Goodbye, Mr Roberts

[Ghent12]

Re: Goodbye, Mr Roberts

Not a shred of evidence was made public.
The detonation of tons of some of the highest energy explosives available, distributed throughout the buildings, would pulverize the buildings, including their steel and concrete and everything contained therein, into clouds of rapidly spreading, very fine, dust.

This really must be some extra-super-special thermite, the most extra-super-special incendiary in history. "Highest energy explosive available," you say? Quite interesting... Especially given that all forms of thermite are incendiary and unlike good ol' High Explosives, which are explosive.

But of course, there's essentially no documented evidence to support this theory of "highest energy explosive available" actually being used. You'd think there would be some video evidence or perhaps some audible evidence of these explosions happening. You know, in those old 1991 Iraq War videos from Baghdad, you can hear the bombs in the far distance. Bombs aren't quiet. Yet all the claims of hearing explosions seem to occur from people very close to the structures, as if they weren't hearing explosions caused by "the highest energy explosive available."

[ThePythonicCow]

Re: Goodbye, Mr Roberts

Especially given that all forms of thermite are incendiary

This was high tech explosive thermite, unlike ordinary incendiary thermite. So far as is known, only a few U.S. military related institutions had the capacity to produce such thermite at that time.

Yes, the material is documented and tested to be such. See further Active Thermitic Material Discovered in Dust from the 9/11 World Trade Center Catastrophe .

Some of the ground level reports from the day of 9/11 were first person video taped reports by people with high explosive expertise. They can distinguish the sound of high explosives from ordinary dynamite. They heard high explosives.

[c1ue]

Re: Goodbye, Mr Roberts

I was hoping you could elaborate on the second or so in which "the collapsed ensued". In particular, what happened in the brief time during which the floors in the impact zone went from load bearing to not load bearing. The theories (which I believe you have been a proponent of) which have the upper building (above the impact zone) smashing down onto the lower building sufficiently to cause catastrophic failure seem to require that a floor or more in the impact zone quite suddenly fail across the entire floor, going from load bearing to providing approximately no resistance at all, in substantially less than the free fall time in gravity over the vertical height of a floor (10 or 20 feet.)

I'm not sure how much more clear I need to be.

Unlike most normal buildings, the WTC was basically a skeleton frame from which floors were suspended.

By its very nature, the WTC is an 'edge' building - i.e. built much closer to the basic tolerances of materials than most buildings.

The impact of an 767 plus the burning of its fuel load absolutely could weaken the skeleton frame on one or more floors; the 20 or more floors above the impact zone represent a huge load which absolutely was stressing the overall building frame.

If merely one or even a dozen of the beams were involved, then it would be unlikely that a full structural collapse could ensue. But it is quite clear that the damage spread across the entire width of one or more floors of the WTC as seen by the damage on the far side of the building (from the impact point).

The quibble which your 9/11 co-conspirators put out is that a steel framed building has never collapsed; this is only true if you mean completely.

The reality is that there are very few 110 story buildings, and even fewer which have had major fires. The sample size thus is completely meaningless.

As for buildings collapsing due to fire, there are plenty of examples beyond the Madrid one.

Here is another:

http://www.youtube.com/watch?v=1h9TOFP7ViY

This building is on fire - there isn't much smoke. But suddenly it collapses.

Sure, it didn't completely collapse, but then again this building is also not a steel frame from which floors are hung. It is a more conventional post and beam design.

But a collapse occurs at 00:45 and is very quick. Now multiply this effect on a much taller, heavier building - one in which a structural failure affects the entire floor.

I still don't see why the conventional explanation is so outlandish.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

I'm not sure how much more clear I need to be.

Apparently my question is not clear yet. I am asking you to focus on less than one second in time and on the most damaged floor or two. Exactly how did that floor lose structural integrity so fast that the upper building dropped on the lower building as if across an air gap, thereby impacting with enough momentum to initiate collapse of the lower building?

Perhaps another mental experiment will help here.

Imagine that (prior to 9/11) the U.S. Military was testing some new super high power airplane mounted laser weapon and intentionally or otherwise had flown near the WTC1 tower and instantly sliced out an entire one millimeter thick slice of that tower, horizontally, all the way through. At that point, the upper building above the slice would have dropped one millimeter onto the lower building below the slice.

I am confident, and I trust you are as well, that this would not initiate immediate and total collapse of the building. Some disconnected beams might start to slip sideways and the building would likely be evacuated as hazardous. But there is a reason that demolition experts slice vertical support beams at an angle, so that the beam will surely slip sideways. Most likely in my view WTC1 would have remained standing after this incident, at least until the next windstorm or airplane impact or other large sideways force. At the very least, we would not see the entire floor below the slice converted to fine dust in the one second following the slice, two floors converted in the next second, four floors in the next, and so on. The shock, the impulse (ft, below), from the upper building dropping one millimeter would be simply insufficient to convert the mass of concrete and steel in a WTC floor to fine dust almost instantly.

Now consider a variation of that mental experiment. Imagine that we increase the power and width of the laser weapon and take out not one millimeter but a horizontal slice twenty feet high, again, instantly. Now that upper building is going to drop twenty feet in free fall onto the lower building. Things get dicier for our WTC1 tower. Personally I still doubt it would initiate the sort of catastrophic collapse sequence we saw on 9/11, but I am no longer so confident of that.

Now ... back to this current thread. The impression I get, though perhaps I'm not reading closely enough, is that those posting here in support of the official story are presenting an explanation rather like my twenty foot slice variation above (without the super laser, of course.)

We all know and agree that the lower portions of WTC towers could support the static weight of upper portions. We also probably all agree that if the upper portion collided with the lower portion at a sufficiently high velocity (say shot out of a Death Star canon at half the speed of light ) then the lower portion would suffer rapid and catastrophic collapse. The question is how fast would the upper portion have to hit the lower portion to cause sudden catastrophic collapse of the lower portion. Now we don't have any Death Stars here (notwithstanding some Death Rays that some of the more Far Friggin Out Truther sites discuss :rolleyes so the question of "how fast" (v, below) becomes a question of "how far" (s, below.) For the upper portion to gain that velocity v, it had to fall more or less unimpeded for some sufficiently large distance s.

ft = mv	impulse = momemtum
v = √(2gs)	terminal velocity depends on distance
g = 32 ft/sec˛	gravity in British units

where:

• f := force
• t := time
• m := mass
• v := velocity
• g := gravity
• s := distance

In the two variations of my mental experiment above, I presume that one millimeter is not enough distance but (perhaps) twenty feet is enough distance.

Pick some distance (a single value or a range) that you consider plausible and then explain (without using a U.S. Military plane mounted super-laser ) to me how the truly unlikely (your words, I believe) simultaneous failure of an entire floor (or whatever height you choose) occurred. This must explain not just a failure sufficient to enable the collapse of the heat weakened tower above that point, but a failure sufficiently uniform and sudden across an entire floor to drop the upper building onto the lower building with sufficient momentum (mv) to generate a sufficiently large impulse (ft) upon hitting the lower building to initiate a catastrophic collapse of that (hitherto undamaged) lower building.

Perhaps now my question is sufficiently clear (it's certainly sufficiently lengthy .)

Indeed, this reply so far is so long that I will use separate replies to respond to some of the other points you make rather then lengthen this reply further.

[Ghent12]

Re: Goodbye, Mr Roberts

Pick some distance (a single value or a range) that you consider plausible and then explain (without using a U.S. Military plane mounted super-laser ) to me how the truly unlikely (your words, I believe) simultaneous failure of an entire floor (or whatever height you choose) occurred. This must explain not just a failure sufficient to enable the collapse of the heat weakened tower above that point, but a failure sufficiently uniform and sudden across an entire floor to drop the upper building onto the lower building with sufficient momentum (mv) to generate a sufficiently large impulse (ft) upon hitting the lower building to initiate a catastrophic collapse of that (hitherto undamaged) lower building.

For all your examination of trees, you seem to have no concept of the forest.

Simultaneous failure? There's evidence that the failure was not simultaneous, and that it occurred first to one side, hence the rotation of the upper section which was rapid until all parts of it impacted the lower sections. Kind of like dropping a hammer.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

For all your examination of trees, you seem to have no concept of the forest.

Simultaneous failure? There's evidence that the failure was not simultaneous, and that it occurred first to one side, hence the rotation of the upper section which was rapid until all parts of it impacted the lower sections. Kind of like dropping a hammer.

Please try not to begin your reply with an insult. It pisses me off.

Yes, for the first WTC tower to fall, WTC2 (the second one hit), the top twisted at some 20+ degrees before the rest of the collapse. This actually presents yet another problem for the official story. How is it that top didn't continue rotating and fall to the side? By the point that it is hidden behind the dust cloud, it had immense momentum rotating and to the side. What happened to that momentum? Why didn't the top continue rotating off to the side, falling to the street? A mass in motion continues in motion unless acted on by some force. There were some 40 or so stories of skyscraper in WTC2 above the impact zone. That's a heck of a lot of mass, moving and rotating rapidly.

The other two buildings did not have that happen.

My long post above to which you responding was rebutting the theory that the lower portions of the buildings disintegrated because the upper portions dropped on them over some substantial gap. That gap would have had to form quickly, over the entire floor, otherwise the upper part would not have built up enough downward momentum to pulverize the lower part. How did that gap form so widely and so quickly?

[Ghent12]

Re: Goodbye, Mr Roberts

Please try not to begin your reply with an insult. It pisses me off.

Yes, for the first WTC tower to fall, WTC2 (the second one hit), the top twisted at some 20+ degrees before the rest of the collapse. This actually presents yet another problem for the official story. How is it that top didn't continue rotating and fall to the side? By the point that it is hidden behind the dust cloud, it had immense momentum rotating and to the side. What happened to that momentum? Why didn't the top continue rotating off to the side, falling to the street? A mass in motion continues in motion unless acted on by some force. There were some 40 or so stories of skyscraper in WTC2 above the impact zone. That's a heck of a lot of mass, moving and rotating rapidly.

The other two buildings did not have that happen.

My long post above to which you responding was rebutting the theory that the lower portions of the buildings disintegrated because the upper portions dropped on them over some substantial gap. That gap would have had to form quickly, over the entire floor, otherwise the upper part would not have built up enough downward momentum to pulverize the lower part. How did that gap form so widely and so quickly?

Very well. You are a kind and gentle cow.

With that said, your stubbornness and faith in a theory with almost no evidence to support it is troublesome.

You obviously have a very different view of the physical world. It is telling that you believe a 100,000 ton object would be more likely to roll off rather than demolish what it impacts. I challenge you to name any structure that can withstand that force. Assuming you cannot, then you must cede that parts of the lower section failed as the upper and lower sections impacted, and that that impact (which skyson loves to claim "destroyed" the upper section) served as much to crush together floors and stop the rotation of the upper section as it did to crush floors and destroy load-bearing capacity of the lower section.

Further assuming you know something about momentum, you realize that the tipping is the result of the center of mass being off-center from the point of remaining support. However, you would quickly realize that the more the part with greater strength didn't fail, the more spin gravity imparted on the upper section; subsequently, that spin results in a greater speed of impact into the lower section, although off-center. Alternatively, the more the part with greater strength began to fail before the tipping impact point, the more centered the transfer of energy.

You ask what happened to the momentum, and it is evident that it was transferred completely in the impact between the sections. Let me ask you this of your version of "the building was removed out of the way" Truther theory: Why didn't the upper section continue to rotate as it fell? After all, the lower section was supposedly removed via demolition, right?

You see, your physical view does not reconcile everything because it is not an accurate model of the physical universe. You asked where the momentum went; I ask you the same thing under your theory? Your answer will be the same: it was transferred into the building. Now you just need to ponder what the effect of this momentum transfer into the lower section would be.


It's not a matter of, "it would take more force, ergo the official story is impossible," as you seem to suggest.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

Very well. You are a kind and gentle cow.

Thanks.

With that said, your stubbornness and faith in a theory with almost no evidence to support it is troublesome.

Yes ... I know the feeling well.

In other less cryptic words, we both need to appreciate that the "other side" finds their position as compelling as we find "our side."

You obviously have a very different view of the physical world. It is telling that you believe a 100,000 ton object would be more likely to roll off rather than demolish what it impacts. I challenge you to name any structure that can withstand that force. Assuming you cannot, then you must cede that parts of the lower section failed as the upper and lower sections impacted, and that that impact (which skyson loves to claim "destroyed" the upper section) served as much to crush together floors and stop the rotation of the upper section as it did to crush floors and destroy load-bearing capacity of the lower section.

If I drop a 40 story skyscraper down on a 80 story skyscraper and if the 40 story one gets off-center and starting to rotate dramatically, then I expect the bulk of that 40 story one to continue rotating, past the edge of the lower one. Sure, there will be some damage to both where they are grinding and crashing together, but the bulk of the upper 40 stories will clear the lower 80, off to the side. If the upper 40 were well constructed, then it likely would get all the way to the ground before (perhaps) being massively demolished.

Is that so odd an expectation?

You ask what happened to the momentum, and it is evident that it was transferred completely in the impact between the sections. Let me ask you this of your version of "the building was removed out of the way" Truther theory: Why didn't the upper section continue to rotate as it fell? After all, the lower section was supposedly removed via demolition, right?

Eh - easy question. It (the upper section) blowed up, real good. Remember - us truthers are the ones with thermite for brains .

You see, your physical view does not reconcile everything because it is not an accurate model of the physical universe. You asked where the momentum went; I ask you the same thing under your theory? Your answer will be the same: it was transferred into the building. Now you just need to ponder what the effect of this momentum transfer into the lower section would be.

Well, no, I don't see, and that was not my answer.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

It is telling that you believe a 100,000 ton object would be more likely to roll off rather than demolish what it impacts.

When one free falling object falls on another, then whether it is more likely to roll off or demolish or smash a little and sit there depends on several things, such as how even the impact and crush zones were, how closely aligned the center of gravity of the falling object is to the stiffest part of the grounded part, how strong the grounded part is, the structural integrity of the falling part, the mass of the falling object, ...

If you drop a skyscraper from 40,000 feet onto Mt Everest, the skyscraper goes splat. If you drop a Abrams M1A1 tank onto my little tin box car, my car goes splat. If you drop a vertical oriented pencil onto another vertical pencil, then unless you get them perfectly aligned, the top pencil falls to the side.

In the particular case of WTC2, I'm saying that (absent explosives) the 40 story top section, already rotated 20+ degrees and falling off to the side with an increasingly rapid rotation, would mostly have fallen off to the side, relatively intact, at least until it hit "ground zero" (or whatever shorter building stood down there.) The massive center core structure of the lower 80 stories of WTC2, having already largely deflected the mass of the upper 40 stories in the videos we see, would have stood relatively unscathed. There may well have been damage to the outer shell of WTC2, along the side where the upper 40 fell, scraping off some of the exterior wall on that side. The opposite side of the lower 80 stories might not have its paint scratched.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

Unlike most normal buildings, the WTC was basically a skeleton frame from which floors were suspended.

By its very nature, the WTC is an 'edge' building - i.e. built much closer to the basic tolerances of materials than most buildings.

The WTC 1 & 2 towers were not simply an edge building and were not built much closer to the basic tolerances of materials than most buildings.

They were substantially overbuilt, with a central core of massive girders.

The perimeter walls were strong enough by themselves to support the weight of the entire building. The core structure by itself was easily strong enough to support the weight of the entire building. The perimeter corners were again sufficiently strong to support the weight of the entire building. The entire structure was sufficient to support four or five times its own weight.

A hat truss sat at the top of this, below the roof, connecting the core to the perimeter. It was strong enough that it could have supported the entire core, hanging from it suspended, if somehow a section of each vertical core column were removed near ground level. The core would have then hung from the hat truss, still supported by the perimeter walls. Or all the perimeter wall verticals could have been sliced at any level of the building and the portion of the perimeter above that slice would have remained in position, suspended from the hat truss which was still supported by the center core.

See further http://911research.wtc7.net/wtc/arch/core.html, http://www.sealane.org/writings/STcollapse.html, http://gordonssite.tripod.com/id2.html, or the Google video Gordon Ross analyses the destruction of the World Trade Center. That's a good video. It is currently the explanation for the details of the tower collapses that makes the most sense to me.

This is perhaps one of the essential reasons we are unable to agree on this thread. The construction of a building makes a substantial difference as to how it will hold up, or fail, in the event of a severe insult. One must understand how a building is constructed to understand how it fails.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

As for buildings collapsing due to fire, there are plenty of examples beyond the Madrid one.

Here is another:

http://www.youtube.com/watch?v=1h9TOFP7ViY

This building is on fire - there isn't much smoke. But suddenly it collapses.

Excellent find. Thank-you. I had not considered that fire and collapse before.

For the benefit of others, it is the May 13, 2008 fire at the main building of the faculty of architecture of the Delft University of Technology in the Netherlands.

The fire started on 6th floor and raged for (IIRC) over 7 hours in the upper floors before the collapse shown in your video. The fire was caused by a short in a coffee maker, which was in turn caused by a water leak above the coffee maker. At the time of the collapse there was little or no fire damage below the 6th floor. The collapse of a portion of the north wing brought burning material to the ground and ignited more fires on lower floors. Still most of the most precious books and of a rare chair collection on the first two floors and in the basement survived unharmed. Almost the entire building remained standing and had to be demolished later on. As you note, the building was a fairly simple post and beam construction.

One thing I cannot tell is whether the lower six floors of the failed north wing fell at the same time as the upper floors. Those lower six floors were relatively undamaged when the upper floors, which had been burning for many hours, collapsed. I can find no pictures of those lower six floors between the time of the collapse shown in your video and the next morning, by which time fire had gutted much of the rest of the building below the 6th story (except the first two stories, where apparently the firemen were able to pour enough water to prevent a general fire.)

But in any case, the timing and the construction are quite different from the WTC, and the degree of damage to the steel framing much less in the end.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

The two best examples we've seen so far of steel frame buildings collapsing due to fire are Madrid and Delft. In both those cases, the collapse was much less than total, and occurred after 7 or 8 hours of raging inferno.

In the case of WTC2, the collapse was total and occurred after just 56 minutes of fire. The fire in WTC2 was less intense than in WTC1, because the plane that hit WTC2 (the second plane, the south tower) hit it at a bit of an angle off-center, causing much of the fuel to ignite immediately and to ignite outside the building in a fireball on the side the plane exited.

From this comparison, the Madrid and Delft fires, in and of themselves, do not provide examples that make the WTC2 collapse plausible.

[ThePythonicCow]

Re: Goodbye, Mr Roberts

There is an interesting looking paper providing a survey of the available evidence on the collapse of the World Trade Center towers by R. Herbst at Mysteries of the Twin Towers (Feb 2009). One brief section near the end of this paper nicely summarizes the work of Gordon Ross, to which I provided a couple of links, including one to a video, three posts back.

That summary states:

7.3 Gordon Ross Four Phase Attack Alternative

According to Gordon Ross, the towers were demolished in four separate steps. The four steps destroyed successively the upper central core, perimeter corners, perimeter sides, horizontal bracing, and lower core.

Ross notes that the chamfered corners of the tower perimeter were capable of supporting the total mass above them, without the help of the perimeter sides or tower cores. He points out that the floor trusses from the core connected only to the mid perimeter columns within the projection of the core width (which makes good sense geometrically). The floor trusses from the four corners outside the projection of the core were connected to a transfer truss, and the transfer truss was connected to the core. Ross suggests that this provided two somewhat independent structural systems; the perimeter corners, and the core and perimeter mid-sides. Each would have been capable of sustaining the towers structure. Ross argues that both of these systems were attacked and destroyed to bring about total collapse.

Upper core failure would result in transfer of the entire load through the hat truss (“building top”) to the perimeter columns. The downward moving core would pull the perimeter mid-side columns inward (inward bowing). Failure of each of the four corners of each tower would also result in a transfer of the load to the perimeter mid-sides columns, which would then fail.

Ross believes, to facilitate collapse, the floor to mid-wall perimeter and core column connections were broken. He notes this would be especially necessary on the mechanical floors, because of their relatively greater design strength. Finally, the lower core was attacked.

Ross provides evidence, including still images and video, for each of the stages of destruction. These include: Survival of the lower core structure until an advanced stage of the collapse; Survival of the corners of the perimeter structure after the collapse front has passed; Inward bowing of the perimeter walls; Sagging of floors; Tilting movement of the upper section; Bending of upper section; Early disintegration of upper section; Early downward movement of the antennae; Ejections of dust & debris simultaneously across whole floors; Behavior of the "spire"; Flashes of light; Color and character changes of smoke emissions; Molten metal ejections; Failure of core structure horizontal bracing; and Angle cut core columns. This scenario would appear to account for the infamous behavior of the top 34 floors of the South Tower, which had seemingly violated the principle of angular momentum. [353]

I have just begun to read the rest of this survey by Herbst, so don't yet have comments on it.

[c1ue]

Re: Goodbye, Mr Roberts

The WTC 1 & 2 towers were not simply an edge building and were not built much closer to the basic tolerances of materials than most buildings.

There we will disagree. 110 story buildings are not common - because they are difficult and dangerous to build.

Even a 32 story building with a post and beam construction is a significant engineering feat.

I'm not saying the WTC was a disaster waiting to happen, but I am saying that the types of margins you see in a 2 story building, as well as the interdependence of the overall structure on its integrity, are fundamentally different for suspension skyscrapers.

But in any case, the timing and the construction are quite different from the WTC, and the degree of damage to the steel framing much less in the end.

Certainly true. But Delft didn't have a plane fly into it.

And as you note, the weight on the lower floors of Delft was significantly less than the weight on the 90th floor of the WTC.

Again, my point isn't that Delft or other examples disprove nano-thermite. It is that sudden collapses of buildings due to structural damage is absolutely possible - which in turn brings into focus the lack of objectivity in many of the 9/11 conspiracy theorists.

[marvenger]

Re: Goodbye, Mr Roberts

its hard to be objective when all the evidence was removed and the money spent on expert opinion and compiling the official investigation on 911 was many times less spent on investigating Clinton's blowjob. FEMA and NISTA or something come up with contradicting collapse sequences so its not like the apparent experts are even claiming to understand what happened.