[Laser] reply to Tom regarding low paths over the sea

[Tom Becker]

> ... The red patch seemed to be about 0.3 degrees above the horizon...

Well, I'm now puzzled.  After a little searching for telescopic sunset and 
sunrise images all I have are more questions about ducting; like I need another 
project!

So far, I've found images of mirrored inferior images, like these: 
http://mintaka.sdsu.edu/GF/explain/simulations/inf-mir/Kaplan_photos.html .  As 
the sun drops, the last visible portion is that of the inferior image, which is 
said to be a grazing thermocline reflection (I think, on a first few reads) and 
the last, American football-shaped bit is viewed from above the horizon, not 
below it, as my impression of ducting should produce.  Under Other Phenomena in 
that link, horizon dip due to refraction is discussed, but still nothing 
specifically about what is under the apparent optical horizon but above the 
water surface.  Much more to learn...


Tom