RE: Starshine impossible behavior!
Allen Thomson (thomsona@flash.net)
Fri, 9 Jul 1999 17:32:19 -0500
Jonathan <lwojack@aol.com> reported
>I was looking at Starshine on 7/5 (I think - I have lost my recording
paper),
>and I tracked it (started around +4.5, then brightened to +3.5 or +3.0).
>When it was at +3, it seemed to completely stop for several minutes, and I
>never saw the point of light move again (!). Most probably, it went into
the
>Earth's shadow. Has anyone seen anything like this?
There probably should be a FAQ on things of this sort. Vision is actually a
quite complicated process, involving mechanical scanning of the eye (called
"saccades") , fairly complex processing in the retina and more obscure and
ill-understood processing upstream from there. The upshot is that there
are all sorts of illusions that can occur, especially when the visual field
is fairly sparse and references are few, as when one is looking at the sky.
I've occasionally seen, for example, satellites appear to jump back and
forth along their trajectory, and EGP hop from side to side across its mean
path.
There's an entertaining discussion of some of this kind of thing in a
different context at http://www.rmhllc.com/wpapers/night3.html.
See also
http://chppm-www.apgea.army.mil/dcpm/vcp/afopnet/ISSUES/UNV_RE~1/tsld025.htm
and, just for a flavor of the complexity,
http://www.brain.uni-freiburg.de/fischer/intro.html