An artifact story
David Ellsworth, former U.S. Secretary of Defense, and us, fooled by an acceleration effect due to a zoom on a video
December 8, 2010
The local channel KCBS showed a short video clip, showing an object rising into the sky, leaving a trail behind. When considering the apparent movement, with a "acceleration", this evokes the launch of a missile. This is what former U.S. Secretary of Defense David Ellsworth had concluded, and we did as well.
On a website dedicated to debunking errors, called "Contrail Science":
there is a file at the address:
http://contrailscience.com/los-angeles-missile-contrail-explained-in-pictures
Before consulting this document, which is simply the result of a complete investigation, I went back to the video that the KCBS channel had shown, which had led David Ellworth (and me) to conclude that the scene we were shown corresponded to a missile launch. My friend Charpentier had come to the same conclusion. We had seen a scene of a few seconds, showing something that looked like a rocket accelerating upwards, climbing into the sky.
What do we see in this short clip? First of all, a zoom. Imagine the scene. A cameraman is in a hovering helicopter, looking for something to film. The sun has just set, and still lights up distant clouds or high altitude ones; cirrus. Above the helicopter, stratocumulus clouds, which are located at low altitude, typically between 600 and 1300 meters above the ground. On that day, these stratocumulus were at an altitude of one thousand meters (see the weather data analysis at the end of the page). The helicopter is flying at low altitude, since the team is looking for a scene taking place on the ground. Let's say it is maybe at 300 meters altitude, under these stratocumulus, which are already in the shadow area. This is what gives the following image, the first of the video:
The following drawing explains why clouds that "seem to be above" are actually very dark.
So this is what our cameraman sees, and which attracts his attention:
Immediately, he will do what any photographer would do in his place. He will zoom in on the object. And this gives this video.
The video broadcast by the KCBS channel
What does the viewer (Ellsworth, me, or you) do? He visually refers to the layer of cirrus visible on these images. The zooming makes the image grow very quickly. Optical illusion: it gives the impression "that an object is accelerating" when in fact it is not. This object is not stationary in the sky, but is moving at a moderate speed, which would be that of any commercial airplane. But the zoom has created this impression of speed, and we all fall for the trick (it must be admitted that there is reason to be deceived).
Optical illusion due to the zoom. The gas plume fills the screen, seems to stretch. The object seems to accelerate, jumps into the sky
End of zoom. The cameraman remains in close-up, full frame on the object.
End of zoom. The angular movement stops, but the cameraman (and the viewer) have the impression that the lens "follows the missile in its flight"
The illusion is perfect. It is likely that the first victim of this effect was the cameraman himself. It is a television team that is more used to filming events from above than missile launches. The team thinks they have a scoop. They repeatedly watch the key image and say "it's a missile", but then we would need the opinion of an expert. Ellsworth is a former U.S. Secretary of Defense. We rush to his house. Seeing these few seconds, he reaches the same conclusions. It should be added, in the midst of this avalanche of coincidences, that in addition the reflection of the sun's rays on the aircraft's fuselage gives the illusion of the glow at the engine exit!
The sequence becomes the scoop of the day. It is picked up, bought at a high price by other channels. Viewership explodes: the Internet goes wild. The military are completely taken by surprise.
A large number of people fall for the trick, and we with them. Michio Kaku, an American scientist, does the same, until he analyzes not the video, but the two (as a second one was made by another channel), frame by frame, and then can see, by comparing them, that the speed of the object is not what it seems to be.
While this rumor grows to the extreme, others have the luck, what Ellsworth and we did not have, to have access to this other video, taken by another television team. Those people operate from a different distance. While the KCBS helicopter was fairly close to the coast, this one observes the scene from a greater distance, and may be flying at a higher altitude, which puts a stratocumulus almost at their level, or at least high enough in the image to obscure the image of the mysterious trail.
**Translation: **The helicopter continues to film for several minutes. The object does not move much (in contrast to what a missile would do)
The helicopter? But it's not the same, it's from another channel! The cloud in the foreground has nothing to do with the one that blocked the trajectory filmed by KCBS. The cameraman, himself, does not zoom in. Thus, the "acceleration effect" that had misled Ellsworth, Michio Kaku, and me is no longer present. In relation to this other reference frame, the object does not move, or very little. So it no longer looks at all like a missile. Missiles could not be pinned on a sky background for so long. If Ellsworth had seen these images, and not the others, he would never have made the conclusions that are known about him. A missile launch does indeed look very much like this kind of image. Some go straight, but others, fired from submarines, wobble before getting on an appropriate trajectory, which curves, as the space shuttle does. To get into "ballistic flight", an intercontinental missile will quickly acquire a horizontal component of speed. If you watch a space shuttle take off, you will see that it also tilts very quickly. In the images shown by the KCBS channel, this was also the case, but it was due to another perspective effect. In short, several effects combined to create the illusion.
A missile launch happens very quickly. An object that would remain fixed in the sky, like that, would be ... anything but an intercontinental missile that had just been fired.
Continuation of this video clip:
Translation: Later, they notice that the object leaves behind a trail, and appears as a dark spot above the old trail, which the winds are dispersing.
The cameraman decides to zoom in and captures an image of a very strange missile, stationary in the sky, with a small plume below.
Translation: They zoom in on this dark spot, and you can see that it somewhat resembles the condensation trail left by an airplane flying...