Couldn't find decent story in english about it, but here's an overview of the results: Active Thermitic Material Found in 9/11 Dust. Here you can get the article, published in the peer reviewed "The Open Chemical Physics Journal": article.

Quote: from the articles abstract: Abstract We have discovered distinctive red/gray chips in all the samples we have studied of the dust produced by the destruction of the World Trade Center. Examination of four of these samples, collected from separate sites, is reported in this paper. These red/gray chips show marked similarities in all four samples. One sample was collected by a Manhattan resident about ten minutes after the collapse of the second WTC Tower, two the next day, and a fourth about a week later. The properties of these chips were analyzed using optical microscopy, scanning electron microscopy (SEM), X-ray energy dispersive spectroscopy (XEDS), and differential scanning calorimetry (DSC). The red material contains grains approximately 100 nm across which are largely iron oxide, while aluminum is contained in tiny plate-like structures. Separation of components using methyl ethyl ketone demonstrated that elemental aluminum is present. The iron oxide and aluminum are intimately mixed in the red material. When ignited in a DSC device the chips exhibit large but narrow exotherms occurring at approximately 430 °C, far below the normal ignition temperature for conventional thermite. Numerous iron-rich spheres are clearly observed in the residue following the ignition of these peculiar red/gray chips. The red portion of these chips is found to be an unreacted thermitic material and highly energetic.

So, this is an interesting discovery, if you believe that this is indeed uncontaminated samples from Manhattan. I don't care to buy into many of the outlandish conspiracy theories out there, but I think this raises some questions. Why on earth would there be nano-composite explosives in office skyscrapers? Now all they found was unreacted thermitic material, and byproducts from a reaction of this material. Proof that this was what brought down the towers is another thing. Tons of the stuff would probably be needed, plus lots of time to install it in the central cores of all three buildings. The best theory I've heard is it was put there to bring them down in a controlled fashion, to avoid damaging nearby buildings/people, if they tipped over due to another bombing like '93. Nevermind it's an incredibly cynical thing to do, but the leaser of WTC had a pretty good insurance against it, and we all know by now how certain players in the financial market thinks :( Anybody got any good theories (possibly not involving aliens or the skull and bones fraternity)? [Edited by - Don Carnage on April 5, 2009 9:08:22 AM]

Quote:
The best theory I've heard is it was put there to bring them down in a controlled fashion, to avoid damaging nearby buildings/people, if they tipped over due to another bombing like '93.

That is what seems logical to me. And it seems to have worked, if that was the purpose of it.

you do have to be quite cynical to believe that someone would send rescue teams in the buildings and then detonate the buildings full of rescue workers.

Quote: Original post by Don Carnage
Anybody got any good theories (possibly not involving aliens or the skull and bones fraternity)?

[rolleyes]Iron is involved in building construction, and tends to rust over the years. Aluminum is also involved in building construction. A collapsing skyscraper tends to turn lots of things into dust and then disperse it.

Quote: The best theory I've heard is it was put there to bring them down in a controlled fashion, to avoid damaging nearby buildings/people, if they tipped over due to another bombing like '93.

That is totally stupid. The way you demolish a building in a controlled fashion is by explosively blowing out its load-bearing elements simultaneously (per floor), so that no side of the building can act as a fulcrum. Using thermite charges to melt the load-bearing elements would accomplish the opposite of that, since the burn rate would never be perfectly even. For that matter, it would take several minutes to melt through the supports, meaning that it would be completely impractical at preventing a tip-over. God, there's credulousness, and then there's willful stupidity.

Yeah, think about it. They were STEEL buildings, steel is mostly iron. Iron rusts over time, and quickly rusts when it is super heated.

A very large hunk of flying aluminum was rammed at a very high speed into the building.

If people didn't find traces of iron and aluminum in the dust, then THAT would be very odd and something worth noting. Most of the dust is likely going to be drywall being crushed, but in a collapse like that there is going to be a lot of grinding actions between all kinds of materials.

Quote: Original post by SneftelThat is totally stupid. The way you demolish a building in a controlled fashion is by explosively blowing out its load-bearing elements simultaneously (per floor), so that no side of the building can act as a fulcrum. Using thermite charges to melt the load-bearing elements would accomplish the opposite of that, since the burn rate would never be perfectly even. For that matter, it would take several minutes to melt through the supports, meaning that it would be completely impractical at preventing a tip-over. God, there's credulousness, and then there's willful stupidity.

Maybe thermite alone would not be suitable, but a combination of thermite and any other explosives would. It would be kind of crazy, to put metal-melting material in a metal structure without any purpose.

Quote: Original post by Talroth
Yeah, think about it. They were STEEL buildings, steel is mostly iron. Iron rusts over time, and quickly rusts when it is super heated.

A very large hunk of flying aluminum was rammed at a very high speed into the building.

If people didn't find traces of iron and aluminum in the dust, then THAT would be very odd and something worth noting. Most of the dust is likely going to be drywall being crushed, but in a collapse like that there is going to be a lot of grinding actions between all kinds of materials.

But I find it hard to believe the scientists of the article didn't know that themselves.

Quote: The red portion of these chips is found to be an unreacted thermitic material and highly energetic.

Unreacted. Wouldn't it be strange if this was formed after the collapse.

I don't claim to any truth about what happened, and I'm sorry that I brought this up. I realize of course that it is still a sensitive subject, as it is for me as well, even though I'm not an American.

I'm sorry to have blown this out of proportions then. What is interesting for me is not out-there theories, but some information that can settle my mind on the matter of how those three buildings could collapse on that day. It just seems too much of a coincidence to me, as it has from day one after seeing the first videos.
Of course the mind sees what it wants to see, and so I could very well be mistaken here.

It still seems incredible to me, as it does to so many other people around the planet, and I'm to believe that these doubts in the official story is the result of conspiracy theorists with video editors. Some of the folks advocating for additional investigation into these matters are quite serious and intelligent researchers, engineers, cultural figures etc.

But check out the article. It clearly states that the residue that was found were nanoscale particles (~100 nm), finely intermixed with tiny aluminum plates, plus some carbon and silicon.
Definitely man-made. Maybe this is the stuff they use to weld with, it burns at low temperature and reacts explosively. It's not the same as thermite which has much larger particles and is just iron oxide + aluminum. This sounds to me like plausible military grade explosives, who am I then to speculate on whether it's effective in knocking down a building?

The article is interesting because if (and it's still only a "theory") the buildings were bombed or taken down with explosives, you'd expect some of the remains of those explosions present in the dust, which is what they claim to have found.

The big mystery to me is still how could all those dust clouds form just from building floors collapsing. Everything practically turned to dust, even the lower floors collapsed when the top was gone.

Edit: also the pools of molten metal in the bottom of the structures is a clue to something, and the multiple explosions that were reported on many media outlets on the day and few days after. Somebody doesn't want us to know about these things, and maybe that's just the way it works. But I'm interested in what I can get to know. We'll see.

If a moderator should find this topic inappropriate, please feel free to close it, but it would be interesting to hear the great minds of GameDev have their take on it.

Quote: Original post by Marmin
Maybe thermite alone would not be suitable, but a combination of thermite and any other explosives would.

Sure, if you left out the thermite. Thermite+explosives is silly -- the explosion would dissipate the thermite before it had a chance to fully combust.

Quote: Original post by Don Carnage
who am I to speculate on whether it's effective in knocking down a building.

Who are you? Why, you're a conspiracy theorist!

Quote: The article is interesting because if (and it's still only a "theory") the buildings were bombed or taken down with explosives, you'd expect some of the remains of those explosions present in the dust, which is what they claim to have found.

The big mystery to me is still how could all those dust clouds form just from building floors collapsing. Everything practically turned to dust, even the lower floors collapsed when the top was gone.

See?

Quote: If a moderator should find this topic inappropriate, please feel free to close it, but it would be interesting to hear the great minds of GameDev have their take on it.

clicky