How could WTC7 Possible have fallen like it did?

[Mick West]

The report includes figures 3.10-13 showing the right side collapse below floor 16 (?) at 0.5, 2.5 (shown above), 4.5 and 6.5 seconds, while the left side remains intact. Apparently everything above Column 79 drops down due to vertical failures' progression - there are free-flying parts. But the remainder of the structure below floor 16 is just locally damaged during 6.5 seconds. Nothing drops down from below = there is no free debris there. You would then expect the upper, intact part to tilt to the right!. The horizontal failures' progression is not clear.

What energy is required to produce all these failures?

Assuming you mean the ones in the figure, then none. If you remove the support from something, then it will fall.

The energy prior to these failure was that required to remove enough supports from around col 79 so that it was no longer stable, and hence buckled. After that there was a progressive collapse that required no additional energy.

 

[Mick West]

I didn't scroll down or read, but you might as well take his challenge given he's that so mentally inept bases his ideas on nonsense.

Why? He would just disagree, and then not give me any money.

Thought experiment: how much weight can an empty soda can support as a multiple of its weight? How much could WTC7 support as a multiple of its weight? Why are these numbers different?

 

[Alchemist]

Are you really trying to attribute that nonsense "pan-cake" theory to WTC 7?

Why did 99.8% of the WTC7 that WASN'T damaged and INTACT offer 0% resistance to the collapse which unfolded?

 

[Mick West]

Are you really trying to attribute that nonsense "pan-cake" theory to WTC 7?

Why did 99.8% of the WTC7 that WASN'T damaged and INTACT offer 0% resistance to the collapse which unfolded?

No. WTC7 collapse by the exterior buckling at the base after the interior had fallen. My point was to illustrate some of the problems of scale.

 

[Alchemist]

The CD theory of WTC 7 is much more scientific and sound than the NIST theory. As I've previously stated, the NIST theory is only there to uphold a fairly tale which has been used to murder millions of people and bringing about a police state here in US to potentially enslave you, your children and grandchildren. Think about who benefits from upholding the official story. Who profits?

NIST theory is false in that the report predicts NO period of free fall as that would violate several known laws of physics.

Instead of wasting time upholding a fairy tale which has been used to kill millions of innocent civilians by the corporate war machine/military industrial complex, don't you think it would be better use of your time to debunk the official theories so that more time is contributed toward identifying criminal elements/corruption within government and corporate institutions and their methods?

Every minute you waste by not debunking REAL bunk like official story of 9/11 -- the corporate war machine & military industrial complex has the green light to continue murdering more innocent civilians and turning this place into a 100% surveillance police state. Is that the kind of world you want your children and grandchildren to live in?

 

[Mick West]

NIST theory is false in that the report predicts NO period of free fall as that would violate several known laws of physics.

That's not true at all. The initial NIST report simply measured the entire duration of the fall, which was (in total) at a rate less than free-fall. The full report broke it down into segments, and found that for a brief period it was essentially in free-fall.

So what exactly is "false" there?

 

[Alchemist]

Freefall can only occur if ALL of the resistence is removed simulataneously across the width of the building.

 

[Boston]

The biggest challenge in debunking 9/11 myths is that the physics is a bit complicated, and yet the believers think they understand it. There's several concepts that are difficult to convey, but the biggest two are:

1) scale and square-cube law
2) static vs. dynamic loading

Unfortunately because it can take some time to understand these two concepts, then nonsense like in your link will always sound enticing. Although perhaps you failed to notice the writer of the page also thought that all the video and photos of the collapse were fake, and that the towers were destroyed from the bottom up, and hence is perhaps not to be taken entirely seriously?

Feel free to explain to me where i've expressed a failure to grok either concept within my discussions on this forum. The square cube law has nothing to do with the demolition of BLD 7 and static vs dynamic loading in structural engineering is known as live vs direct loads sometimes called dead loads.

So whats your point, we're all a bunch of idiots who just can't fathom the physics or the mumbo jumbo of NIST just doesn't translate into actual physics real well ?

I'll go with option 2

 

[Mick West]

Freefall can only occur if ALL of the resistence is removed simulataneously across the width of the building.

And how would you do that then? Blow up every column on every floor? How many is that?

 

[Alchemist]

And how would you do that then? Blow up every column on every floor? How many is that?

So all 24 STEEL CORE COLUMNS would have to fail simultaneously in order for there to be any free-fall for ANY period of time.

 

[Mick West]

Feel free to explain to me where i've expressed a failure to grok either concept within my discussions on this forum. The square cube law has nothing to do with the demolition of BLD 7 and static vs dynamic loading in structural engineering is known as live vs direct loads sometimes called dead loads.

How do you think the dynamic load of a building falling a few feet compares to the dynamic load the building is designed to withstand, for the occupants and contents?

 

[MikeC]

And if you TRULY want to claim that redundancy was NO FACTOR in WTC 7, here's a €1,000,000 challenge for you: http://heiwaco.tripod.com/chall.htm

Might as well make some money if you're going to attempt to prove the impossible.

that might be true if you believed the money actually existed or Bjorkman had any intention of accepting any submission - but the guy is a total loonie who is on record as saying that steel structures are indestructible, even by nuclear weapons, while simultaneously saying that about 10 tons of HE would do the job....among other "interesting" claims.

 

[Mick West]

So all 24 STEEL CORE COLUMNS would have to fail simultaneously in order for there to be any free-fall for ANY period of time.

I was asking a question there, how many explosive charges would your theory require to be placed to get the conditions you say are needed for free fall?

 

[Boston]

Assuming you mean the ones in the figure, then none. If you remove the support from something, then it will fall.

The energy prior to these failure was that required to remove enough supports from around col 79 so that it was no longer stable, and hence buckled. After that there was a progressive collapse that required no additional energy.

Your missing the point Mick, it doesn't matter that one column lost support, we're not talking about one column, we're talking about every visible column fell in perfect unison at free fall speed for some period of time. Which requires that every column experience some amount of time in resistance free failure, symmetrically. Even if the columns just had to skip off to the side, they'd have to do it all at once and they'd have to do it in perfect sequence in order to result in whats seen. Even at that you'd still not get free fall because the pieces would run into themselves eventually. Progressive failure means that the failure progressed throughout the structure, but what we see in the film evidence is an instantaneous failure at all four corners following a kink which developed symmetrically across the entire building, yet these corners where at different distances from the kink, there for in a progressive failure it would have taken "time" for the progress of the failure to reach the furthest corner, it didn't.

 

[Boston]

I was asking a question there, how many explosive charges would your theory require to be placed to get the conditions you say are needed for free fall?

You'd have to talk to a demolitions expert experienced in that particular type of product used.

 

[Mick West]

Your missing the point Mick, it doesn't matter that one column lost support, we're not talking about one column, we're talking about every visible column fell in perfect unison at free fall speed for some period of time. Which requires that every column experience some amount of time in resistance free failure, symmetrically. Even if the columns just had to skip off to the side, they'd have to do it all at once and they'd have to do it in perfect sequence in order to result in whats seen. Progressive failure means that the failure progressed throughout the structure, but what we see in the film evidence is an instantaneous failure at all four corners following a kink which developed symmetrically across the entire building, yet these corners where at different distances from the kink, there for in a progressive failure it would have taken "time" for the progress of the failure to reach the furthest corner, it didn't.

But in the NIST hypothesis the interior columns do not collapse at free fall. They have already collapsed (in a progressive manner) before the exterior of the building started to collapse.

So we are only taking about the exterior columns, right? It's a bit like a tin can at this point, a skin, with the interior collapsed or collapsing.

 

[Mick West]

You'd have to talk to a demolitions expert experienced in that particular type of product used.

That's not what I'm asking. You say you have to remove all resistance. I'm asking how you remove the columns. If you just put explosives on the bottom floor then (under your assumptions) there would be resistance from floor 2 when it hits the ground, right?

 

[Jazzy]

So all 24 STEEL CORE COLUMNS would have to fail simultaneously in order for there to be any free-fall for ANY period of time.

They had already gone. You can see this in the collapse videos - through the windows of WTC7.

The videos only show the exterior of the building. Its interior fell with the penthouse before the exterior buckled at its base.

Vertical columns (in this case a fascia of columns) buckle silently, and rapidly approach near-free-fall acceleration.

 

[MikeC]

For information - the kinematic equation for velocity after fallin some distance is V(final)^2 = v(initial)^2 + 2ad

so for a fall of 3.7 metres, with initial velocity = 0, the final velocity will be sqrt(2*9.81*3.7) = 8.5m/sec

The static load of a mass m = ma = where a = gravity or m*9.81m/sec^2

the kinetic energy of that mass having fallen 3.7m is 0.5*mv^2, which for our 3.7 meter fall will be 0.5*8.5^2*m = about 36.125 * m......or a bit more than 3 times as much energy as the same mass has when static.

I think....

 

[Alchemist]

According to the official story, the collapse of the building was initiated by the collapse of column 79, which lead to the visual fall of the east mechanical penthouse.

NIST claims that column 79 began to accelerate downwards about 0.2 seconds after it had buckled:

"Once Column 79 buckled, the column section above Floor 14 began to descend downward. Column 79 began moving downward at the roof level approximately 0.2 s after Column 79 buckled and 0.6 s before Column 80 buckled."

This means that the vertical dispalcement of column 79 at the roof level was 0.83 meters in 0.6 seconds which implies that within ONE second of buckling, column 79 was moving downwards with an acceleration of 4.6 m/s2. So in 1/5th of a second, for more than 30 floors above where the buckling occured, 79th column's lateral supports from all UNDAMAGED interconnections in this WIDE, MAMMOTH NETWORK of STEEL were RIPPED FREE.

That's ASTOUNDING... considering that the column was still RESTRAINED by countless STEEL framing beams and girders that were UNDAMAGED and UNHEATED.

 

[Jazzy]

For information - the kinematic equation for velocity after fallin some distance is V(final)^2 = v(initial)^2 + 2ad

so for a fall of 3.7 metres, with initial velocity = 0, the final velocity will be sqrt(2*9.81*3.7) = 8.5m/sec The static load of a mass m = ma = where a = gravity or m*9.81m/sec^2 the kinetic energy of that mass having fallen 3.7m is 0.5*mv^2, which for our 3.7 meter fall will be 0.5*8.5^2*m = about 36.125 * m......or a bit more than 3 times as much energy as the same mass has when static. I think....

This beats the static loading of fire-weakened floor-to-column/beam connections, suggesting that once a single floor detaches, it is likely to bring down the next and the next, etc. Once a few floors are falling together, then undamaged floors will stand no chance.

Considering the fascia (which is all you see in the videos), once any part of it began to buckle all of it was awaaaaaaaaaay...

A 47-floor-high single column, thick though it may be at its base, cannot stand without buckling. It relies on all 46 lateral connections to stabilize it.

A line of such columns, making a building face, will FOLD as soon as it receives some extraneous lateral force. This was provided by the bursting pile of collapsed floors within it.

 

[Mick West]

For information - the kinematic equation for velocity after fallin some distance is V(final)^2 = v(initial)^2 + 2ad

so for a fall of 3.7 metres, with initial velocity = 0, the final velocity will be sqrt(2*9.81*3.7) = 8.5m/sec

The static load of a mass m = ma = where a = gravity or m*9.81m/sec^2

the kinetic energy of that mass having fallen 3.7m is 0.5*mv^2, which for our 3.7 meter fall will be 0.5*8.5^2*m = about 36.125 * m......or a bit more than 3 times as much energy as the same mass has when static.

I think....

The energy of a mass does not change in quantity as it falls. It just changes in type from potential to kinetic.

The important number here is force. F = ma. Or if we are just considering a single mass in two situations, then it's the acceleration. And in this case it's the force from deceleration, vs. the force of gravity.

It's a little complicated. Which is the problem.

 

[Mick West]

According to the official story, the collapse of the building was initiated by the collapse of column 79, which lead to the visual fall of the east mechanical penthouse.

NIST claims that column 79 began to accelerate downwards about 0.2 seconds after it had buckled:


This means that the vertical dispalcement of column 79 at the roof level was 0.83 meters in 0.6 seconds which implies that within ONE second of buckling, column 79 was moving downwards with an acceleration of 4.6 m/s2. So in 1/5th of a second, for more than 30 floors above where the buckling occured, 79th column's lateral supports from all UNDAMAGED interconnections in this WIDE, MAMMOTH NETWORK of STEEL were RIPPED FREE.

That's ASTOUNDING... considering that the column was still RESTRAINED by countless STEEL framing beams and girders that were UNDAMAGED and UNHEATED.

Why is it astounding? If it failed by buckling that meant that the entire column had to be moving downwards already.

 

[Jazzy]

According to the official story, the collapse of the building was initiated by the collapse of column 79, which lead to the visual fall of the east mechanical penthouse. NIST claims that column 79 began to accelerate downwards about 0.2 seconds after it had buckled. This means that the vertical displacement of column 79 at the roof level was 0.83 meters in 0.6 seconds which implies that within ONE second of buckling, column 79 was moving downwards with an acceleration of 4.6 m/s2. So in 1/5th of a second, for more than 30 floors above where the buckling occurred, 79th column's lateral supports from all UNDAMAGED interconnections in this WIDE, MAMMOTH NETWORK of STEEL were RIPPED FREE. That's ASTOUNDING... considering that the column was still RESTRAINED by countless STEEL framing beams and girders that were UNDAMAGED and UNHEATED.

Not astounding at all. It's the reason why hammers are available in hardware stores. They only weigh a few pounds, but they can create instantaneous loadings of tons. It's (half the) mass times the square of the velocity...

And 4.6 m/s2 is only half the acceleration due to gravity. The rest of that momentum was being lost doing work on the structure.

Understanding vertical column buckling isn't easy. Mick's video makes it very clear. A vertical column can fail in buckling without physical damage - initially, at least.

It doesn't fail by crushing. It simply deflects, or bends, until it no longer carries its load. This load must then be carried (through its connections) to the rest of the structure, which may or may not hold up. Generally, it's the connections that fail because they are designed for static perpendicular and horizontal forces only.

 

[MikeC]

The energy of a mass does not change in quantity as it falls. It just changes in type from potential to kinetic.[/quoet]

Yes - I keep confounding energy, force and work - even when I was in school!!

 

[Alchemist]

Why is it astounding? If it failed by buckling that meant that the entire column had to be moving downwards already.

Given the fact that column 79 had been secured for more than 30 floors by beams, girders, and interconnected to other core columns that had suffered no damage, how could it have been accelerating downward within only 0.2 seconds?

 

[Boston]

But in the NIST hypothesis the interior columns do not collapse at free fall. They have already collapsed (in a progressive manner) before the exterior of the building started to collapse.

So we are only taking about the exterior columns, right? It's a bit like a tin can at this point, a skin, with the interior collapsed or collapsing.

sure but the invisible is a little hard to debate, IE they have no evidence of this internal collapse beyond the collapse of the pent house structures. So there really is no way to verify or negate the internal collapse theory, IE the invisible is kinda hard to debate.

Its that exterior of the building that we can see and that does fall at free fall speeds, all four corners at once, in unison, at free fall speed for some number of seconds, quite a few actually. Its this instantaneous loss in structural integrity among the visible components of the building, in beautiful symmetry that is however, the issue. This symmetrical collapse is a virtual impossibility as a result of asymmetrical damage or progressive collapse.

And no its nothing like a tin can, its more like a 47 story building.

 

[MikeC]

Given the fact that column 79 had been secured for more than 30 floors by beams, girders, and interconnected to other core columns that had suffered no damage, how could it have been accelerating downward within only 0.2 seconds?

how could it not?

You have a poor understanding of physics - once it is no longer supported it accelerates due to gravity - any time after "0" (zero) seconds it is accelerating.

If you drop something from your hand does it wait for some period before it starts falling??

 

[Soulfly]

If you drop something from your hand does it wait for some period before it starts falling??

It does if it's a slinky.

 

[Alchemist]

how could it not?

You have a poor understanding of physics - once it is no longer supported it accelerates due to gravity - any time after "0" (zero) seconds it is accelerating.

If you drop something from your hand does it wait for some period before it starts falling??

You do realize you're referring to a minor failure of a SINGLE column connected to a MONSTROUS network of steel beams, columns & girders?

 

[Jazzy]

sure but the invisible is a little hard to debate, IE they have no evidence of this internal collapse beyond the collapse of the pent house structures. So there really is no way to verify or negate the internal collapse theory, IE the invisible is kinda hard to debate.

How can that penthouse structure fall with its supports intact? It cannot. Yet it does. Ergo its support is dropping too.

Its that exterior of the building that we can see and that does fall at free fall speeds, all four corners at once, in unison, at free fall speed for some number of seconds, quite a few actually. Its this instantaneous loss in structural integrity among the visible components of the building, in beautiful symmetry that is however, the issue. This symmetrical collapse is a virtual impossibility as a result of asymmetrical damage or progressive collapse.

It isn't damaged at all. It also isn't stable at all, and buckles. Buckling involves an almost instantaneous shedding of its own weight load, which means an almost instantaneous downward acceleration of G.

And no its nothing like a tin can, its more like a 47 story building.

A 47 story rectilinear shell, with no internal bracing? Not like a cylindrical shell, with no internal bracing?

It does if it's a slinky.

The top of the slinky falls immediately, at a rate faster than G, as the tension within it adds to the acceleration..

The center of mass of the slinky falls at G.

The base of the slinky may rise, stay where it is, or fall more slowly than G as the tension within it subtracts from the acceleration due to G.

 

[MikeC]

You do realize you're referring to a minor failure of a SINGLE column connected to a MONSTROUS network of steel beams, columns & girders?

No I am not.

I am referring to a CRITICAL failure of a single column connected to a monstrous (no not really - but it is your emotive word) network of ..etc...

 

[Jazzy]

You do realize you're referring to a minor failure of a SINGLE column connected to a MONSTROUS network of steel beams, columns & girders?

Vertical column buckling failure isn't normally minor. All the other columns are carrying their own loads too, and have to take over the task of the failed column.

This may be OK in a building which is undamaged by impact and fire. Except that ALL the 184 floor edges and beams supported by that column are now cantilevers, and may themselves collapse.

If floors do collapse, then the floors beneath them are going to be struck by these floors at a speed, according to MikeC (and I agree), of 8.5 m/sec.

And so on...

 

[Alchemist]

No I am not.

I am referring to a CRITICAL failure of a single column connected to a monstrous (no not really - but it is your emotive word) network of ..etc...

... in a building with inbuilt REDUNDANCY which wouldn't allow for such failure of columns to lead to a global collapse.

 

[MikeC]

No - in a building where the redundancy had not been properly designed to account for this failure.

you seem to think that saying something has "redundancy" means all potential single point failures are automatically impossible. That is not so. Redundancy has to be designed, and it can be incomplete.

Designers do go to a great deal of effort to identify and avoid single point failures - but they do not always get it right.

I'm tossing up whether to ignore you as a troll or as a sufferer of the Dunning-Kruger effect..... (wiki article here) ....I expect you to select my reason shortly.....

 

[Alchemist]

No - in a building where the redundancy had not been properly designed to account for this failure.

you seem to think that saying something has "redundancy" means all potential single point failures are automatically impossible. That is not so. Redundancy has to be designed, and it can be incomplete.

Designers do go to a great deal of effort to identify and avoid single point failures - but they do not always get it right.

If NIST's simulations are supposed to "accurately" reflect what happened to WTC 7, then why did it collapse vertically with it's roof line remaining essentially horizontal through the first 5 seconds of its downward motion, when NIST's simulations show the eastern side of the building starting to collapse 4 seconds before the western half?

 

[MikeC]

References and relevance?

Is part of what the NIST said wrong - why?

Here's the actual simulation - which part are you talking about? It might be a good idea to illustrate your point by taking some screenshots and highlighting them for clarity.

 

[Jazzy]

If NIST's simulations are supposed to "accurately" reflect what happened to WTC 7, then why did it collapse vertically with it's roof line remaining essentially horizontal through the first 5 seconds of its downward motion, when NIST's simulations show the eastern side of the building starting to collapse 4 seconds before the western half?

There are many possible reasons. Variability of fixings. Variability of steel UTS. Extra work or remedial work not according to plan. Extra loadings due to equipment installed after construction. All of these are quite usual and impossible to foresee.

It is also difficult to simulate the exact order in which floors might tumble and where they exactly end up, considering they may be carrying these possibly unforeseen pieces of equipment attached to them, or be dragged back by attached piping, wiring, and ductwork.

They seemed quite reasonably "not quite accurate" to me, as I am fairly familiar with simulation techniques and their marginal inaccuracies. If the simulation had been identical I would have suspected something.

More importantly, are you acknowledging and understanding the explanations you have thus far received, and not just moving on without taking them up? You are not saying...

 

[Pete Tar]

... then why did it collapse vertically with it's roof line remaining essentially horizontal through the first 5 seconds of its downward motion...

It clearly is observable this is not true, it sags in the middle, probably at least a meter lower than the higher line of the edges.

 

[Alchemist]

Why does NIST enjoy a gospel-status on this forum? Their conclusions are not based on any physical evidence that can be tested and confirmed, just computer simulations.

There are THOUSANDS of well-informed scientists, architects, engineers, demolition experts and structural engineers that are not affiliated with any organization who disagree with the NIST report.

The collapse sequence used by NIST is the one taking place in their computer simulation under direct control of NIST analysts.

And you have investigators who are directly affiliated with an agency which stood to PROFIT from upholding the official story. This is NO DIFFERENT than Obama ordering Eric Holder to investigate DOJ concerning illegal wiretapping of reporters, when under his direct leadership, DOJ illegally wiretapped reporters. This is like asking an Al Qaeda-linked organization to investigate 9/11 and referring to their conclusions as if it's some work of God.

Not to mention this was an over-engineered, highly secure building which housed the CIA, Secret Service, IRS, Department of Defense and Securities and Exchange Commission.