was insufficient to cause the "downward" shift, i.e. total collapse progression.

 

[Mikeys]

I see no mention of, or reference to, engineering or math in your post. You assert with no evidence, so I can reject with no evidence.

Let's strip the cladding and look at the naked truth. Perimeter columns at the bottom were 5in thick and towards the top 1/4 only. It should tell you enough without the need to reference to exact specs and dividing it along the building.

Which loose top of rubble? What evidence do you have that the top 12, 15, 28, 30 or whatever floors were "rubble" by the time "global collapse was ... induced"?

Perhaps not rubble, but integrity must have been compromised. It doesn't really matter and it is impossible to say what fell apart when the top shifted down.

A hundred times? Is that a guess, an exaggeration, or is that supposed to be an actual argument?
What was the mass of "the loose top of rubble" (an upper bound will do)?
What was the mass of "the undamaged bottom" (a lower bound will do)?
I need numbers here.

I guess it would be about 50 times heavier with the top being around 50K tons, not sure about the weight of the bottom so 50 times is ballpark

But anyway, what does it matter? If I hit your head with a 1-kg-hammer that falls from, say, 3 meters down, does it make much of a difference to your head if the undamaged bottom of your body weights 50 kg or 150 kg?

What hammer you need to squash a body?

What was the available KE (an upper bound will do)?
What was the KE necessary "to advance downward shift" (a lower bound will do)?

It doesn't matter. Enough energy to compress the structure to a breaking point would result in a local failure and the top would fell down to a side and down leaving the rest of the building still standing. Whatever you put on it, it will not do the things shown and claimed on TV. You could not even be able to collapse it symmetrically, in theory, all the way down, due to the height and the nature of structure.

Which force was that?
Which direction does that force usually push?
Oh - you said it: Down! So a force that pushes down goes "sidewise"? You have a strange definition of "down" and "sidewise"

You should not forget the building was a quarter mile tall.

 

[Carlos]

Both statements are irrelevant.The claim has no merit. Where are you going with it? Impact, well, lets call it initial impact, and fire may have severed and collapsed the top, you still have most of the building structurally intact.In reality I doubt it was structurally intact although forces and means used were more calculative than fire.

These structurally intact floors was not designed to support the upper floors mass on movement.

Do you know the difference between static and dynamic loads?

 

[brazenlilraisin]

Enough energy to compress the structure to a breaking point would result in a local failure and the top would fell down to a side and down leaving the rest of the building still standing. Whatever you put on it, it will not do the things shown and claimed on TV.

Let's get this straight: Your contention is that not only have the images of planes been inserted into 9/11 videos, but footage of the collapses has been altered as well?! Congratulations, you've added a brand new layer of stupid to 9/11 twoof!

 

[Mikeys]

Let's get this straight: Your contention is that not only have the images of planes been inserted into 9/11 videos, but footage of the collapses has been altered as well?! Congratulations, you've added a brand new layer of stupid to 9/11 twoof!

Its not my contention. I am not a CGI expert. The contention the video collapses just like everything else shown are fake is held by researchers. Obviously, thee is no point of inserting fake planes and fake collapses into a fake footage.

 

[beachnut]

...
Enough energy to compress the structure to a breaking point would result in a local failure and the top would fell down to a side and down leaving the rest of the building still standing. Whatever you put on it, it will not do the things shown and claimed on TV. You could not even be able to collapse it symmetrically, in theory, all the way down, due to the height and the nature of structure. ...

The WTC did not collapse symmetrically. It is math that leaves 911 truth unarmed and harmless. No math for 911 truth. Do you know what symmetrically means? No

 

[twinstead]

Let's get this straight: Your contention is that not only have the images of planes been inserted into 9/11 videos, but footage of the collapses has been altered as well?! Congratulations, you've added a brand new layer of stupid to 9/11 twoof!

I was getting tired of the old stupid; maybe it's a good thing that a brand new layer has been added.

 

[Sceptic-PK]

I don't understand why some people are unable to grasp why the towers collapsed the way they did.

http://northerngoodies.com/site_files/WTC_SUN_PICTURE.jpg

Edited by Loss Leader: 

Edited hotlinked image

 

[Justin39640]

I don't understand why some people are unable to grasp why the towers collapsed the way they did.

[qimg]http://northerngoodies.com/site_files/WTC_SUN_PICTURE.jpg[/qimg]

That's how fanaticism works... (shrugs)

Love that pic. *********** bastards (@AQ)

 

[Oystein]

Let's strip the cladding and look at the naked truth. Perimeter columns at the bottom were 5in thick and towards the top 1/4 only. It should tell you enough without the need to reference to exact specs and dividing it along the building.

What mass could a single 5in thick perimeter support statically, and what could it support dynamically, if that mass moved at, say, 20 m/s, to arrest that fall?

I frankly lack reliable intuition to guesstimate how strong 1/4 inch or 5 inch thick steel is, relative to a tower that weighs 300,000 tons. It ois far outside the envelop of immediate personal experience. You'd really need engineering calculkations here, or very solid on-the-job experience (i.e. having done such calculations over and over in the past).

To think that your or mine imagination suffices is more than stupid.

Perhaps not rubble, but integrity must have been compromised. It doesn't really matter and it is impossible to say what fell apart when the top shifted down.

Well, how about "the top shifted down"?

I guess it would be about 50 times heavier with the top being around 50K tons, not sure about the weight of the bottom so 50 times is ballpark

50 times 50K tons is 2,500,000 tons. That's wrong by a factor of about 10. The mass of an entire tower was about 300,000 tons. Subtract your estimate of 50,000 tons for the top, that makes the bottom ca. 250,000 tons. So the bottom part would be 5 times as heavy, not 50 times as heavy.

See how easily your intuition is wrong by an order of magnitude?

What hammer you need to squash a body?

Your argument was that more mass further below would somehow help the structure above avert collapse. But this isn't so.

When the top started "shifting down" (better word is: descending), it met one floor higher up, not the entire 250,000 tons further down.
The question is: Can and will the falling mass overwhelm and crush the next floor below?

And the anser is: A very resounding YES. Once a floor is crushed, all the mass, increased by the mass of the crushed floor, keeps falling another floor - and picks up speed as it does. So the next floor faces more mass at higher speed.

And the next floor faces even more at even more speed.

And so on.

So even though the lower floors have heavier steel columns, they still will fail because by the time the collapse front arrives there has more mass, more velocity, and hence MUCH more kinetic energy than it had further up.


And all this is ignoring that the columns were mostly bypassed - the main failure mode was breaking of the floor-to-column connections, which did not increase in strength further down.

It [numbers for KE available and necessary] doesn't matter.

Mikeys, could you please acknowledge, explicitly:

"I, Mikeys, don't know how much KE was available and can't provide an upper bound
I, Mikeys, don't know how much KE would have been necessary to cause total collapse, and can't provide a lower bound.
I, Mikeys, therefore retract my earlier claim that "The KE needed would have to be of much much grater scale to advance downward shift", which implied a claim that necessary KE was greater than available KE, two number I am unable to estimate."​

Enough energy to compress the structure to a breaking point would result in a local failure and the top would fell down to a side and down leaving the rest of the building still standing.

Which force would push and accelerate the top part sideways? Which side would it move to, and why that side and not another?

You made that up, right? You have some comic or cartoon in mind, perhaps?

Whatever you put on it, it will not do the things shown and claimed on TV. You could not even be able to collapse it symmetrically, in theory, all the way down, due to the height and the nature of structure.

You should not forget the building was a quarter mile tall.

You truly don't understand physics at all. You truly do not understand that buildings are mostly hollow.

A tall building can't topple like a tree, and no force is available to "shift" multipleentire floors sideways the entire width of the building.

You should not forget that the building was wider than a football field (American football)!

 

[Sunstealer]

The OP has made a classic mistake. The OP is is way, way, way too complicated for truthers to answer. Just look at how Mikeys has successfully managed to derail the thread and others are now clamouring to respond to him.

When dealing with truthers you have to go much much slower and ask one simple question per thread. These threads can then lead to a conclusion.

However, before that, they need about 5 years of schooling so they can do the basic maths, chemistry and physics to understand the questions in those threads.

You'd then need another 50 to simply get them to understand engineering terms and the maths behind them.

e.g:

Does steel lose strength with increasing temperature?

Followed by another thread by

What is creep? etc etc.

Then you'd require about 20 threads purely on how the WTC were constructed. No truther I've seen actually understands how they were constructed.

Mikeys makes the classic mistake of trying to say the mass of the top can't damage the mass of the bottom. Classic Gage box-boy nonsense.

How can you expect to get answers from people who are completely unaware of the basics? They've had 11 years - in that time they could have done 5 years of secondary school, 2 years at college and 3 years at university. 10 years of education.

 

[phunk]

What difference does it make how thick the columns were at the bottom? The stuff didn't fall on the columns, it fell between them.