Way back in post
#297, Gordy posted a couple of images in which he claimed the loop emerging from under or over a net produced lift or drop, depending on the orientation of the loop. The images were screen captures derived from
this video.
I asked him to trace markers
on the line because the initial starting conditions of the line in each cast were definitely different and his images were produced in a way that represented them to be the same. He has even labeled both of them to show the initial loop traced path of -5 degrees.
I objected because the white traces of the initial loop were duplicated in each cast, implying the
only reason the emerging loops had different trajectories was due to different loop orientations. In fact, the white trace in these two images was derived from one cast only. He did not show the initial loop trace of the other cast.
Gordy chose not to correct the error.
These are Gordy's images:
Now that I have some software to trace markers, I can produce the images that Gordy would not produce and correct this obvious error. This first image shows the path of a marker on the fly leg for the loop emerging (reforming) over the net (the upright loop.)
The next image shows the trace of a marker on the line where the loop emerged under the net (the inverted loop)
Note that for each cast, the path of a marker on the fly leg does not significantly alter at any time, even though the initial loop had been destroyed and a new loop had formed. Normal or inverted loop, crash or no crash, the path of a marker on the fly leg is not significantly altered by the loop's existence or orientation.*
The loop is producing neither lift nor drop in the fly leg's trajectory. The fly leg maintains a steady state of motion unless a force acts on it, as per Newton's First Law of Motion.
Cheers,
Graeme
* If anybody would like to check my results, I'll send them the tracker files. You'll need to install
the software, but it's free and pretty easy to use.
)