[Bobby Shafto]

In the attached image, there appears to be a clear, sharp horizon between earth and sky (see red line index drawn on the right hand side of the picture).

Is this the "true horizon?" Or does it just appear to be a horizon and the actual horizon is actually higher or lower? Is it even possible to tell?

I'm not planning on lecturing, as if I know the answer. I do have an answer I think is right, but I'd like to see what others think first.  I'm just going to set this to run for a day, after which I'd like to talk about it.

[Bobby Shafto]

Here is the full image from which that segment was cropped:



The inferior mirage conditions are now apparent with the addition of some identifiable land elevation, whose "mirroring" can be distinguished from the sky.

But does it make identifying where the actual horizon is any easier?

Previously, I marked a black line as the highest proposed horizon line, using some speckling of apparent land surviving through the warm surface air layer that is causing the mirage. But with the rising mountain, you can see where the "fold" of the mirror is, which is higher still than where the black line had been.

So, where IS the horizon, really? If you could see through the mirage, what would you see? More desert rising to that fold line? Or would sky and land meet somewhere in that band between the false horizon and the "fold?"

I honestly can't say I know the answer to that. I've been keeping an eye on the Coronado Islands for a good day to record horizon levels with elevation changes, but for weeks now, when I have what appears to be a good, sharp horizon, I can also see obvious inferior mirage when viewing the island from 100' or lower.



The effect of the inferior mirage on a sea horizon is that it will be perceived as lower than the actual horizon because light rays from the sky penetrate the inversion layer and are refracted upward by the warm air near the surface. So they come to the eye at an upward angle, and you see an inverted band of sky/cloud where (I think) sea would be. You just don't notice it because it blends with the true sky. It takes a ship or a landmark or anything other than blending sky to provide a reference and reveal that it's a mirage.

Since my horizon experiment is trying to detect "dip"  or "no dip" to address curvature/no curvature question, getting a false "dip" due to inferior mirage conditions is concerning. It would present incorrect evidence for curvature when it's actually the mirage creating a false "dip" in the horizon.

I put this out there because I see flat earth and globe earth defenders stating interpretations of infractions and "convergence layers" that are wrong. Or at least I think they are. Obviously, atmospheric conditions can impact observations of horizons and things on the horizon. But how we explain those conditions and phenomena they cause significantly impacts analysis. What I'm seeking is confirmation of what would be seen in that "band" obscuring our observation were it not there? Where in that band IS the horizon we should be hoping to find to determine if it's a surface curving away or the result of flat planes converging to a vanishing line, and whether or not it's at the same level as the eye?