RE: [escepticos] 11/S y escepticismo (y presentación)

[carlos ponte]

David-
Dar que pensar exactamente que? Imaginemos que el aluminio no brilla a la
luz del día, incuso de un día nublado como por lo que recuerdo era el 11S en
NY. ¿Exactamente qué consideras que demostraría, eso?

Carlos
Ya lo he explicado más de una vez, pero bueno. Aquí te pongo el enlace al
FAQ del NIST (National Institute of Standards and Technology) en cuanto a la
investigación oficial que llevaron a cabo para el gobierno de los EEUU sobre
las torres gemelas
http://www.nist.gov/el/disasterstudies/wtc/faqs_wtctowers.cfm

Te rescato algunos fragmentos, aunque los leerás más cómodamente en el
enlace que pongo. Dicen que lo que chorreó fue aluminio plateado con
trocitos incandescentes de mobiliario que le darían la luminosidad (ole).
Además dicen que lo que sucediera a partir del inicio del colapso no les
compete. Tiene tela teniendo en cuenta la importancia del suceso. Por eso no
mencionan las vigas fundidas ni los análisis del polvo.

En cuanto a tu última pregunta, ya está contestada en otro mensaje.

Un saludo 


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15. Since the melting point of steel is about 1,500 degrees Celsius (2,800
degrees  Fahrenheit) and the temperature of a jet fuel fire does not exceed
1,000 degrees  Celsius (1,800 degrees Fahrenheit), how could fires have
impacted the steel  enough to bring down the WTC towers?

In no instance did NIST report that steel in the WTC towers melted due to
the fires. The melting point of steel is about 1,500 degrees Celsius (2,800
degrees Fahrenheit). Normal building fires and hydrocarbon (e.g., jet fuel)
fires generate temperatures up to about 1,100 degrees Celsius (2,000 degrees
Fahrenheit). NIST reported maximum upper layer air temperatures of about
1,000 degrees Celsius (1,800 degrees Fahrenheit) in the WTC towers (for
example, see NCSTAR 1, Figure 6-36).
However, when bare steel reaches temperatures of 1,000 degrees Celsius, it
softens and its strength reduces to roughly 10 percent of its room
temperature value. Steel that is unprotected (e.g., if the fireproofing is
dislodged) can reach the air temperature within the time period that the
fires burned within the towers. Thus, yielding and buckling of the steel
members (floor trusses, beams, and both core and exterior columns) with
missing fireproofing were expected under the fire intensity and duration
determined by NIST for the WTC towers.
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21. Why does NIST state that a yellow stream of molten metal seen in some
photographs pouring down the side of WTC2 was aluminum from the crashed
plane, even though aluminum burns with a white glow?

NIST reported (NIST NCSTAR 1-5A) that just before 9:52 a.m., a bright spot
appeared at the top of a window on the 80th floor of WTC 2, four windows
removed from the east edge on the north face, followed by the flow of a
glowing liquid. This flow lasted approximately four seconds before
subsiding. Many such liquid flows were observed from near this location in
the seven minutes leading up to the collapse of this tower. There is no
evidence of similar molten liquid pouring out from another location in WTC 2
or from anywhere within WTC 1.
Photographs, as well as NIST simulations of the aircraft impact, show large
piles of debris in the 80th and 81st floors of WTC 2 near the site where the
glowing liquid eventually appeared. Much of this debris came from the
aircraft itself and from the office furnishings that the aircraft pushed
forward as it tunneled to this far end of the building. Large fires
developed on these piles shortly after the aircraft impact and continued to
burn in the area until the tower collapsed.
NIST concluded that the source of the molten material was aluminum alloys
from the aircraft, since these are known to melt between 475 degrees Celsius
(900 degrees Fahrenheit) and 640 degrees Celsius (1,200 degrees
Fahrenheit)—depending on the particular alloy—well below the expected
temperatures (about 1,000 degrees Celsius or 1,800 degrees Fahrenheit) in
the vicinity of the fires. Aluminum is not expected to ignite at normal fire
temperatures and there is no visual indication that the material flowing
from the tower was burning.
Pure liquid aluminum would be expected to appear silvery. However, the
molten metal was very likely mixed with large amounts of hot, partially
burned, solid organic materials (e.g., furniture, carpets, partitions and
computers) which can display an orange glow, much like logs burning in a
fireplace. The apparent color also would have been affected by slag
formation on the surface.


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23. Why didn’t the NIST investigation consider reports of molten steel in
the wreckage from the WTC towers?

NIST investigators and experts from the American Society of Civil Engineers
(ASCE) and the Structural Engineers Association of New York (SEONY)—who
inspected the WTC steel at the WTC site and the salvage yards—found no
evidence that would support the melting of steel in a jet-fuel ignited fire
in the towers prior to collapse. The condition of the steel in the wreckage
of the WTC towers (i.e., whether it was in a molten state or not) was
irrelevant to the investigation of the collapse since it does not provide
any conclusive information on the condition of the steel when the WTC towers
were standing.
Under certain circumstances it is conceivable for some of the steel in the
wreckage to have melted after the buildings collapsed. Any molten steel in
the wreckage was more likely due to the high temperature resulting from long
exposure to combustion within the pile than to short exposure to fires or
explosions while the buildings were standing.

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