how did flat-earth believers explain the horizon?

That is, at sea. If you believe the Earth is flat, why is there such a clear demarcation between sea and sky, and why is it always the same distance away?

http://en.wikipedia.org/wiki/Flat_Earth_Society#Physics_of_a_Flat_Earth

Incidentally, you do realize, don’t you, that belief in a flat Earth has been rare ever since the time of the ancient Greeks?:

http://en.wikipedia.org/wiki/Spherical_Earth

I don’t understand the question. The difference in the appearance of sea and sky on an infinite flat-earth and our very large round-earth is barely noticeable. Hull-first disappearance is only visible with tall ships and very clear and calm days, and can easily be missed by casual observation.

But certainly not non-existent
And Cyrus Teed may not have believed in a Flat Earth, but his beliefs still would’ve ruled out a horizon:

http://en.wikipedia.org/wiki/Cyrus_Teed

True, but it was mostly believed by people who weren’t interested in things like rational argument anyway.

http://en.wikipedia.org/wiki/Flat_Earth_Society

Lyndon Johnson liked to tell the story about a young, impoverished teacher, desperate for work during the Great Depression, who was interviewed for a job by a rural Texas school board. The interview went well until one board member drawled, “We have some people around here who believe that the Earth is flat, and some who believe it’s round. What do you think?”

The teacher eagerly said, “I can teach it either way!”

The flat earth society is like discordianism: its a satirical group. There’s no real flat earth thesis since about 500bc or so is when the spherical earth was a given. So youre asking if we have any documentation of someone from before 500bc was engaged into a rational debate about the horizon? Err, I doubt it.

On top of it, the flat earth believed in ancient times was like an island on an infinite sea. Im sure if you asked an 800bc person about this the answer would involve things like turtles holding up the earth or magic wizards and unicorns. Youre not getting a rational answer.

Thanks, this makes sense. 500 bc is quite a lot longer ago than I was taught in elementary school, but it certainly isn’t the first time.

The demarkation line is where the vault of the sky meets the ground. It alwas looks the same distance away because the distance you can travel in a lifetime is very small compared to the distance it is from us, although i am sure it is more noticable to those peoples who live nearer to the edge than we do. The clearly observed fact that we live at or close to the center is a sign of our being favourites of the gods, not like those frog-faced heathens over there…

Most people are taught that Columbus proved the world was round and that the resistance to his voyage was due to belief in a flat Earth.

In fact, the resistance was a dispute over how big the Earth was. Ironically, the authorities of the day not only believed in a round Earth, but they had the right size. They knew Asia was way the hell too far away. Columbus was entirely wrong; he thought the world was much smaller. When he got lucky and found something else, he insisted it was Asia (despite any real evidence for that).

Have you read the posts on the Flat Earth Forum? It doesn’t look satirical to me. There is no position, however absurd or outdated, which will not have true believers somewhere.

>Have you read the posts on the Flat Earth Forum? It doesn’t look satirical to me.

Sounds like you’re bumping up against Poe’s Law:
http://tvtropes.org/pmwiki/pmwiki.php/Main/ptitlehkm94ato?from=Main.PoesLaw

From the Flat Earth FAQ

I’ve been browsing the forum. Some of these guys are definitely for real.

I was taught that Columbus proposed a round earth and met resistance, having difficulty getting his explorations supported for this reason, similar to what dracoi says. It’s funny, though, that paintings from around his time sometimes show mariners holding octants (an earlier form of sextant) that would not have any function if the world were flat.

And, though I kept getting shot down for this before, I still offer the observation that I can’t for the life of me tell the Earth is a sphere by looking at the horizon, boats or not. Things further away on the ocean keep looking smaller, but I can’t see their lower portions disappear, not even in binoculars. What I see is things getting dimmer and hazier and smaller, and various subtle horizontal (meaning orthagonal to vertical) features at different altitudes (meaning angle from said horizontal). It isn’t even obvious what element of the image I see IS the horizon. Even from a jet at 55,000 feet I don’t see a curve - and this is no surprise, as I’m only a quarter percent further from the center of the earth than sea level.

Not that I’m calling anybody here a liar, but I think most people are too easily dismissive of this old misunderstanding. No Greek would have had to measure shadows in a well to figure out that the Earth is a sphere if you could see it!

You can see it next time there is a lunar eclipse. And the ancient Greeks knew how those worked. (Well, except for the whole heliocentricity thing, but that’s largely irrelevant.)

The earth is obviously round, the greeks realized this by looking at the shadow it casts on the moon. Stars rise and fall, so it cant be too flat of a disc. Now is it like a quarter or is it like a baseball? Considering you can see the curvature on a flat plain its most likely like a sphere.

Ancient Indians and Arabs came to the same conclusions. So yes, its pretty trivial for an ancient astronomer to figure this stuff out.

From wikipedia:

Washington Irving’s 1828 biography of Columbus popularized the idea that Columbus had difficulty obtaining support for his plan because Europeans thought the Earth was flat.[8] In fact, the primitive maritime navigation of the time relied on the stars and the curvature of the spherical Earth. The knowledge that the Earth was spherical was widespread, and the means of calculating its diameter using an astrolabe was known to both scholars and navigators.[9] A spherical Earth had been the general opinion of Ancient Greek science, and this view continued through the Middle Ages (for example, Bede mentions it in The Reckoning of Time). In fact Eratosthenes had measured the diameter of the Earth with good precision in the second century BC.[10] Where Columbus did differ from the generally accepted view of his time is his (incorrect) arguments that assumed a significantly smaller diameter for the Earth, claiming that Asia could be easily reached by sailing west across the Atlantic. Most scholars accepted Ptolemy’s correct assessment that the terrestrial landmass (for Europeans of the time, comprising Eurasia and Africa) occupied 180 degrees of the terrestrial sphere, and dismissed Columbus’s claim that the Earth was much smaller, and that Asia was only a few thousand nautical miles to the west of Europe. Columbus’s error was put down to his lack of experience in navigation at sea.[11]

Parmenides realized that the Earth was round when he saw its shadow on the moon during a lunar eclipse.

[Mind you, he did not think it happened really. He did not thing anything ever happened really. And he thought everything, which was the only thing that really existed, was round. Strange man.]

Absolute hogwash. The horizon would be round even on an infinite flat earth.