October-November 2006

from QuestionsQuestions Website

The following shows a diagram of a 767-200 overlaid on the Evan Fairbanks footage (below video) in After Effects, a video compositing program.

By overlaying the 767 graphic over the plane the motion can be matched and any differences in speed of the actual plane will be reflected in the speed of the graphic overlay.

After Effects shows the speed, in pixels per second, of a composited image in numeric and graphical form (highlighted in yellow).

Stefen Grossmann cites an MIT professor's analysis which claims that the plane would have lost about 25% of its kinetic energy in the collision with the building.

The kinetic energy of a moving object varies as the square of its speed. If an object doubles in speed, its kinetic energy quadruples. The inverse is also true: if an object loses half its speed, its kinetic energy is quartered.

Therefore, a loss of 25% of kinetic energy translates into only about a 13% loss of speed, assuming that the loss of kinetic energy is purely from reduction of speed and not also through the deformation of the plane's material.

As can be readily observed in the diagrams below, the plane DOES decelerate when it hits the building: a small amount when the nose hits and a larger decrease when the wings and engine hit the wall. While the plane is in the clear the speed of the matched graphic overlay averages about 612 pixels per second.

By the point of the last possible measurement, when the tail is just outside the building, the speed has decreased to about 502 pixels per second. That means that the plane in the Fairbanks footage lost about 18% of its speed, which is even greater than what Grossman claimed should be visible.

This analysis clearly disproves the no-planer's claim that no deceleration was visible, which in turn supported their claim that the images showed a computer-generated plane.

Update
3 November 2006

The following is a rebuttal to Rick Rajter's deceleration analysis in Appendix A of the article by Reynolds and Ratjer "Exploding the Airliner Crash Myth" in which Rajter claims to have found fatal flaws in my deceleration analysis and no deceleration in his own analysis of the Scott Myers footage.

Rajter did discover one genuine mistake in my analysis:

the diagram is not overlayed correctly over the final frame, being placed a little bit behind the plane in the video.

But Rajter's treatment of this mistake seems to be deliberately misleading.

Here's what he says:

outside the building "excess" tail wing shows to the left of the outline, but inside the building, this excess disappears. Therefore, Salter artificially slows down his plane trace yet the plane blur goes off ahead and Voila! Deceleration falsely established.

First of all, what he doesn't say that in the next to last frame, which is not misaligned, the plane has already experienced a deceleration of 8.5%!

(Note that because of the key-frame interpolation method used here in After Effects, the program I used to make this analysis, the speed value displayed is that of the next key-frame forward, so you have to read the speed value from one frame back).

Instead, he skips over this inconvenient fact and just shows the last misplaced frame, in order to try to throw into question the entire analysis. I'm really surprised he tried to get away with this obfuscation. Or maybe I'm not surprised.

Here are the last 3 frames of the sequence with a better alignment of the last frame:

As you can see, the deceleration is less, but still measures about 10%.

Hardly the falsified deceleration that Ratjer claims and still close to the figure of a 13% reduction in speed derived from the MIT figure of a 25% reduction of kinetic energy by the impact on the outer wall.

In addition, Rajter misunderstands the method used for aligning the diagram:

There is a major flaw in Salter's analysis.

He used an overlay or "trace" to match the blurry 767 image to judge its speed. The problem is that it is hard to match a wide-line trace or outline of a plane against a blurry plane image with real consistency. Salter is inconsistent in choosing an anchor point to locate his trace against the video plane image.

When the image is outside the building, Salter anchors the trace at the main wings. After the plane is mostly inside the building, Salter switches and anchors the trace at the back of the tail wing.

I never state that I used the wings when the plane is outside the building. This is an unsupported assumption made by Ratjer. In fact, the entire visible profile of the plane was used to align the diagram.

This probably should have been mentioned originally, but I thought it was obvious. Far from being a major flaw, this method compensates for a slightly blurred image by using every single point possible, and finding the best fit overall. And it is perfectly clear looking at my timeline that there is a very regular alignment of the plane over the entire sequence except for the last frame.

It is quite easy to confirm that there is deceleration in the Fairbanks footage that exceeds any possible error in the method I used.

The following graphic shows that for the speed to remain constant, the diagram must be moved ahead of the image of the plane:

Ratjer's complaint that the wall of the WTC is moving in the Fairbanks footage is true:

there is a slight camera motion, but it is a constant movement, at least in the horizontal axis. Only an uneven movement would have introduced an error in the measurement.

The same deceleration measurement is achieved with a stabilized version of the Fairbanks footage.

Rajter's analysis of the Myers footage uses a sequence of still frames that were aligned by hand using a difference filter. This method has the potential to introduce a degree of error in the positioning, especially because the image of the plane is fairly low resolution, which makes it difficult get a perfect match with a difference filter. This is the reason I passed over this footage for analysis in the first place. If the full-resolution Myers video becomes available then analysis of the footage would be more trustworthy.

Even if Rajter's analysis is accurate, is it a significant finding? No.

Here's why: there is an interesting logical contradiction in the no-planer complaints about the lack of deceleration. Rajter says that the Fairbanks footage is suspicious because it was in the FBI's hands; a typical unsubstantiated no-planer allegation. Does he want us to assume that the Myers' footage that he uses is not suspicious? After all it shows a 767, so by his standards it too must be faked.

So why then does he think it's reliable?

Those behind 9/11 could have done whatever they wanted with faked videos, including leaving out deceleration - or any other phenomenon - in order to encourage the no-plane psy-op. This leads to the inevitable conclusion that any faked footage would have no evidentiary value whatsoever in demonstrating the absence of a 767 on 9/11.

Alleged anomalies would only be potential evidence for faked video. The only legitimate visual evidence for no-planes would be an actual no-plane video or photo showing something other than a 767. Of course, no such thing exists.

Lastly, the kinetic energy loss through deceleration shown in any visual analysis should be considered only a part of the total kinetic energy loss. In the Sandia laboratory tests, the F4 plows into the concrete wall without significant deceleration. Forward motion continued until the last bit of the tail hits the wall. If you measure conversion of kinetic energy solely by the motion of the fuselage, you would have to conclude that only a fraction of the F4's kinetic energy was converted in the collision, which is obviously false.

Therefore it's a mistake to measure all kinetic energy conversion by deceleration alone.

The same consideration should be made with the 767 impact, which leads to the possibility that more kinetic energy conversion happened then what can be measured by deceleration. So even if my measurements of the Fairbanks footage are incorrect and the deceleration was a smaller or even negligible figure, this would not by itself indicate an anomaly in the impact physics.

The same could be said for any analysis that shows a small amount of deceleration, such as Rajter's. Thus, his claim that the plane retained at least 96% of its KE after penetrating the outer wall is not reliable at all and almost certainly overstated.

Not only does Rajter's flawed and deceptive critique of my analysis fall short of demonstrating error, there is nothing in the arguments he or the other no-planers are making about deceleration, or lack thereof, which qualifies as anything more than possible evidence for faked videos, something which those who believe in 767 impacts are perfectly happy to live with.

After all, only one of the dozens of 767 images needs to be authentic to utterly destroy the no-plane theory forever.