Rockets at the World Trade Center

When I did the video "South Tower Smoking Guns" I called attention to
the downward moving projectile that raced ahead of the rest of
the falling debris while trailing white smoke. I loosely referred to it as a "rocket projectile"
because of its appearance but I was not really certain
that the material emitting the smoke was providing enough thrust
to literally act like a rocket. I assumed that the fast downward
projectile was kicked downward by an initial explosion
which gave it its high speed. Once it was in motion gravity
would continue to pull downward and air resistance would
provide an upward force.

So the acceleration should be
actually less than gravity alone. In fact at its higher speed
the air resistance would be greater so I would expect its acceleration
to be even less than surrounding slower moving objects. This projectile came up
in a discussion with Niels Harrit at the Toronto Hearings. Niels believes we're seeing
nanothermite in action, literally acting as a rocket propellant.

I figured that it was the cause
of the smoke and fragmentation that we see in other projectiles. But I was not convinced that
the unconfined expanding gasses on an open surface by itself
would produce significant thrust. So I decided to take another look. I went back to a clean copy of the video released to the Center of International
9/11 Studies through a FOIA request.

I registered the frames to compensate
for the camera motion and brightened the images. When I tracked the projectile I noticed there was an outburst
of white smoke part way down. I was surprised to find that
the visible outburst coincided with a slight change in direction and a very noticeable change in
the downward acceleration. Prior to the outburst the downward acceleration was about a third of gravity as I expected.

Since this object was already significantly
ahead of its neighbours this is evidence of an initial
explosive kick launching it downward. In the half second following
the outburst however the downward acceleration
rose sharply to 15 m/sec, or about 1.5 G. Thereafter the acceleration continued
but fell back to a little less than G. The outburst gave the object a major kick
and then continued to provide enough thrust to largely compensate for air resistance.

It is clear that we're looking
at a very energetic material on the object. Niels is right: We are looking at a literal "rocket projectile". The object by the way appears
from other photographs to be a perimeter wall unit, 30 feet long, 10 feet wide and weighing about 4 tons. To accelerate something that massive
required a major kick indeed.

From here on out I'm taking the quotes off
the phrase "rocket projectile"..