"See, in my line of work you got to keep repeating things over and over and over again for the truth to sink in...to kind of catapult the propaganda."
-G.W. Bush
I'm not going to repeat what UM said, and I hope you don't repeat the same list of links again(see above quote). That's impolite. But since you asked for some rebuttal, some refutation of your sources, I'm more than willing to have another go at it.
Rebuttal of the NIST rebuttal:
"To weaken something 50 feet away would have melted you to be in the vicinity. Logically, physically, no way could have caused a collapse in any way. It could not have affected the collapse of the WTC. Impossible."
-Jim Nesch, referring to temperatures in the WTC.
No one, the NIST included, claimed that the heat inside the WTC melted steel. They did claim that it weakened the steel. Nesch's response seems to imply that either there was no heat or that heat could not weaken the steel. Logically, physically, heat weakens steel. There was heat. In fact, the NIST found that burning couches could create temperatures as high as 1100 C on the ceiling above them. Impossible? Not really. That sort of experiment is incredibly easy to replicate, by the way, not that I've done so. Steve Jones should have burned a couch to test it, though.
The next guy says that the material coming out of the tower can't be aluminum. Fine. But it can't be molten steel either(the fires are too cool to melt steel). It's got to be thermite, right? Read on:
Several times over the last year I have been asked to comment on a photo of one of the Trade Center Towers. The photo shows a molten flow from one of the windows. The flow falls down along the building. It appears orange and turns to a gray color as it cools.
The questions usually want me to address "Is this photo a fake?" and "Is the flow steel or aluminum?" "Is this situation possible?"
First, I will address the temperature range, then the color of the flow.
I am working in imperial units and temperature in degrees F [To convert to C use this link]
Metals lose about 50% of their strength at 60% of their melting temperature. This is common knowledge and may be found in any undergraduate text regarding "Fracture and Deformation of Materials."
If the approximate melting temperature of steel is 2750 F the the material would be plastic at 1650 F. Even assuming a safety factor of 3, you would expect the bolts or other structural members to deform and fail near this temperature, especially with the additional weight if a jet air liner. I would assume that the live load calculations did not include the typical office equipment and an airliner plus a factor of 3. THEREFORE I assume that the flow is not steel and that the temperature of the steel members at the time of the photo is less than 1650 F.
Assuming that the flow would be molten aluminum from the airliner and the color of molten aluminum is silver then why is the flow orange?
The color of pure molten aluminum is silver, It has an emissivity of .12. Steel has an emissivity of .4 and appears orange in the temperature range of molten aluminum.
The emissivity of aluminum oxide is .44 and also appears orange in the melting temperature range of molten aluminum.
The emissivity of plate glass is .937 It begins to soften at 1000 F and flows around 1350 F. Silica has an emissivity of .8
Copper oxide also has an emissivity of .8. however I will assume that their effect is negligible.
Aluminum oxidizes readily in the foundry under ideal melting conditions. Large surface area relative to thickness, turbulence, the presence of water or oil greatly increases the oxidation of aluminum. A jet airliner is made of thin aluminum sheet and most probably suffered considerable oxidation especially in contact with an open flame and being in contact with jet fuel. If you don't believe this, try melting a few soda cans over coals or open flame. If you are lucky you will end up with only 50% aluminum oxide. However, the cans may completely burn up.
The specific gravity of aluminum is 2.7. The specific gravity of aluminum oxide (Al2O3-3H2O) is 2.42 the specific gravity of Si = 2.40 and Glass is 2.65 these are all very similar and likely to be entrained in a molten aluminum flow. Don't believe it? lightly stir the dross into molten aluminum. The surface tension is so high is is almost impossible to separate them.
THEREFORE assuming that the flow consist of molten aluminum and considerable oxides, and assuming that the windows in the trade center were plate glass and also in a plastic state and that they were also likely entrained in the molten aluminum. I would expect the flow to appear to be orange in color. Especially since both the entrained materials have emissivities equal to or more than twice that of iron.
Also since dross cools to a gray color and glass with impurities also turns dark. I would expect that the flow would darken upon cooling.
I would also suggest that not only is the photo possible, but entirely likely.
Summary: The flow is not steel because the structural steel would fail well below the melting temperature. The flow is likely to be a mixture of aluminum, aluminum oxides, molten glass and coals of whatever trash the aluminum flowed over as it reached the open window. Such a flow would appear orange and cool to a dark color. Stephen D. Chastain-Mechanical Engineer
I could have just posted a link, of course, but this way is more polite, I think. Keep in mind that the flow may not even be mostly aluminum. Also keep in mind that thermite/thermate is totally unnecessary if the plan is to knock out the building with bombs anyway. And if those were used to knock out the 'huge' support columns with thermite/thermate, the firefighters in the building would probably have noticed giant rivers of molten iron flowing into the lower floors. Did anyone see anything like that?
The next guy argues on structural grounds that the WTC towers could not have fallen as a result of the airliners crashing into them because they were designed to not fall when airliners crashed into them. Is this really an argument? I could just as well argue that the government did not bring down the WTC towers because the government is supposed to keep that sort of thing from happening and has many agencies to do just that. Design is not infallible.
It's easy to simply point out that no one had actually crashed airplanes into the towers to find out if they could really survive the impact and subsequent conflagration. Sometimes engineers do make mistakes.
Then they talk about the timing of the fall. He points to some seismographs to indicate the time of the fall was about 10 seconds. The group that measured the seismographs says they show clearly that the readings build up over time, which strongly refutes the bomb hypothesis, which would show sudden spikes. Yet bombs are supposedly the only things that could make the towers fall so quickly. It is then claimed that the actual time the collapse should have taken was somewhere in the range of 40 seconds, which seems unrealistic since the towers could simply fall over on their sides in less time.
Here's the seismographs, so you can see them.
[IMG]file:///C:/DOCUME%7E1/BEARHU%7E1/LOCALS%7E1/Temp/moz-screenshot.jpg[/IMG][IMG]file:///C:/DOCUME%7E1/BEARHU%7E1/LOCALS%7E1/Temp/moz-screenshot-1.jpg[/IMG]
Recall that steel structures can suffer progressive collapse(truss bridges) and that the material of the WTC didn't fall straight down. It fell a great deal to the sides, as if falling straight down offered some sort of resistance.
The clip ends after the structural argument. I'm sure there's much, much more than that elsewhere that I haven't gotten around to refuting. Please accept this humble morsel of evidence in the meantime. 
[IMG]file:///C:/DOCUME%7E1/BEARHU%7E1/LOCALS%7E1/Temp/moz-screenshot-2.jpg[/IMG]
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