A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Tony Oz
Date: 2018 Apr 14, 15:34 -0700
Today I noticed something new/strange about the refraction.
The day on the Finnish Gulf was sunny and warm, the wind - if at all - was very calm. I was watching fishermen on the ice with a 6x monocular. If I'm not mistaken - it was a negative refraction today. The lighthouse that is normally visible on the horizon - was not there, the distant fort had very small vertical size - much smaller that usually. I was sitting at HoE (height of the eye) of 5 meters and could see the horizon line rather distinctively.
The effect that puzzled me was visible apparently much closer that the horizon - and it was happening much lower than the horizon. I could see the fishermen walking away from the shore and coming back, and when they were crossing certain distance - their figures become VERY distorted. For example a man walking away - when reaching that certain distance would gradually seem taller, then his "head" stopped coming up and - as he went on - his "feet" start looking shorter. With the distance increasing - the figure of a man became a dot. After some more distance - and some distorted figure transformations - the proper figure of a man could be seen again - beyond that "critical" range. Returning fishermen underwent the similar transformations in reverse order.
It all looked like a cylindrical lense was hanging in the air - but not at the horizon where I expected all the mirages and refraction effects to happen. I could see some objects above that lense - undistorted despite they were further away than the lense. The objects infront of the lense were obviously undistorted - as expected. Only those objects were affected that were near/in the lense.
Was this a usual "mirage" - and I was surprised just because all my previous observations of the negative refraction effects were made from lower HoE - placing that lense on the horizon?
Can you see a horizon - the real horizon - above the mirage?