Quote: Original post by Don Carnage
@LessBread: you make good points here, I agree. I can well imagine that some if not all these scientists are biased as to what conclusions they'd like to draw, as in "explosives were used". But since this is the largest university in Denmark, I think bad science would ruin your career. So I'll accept their analysis of the chemical subject, but not automatically their speculations on it's use or origin.

I wish they'd have provided some figures with estimates on the volume of stuff found vs. estimate of how much dust was produced, to at least make the idea plausible, but I guess that would make the chemical article less serious and credible.

I also had to look up the 100 nm scale an extra time, that's really small!

I'm not doubting that the scientists found what they claim to have found, I'm just saying that it's a huge stretch to say that the presence of microscopic quantities of iron oxide (rust) and aluminum in a dust sample is indicative of a thermite reaction. If they found aluminum oxide and elemental iron, products of a thermite reaction, in similar samples of dust, that wouldn't confirm a thermite reation either. If you cut your finger on a can of soda pop, between the iron in your blood and the aluminum in the can you'd find more iron and aluminum oxide than what this study claims.

To put these claims into perspective another way, dust particles max out in size around 500 micrometers. That's 1e−6 meters. The width of human hair is 1e-4 meters, red blood cells are almost 1e-5 meters in diameter (source). Furthermore, "1000 dust particles per square centimeter settle on domestic surfaces every hour." Combined with the prevalence of naturally occurring mineral dust, "mainly constituted of the oxides (SiO2, Al2O3, FeO, Fe2O3, CaO, and others)", it's reasonable to assert that there's probably a lot more iron oxide and aluminum oxide in the dust built up around the power supply of a typical personal computer than what was found in these samples. In spite of that potential evidence, no one would take it seriously as evidence of a thermite reaction on your desktop.

One last comparison. The normal concentration of uranium in soil is 300 μg/kg to 11.7 mg/kg. Taking the low end of that range, that would be 3e-4 grams of uranium per kilogram of soil. Applying a molar mass of 238.02891 grams, that's 1.2603511060904324604939794918189e-6 moles or approximately 759,001,306,605,991,684 atoms (if I did the math correctly). That is at least ten orders of magnitude more atoms than were involved in these samples. It would be absurd for anyone to point to the soil in your backyard as evidence that you were engaged in the production of a weapon of mass destruction, but there's more evidence to support that assertion than the evidence presented by this paper in support of the assertion that the WTC was taken down with a thermite reaction.

I don't need any chips to smell the shit from 20,000 miles away this whole 9/11 thingy was.

How many lifes this event destroyed? And I'm not talking just about the people that got killed in the WTC.

IMO the current global financial crisis is a direct consecuence of this.

-- Im not concerned about the topic, but I just wanna point out a logical flaw with the above piece

the size/amount of said particles aint important
when rutherford was 'spliting the atom' u didnt hear ppl complain but but mate youre only dealing with millionths of micrograms of matter, thus your experiment is invalid

instead what is important is the probability of said particles being there naturally
perhaps the odds of such a percentage being there are 20,000,000,000,000:1

(aka enuf to help send a criminal to the electric chair :) )

Quote: Original post by LessBread

Quote: Original post by Don Carnage
@LessBread: you make good points here, I agree. I can well imagine that some if not all these scientists are biased as to what conclusions they'd like to draw, as in "explosives were used". But since this is the largest university in Denmark, I think bad science would ruin your career. So I'll accept their analysis of the chemical subject, but not automatically their speculations on it's use or origin.

I wish they'd have provided some figures with estimates on the volume of stuff found vs. estimate of how much dust was produced, to at least make the idea plausible, but I guess that would make the chemical article less serious and credible.

I also had to look up the 100 nm scale an extra time, that's really small!

I'm not doubting that the scientists found what they claim to have found, I'm just saying that it's a huge stretch to say that the presence of microscopic quantities of iron oxide (rust) and aluminum in a dust sample is indicative of a thermite reaction.

wait. Why microscopic quantities? Read the article, it just says that particles of aluminium in the sample are really tiny, not that there is very little quantity of aluminium. Also it says they found some 'burned out' samples as well (with elemental iron and aluminium oxide). There are optical microscopic photographs of iron spheres formed as result of ignition (in lab), as well. That thing did actually burn in the lab, releasing heat.

My view on this thing has shifted - if paper does not contain plain lies, those samples do not look like something formed accidentally. It would certainly be difficult to explain how it formed, "there was some aluminium at offices" wont suffice.

As for usefulness of that stuff for controlled demolition,

Quote:
3. Could the Red Material Be Unreacted “Super-
Thermite”?
We have noted that ordinary thermite acts as an incendi-
ary when ignited. However, when the ingredients are ultra-
fine-grain and are intimately mixed, the mixture reacts very
rapidly, even explosively [20]. Thus, there is a highly ener-
getic form of thermite known as an energetic nanocomposite
or “super-thermite,” composed of aluminum and iron oxide
with at least one component being approximately 100 nm or
less, often along with silicon and carbon [19-28].


“Reaction rates between nanosize aluminum
and metal oxides can be significantly greater
than those observed with traditional micron-size
thermite powders. Reactions occurring between
metal and metal oxide powders are accompa-
nied by the generation of high temperatures
(>3000 K). Super-thermites, formed by mixing
of aluminum and metal oxide nanopowders re-
sult in energy release rate by two orders of
magnitude higher than similar mixtures consist-
ing of micron size reactants” [22].

makes sense, reaction speed is inversely proportional to particle size. Two orders of magnitude that's 1 minute vs 0.6 seconds.

[Edited by - Dmytry on April 6, 2009 4:03:35 AM]

Quote: Original post by Dmytry

Quote: Original post by LessBread

Quote: Original post by Don Carnage
@LessBread: you make good points here, I agree. I can well imagine that some if not all these scientists are biased as to what conclusions they'd like to draw, as in "explosives were used". But since this is the largest university in Denmark, I think bad science would ruin your career. So I'll accept their analysis of the chemical subject, but not automatically their speculations on it's use or origin.

I wish they'd have provided some figures with estimates on the volume of stuff found vs. estimate of how much dust was produced, to at least make the idea plausible, but I guess that would make the chemical article less serious and credible.

I also had to look up the 100 nm scale an extra time, that's really small!

I'm not doubting that the scientists found what they claim to have found, I'm just saying that it's a huge stretch to say that the presence of microscopic quantities of iron oxide (rust) and aluminum in a dust sample is indicative of a thermite reaction.

wait. Why microscopic quantities? Read the article, it just says that particles of aluminium in the sample are really tiny, not that there is very little quantity of aluminium. Also it says they found some 'burned out' samples as well (with elemental iron and aluminium oxide). There are optical microscopic photographs of iron spheres formed as result of ignition (in lab), as well. That thing did actually burn in the lab, releasing heat.

Nanometers are microscopic. The pictures in the paper - Photomicrographs according to the caption - indicate a millimeter and micrometer scale. They also used a scanning electron microscope. "The chips are typically small but readily discernible by eye due to their distinctive color. They are of variable size with major dimensions of roughly 0.2 to 3 mm. Thicknesses vary from roughly 10 to 100 microns for each layer (red and gray)." ... "At approximately 2.5 mm in length, the chip in Fig. (2a) was one of the larger chips collected. The mass of this chip was approximately 0.7 mg." There are the parameters for "ballparking".

Quote: Original post by Dmytry
My view on this thing has shifted - if paper does not contain plain lies, those samples do not look like something formed accidentally. It would certainly be difficult to explain how it formed, "there was some aluminium at offices" wont suffice.

Aluminum in the airplanes too. Iron oxide in dust everywhere. I'd rather give them the benefit of the doubt regarding their sincerity, but eventually the people who collected the samples should be scrutinized too.

I found these sentences from the intro somewhat off putting:

Quote:
The collapses of the three tallest WTC buildings were
remarkable for their completeness, their near free-fall speed
[11] their striking radial symmetry [1, 12] and the surprisingly
large volume of fine toxic dust [13] that was generated.
In order to better understand these features of the destruction,
the authors initiated an examination of this dust.

It seems to me that they should have focused on the dust and omitted the remarks about completeness, free fall and radial symmetry. If this paper was supposed to be about the dust, then it should focus on the dust. For example, "The collapses of the three tallest WTC buildings were remarkable for the surprisingly large volume of fine toxic dust [13] that was generated." The other points are extraneous to this particular detail. Nevertheless, I realize this is a minor complaint.

Quote: Original post by Dmytry
As for usefulness of that stuff for controlled demolition,

Quote:
3. Could the Red Material Be Unreacted “Super-
Thermite”?
We have noted that ordinary thermite acts as an incendi-
ary when ignited. However, when the ingredients are ultra-
fine-grain and are intimately mixed, the mixture reacts very
rapidly, even explosively [20]. Thus, there is a highly ener-
getic form of thermite known as an energetic nanocomposite
or “super-thermite,” composed of aluminum and iron oxide
with at least one component being approximately 100 nm or
less, often along with silicon and carbon [19-28].

“Reaction rates between nanosize aluminum
and metal oxides can be significantly greater
than those observed with traditional micron-size
thermite powders. Reactions occurring between
metal and metal oxide powders are accompa-
nied by the generation of high temperatures
(>3000 K). Super-thermites, formed by mixing
of aluminum and metal oxide nanopowders re-
sult in energy release rate by two orders of
magnitude higher than similar mixtures consist-
ing of micron size reactants” [22].

makes sense, reaction speed is inversely proportional to particle size. Two orders of magnitude that's 1 minute vs 0.6 seconds.

Sure it makes sense, it describes thermite. It doesn't necessarily describe what they found. Here's the snippet that I found most telling:

Quote:
We would like to make detailed comparisons of the red
chips with known super-thermite composites, along with
comparisons of the products following ignition, but there are
many forms of this high-tech thermite, and this comparison
must wait for a future study.

Postponed! It seems to me that control samples are needed to reach a firm conclusion. Some comparative spectroscopy would be nice too. Show me the spectra! [grin] They said they compared their samples with commercially available macro-thermite. Too bad they omitted that data. Too bad they didn't compare with ordinary house dust taken from areas that were upwind from the disaster, upwind to lessen the chance that those dust samples would be contaminated with WTC dust and even though several years have passed. Even Danish dust would have provided a sufficient comparison, just to show that those globules were unique to the sampled dust and not something that could be found in ordinary dust. They reference papers concerning the creation of super-thermite prior to the disaster. Too bad they weren't able to get their hands on some of it. It seems to me that they wouldn't need very much of it to compare with, a few grams at most.

Quote: Original post by LessBread

Quote: Original post by Dmytry

Quote: Original post by LessBread

Quote: Original post by Don Carnage
@LessBread: you make good points here, I agree. I can well imagine that some if not all these scientists are biased as to what conclusions they'd like to draw, as in "explosives were used". But since this is the largest university in Denmark, I think bad science would ruin your career. So I'll accept their analysis of the chemical subject, but not automatically their speculations on it's use or origin.

I wish they'd have provided some figures with estimates on the volume of stuff found vs. estimate of how much dust was produced, to at least make the idea plausible, but I guess that would make the chemical article less serious and credible.

I also had to look up the 100 nm scale an extra time, that's really small!

I'm not doubting that the scientists found what they claim to have found, I'm just saying that it's a huge stretch to say that the presence of microscopic quantities of iron oxide (rust) and aluminum in a dust sample is indicative of a thermite reaction.

wait. Why microscopic quantities? Read the article, it just says that particles of aluminium in the sample are really tiny, not that there is very little quantity of aluminium. Also it says they found some 'burned out' samples as well (with elemental iron and aluminium oxide). There are optical microscopic photographs of iron spheres formed as result of ignition (in lab), as well. That thing did actually burn in the lab, releasing heat.

Nanometers are microscopic. The pictures in the paper - Photomicrographs according to the caption - indicate a millimeter and micrometer scale. They also used a scanning electron microscope. "The chips are typically small but readily discernible by eye due to their distinctive color. They are of variable size with major dimensions of roughly 0.2 to 3 mm. Thicknesses vary from roughly 10 to 100 microns for each layer (red and gray)." ... "At approximately 2.5 mm in length, the chip in Fig. (2a) was one of the larger chips collected. The mass of this chip was approximately 0.7 mg." There are the parameters for "ballparking".

err. you understand distinction between "microscopic particles" and "microscopic quantity" do you? The dust samples evaluated had 0.1 percent (one part in thousand) of those chips, which would make some rather big quantity if we assume that rest of dust had comparable composition, given how many tons of dust were here. (hundreds tons of dust means hundreds kilograms of that stuff.)

airplane aluminium: yes that's what I'm saying, this might have formed from airplane grinding against rust (or might not). Needs proper study, and until there is some study showing formation of anything like that in aluminium impact, the "conspiracy" clearly scores 1:0 on science here.

house dust: don't know about you, but I'm fairy certain my house dust does not contain anything even remotely resembling those "chips". Surely i got some aluminium in my dust, and some iron oxide and a lot of other components. But those would be dispersed among other components of dust, rather than form millimetre sized chips of iron oxide&aluminium mix.

[Edited by - Dmytry on April 6, 2009 7:55:47 AM]

Quote: Original post by Dmytry

Quote: Original post by LessBread

Quote: Original post by Dmytry

Quote: Original post by LessBread

Quote: Original post by Don Carnage
@LessBread: you make good points here, I agree. I can well imagine that some if not all these scientists are biased as to what conclusions they'd like to draw, as in "explosives were used". But since this is the largest university in Denmark, I think bad science would ruin your career. So I'll accept their analysis of the chemical subject, but not automatically their speculations on it's use or origin.

I wish they'd have provided some figures with estimates on the volume of stuff found vs. estimate of how much dust was produced, to at least make the idea plausible, but I guess that would make the chemical article less serious and credible.

I also had to look up the 100 nm scale an extra time, that's really small!

I'm not doubting that the scientists found what they claim to have found, I'm just saying that it's a huge stretch to say that the presence of microscopic quantities of iron oxide (rust) and aluminum in a dust sample is indicative of a thermite reaction.

wait. Why microscopic quantities? Read the article, it just says that particles of aluminium in the sample are really tiny, not that there is very little quantity of aluminium. Also it says they found some 'burned out' samples as well (with elemental iron and aluminium oxide). There are optical microscopic photographs of iron spheres formed as result of ignition (in lab), as well. That thing did actually burn in the lab, releasing heat.

Nanometers are microscopic. The pictures in the paper - Photomicrographs according to the caption - indicate a millimeter and micrometer scale. They also used a scanning electron microscope. "The chips are typically small but readily discernible by eye due to their distinctive color. They are of variable size with major dimensions of roughly 0.2 to 3 mm. Thicknesses vary from roughly 10 to 100 microns for each layer (red and gray)." ... "At approximately 2.5 mm in length, the chip in Fig. (2a) was one of the larger chips collected. The mass of this chip was approximately 0.7 mg." There are the parameters for "ballparking".

err. you understand distinction between "microscopic particles" and "microscopic quantity" do you? The dust samples evaluated had 0.1 percent (one part in thousand) of those chips, which would make some rather big quantity if we assume that rest of dust had comparable composition, given how many tons of dust were here. (hundreds tons of dust means hundreds kilograms of that stuff.)

Yes. Remember, when I first used that term I was thinking that they had analyzed specs 100 nm cubed. Hundreds of tons of dust only means hundreds of kilograms of that stuff if there was a uniform composition to the dust. I doubt that was the case or there would have been more than a few reports of strange red chips in the WTC dust.

Quote: Original post by Dmytry
airplane aluminium: yes that's what I'm saying, this might have formed from airplane grinding against rust (or might not). Needs proper study, and until there is some study showing formation of anything like that in aluminium impact, the "conspiracy" clearly scores 1:0 on science here.

Another possibility is that the chips may have been leftover from a legitimate building demolition in the area and became mixed up with the WTC dust and blown around. That assumes, however, that these chips are indeed thermite.

Quote: Original post by Dmytry
house dust: don't know about you, but I'm fairy certain my house dust does not contain anything even remotely resembling those "chips". Surely i got some aluminium in my dust, and some iron oxide and a lot of other components. But those would be dispersed among other components of dust, rather than form millimetre sized chips of iron oxide&aluminium mix.

There were some pictures in the study towards the end that looked like mineral dust.

To boil this down, they need to show that:

1. These chips are thermite.
2. These chips came from the WTC and not some other source.

Here is another possibility regarding the identification of these chips, they could well be paint chips.

Transparent Iron Oxide Pigments for Automotive Applications

Quote: Transparent iron oxides are most commonly used in combination with micaceous or aluminum flakes to produce metallic effect finishes for automobiles.2 The natural color space of transparent iron oxide is yellow to brown. In combination with aluminum flake they give rise to colors from burnished silvers through gold to bronze. These colors, often called "autumn" shades or earth tones, are re-emerging as popular colors in U.S. automotive market. (2 Coatings World, July 2001, pg16.)

Thermal Finishes This is a long table listing various kinds of paints, including paints made with aluminum and iron oxide.

Metal Coating This describes methods for applying paint to metal, including aluminum coated steel used in a variety of products that could have been found in the WTC and related debris - air conditioners, microwave ovens, automobile mufflers.

Here's a treat I found looking up the above links: PRACTICAL AND MYSTIFYING HOME TESTS YOU CAN MAKE WITH IRON (Popular Science Aug, 1933) Check out the caption on the upper left hand side of the page. // edit - it basically says that thermite can be made using aluminum paint and rust

Here's another development, totally unrelated to the OP, but interesting and worth sharing: Cheap paint could protect against super-fast wireless Japanese researchers have developed an aluminum iron oxide paint that blocks wifi.

[Edited by - LessBread on April 6, 2009 3:08:06 PM]

Quote: Original post by Sneftel

Quote: Original post by Dmytry
If you believe in official explanation you must also agree that termite would do the job just fine. Why something that would work would be stupid?

Because it wouldn't a sure thing in the first place, and in any case it would take far too long to be useful for a "just in case" controlled demolition as is being described here.

I've always kind of wondered just how lucky we were that the buildings fell completely straight down.

Since both of them did it I'm more inclined to believe that they were designed to do so, rather than it being a fluke.


But I still wonder...

I don't think it was thermite. It was actually termites.

Quote: Original post by Mithrandir
I've always kind of wondered just how lucky we were that the buildings fell completely straight down.

Since both of them did it I'm more inclined to believe that they were designed to do so, rather than it being a fluke.


But I still wonder...

I thought that it was due to the unique construction of the twin towers with a core of elevator shafts, an outside shell, and not much in between.

Here we go: see http://www.tms.org/pubs/journals/JOM/0112/Eagar/Eagar-0112.html

Quote: THE DESIGN
The towers were designed and built in the mid-1960s through the early 1970s. They represented a new approach to skyscrapers in that they were to be very lightweight and involved modular construction methods in order to accelerate the schedule and to reduce the costs.

To a structural engineer, a skyscraper is modeled as a large cantilever vertical column. Each tower was 64 m square, standing 411 m above street level and 21 m below grade. This produces a height-to-width ratio of 6.8. The total weight of the structure was roughly 500,000 t, but wind load, rather than the gravity load, dominated the design. The building is a huge sail that must resist a 225 km/h hurricane. It was designed to resist a wind load of 2 kPa—a total of lateral load of 5,000 t.

In order to make each tower capable of withstanding this wind load, the architects selected a lightweight “perimeter tube” design consisting of 244 exterior columns of 36 cm square steel box section on 100 cm centers (see Figure 3). This permitted windows more than one-half meter wide. Inside this outer tube there was a 27 m × 40 m core, which was designed to support the weight of the tower. It also housed the elevators, the stairwells, and the mechanical risers and utilities. Web joists 80 cm tall connected the core to the perimeter at each story. Concrete slabs were poured over these joists to form the floors. In essence, the building is an egg-crate construction that is about 95 percent air, explaining why the rubble after the collapse was only a few stories high.

...

The egg-crate construction made a redundant structure (i.e., if one or two columns were lost, the loads would shift into adjacent columns and the building would remain standing). Prior to the World Trade Center with its lightweight perimeter tube design, most tall buildings contained huge columns on 5 m centers and contained massive amounts of masonry carrying some of the structural load. The WTC was primarily a lightweight steel structure; however, its 244 perimeter columns made it “one of the most redundant and one of the most resilient” skyscrapers.1

And:

Quote: THE COLLAPSE
Nearly every large building has a redundant design that allows for loss of one primary structural member, such as a column. However, when multiple members fail, the shifting loads eventually overstress the adjacent members and the collapse occurs like a row of dominoes falling down.

The perimeter tube design of the WTC was highly redundant. It survived the loss of several exterior columns due to aircraft impact, but the ensuing fire led to other steel failures. Many structural engineers believe that the weak points—the limiting factors on design allowables—were the angle clips that held the floor joists between the columns on the perimeter wall and the core structure (see Figure 5). With a 700 Pa floor design allowable, each floor should have been able to support approximately 1,300 t beyond its own weight. The total weight of each tower was about 500,000 t.

As the joists on one or two of the most heavily burned floors gave way and the outer box columns began to bow outward, the floors above them also fell. The floor below (with its 1,300 t design capacity) could not support the roughly 45,000 t of ten floors (or more) above crashing down on these angle clips. This started the domino effect that caused the buildings to collapse within ten seconds, hitting bottom with an estimated speed of 200 km per hour. If it had been free fall, with no restraint, the collapse would have only taken eight seconds and would have impacted at 300 km/h.1 It has been suggested that it was fortunate that the WTC did not tip over onto other buildings surrounding the area. There are several points that should be made. First, the building is not solid; it is 95 percent air and, hence, can implode onto itself. Second, there is no lateral load, even the impact of a speeding aircraft, which is sufficient to move the center of gravity one hundred feet to the side such that it is not within the base footprint of the structure. Third, given the near free-fall collapse, there was insufficient time for portions to attain significant lateral velocity. To summarize all of these points, a 500,000 t structure has too much inertia to fall in any direction other than nearly straight down.

It's hard to think what would have happened had the buildings been constructed using a different design that made them more prone to tipping over.