Originally posted by RFBurns
As I posted earlier in reply to another member (post above), I do know something about Celestrial Mechanics. Though quite complex and formulas take up
far more than what the 10,000 maximum character limit in this reply will allow, there isnt anything in the OP video providing outside influence on
this object's movements.
There isn't anything in the video that we can see as acting on the object, that is true, but that does not mean
that there isn't anything affecting it.
Gravity, for example, is affecting it, although I am not saying that gravity is the force that makes it change direction, and as you know about
Celestial Mechanics you know how complex the gravitical interactions between objects are, and none of those forces are visible on a video.
As we do not even know (at least I don't know) in which direction is the camera pointing, we cannot know if there was an obvious force affecting that
object that could be seen, for example, if the camera zoomed out a little.
That is the key thing here, where is the outside influence to affect the object's initial trajectory and speed, plus the effect to make it
slow down, then the affect to make it almost stop, and then the effect that makes it turn and move away from where it almost stops?
As I tried
to explain, what we are seeing is the projection of the object's trajectory on the plane of the camera, not its real three dimensional trajectory, so
we are limited by our point of view.
A balistic trajectory would have the same look as this object's trajectory if seen almost paralel with the direction in which the object in a
balistic trajectory was thrown, but when seen in a side view we would see a parabolic trajectory.
That was what I meant to say, as we can see in a fast version of the video, the object does not return in exactly the same way it came in.
Maybe this accelerated version (at 500 fps instead of the original 30) can show what I mean about the object's trajectory. It also shows that there
are more objects moving, but they are moving very slowly.

(click to open player in new window)