Moderated Steel structures cannot globally collapse due to gravity alone

From Gravy's picture with the yellow line and the red piece of structure from WTC1 in front of the Winter Gardens it seems to be proven that at least one 4-ton chunk from WTC1 travelled 500 feet. That's close on the same distance as two football fields placed end-to-end. How could a gravity collapse achieve this ? Gravity means straight-down-to-the-ground. Springing is ruled out because you cannot flex a box-column to store potential energy and no kind of deflection can account for that kind of distance. That must mean that some other powerful force was secretly at play.
 
Chris,

Forgive me for assuming, but are you suggesting that the beams were thrown to the side by explosives?

You do realize, don't you, that any energy of the explosive that causes any "cut" member to be bodily thrown anywhere is energy that is LOST to the action of cutting? That a cutting charge acts like a sword, not like a bat. That, unlike a bat, a sword doesn't throw the things it cuts anywhere.

You also realize, I hope that virtually every single column shown in the pictures your post http://www.internationalskeptics.com/forums/showpost.php?p=4460662&postcount=804 on the previous page, shows columns with finished, machined (i.e., straight) ends. NOT the obvious jagged, splayed ends that you'd get if you blew them apart.

You are welcome to go thru the images from the Winter Gardens with a microscope. In the same way that I've pored thru the highest resolution images I could find of Ground Zero, looking for ANY sign of a blown apart beam. I've found nothing.

But it's not really necessary to do so. You can immediately see several 3-beam & spandrel assemblies lying about the Winter Gardens. If any ONE assembly can get thrown that far without explosives, than, QED, it is possible to get thrown that far without the use of explosives.

tk
 
bill smith said:
From Gravy's picture with the yellow line and the red piece of structure from WTC1 in front of the Winter Gardens it seems to be proven that at least one 4-ton chunk from WTC1 travelled 500 feet. That's close on the same distance as two football fields placed end-to-end. How could a gravity collapse achieve this ? Gravity means straight-down-to-the-ground. Springing is ruled out because you cannot flex a box-column to store potential energy and no kind of deflection can account for that kind of distance. That must mean that some other powerful force was secretly at play.
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Why not?
 
Hellbound said:
Christopher7 . . . . according to his understanding of physics bank shots are impossible, as well as anything except a perfectly aligned cue-ball-hole shot.
But they do provide a good example for how a force is translated from one direction to another.
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:D

Hellbound
"bank shots are possible analogy"
Do you know the difference between a cue ball and a steel framed building?

BenBurch
"watermelon pip squeezed between fingers analogy"
Do you know the difference between a watermelon pip and a 4 ton frame section?

T.A.M.
"the fist falling on a Big Mac analogy"
Do you know the difference between a duck? :cool:
 
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bill smith said:
From Gravy's picture with the yellow line and the red piece of structure from WTC1 in front of the Winter Gardens it seems to be proven that at least one 4-ton chunk from WTC1 travelled 500 feet. That's close on the same distance as two football fields placed end-to-end. How could a gravity collapse achieve this?
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Well, by my calculations it would require that the debris be ejected sideways with a lateral component of velocity similar to the collapse velocity of the debris at that point. Several people have suggested means by which vertical momentum can be converted to horizontal momentum.

bill smith said:
Gravity means straight-down-to-the-ground.
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An unusual definition, but what I assume you mean is that the force due to the Earth's gravity is normal to its surface, which is a reasonable statement. Can I assume, therefore, that you don't feel that the near-vertical drop of the falling blocks of both buildings is in any way suspicious?

bill smith said:
Springing is ruled out because you cannot flex a box-column to store potential energy
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If true, this would invalidate Heiwa's argument that elastic buckling was a sufficiently large energy sink to absorb the part of the upper block's potential energy that he didn't choose to discard as being too inconvenient to his predetermined conclusions (i.e. less than half of it). However, steel is elastic, even formed into a box column, and in fact it can store quite a large amount of energy.


bill smith said:
and no kind of deflection can account for that kind of distance.
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That's an assertion that I'd like to see justified. At the moment all you seem to be offering is a classic argument from incredulity.

bill smith said:
That must mean that some other powerful force was secretly at play.
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Nobody has yet been able to identify any such force. Have you tried to determine how much explosive would be needed to produce this distance in a single 4-ton column tree, how much noise it would make, and - most tellingly - how much further it would eject smaller pieces of debris from the same area? This is one very clear reason not to suspect explosives were responsible for the column ejections; they seem to have done nothing else, which is not expected behaviour for explosives.

Dave
 
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Dave Rogers said:
That's very difficult to say for certain from the videos available. Some don't have the resolution to be entirely certain which parts of the structure have and which haven't collapsed; there's at least one I know of WTC1 that appears, in the early stages, to show the building simply shortening in places, with no clear visibility of the collapse front at all. Later on, of course, when the entire collapse becomes obscured by dust, there's no way to determine any details of the collapse wave at all. And, of course, if columns are being forced outwards by oblique impacts from within, it's the unseen inner collapse that makes the difference.



I don't know where you get "almost all" from. Remember that the connections between perimeter column trees were bolted. How far can one of the bolts rotate before it snaps? You'd have to ask a structural engineer, but I'd be surprised if they could be bent through anywhere near a right angle before snapping. If the bolts snap while the column is still rotating, they'll have very little effect on the horizontal velocity component; the forces on the base of the column tree are compressive and torsional, so the bolts never act in tension.

What's your source for the 70mph ejection speed, and is that the lateral component or the magnitude of the velocity?

Dave
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At a certain point we all saw the collapse wave rolling downwards just like a perfect line of surf. Then it all became obscured in dust but the collapse appeared to progress in that pattern all the way to the ground. If it had not the collapse wold have become assymmetrical and most likely the building would not have entirely disappeared.

As regards the snapping of the bolts- the falling mass on the inside would have bent the bottom-attached columns outwards before the bolts snapped.and he rubble inside would have extruded out on top of them in one motion. The tendency is all wownwards and not outwards.

A physics teacher calld Chandler performed the analysis for the speed of the ejected colmns. Some at 70 mph. I'll post the link when I can.
 
tfk said:
C7,

Ever hit a nail with a hammer & had it fly off sideways?
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Yes. Entirely different conditions.
I'll add that analogy to the Big Mac file.

if a 4 ton beam asembly is thrown to the side with enough horizontal velocity to make it 400 - 500 feet, then, BY DEFINITION, it has enough energy to embed itself into whatever it might contact at that point.
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Correct. All that energy directed sideways was not caused by the top section of the tower falling straight down.
 
Christopher7 said:
Yes. Entirely different conditions.
I'll add that analogy to the Big Mac file.

Correct. All that energy directed sideways was not caused by the top section of the tower falling straight down.
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Why would that be totally different (except for the obvious scale the concept is the same)? Be specific, I can handle the science.
 
Has anyone determined where the snagged box column section came from? IF it came from the collapse invitation zone or above?

Lets take a fly swatter analogy as an example

Place a projectile in the mat of a fly swatter and restrain that mat while bending the swatter with your thumb. The length of the fly swatter would represent an intact perimeter wall. your thumb would represent the collapse wave debris force acting on the back of the perimeter wall. the projectile on the top of the flyswatter mat would be a section of column tree from at or above the collapse initiation zone but snagged in the fork like top of the somewhat intact perimeter wall. As this wall peels outward the snagged column section is catapulted across west street.

you can repeat this experiment with all kinds of household objects
Forks
yardsticks
rulers
spatulas
etc
 
bill smith said:
At a certain point we all saw the collapse wave rolling downwards just like a perfect line of surf.
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Having seen plenty of lines of surf in my time, I wouldn't use them as good examples of a perfect line. In fact, just like the collapse wave, they're a chaotic process that only looks smooth if you reduce the resolution to the point of exclusion of most of the detail.

bill smith said:
Then it all became obscured in dust but the collapse appeared to progress in that pattern all the way to the ground. If it had not the collapse wold have become assymmetrical and most likely the building would not have entirely disappeared.
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This is nothing more than guesswork. As a counter-argument, both of the twin towers left highly asymmetrical spires of core coluns standing for a few seconds after the main collapse, suggesting that there was indeed some inhomogeneity in the progress of the collapse wave.


bill smith said:
As regards the snapping of the bolts- the falling mass on the inside would have bent the bottom-attached columns outwards before the bolts snapped.
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Again, this looks like pure guesswork. I suggest you look up the type of bolt used, then determine how far they would be expected to bend before breaking. What's crucial here is how far the columns would have to bend before the bolts snapped, and you're offering no information on that score.

bill smith said:
and he rubble inside would have extruded out on top of them in one motion. The tendency is all wownwards and not outwards.
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If you're saying that the observed tendency of the motion of the debris is "all downwards and not outwards", then you're contradicting the point about the columns being ejected, not to mention the dust. If you're saying that the expected tendency of the motion of the debris is downwards and not outwards, then you're simply re-stating your conclusion as evidence in favour of your conclusion, which is a circular argument. Either way, this statement doesn't really serve much purpose.

Dave
 
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Physically, Christopher, there is no difference at all. Downward force becomes horizontal velocity quite easily if there is any resistance to that downward force, and there absolutely was. This is proven by the fact that the fall of the towers was significantly longer than free-fall speed. The only thing I am slightly surprised by is that more stuff didn't get pushed out at higher speeds.
 
Christopher7 said:
Hellbound
"bank shots are possible analogy"
Do you know the difference between a cue ball and a steel framed building?
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Yes.

But, unlike you, I also know that both are governed by Newton's Laws.

Try it with any type of material item you want. Hit one with the other and see if they move in a stright line. You are correct that gravity only pulls downward. You do seem to understand that gravity was not the only force affecting them. However, you then make the unsupported jump that this meant there was some man-made influence.

There were a lot of collisions during the collapse, and a lot of forces at play. Unless you want to make the statement that every part of the building hit every other part perfectly square and imparted force only in a direct, downward angle (something trivally disproven simply because the top of the buildings tilted slightly at collapse initiation), then you are simply ignoring the laws of inertia and momentum.

For a simple example, what happens when the mass of rubble impacts a floor? The rubble will be deflected sideways until the floor fails, this seems pretty simple. This would have the effect of tending to push the exterior columns and cladding outward. But, there's still a lot of mass behind this initial impact. So you have an exterior column section, tilted outward, that then gets impacted from above. What direction will it move in? How will the momentum be transferred?
 
bill smith said:
Imagine a 10 foot tall slender cadboard box ? Now imagine bending it into an bow shape ? At what point do you think it would get a kink in it ?
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I'm a builder/iron worker. I can flex box columns and show you how much energy they can store. (do you live near Boston?). Now stop with the stupid statements.
 
Dave Rogers said:
At the point at which the deformation exceeds the elastic limit of cardboard. Your point?

Dave
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If he was right, every time the wind blew against a tall building it would keep leaning until it finally collapse (it couldn't spring back). It makes no sense. Unless he doesn't think that tall (more or less any) buildings "sway".
 
tfk said:
You also realize, I hope that virtually every single column shown in the pictures your post
http://www.internationalskeptics.com/forums/showpost.php?p=4460662&postcount=804
on the previous page, shows columns with finished, machined (i.e., straight) ends. NOT the obvious jagged, splayed ends that you'd get if you blew them apart.

You are welcome to go thru the images from the Winter Gardens with a microscope. In the same way that I've pored thru the highest resolution images I could find of Ground Zero, looking for ANY sign of a blown apart beam. I've found nothing.
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Very astute observation. Framework sections being torn apart in a violent and chaotic collapse would also have jagged, splayed ends, not finished, machined (i.e., straight) ends.

The ends of all these columns have been cut, not torn apart.
 
Dave Rogers said:
Having seen plenty of lines of surf in my time, I wouldn't use them as good examples of a perfect line. In fact, just like the collapse wave, they're a chaotic process that only looks smooth if you reduce the resolution to the point of exclusion of most of the detail.



This is nothing more than guesswork. As a counter-argument, both of the twin towers left highly asymmetrical spires of core coluns standing for a few seconds after the main collapse, suggesting that there was indeed some inhomogeneity in the progress of the collapse wave.




Again, this looks like pure guesswork. I suggest you look up the type of bolt used, then determine how far they would be expected to bend before breaking. What's crucial here is how far the columns would have to bend before the bolts snapped, and you're offering no information on that score.



If you're saying that the observed tendency of the motion of the debris is "all downwards and not outwards", then you're contradicting the point about the columns being ejected, not to mention the dust. If you're saying that the expected tendency of the motion of the debris is downwards and not outwards, then you're simply re-stating your conclusion as evidence in favour of your conclusion, which is a circular argument. Either way, this statement doesn't really serve much purpose.

Dave
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The still-standing spires of core columns are a whole other story. For the rest I think 'deduction' is a better word than 'guesswork'.

The mass was coming in a collapse wave from abpve and pushing outwards from inside. So when the columns became disconnected at the top the internal rubble would have extruded immediately and pushed the columns outwards and downwards. Even a momentary resistence from the bottom connections should have ensured a tiny delay- long enough for the mass of falling rubble to smother any spitting out of columns.
 
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