Using the boat model/perspective/telescope, wouldn't the Sun be the same? After it's gone below the horizon due to perspective, couldn't we be able to see it again using a telescope? Apologies if this has been asked already, I couldn't find it using search..
Edit: just found someone asking the same question but no good answers...
Samuel Birley Rowbotham EXAMINATION OF THE SO-CALLED "PROOFS" OF THE EARTH'S ROTUNDITY.--
WHY A SHIP'S HULL DISAPPEARS BEFORE THE MAST-HEAD.
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Before explaining the influence of perspective in causing-the hull of a ship to disappear first when outward bound, it is necessary to remove an error in its application, which artists and teachers have generally committed, and which if persisted in will not only prevent their giving, as it has hitherto done, absolutely correct representations of natural things, but also deprive them of the power to understand the cause of the lower part of any receding object disappearing to the eye before any higher portion--even though the surface on which it moves is admittedly and provably horizontal.
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"The range of the eye, or diameter of the field of vision, is
110°; consequently this is the largest angle under which an object can be seen. The range of vision is from 110° to 1°. . . . The smallest angle under which an object can be seen is upon an average, for different sights, the sixtieth part of a degree, or one minute in space; so that when an object is removed from the eye 3000 times its own diameter, it will only just be distinguishable; consequently the greatest distance at which we can behold an object like a shilling of an inch in diameter, is 3000 inches or 250 feet."
The above may be called the law of perspective. It may be given in more formal language, as the following:. when any object or any part thereof is so far removed that its greatest diameter subtends at the eye of the observer, an angle of one minute or less of a degree, it is no longer visible.
From: Samuel Birley Rowbotham, Earth is Not a Globe, CHAPTER XIV.
This is
reasonably correct and it would lead to the
vanishing point of the sun at about
3000 x 50 = 150,000 km.
So the sun, especially so extremely bright, should be easily visible even when the sun is at its furthest distance of about 32,000 km.
JRoa will undoubtedly claim the imperfect clarity of the
atmoplane, but that doesn't hold water.
PS Rowbotham later "modifies" this when it doesn't fit observations and somehow limits vanising points further than the visible horizon.