A Truther writes...

[angrysoba]

Someone on another forum is very pleased with themselves at having come up with a fool-proof demolition of the "official story" and believe that it is refuted by applying the conservation of momentum. They also link to some execrable page from the execrable "What Really Happened" website. But does anyone feel like giving a concise reason for why the conservation of momentum argument is wrong or misapplied here? (I'm not an engineer!)

Quote:

Perhaps the key point to the entire implausibility of the 'pancake collapse' theory is considering a very old law - conservation of momentum.
Conservation of momentum comes from Newton's first law. A body will remain at rest or travel in uniform motion in a straight line unless acted upon by another force.
Consider the initial collapse of the top sections, which in each case would have the lightest top portion of the building, being the thinnest part of the core. We are expected to believe that as it suddenly (with a flash) lost all its structure and fell onto the floor below, the combined weight of the section above the disintegrated floor lands on the floor below. That causes the floor below to collapse under the strain, and the entire new mass falls onto the next floor. This progression continues neatly all the way down.
That's fine, apart from one very important detail - how does each new floor suddenly assume the accumulated velocity of the falling floors above? We're talking about a progressively heavy core structure (it having been built to bear the weight of the entire structure above, at each stage). So why did it not _substantially_ arrest the downward motion?
As Frank Verismo points out, a great deal of the mass was pulverised in any case, so the full weight of the above sections were dispersed each time a new floor was reached by the downward progression.
How did the really heavy mid to lower sections suddenly start moving at the same pace as the falling upper sections, unless they were offering _virtually no resistance at all_ - unless they were already falling themselves immediately before the progression hit them.
The towers did not come down quite at free-fall speed, but it was not far off it. It was way too close to free-fall acceleration to believe even for a moment than a substantial structure of increasing strength was being crushed by the powdered remains of the floors above.
*
If the motion was entirely downwards, with no other force than downward gravity operating after collapse was initiated, why do we see massive steel girders ejected out laterally for hundreds of feet? Why did tiny body parts (sections of finger, etc.) appear on rooftops hundreds of yards away?
In standard building collapses, one would find at least a few things intact. A chair, a monitor, something. How come the biggest items found were fragments of telephone keypads?
Look at the column on the last picture on this page: How did it acquire that precise cut, consistent with a controlled demolition?
http://whatreallyhappened.com/WRHARTICLES/thermite.htm
*
But back to conservation of momentum. Inertia dictates that a mass will not suddenly assume the velocity of the moving object falling onto it, even if it is so tenuously structured that a feather falling onto it would initiate its collapse. In this case, we are talking about an increasing substantial structure the further down the building we go. Yet it offered little more resistance than fresh air on the day of 9/11.

[BNRT]

I think he forgot there already is a force acting on the floors all the time. It's called gravity.

[T.A.M.]

What a *********** idiot.

TAM

[Seymour Butz]

2 points.

1- he accepts that stuff falling on the floors will break them up, and then asks how the falling mass destroys the columns. This line of thinking is as odds. Once he admits that stuff falls on the floors, then the strength of the columns is NOT the determining factor. the strength of the floors and their connections are, Whather or not core columns fail depends on the bracing they have AFTER the debris passes through, and any rational mind will admit that the core floors/bracing will be destroyed as well by the debris.

2- he also mentions something about the floors being broken up before the debris hits it. Well, Bazant describes this very thing as likely to have happened by air pressure from the descending debris cracking apart the concrete SLIGHTLY AHEAD OF the debris impacts.

[The Big Dog]

"Look at the column on the last picture on this page: How did it acquire that precise cut, consistent with a controlled demolition?"

Welcome to 2005!

Gee an angle cut column is "Consistent with controlled demolition"??? Jesus, who are they kidding?

My suggestion is that you link to verinage demolition videos and tell the knucklehead to STFU and GBTW.

http://www.dailymotion.com/video/xbp...t-jean-vu_news

[W.D.Clinger]

Originally Posted by angrysoba

But does anyone feel like giving a concise reason for why the conservation of momentum argument is wrong or misapplied here? (I'm not an engineer!)

Originally Posted by T.A.M.

What a *********** idiot.

TAM

TAM's response is accurate and concise.

Here are a few supporting details. All quotations are from the Truther quoted in the original post.

Quote:

That's fine, apart from one very important detail - how does each new floor suddenly assume the accumulated velocity of the falling floors above? We're talking about a progressively heavy core structure (it having been built to bear the weight of the entire structure above, at each stage). So why did it not _substantially_ arrest the downward motion?

When an upper section consisting of 12 floors collides inelastically with the floor below, the loss of velocity due to conservation of momentum is about 1/13 of the upper section's velocity just before the collision. You aren't likely to see that with the naked eye.

Gravity continues to accelerate the upper section through the collision, so poor video analysis doesn't always show it either. Competent video analysis shows diminutions of velocity considerably in excess of what is predicted by conservation of momentum. In other words, the effect predicted by conservation of momentum was small relative to the reduction in velocity caused by the supporting strength that remained within the compromised structure below.

As the collapse progresses, the falling mass grows larger. That means the diminution of velocity attributable to conservation of momentum, which was already less than 10% for the first collision, becomes even less noticeable in subsequent collisions.

Quote:

The towers did not come down quite at free-fall speed, but it was not far off it.

The average downward acceleration was about two-thirds the acceleration of gravity.

Quote:

But back to conservation of momentum. Inertia dictates that a mass will not suddenly assume the velocity of the moving object falling onto it, even if it is so tenuously structured that a feather falling onto it would initiate its collapse. In this case, we are talking about an increasing substantial structure the further down the building we go. Yet it offered little more resistance than fresh air on the day of 9/11.

Fresh air does not reduce the acceleration of gravity by one-third.

[Thunder]

A truther says what?

[bill smith]

Originally Posted by angrysoba

Someone on another forum is very pleased with themselves at having come up with a fool-proof demolition of the "official story" and believe that it is refuted by applying the conservation of momentum. They also link to some execrable page from the execrable "What Really Happened" website. But does anyone feel like giving a concise reason for why the conservation of momentum argument is wrong or misapplied here? (I'm not an engineer!)

'' How did the really heavy mid to lower sections suddenly start moving at the same pace as the falling upper sections, unless they were offering _virtually no resistance at all....''

Well put. I hope Heiwa reads it. It would play well for him..

[Edx]

lol he promotes the thermal lance cut column picture as evidence of thermite lol.

[Oystein]

Quote:

...We are expected to believe that as it suddenly (with a flash) lost all its structure and fell onto the floor below, ...

It doesn't matter at all if the top section above the burning floors lost all their support in a flash or somewhat gradually. All that matters is that a cross-section of the tower crashed (columns/joints buckling and breaking) and the top section picking up some speed as it is accelerated by gravity.

Quote:

...how does each new floor suddenly assume the accumulated velocity of the falling floors above?

Strawman. It doesn not assume the speed, it assumes the momentum, thereby losing some speed (as some of the mass starts out at rest)

Quote:

We're talking about a progressively heavy core structure (it having been built to bear the weight of the entire structure above, at each stage). So why did it not _substantially_ arrest the downward motion?

As lower stories became progressively heavy (and strong), so did the weight and the speed of the already falling top part accumulate. So while the static strength of the lower stories increased basically in a linear function, the momentum of the fall increased basically with a function that contains a power of 2 - momentum increased faster than resisting static force.

Quote:

As Frank Verismo points out, a great deal of the mass was pulverised in any case, so the full weight of the above sections were dispersed each time a new floor was reached by the downward progression.

When we are looking at conservation of momentum, it doesn't matter if the mass you want to arrest is already pulverized or still structurally intact. If you want to arrest the collapse, you need to arrest the downward momentum of all the masses involved, as it wouldn't do much good to stop the intact parts and let the pulverized parts keep falling (all the way).

Quote:

How did the really heavy mid to lower sections suddenly start moving at the same pace as the falling upper sections, unless they were offering _virtually no resistance at all_ - unless they were already falling themselves immediately before the progression hit them.

Because the dynamic load of n upper stories at velovity v with mass m is magnitudes greater than the static load these mid to lower sections were designed to carry. They were designed to excert the upward force of several (3-5?) times the weight of all the floors above, but to arrest these floors within the short distance that the columns still remain elastic would require a force much more than 10 times the weight.

Quote:

The towers did not come down quite at free-fall speed, but it was not far off it. It was way too close to free-fall acceleration to believe even for a moment than a substantial structure of increasing strength was being crushed by the powdered remains of the floors above.

Towers came down around 2/3rds of free fall speed which actually is a considerable distance off.
Plus Argument from incredulity.

Quote:

If the motion was entirely downwards, with no other force than downward gravity operating after collapse was initiated, why do we see massive steel girders ejected out laterally for hundreds of feet? Why did tiny body parts (sections of finger, etc.) appear on rooftops hundreds of yards away?

Drop a paper bag full with assorted things (screws, tomatoes, marbles, toys) from your upper floor down onto your terrace. Watch what happens. See how some of the things are flung sideways?

Quote:

In standard building collapses, one would find at least a few things intact. A chair, a monitor, something. How come the biggest items found were fragments of telephone keypads?

Twin Towers were non-standard building collapses. They were just so very much bigger than anything we've seen so far. Potential energy of one tower, just standing erect, equals that of a formidable nuke. That is as much "standard building collapse" as Hiroshima was "standard bombing".

Quote:

Look at the column on the last picture on this page: How did it acquire that precise cut, consistent with a controlled demolition?
http://whatreallyhappened.com/WRHARTICLES/thermite.htm

As has been pointed out before: Welcome to the dark ages of trutherism.

Quote:

But back to conservation of momentum. Inertia dictates that a mass will not suddenly assume the velocity of the moving object falling onto it, even if it is so tenuously structured that a feather falling onto it would initiate its collapse. In this case, we are talking about an increasing substantial structure the further down the building we go. Yet it offered little more resistance than fresh air on the day of 9/11.

Increasing substantial structure met even faster increasing momentum the further down the building we go.

[Bell]

Originally Posted by bill smith

'' How did the really heavy mid to lower sections suddenly start moving at the same pace as the falling upper sections, unless they were offering _virtually no resistance at all....''

Well put. I hope Heiwa reads it. It would play well for him..

Just to make sure we are on the same pace here.
The WTC towers were constructed with these flimsy floors:



I have no idea how those flimsy floors could stop a falling block like this:



Do you have any idea? Maybe Heiwa knows?
After all he is a naval architect and marine engineer.

[bill smith]

Originally Posted by Bell

Just to make sure we are on the same pace here.
The WTC towers were constructed with these flimsy floors:

http://www.internationalskeptics.com...df7b2e709f.jpg

I have no idea how those flimsy floors could stop a falling block like this:

http://www.internationalskeptics.com...df7bfd686f.jpg

Do you have any idea? Maybe Heiwa knows?
After all he is a naval architect and marine engineer.

...and don't forget that he is a formidable structural damage analyst..

[Bell]

Originally Posted by bill smith

...and don't forget that he a formidable structural damage analyst..

... of shipwrecks. You are not even trying are you?

[bill smith]

Originally Posted by Bell

... of shipwrecks. You are not even trying are you?

Not at the moment. You will know when I am..

[Bell]

Originally Posted by bill smith

Not at the moment. You will know when I am..

Cool!

[bill smith]

Originally Posted by Bell

Cool!

Thank you.

[dafydd]

Originally Posted by Bell

... of shipwrecks. You are not even trying are you?

No,Bill has lost the trolling touch.Telltale Tom is at number one at the moment.

[jhunter1163]

I'm trying to figure out what 11-letter bad word TAM used.

*thinking*

*thinking*

*thinking*

Oh, OK. Got it.

[T.A.M.]

*********** idiot

How many letters now?

TAM

[T.A.M.]

The autosensor puts in more * then are needed. The curse word I used above, and in the original post, was only 7 letters long.

TAM

[Bell]

Originally Posted by dafydd

No,Bill has lost the trolling touch.Telltale Tom is at number one at the moment.

Tom is not a troll. Imho.

[Dog Town]

Originally Posted by Bell

Tom is not a troll. Imho.

Right! Parody is the word people are looking for. I know it's hard to tell, parodies of twoof, considering the original content. TT has a great wit.

[T.A.M.]

TT is so dry I sometimes forget he is a parody, and lash out at his "stupidity".

TAM

[angrysoba]

Thanks very much for the replies, especially for Oystein's point-by-point rebuttal. I think that the two main problems are that 1) I don't know anything about engineering or how the structure could have fallen down and 2) neither does my opponent.

I prefer to ask

a) What would be the point in demolishing the Towers in the first place? It would serve no purpose whatsoever except to tip off structural engineers such as David Ray Griffin that something weird was going on.

b) If they were demolished by controlled demolition there would have been sounds of explosions - there were not - and other phenomenon consistent with explosive force that the Truther says flung steel beams hundreds of feet out laterally. How far, for example, would the glass be flung out?

But the Truther in question is so adamant that they have exposed the "official story" as a lie that they don't feel the need to offer any alternative scenarios.

[Oystein]

Originally Posted by angrysoba

Thanks very much for the replies, especially for Oystein's point-by-point rebuttal. I think that the two main problems are that 1) I don't know anything about engineering or how the structure could have fallen down and 2) neither does my opponent.

I am not an engineer of any kind, and whatever I write about engineering is basically what I picked up from real engineers (some of them here at JREF), or what I would consider a good measure of common education.

However, the "Truther" you are dealing with purports to base his argument on specifically the "conversation of momentum", a basic physical law. You can argue on that ground without going too much into actual engineering, as all engineering is ultimately subject to physical laws.

I once came up with my own little one-dimensional collapse model, using old-fashioned paper and pencil, and the physics I learned in high school. I made some assumptions about the properties of structural elements that were surely naive and uneducated, but made them such that I was sure to err on the side that would make total collapse less, not more, likely.
My result was, that collapse would progress at an acceleration of about half G, thus a little slower than it did; which is no doubt due to my assumptions being unrealistically conservative.

Here is a rough ouline of my model:

Assumptions:

• I modelled a tower as a stack of 110 columns, each 3.5 meters high.
• Each column (=story) would have a mass of unspecified dimension, with the top column having a mass of 1.
• Each column would have to be able to support the 3 times weight of all columns above it. Accordingly, the mass of columns would increase top to bottom.
• I assumed that a column could support the full 3 times weight of all stories bove it even if compressed or bent, until it is shortened by 10%. At that point, the column would break and offer 0 resistance. "Support the full 3 times weight" means "excert a an upward force 3 times the gravity of the static load".
• Only the column immediately touched by the falling top block would bear the full dynamic load; no wave propagation to stories below
• Collapse initiation would be such a failure event: a story that had already sagged by 10% of its weight breaks and falls freely the remaining 90% of story height.
• g=10 m/s²

Equations needed:

• mass of falling top block above story N: m(N) = sum_n=N+1..110(m_n), where m_n is the mass of the n-th column or story
• Force of gravity: G = m*g
• Upward force of intact columns: A_c = -3*G = -3*m*g
• Deceleration of falling top part by upward force: delta-v = A_c * delta-t
• Conversation of momentum: m(N) * v(N) = (m(N) + m_N) * v(N-1)

What happens story by story is this:
1. The combined weight of stories N+1...110 falls freely a height of 90% of 3.5m = 3.15m and gains speed according to delta-v = g * delta-t
2. The block impacts (collides inelastically with) story N. As the mass of the top section always greately exceeds the mass of the single story below, the downward velocity is reduced by a few percent only
3. The impacted column now excerts an upward force to the falling block; since at the same time, gravity is still pulling downwards, that deceleration has a value of only 2g. Deceleration takes place for a vertical distance of 10% of story height, or 0.35m, which means columns get elastically compressed or bent.
4. If downward velocity reached 0 before the 10% are expended, the fall is arrested. This never happens. Instead, colum will break at this point. Goto 1.

It turns out that v increases by the same amount from story to story. In other words: We have a constant average acceleration downwards. With my assumptions, that average was slighly below 0.5*g. It would decrease if you assume a safety margin greater than 3* static load (a factor of 5 could be equally reasonable), it increases if you assume that columns (or their joints) break sooner than I assumed (in fact, I am sure that I was very generous here).

Originally Posted by angrysoba

I prefer to ask

a) What would be the point in demolishing the Towers in the first place? It would serve no purpose whatsoever except to tip off structural engineers such as David Ray Griffin that something weird was going on.

Hey, but think at the sinister laughs that can be had whilst devising such fiendish plans!
I hope you are being sarcastic about Dave the Builder??

Originally Posted by angrysoba

b) If they were demolished by controlled demolition there would have been sounds of explosions - there were not - and other phenomenon consistent with explosive force that the Truther says flung steel beams hundreds of feet out laterally. How far, for example, would the glass be flung out?

uhm... if forces and momentum are available to fling large things laterally, the same forces and momentum would be available to fling small pieces, no matter what the source of the force and momentum, not? I am pretty sure that lots of glass and other small pieces were flung out even farther than the steel beams. In fact, lots of lower Manhattan was littered with small things (dust...), only small portions with big things.

Originally Posted by angrysoba

But the Truther in question is so adamant that they have exposed the "official story" as a lie that they don't feel the need to offer any alternative scenarios.

JAQing off, aren't they

[angrysoba]

Quote:

uhm... if forces and momentum are available to fling large things laterally, the same forces and momentum would be available to fling small pieces, no matter what the source of the force and momentum, not? I am pretty sure that lots of glass and other small pieces were flung out even farther than the steel beams. In fact, lots of lower Manhattan was littered with small things (dust...), only small portions with big things.

Good point. I think, however, that the glass would have scattered far wider if the columns on every floor had been blown out with explosives given that the forces and momentum would have originated from a different place than the force of a top-down collapse.

Quote:

I hope you are being sarcastic about Dave the Builder??

Are you saying retired theologians aren't the best authorities on structural engineering?!!??!?!?!??!

Thanks also for the model of the collapse you sketched out as well.

[Oystein]

Originally Posted by angrysoba

Good point. I think, however, that the glass would have scattered far wider if the columns on every floor had been blown out with explosives given that the forces and momentum would have originated from a different place than the force of a top-down collapse.

Well maybe, but that is merely what you can imagine, and might stand against what others maybe can't imagine

Originally Posted by angrysoba

Are you saying retired theologians aren't the best authorities on structural engineering?!!??!?!?!??!

Why yes, they take it directly from God, the Supreme Structural Engineer of the Universe

Originally Posted by angrysoba

Thanks also for the model of the collapse you sketched out as well.

My model is pretty bad compared with what's out there. I just wanted to point out that everybody with a basic understanding of mechanics (ETA: the branch of physics) can get down to work with the roughest of assumptions and come up with a basic understanding of the dynamics involved.

In the same vein, I did a very simple experiment:
I took a bundle of drinking straws, cut them to about 10cm to give them a little more strength per cm, put them upright on my table top, and carefully rested my hands on them. Then I removed straw by straw until there wer so few left that they could not support my hand and snapped. Turned out, at least 3 straws were required to statically support my hand.

Then I took 3 times that number: 9 straws. Bundled them. Put them upright. And let my hand freely drop on to them from a height of about 20cm

Turns out, all 9 instantly snap and can't support the now dynamic load of my hand.

Simple experiment, but very instructive to the layman's intuition.

[angrysoba]

Thanks again. Also, how about the amount of mass that was lost from it spilling down the sides of the buildings?

I realize that to some extent this shows that the remaining building was resisting far more than thin air (unlike the claim being made) as it obviously wasn't going straight down.

But doesn't this skew the calculations regarding how much downward momentum there was?

[Oystein]

Originally Posted by angrysoba

Thanks again. Also, how about the amount of mass that was lost from it spilling down the sides of the buildings?

I realize that to some extent this shows that the remaining building was resisting far more than thin air (unlike the claim being made) as it obviously wasn't going straight down.

But doesn't this skew the calculations regarding how much downward momentum there was?

Hmm obviously, as anything that falls outside of the footprint would not impact any intact portions of the building. How much fell outside of the footprint? Hard to guess. Probably less than half of the mass (until it all piled up in a heap on the ground and much spilled sideways from there).
Calculations show that momentum and energy available exceeded maximum design load by a magnitude or more. If you deduct half the mass, you only deduct half the momentum and half the energy, and still remain well above design limits.


More importantly, if your truther is one of the many who argue that the towers fell onto their own footprint and that because of this the case for controlled demolition is strengthened, you need to point out that they can't have it both ways: They can then not claim at the same time that a significant portion of the towers' masses fell outside of the footprint.

[angrysoba]

Originally Posted by Oystein

More importantly, if your truther is one of the many who argue that the towers fell onto their own footprint and that because of this the case for controlled demolition is strengthened, you need to point out that they can't have it both ways: They can then not claim at the same time that a significant portion of the towers' masses fell outside of the footprint.

Ah, yes. I did notice that.

Although it isn't so much "a truther" as a whole nest. The thread has been going for months but participation has now thinned out.

http://www.craigmurray.org.uk/archiv..._911_post.html

[The Big Dog]

Originally Posted by angrysoba

Ah, yes. I did notice that.

Although it isn't so much "a truther" as a whole nest. The thread has been going for months but participation has now thinned out.

http://www.craigmurray.org.uk/archiv..._911_post.html

Angrysoba, I had missed the fact that you were one of the truthers in that truther nest.

Ah.

Did you take the time to review the verinage video I linked above? According to your truther friend, that should not have worked. You will also note that a substantial portion of the structure (the facade) "spilled down the side of the building."

[angrysoba]

Originally Posted by 16.5

Angrysoba, I had missed the fact that you were one of the truthers in that truther nest.

Ah.

Did you take the time to review the verinage video I linked above? According to your truther friend, that should not have worked. You will also note that a substantial portion of the structure (the facade) "spilled down the side of the building."

Truther? No, not me. As you would be able to see if you read any of my comments there.

I have seen the verinage demolitions before and in fact posted videos of them over there. Of course there was plenty of wailing and gnashing of teeth and insistence that it didn't apply to the Twin Towers collapses for various reasons. Regarding the conservation of momentum they argued that in the verinage demolitions there was a considerable visible slowdown in each whereas there wasn't for the towers.

They're just too fond of their little world of denial.

[CORed]

Originally Posted by BNRT

I think he forgot there already is a force acting on the floors all the time. It's called gravity.

Truthers seelm to have a lot of difficulty with advanced physics concepts like gravity and thermal expansion.

[CORed]

Quote:

As Frank Verismo points out, a great deal of the mass was pulverised in any case, so the full weight of the above sections were dispersed each time a new floor was reached by the downward progression.

Yes, when you break something into pieces, its mass disappears. That's why avalanches and rockslides never snap large tree trunks or knock down buildings.

If you want to use physics to try to debunk the "official story", it helps if you're not completely ignorant of physics.

[bill smith]

Originally Posted by angrysoba

Thanks again. Also, how about the amount of mass that was lost from it spilling down the sides of the buildings?

I realize that to some extent this shows that the remaining building was resisting far more than thin air (unlike the claim being made) as it obviously wasn't going straight down.

But doesn't this skew the calculations regarding how much downward momentum there was?

Here's another model

'' Take 240 long spaghetti sticks to act as as the perimeter columns with an aditional 47 x 6-stick bundles to represent the stronger core columns spaced in a rectangle to cover about 60% of the centre of the structure. Then you have 110 x compressed glue and superfine sugar floors made to scale with holes drilled to correspond to the column locations. Then each floor is carefully slid down over he spaghetti columns and glued into position corresponding to the 110 floors of the WTC Towers. Allow to dry. Then anchor the column bases in a solid surface. Allow to dry.

Finally, lift up the top (and lightest) 10% (C) of the model and drop it say 12'' onto the lower 90% (A).

Will the top 10% (C) crush the lower 90% (A) right down flat on the ground ?

That is what happened at the WTC on 9/11 for the first time on the recorded history of the Planet Earth and not only once but twice in an hour.

[angrysoba]

Originally Posted by bill smith

Here's another model

'' Take 240 long spaghetti sticks to act as as the perimeter columns with an aditional 47 x 6-stick bundles to represent the stronger core spaced in a rectangle to cover about 60% of the centre of the structure. Then you have 110 x compressed glue and superfine sugar floors made to scale with holes drilled to correspond to the column locations. Then each floor is carefully slid down over he spaghetti columns and glued into position corresponding to the 110 floors of the WTC Towers. Allow to dry. Then anchor the column bases in a solid surface. Allow to dry.

Finally, lift up the top (and lightest) 10% (C) of the model and drop it say 12'' onto the lower 90% (A).

Will the top 10% (C) crush the lower 90% (A) right down flat on the ground ?

That is what happened at the WTC on 9/11 for the first time on the recorded history of the Planet Earth and not only once but twice in an hour.

This one's better Bill:



Some Truthers I know are incensed when that picture is shown, "OoooOOoooh! You're making Gage look stupid!" They howl!

No, Gage makes Gage look stupid. And he keeps doing it.

[bill smith]

Originally Posted by bill smith

Here's another model

'' Take 240 long spaghetti sticks to act as as the perimeter columns with an aditional 47 x 6-stick bundles to represent the stronger core columns spaced in a rectangle to cover about 60% of the centre of the structure. Then you have 110 x compressed glue and superfine sugar floors made to scale with holes drilled to correspond to the column locations. Then each floor is carefully slid down over he spaghetti columns and glued into position corresponding to the 110 floors of the WTC Towers. Allow to dry. Then anchor the column bases in a solid surface. Allow to dry.

Finally, lift up the top (and lightest) 10% (C) of the model and drop it say 12'' onto the lower 90% (A).

Will the top 10% (C) crush the lower 90% (A) right down flat on the ground ?

That is what happened at the WTC on 9/11 for the first time on the recorded history of the Planet Earth and not only once but twice in an hour.

It seems crazy to contemplate that the top 10% of anything, large or small can crush the lower and stronger-built 90% of the same structure down to the ground by gravity alone. There is however a very good reason for thinking that. Because it IS totally cazy to contemplate ..

[The Big Dog]

Originally Posted by angrysoba

Truther? No, not me. As you would be able to see if you read any of my comments there.

I have seen the verinage demolitions before and in fact posted videos of them over there. Of course there was plenty of wailing and gnashing of teeth and insistence that it didn't apply to the Twin Towers collapses for various reasons. Regarding the conservation of momentum they argued that in the verinage demolitions there was a considerable visible slowdown in each whereas there wasn't for the towers.

They're just too fond of their little world of denial.

Am I reading that web site wrong?

Quote:

"Posted by: angrysoba at January 28, 2010 7:36 AM
No matter whether the buildings were properly constructed or not, the undisputed facts are that all three buildings collapsed in freefall time. Unless Newtonian physics were suspended in NY on 9/11, that implies that all of the potential energy the buildings possessed by virtue of their height had to be converted to kinetic energy to make it to the ground in the time they did. No further energy would be left to collapse the building and break the joints. It is impossible for the buildins to have collapsed of their own accord, particularly as the path was that of the greatest resistance."

Wow, that site is insanely misleading, I can't tell whether you wrote that or not.

But no matter, tell your friends that whether or not the "slowdown" in the towers was "visible" the fact is that the collapse was not in free fall or even close.

It is a damn good thing that physics is not limited to what is visible to the naked eye on crappy you tube videos.

[DGM]

Originally Posted by bill smith

It seems crazy to contemplate that the top 10% of anything, large or small can crush the lower and stronger-built 90% of the same structure down to the ground by gravity alone. There is however a very good reason for thinking that. Because it IS totally cazy to contemplate ..

The problem is the top 10% did not crush the bottom 90%. This is propaganda promoted by the "truth" movement. The top 10% crushed 1% of the bottom 100%. Do you know what the difference is? After that the 1% is added to the top 10% so it can work on the next 1% of the bottom 100%. (numbers simplified)

[bill smith]

Originally Posted by DGM

The problem is the top 10% did not crush the bottom 90%. This is propaganda promoted by the "truth" movement. The top 10% crushed 1% of the bottom 100%. Do you know what the difference is? After that the 1% is added to the top 10% so it can work on the next 1% of the bottom 100%. (numbers simplified)

If 10% of an item can crush the lower and stronger 90% of the same structure by gravity alone then you will surely be able to show the readers other examples of this happening. Choose any example from the recorded history of this planet