WTC7 in Freefall No Longer Controversial

This is a revised analysis of the downward
acceleration of the WTC building 7 which collapsed in a manner suggestive of
controlled demolition on September 11th of 2001. My earlier analysis which is posted
on YouTube under my own name was based on the best information
I had at the time. But now I've been able to improve on my results using new information available in the recently released NIST final report on building 7. Despite the accurate data available to NIST.

Their report makes dishonest claims
about the rate of fall of the building. I'll come back to the NIST report
at the end of this video. In my earlier video analysis
I used the width of the building, which is known to be 100 meters, to calibrate the scale of the image. In this remake I've used
the vertical spacing of the windows visible as horizontal streaks
on the face of the building.

From this I was able
to identify the 29th floor which is listed in the NIST document
as having a height of 683 feet, 6 inches, measuring from some baseline,
which they don't specify. They have the blueprints. I don't. But I take this measurement to be reliable.

The other measurement they give
is the hight of the roofline which they state is 925 feet,
4 inches, above their baseline. The difference of these two heights
converted to meters is the basis for the calibration
of this video. The actual measurements
were done exactly as before. The cursor was placed
on the corner of the building and marks were placed frame by frame.

The built-in functions
of the Physics Toolkit software capture the positions and times
of these marks in a data table from which it computes and displays
various kinds of graphs. I'm here plotting velocity
as a function of time. The slope of this kind of graph
gives the acceleration. Notice that the data hovers
close to zero for nearly a second.

And then it drops precipitously. From the moment of the drop the slope of the line appears essentially constant
for about two-and-a-half seconds. By marking two data points the program
can compute the best straight line to fit the data for the linear portion
of the graph. The slope of the line is the acceleration.

Down here at the bottom
the computed acceleration is shown. Minus 9.885 M/sec. The minus sign indicates downward acceleration. The acceleration of gravity
for New York City is 9.802 M/sec.

So the measured acceleration is within
one percent of the acceleration of gravity. Given the graininess and size of the image one percent is not a significant difference
from the actual acceleration of gravity. So the most accurate way to characterize
the result is to say: The acceleration of the building
is indistinguishable from free-fall. Notice that a little after
the three second mark on our graph, about two-and-a-half seconds
after the building drops, the acceleration ceases to be uniform.

This indicates that the falling building
is starting to encounter more resistance. Any measurement of the average acceleration that continues for more than
the first two-and-a-half seconds of fall will show a lower average acceleration, masking the fact that for a significant
two-and-a-half seconds the building was in literal free-fall. Free-fall can only be achieved
if there is zero resistance to the motion. In other words: The gravitational
potential energy of the building is not available to crush or deform anything.

During free-fall all of the gravitational
potential energy of the building is beeing converted into kinetic energy,
and nothing else. Any breaking, bending, crushing
or pulverizing of the building components is occurring without the assistance
of the free-falling portion of the building. Any force the top part of the building
might exert on the lower portion would be reflected in a reaction force that would produce an observable
slowing of the rate of fall. Reaction forces are observable
in this graph only in the last seconds when the velocity strays
from the straight line.

Let's return to NIST's draft
of the final report on WTC7. I would like to clarify one thing right away. On page 40 there's a phrase. Quote: "Assuming that the descent speed
was approximately constant" [unquote].

The assumption is clearly false
from even casual observation. However, the fact that they proceed
to use a formula for constant acceleration
clearly indicates that the constant speed reference
is a misstatement. They're actually assuming constant acceleration. More bizarre is the claim that quote: "...

The actual time
for the upper 18 stories to collapse based on video evidence,
was approximately 40 percent longer than the computed
free-fall time ..." [Unquote] If you start with a forty percent
increase in the time of fall and work backwards to compute
the effective acceleration, their claim is equivalent to saying "acceleration of the building is only
5 meters per second squared" which is 51 percent
of acceleration of gravity. Our results however clearly show
a significant stretch of time in which the acceleration
of the building is indistinguishable from the acceleration of gravity itself. In other words: complete free-fall. They did not use a method
that sampled position versus time to show the velocity profile as was done here.

The NIST report uses only two data points: The supposed start of the collapse and the time the roofline disappears from view. By choosing an early starting time, several seconds prior to the onset of free-fall and computing only the average acceleration between that point
and the disappearance of the roofline they gloss over everything
that happened in between. I'm sure they detected
some movement of the roofline at the point where they started the clock
as a rational for choosing that point. Even our data here shows a tiny amount
of motion in the first second.

But what was going on during that time was qualitatively different
from what happens moments later. The event triggering the start
of their measurement could more accurately be described
as precursor-movement. This is like timing the acceleration
of a car in a drag race when the starting light goes on
and the driver revs his engine a few times before letting out the clutch. It may be a fair way to penalize a sloppy driver but doesn't say anything about
the acceleration of the car once it is actually moving.

NIST's method tells us nothing about
the nature of the motion itself. They merely assume uniform acceleration over a time interval in which it is clear
that the acceleration is not uniform. Mislabeling their assumption to be constant
speed indicates sloppy work. But asserting uniform acceleration
for an interval for the building sits nearly motionless
for several seconds then drops for several seconds
in free-fall is beyond incompetence.

It is a crude blatant lie. The average acceleration
is a meaningless quantity. It is the instantaneous acceleration
that is significant. Because the acceleration at any moment
is an indication of the forces at work.

To measure and publish
a meaningless average acceleration when sufficient data and a multi-million
dollar budget are available to measure the actual velocity profile
constitutes either gross incompetence or an attempt to obfuscate the issue. This is high school physics we're talking about. If they can't get the high school physics right what confidence can we have in their multi-colored computer-animated
whiz-bang simulations that tell us the exact sequence of girder failures without any physical evidence for any of it? I'm a high school teacher. I teach my students better lab practice
than NIST demonstrates here.

In this video I have measured the velocity profile and the instantaneous acceleration of the building with orders of magnitude
better precision than NIST. And I did it with zero budget,
a free software tool commonly used in high school physics classes, and a copy of a video downloaded
from the internet. I know that the guys at NIST
are not incompetent. What I'm left to conclude is that their only
purpose in even mentioning free-fall is to muddy the water
and derail the discussion.

The rate of fall of the building is
an embarrassment to the official theory. Free-fall is a small detail
in the whole complex analysis. But it is not a minor issue. Buildings can not fall
at free-fall through themselves because even a weakened building
requires energy to break up the pieces, crush the concrete and push things around.

When the falling building pushes things,
the fall is not free: the "things" push back. And the reaction forces will measurably
slow the descent of the building. This is why one would reasonably
expect crumbling structures to come down in a tumbling,
halting, irregular manner. In short: the evidence is clear.

We're witnessing not the collapse
of a building but its demolition. And we've received not a report from an independent scientific investigation but a cover-up by a government agency. [Voice of journalist Dan Rather] It's amazing. Amazing, incredible, pick your word.

For the third time today. It's remeniscent of those pictures we've all seen
too much on television where a building was deliberately destroyed
by well-placed dynamite to knock it down..