It looks like you're using an Ad Blocker.
Please white-list or disable AboveTopSecret.com in your ad-blocking tool.
Some features of ATS will be disabled while you continue to use an ad-blocker.
Google Video Link
Closeups of the Plane Shape Hole and Edna Cintron waving. Standing 93 stories in the air looking out over Manhattan as she tirelessly waved for rescue during the last hour of her life. I've made enlargements from a variety of footage from Dias que marcaron al mundo (BBC Horizon - Fall Of The World Trade Center-Not cropped) and 11 Septembre Dans Les Tours Jumelles (Inside The Twin towers-FR2) which were never televised in America. the originals I worked with can be found thewebfairy.com... Edna is not alone, tho the others aren't as easy to see, or as persistant. There is some spiritual dimension to Edna's last hour that deserves mythic status for being true and real in a world where so little is either one.
Google Video Link
Originally posted by Wolfenz
Adding a log !! for People that believes in the Fuel Melting Steel Party...
Review of Causes of WTC Collapse
Although the structural damage inflicted by aircraft was severe, it
was only local. Without stripping of a significant portion of the
steel insulation during impact, the subsequent fire would likely
not have led to overall collapse (Bažant and Zhou 2002a; NIST
2005). As generally accepted by the community of specialists in
structural mechanics and structural engineering (though not by a
few outsiders claiming a conspiracy with planted explosives), the
failure scenario was as follows:
1. About 60% of the 60 columns of the impacted face of framed
tube (and about 13% of the total of 287 columns) were severed,
and many more were significantly deflected. This
caused stress redistribution, which significantly increased the
load of some columns, attaining or nearing the load capacity
for some of them.
2. Because a significant amount of steel insulation was stripped,
many structural steel members heated up to 600°C, as confirmed
by annealing studies of steel debris (NIST 2005) [the
structural steel used loses about 20% of its yield strength
already at 300°C, and about 85% at 600°C (NIST 2005);
and exhibits significant viscoplasticity, or creep, above
450°C (e.g., Cottrell 1964, p. 299), especially in the columns
overstressed due to load redistribution; the press reports right
after September 11, 2001 indicating temperature in excess of
800°C, turned out to be groundless, but Bažant and Zhou’s
analysis did not depend on that].
3. Differential thermal expansion, combined with heat-induced
viscoplastic deformation, caused the floor trusses to sag. The
catenary action of the sagging trusses pulled many perimeter
columns inward (by about 1 m, NIST 2005). The bowing of
these columns served as a huge imperfection inducing multistory
out-of-plane buckling of framed tube wall. The lateral
deflections of some columns due to aircraft impact, the differential
thermal expansion, and overstress due to load redistribution
also diminished buckling strength.
4. The combination of seven effects—(1) Overstress of some
columns due to initial load redistribution; (2) overheating
due to loss of steel insulation; (3) drastic lowering of yield
limit and creep threshold by heat; (4) lateral deflections of
many columns due to thermal strains and sagging floor
trusses; (5) weakened lateral support due to reduced in-plane
stiffness of sagging floors; (6) multistory bowing of some
columns (for which the critical load is an order of magnitude
less than it is for one-story buckling); and (7) local plastic
buckling of heated column webs—finally led to buckling of
columns (Fig. 1(b)). As a result, the upper part of the tower
fell, with little resistance, through at least one floor height,
impacting the lower part of the tower. This triggered progressive
collapse because the kinetic energy of the falling upper
part exceeded (by an order of magnitude) the energy that
could be absorbed by limited plastic deformations and fracturing
in the lower part of the tower.
In broad terms, this scenario was proposed by Bažant (2001),
and Bažant and Zhou (2002a,b) on the basis of simplified analysis
relying solely on energy considerations. Up to the moment of
collapse trigger, the foregoing scenario was identified by meticulous,
exhaustive, and very realistic computer simulations of
unprecedented detail, conducted by S. Shyam Sunder’s team at
NIST. The subsequent progressive collapse was not simulated at
NIST because its inevitability, once triggered by impact after column
buckling, had already been proven by Bažant and Zhou’s
(2002a) comparison of kinetic energy to energy absorption capability.
The elastically calculated stresses caused by impact of the
upper part of tower onto the lower part were found to be 31 times
greater than the design stresses (note a misprint in Eq. 2 of Bažant
and Zhou 2002a: A should be the combined cross section area of
all columns, which means that Eq. 1, rather than 2, is decisive).
Before disappearing from view, the upper part of the South
tower was seen to tilt significantly (and of the North tower
mildly). Some wondered why the tilting (Fig. 1(d)) did not continue,
so that the upper part would pivot about its base like a
falling tree [see Fig. 4 of Bažant and Zhou (2002b]. However,
such toppling to the side was impossible because the horizontal
reaction to the rate of angular momentum of the upper part would
have exceeded the elastoplastic shear resistance of the story at
least 10.3X (Bažant and Zhou 2002b).
The kinetic energy of the top part of the tower impacting the
floor below was found to be about 8.4X larger than the plastic
energy absorption capability of the underlying story, and considerably
higher than that if fracturing were taken into account
(Bažant and Zhou 2002a). This fact, along with the fact that
during the progressive collapse of underlying stories [Figs. 1(d)
and 2] the loss of gravitational potential per story is much greater
than the energy dissipated per story, was sufficient for Bažant and
Zhou (2002a) to conclude, purely on energy grounds, that the
tower was doomed once the top part of the tower dropped through
the height of one story (or even 0.5 m). It was also observed that
this conclusion made any calculations of the dynamics of progressive
collapse after the first single-story drop of upper part superfluous.
The relative smallness of energy absorption capability compared to the kinetic energy also sufficed to explain, without
any further calculations, why the collapse duration could not have
been much longer (say, twice as long or more) than the duration
of a free fall from the tower top.
Therefore, no further analysis has been necessary to prove that
the WTC towers had to fall the way they did, due to gravity alone.
However, a theory describing the progressive collapse dynamics
beyond the initial trigger, with the WTC as a paradigm, could
nevertheless be very useful for other purposes, especially for
learning from demolitions. It could also help to clear up misunderstanding
(and thus to dispel the myth of planted explosives).
Its formulation is the main objective of what follows.
Originally posted by berrygurrl
After the towers fell, was there any remainders of the planes that had crashed?
The reason I ask is because I heard that the planes were holograms.....Just curious.
The falling upper section with a velocity of no more than 8.5 metres per second at impact would meet resistance from the impacted columns and have as its first task the necessity to load these columns through their elastic range and thereafter through the plastic shortening phase. We shall firstly examine this incremental time period.
Bazant/Zhou  show in their analysis that elastic and plastic behaviour of a steel column under a dynamic buckling load can be shown to consist of three distinct phases. These can be shown on a load against vertical deflection graph and consist of an initial elastic phase, a shortening phase and a rapid plastic deformation phase.
1/ The elastic phase shows a linear relationship between load and deflection up to the elastic limit. The load at this point is the failure load and the deflection at the elastic limit for steel is generally 0.2% of the initial length.
2/ The shortening phase allows for the same failure load to be applied until the vertical deformation reaches 3% at which point the column begins to form buckle points.
3/ The third phase shows a rapid decrease in the load requirement to continue deformation, this load necessarily being less than the failure load. This phase lasts until the total vertical deformation equals the original length. In other words the column is bent in two.
To shorten the columns of the first impacted storey by 3%, sufficient to complete the plastic shortening phase, a distance of about 0.111 metres, and allowing a constant speed of 8.5 metres per second, would take a minimum of 0.013 seconds.
The speed of the propagation wave through a medium is given by the general formula for wave propagation
Originally posted by plube
the tops of the buildings DISINTEGRATED before they collpased onto the lower parts of the building...negating the acountability for the mas in their Equations...