Sunday, February 26, 2006
How To Debunk 9-11 WTC Collapse Conspiracy Garbage
How To Debunk 9-11 WTC Collapse Conspiracy Garbage in Three Easy Steps
1. Use common sense.
2. Don't believe everything you read on conspiracy websites.
3. See step 1.
Re: Molten Metal in the basements:
Why is it immediately assumed that it was molten steel, when it was more likely aluminum. Aluminum melts at a mere 660.37°C, which is why molten aluminum can commonly be found after fires of greater-than-average intensity. Each of the 236 exterior columns of the WTC towers had an aluminum cover 14 inches across. 236 columns x 14in x 1368ft x however thick is a lot of aluminum, no? Furthermore, the basements of the towers included shopping malls, equipment rooms, etc, plenty of aluminum to be found down there. Steel however melts at an amazing 1370°C +/- varying by grade. The thermal images recorded of the WTC site on Sept 16th do not show temperatures in excess of 747°C, nowhere near hot enough to be molten steel, but certainly hot enough to be molten aluminum.
USGS Thermal Imaging
Re: Fires not hot enough:
Steel doesn't have to melt into goop in order to weaken. Steel loses 30% of it's strength at a mere 400°C, and a full 50% at 600°C.
Two other properties of steel add to its unreliability under extreme temperature conditions:
1. Thermal expansion, which causes massive increases in stress on assembly connections, and
2. Creep, which will cause steel to gradually undergo plastic (inelastic) deformation and therefore loss of load-bearing capacity, well before yield points.
Combine the loss of load-bearing capacity of steel support components due to elevated temperatures with a structure already damaged by the plane impacts, and the towers were doomed. Before the impacts, the demand-capacity ratios of many components of these aging structures were ALREADY in excess of 1.0. The redistribution of load from temperature-weakened and impact-damaged columns to the remaining columns was enough to push these DCRs well into the failure region.
Re: Squibs:
The compression caused by the descending mass of the air contained in the structures is more than sufficient to create massive overpressure in individual floors. Pressure x Volume is a constant; if you halve the volume, you double the pressure. Cram twice as much air into one floor as was initially there and you will achieve a pressure of 2atm = 29.4psi = 14.7psi of overpressure. A mere 1psi of overpressure is sufficient to burst out windows. A few psi of overpressure will kill you. 14.7psi will easily cause jets of air and concrete dust from the collapse region to be forcibly ejected from burst windows, which is exactly what we saw. No need for explosives here.
Re: Collapse time:
A chain is only as strong as its weakest link. The inferior truss seat connections were the weak link in the towers construction. They were capable of supporting the dead and live loads they were initially rated for, of course, but not stories of building crashing down on them, with more weight added with each floor crushed, was not factored into those design loads. As for the allegedly "indestructible" core, without the lateral support of the floors connected to the perimeter columns, they were easily susceptible to buckling and shear forces applied by the grinding action of the falling mass. Exacerbating this was the fact that the WTC core was constructed without diagonal bracing for lateral strength as other structures are. Collapse times cited as being the same as free fall have no basis in reality and are consistently unsupported by analyses to support said claims, and are refuted by the observation of free debris falling much faster than the collapses progressed . A collapse time of between 12 and 16 seconds for each tower is supportable by observation of video footage, and is consistent with the expected resistance from a structure absent lateral bracing in the event of floor connections being severed.
Re: Energy deficit:
Jim Hoffman's famous paper on the expansion of the dust cloud and the apparent energy deficit with gravitational potential as the only energy source includes, by Hoffman's own admission, the uncertainty factor of the water in the concrete. Water expands to many times its original volume when vaporized, which will cause the dust cloud to expand in a pyroclastic manner as was observed. Hoffman assumes 1% water by weight for the concrete, however this varies by cement type, relative humidity on the day, efficiency of the air-conditioning, and more. An RH value for the concrete of little more than 2% would account for all of the supposed energy deficit on the expansion of the dust cloud. Again, no need for explosives here.
Re: Angular momentum of the caps:
Angular momentum is only preserved if the fulcrum provides sufficient resistance. The crushing and grinding action of the caps destroyed the integrity of the fulcrums below, negating that resistance and slowing the angular deflection velocity. The caps did continue to tilt, but much slower due to a progressively weakened fulcrum. The caps simultaneously lost their rigidity in equal amounts to the structure beneath as a natural part of the grinding process, further reducing the angular moment, until finally the caps were obscured by the dust clouds and unable to be observed before finally being completely disintegrated.
Re: Explosions from across the river (911eyewitness):
Nowhere else were these explosions recorded. Not in the Naudet film, over which the brothers retained creative control, and not in any other footage captured, whether private or from the MSM. Massive explosions able to be heard from across the Hudson would register quite clearly on the seismic records. They did not. It seems likely that the explosion sounds were added to the footage in post-production.
Re: Ejection of debris:
The towers were 1368ft and 1362ft tall for WTC1 and 2 respectively. Debris patterns and distribution were consistent with parabolic trajectory of debris falling from such an immense height and acted upon by the force of thousands of tons of building smashing into it and pushing it out. No need for explosives here.
Re: Symmetry of the collapses:
If the towers were completely solid, single objects, they would be expected to fall over sideways like a tree. They were not solid objects. Structures are, obviously, comprised of millions of individual components connected together. As these connections were severed by the mechanical action of the collapse, the only way they could act was as individual objects, falling under gravity. The components could not retain enough rigidity and provide enough resistance to the falling structure for it to act like a tree, nor to fall in any other way than symmetrically.
LibertyForum.org
1. Use common sense.
2. Don't believe everything you read on conspiracy websites.
3. See step 1.
Re: Molten Metal in the basements:
Why is it immediately assumed that it was molten steel, when it was more likely aluminum. Aluminum melts at a mere 660.37°C, which is why molten aluminum can commonly be found after fires of greater-than-average intensity. Each of the 236 exterior columns of the WTC towers had an aluminum cover 14 inches across. 236 columns x 14in x 1368ft x however thick is a lot of aluminum, no? Furthermore, the basements of the towers included shopping malls, equipment rooms, etc, plenty of aluminum to be found down there. Steel however melts at an amazing 1370°C +/- varying by grade. The thermal images recorded of the WTC site on Sept 16th do not show temperatures in excess of 747°C, nowhere near hot enough to be molten steel, but certainly hot enough to be molten aluminum.
USGS Thermal Imaging
Re: Fires not hot enough:
Steel doesn't have to melt into goop in order to weaken. Steel loses 30% of it's strength at a mere 400°C, and a full 50% at 600°C.
Two other properties of steel add to its unreliability under extreme temperature conditions:
1. Thermal expansion, which causes massive increases in stress on assembly connections, and
2. Creep, which will cause steel to gradually undergo plastic (inelastic) deformation and therefore loss of load-bearing capacity, well before yield points.
Combine the loss of load-bearing capacity of steel support components due to elevated temperatures with a structure already damaged by the plane impacts, and the towers were doomed. Before the impacts, the demand-capacity ratios of many components of these aging structures were ALREADY in excess of 1.0. The redistribution of load from temperature-weakened and impact-damaged columns to the remaining columns was enough to push these DCRs well into the failure region.
Re: Squibs:
The compression caused by the descending mass of the air contained in the structures is more than sufficient to create massive overpressure in individual floors. Pressure x Volume is a constant; if you halve the volume, you double the pressure. Cram twice as much air into one floor as was initially there and you will achieve a pressure of 2atm = 29.4psi = 14.7psi of overpressure. A mere 1psi of overpressure is sufficient to burst out windows. A few psi of overpressure will kill you. 14.7psi will easily cause jets of air and concrete dust from the collapse region to be forcibly ejected from burst windows, which is exactly what we saw. No need for explosives here.
Re: Collapse time:
A chain is only as strong as its weakest link. The inferior truss seat connections were the weak link in the towers construction. They were capable of supporting the dead and live loads they were initially rated for, of course, but not stories of building crashing down on them, with more weight added with each floor crushed, was not factored into those design loads. As for the allegedly "indestructible" core, without the lateral support of the floors connected to the perimeter columns, they were easily susceptible to buckling and shear forces applied by the grinding action of the falling mass. Exacerbating this was the fact that the WTC core was constructed without diagonal bracing for lateral strength as other structures are. Collapse times cited as being the same as free fall have no basis in reality and are consistently unsupported by analyses to support said claims, and are refuted by the observation of free debris falling much faster than the collapses progressed . A collapse time of between 12 and 16 seconds for each tower is supportable by observation of video footage, and is consistent with the expected resistance from a structure absent lateral bracing in the event of floor connections being severed.
Re: Energy deficit:
Jim Hoffman's famous paper on the expansion of the dust cloud and the apparent energy deficit with gravitational potential as the only energy source includes, by Hoffman's own admission, the uncertainty factor of the water in the concrete. Water expands to many times its original volume when vaporized, which will cause the dust cloud to expand in a pyroclastic manner as was observed. Hoffman assumes 1% water by weight for the concrete, however this varies by cement type, relative humidity on the day, efficiency of the air-conditioning, and more. An RH value for the concrete of little more than 2% would account for all of the supposed energy deficit on the expansion of the dust cloud. Again, no need for explosives here.
Re: Angular momentum of the caps:
Angular momentum is only preserved if the fulcrum provides sufficient resistance. The crushing and grinding action of the caps destroyed the integrity of the fulcrums below, negating that resistance and slowing the angular deflection velocity. The caps did continue to tilt, but much slower due to a progressively weakened fulcrum. The caps simultaneously lost their rigidity in equal amounts to the structure beneath as a natural part of the grinding process, further reducing the angular moment, until finally the caps were obscured by the dust clouds and unable to be observed before finally being completely disintegrated.
Re: Explosions from across the river (911eyewitness):
Nowhere else were these explosions recorded. Not in the Naudet film, over which the brothers retained creative control, and not in any other footage captured, whether private or from the MSM. Massive explosions able to be heard from across the Hudson would register quite clearly on the seismic records. They did not. It seems likely that the explosion sounds were added to the footage in post-production.
Re: Ejection of debris:
The towers were 1368ft and 1362ft tall for WTC1 and 2 respectively. Debris patterns and distribution were consistent with parabolic trajectory of debris falling from such an immense height and acted upon by the force of thousands of tons of building smashing into it and pushing it out. No need for explosives here.
Re: Symmetry of the collapses:
If the towers were completely solid, single objects, they would be expected to fall over sideways like a tree. They were not solid objects. Structures are, obviously, comprised of millions of individual components connected together. As these connections were severed by the mechanical action of the collapse, the only way they could act was as individual objects, falling under gravity. The components could not retain enough rigidity and provide enough resistance to the falling structure for it to act like a tree, nor to fall in any other way than symmetrically.
LibertyForum.org
# posted by Ace Lannigan : 1:04 PM
