Western route to Asia if no Americas

Ok, just so we’re clear, when you said:

…it seems you did so without evidence.

No, as I said, every cite here backs me up, I have said that several times, are you not reading?

Excerpt from the cite quoted by @DrDeth

And that is factually false. Or at least is deliberately misleading rhetoric.

The boat and the waves at the distant horizon are the same physical height (in feet or meters) as if seen up close. And they both shrink in angular height (seen in degrees) as they get more distant.

The snip I excerpted tries some sleight of hand, saying the height of the distant waves in meters is constant while the height of the distant boat in degrees shrinks. Both sub-clauses are true. But it forms an invalid and hence meaningless comparison.

Indeed. I think it would be a mistake to presume that the willful ignorance of modern flat-earthers should be projected onto ancient peoples. It says nothing about how common people prior to the modern era viewed the world.

@DrDeth, what we are essentially dealing with is three propositions, A, B, and C, of which you have positively asserted that A is true:

A - Common people of Columbus’ era believed the Earth was flat (actually, what you’ve said is much broader: that “primitive” cultures–whatever that means"–view the world as flat, and you’ve asserted that without qualification)
B - Educated people of Columbus’ era (and going back several centuries) believed the Earth was round
C - modern flat Earthers have rejected all evidence, including evidence that even a common person of Columbus’ era could have observed on their own (for example, ships putting out to or returning from sea, and the land as viewed from it and vice versa), that the Earth is round, by concluding that it is flat in spite of the evidence

You have yet to provide evidence for proposition A. Evidence of B, which others have provided, is not evidence of A. Nor is evidence of C.

Evidence of B is evidence that at least some people of Columbus’ era knew the Earth was round. Evidence of C is evidence that at least some people of our own era (and presumably going back centuries) are willing to adopt fringe views that run contrary to all evidence.

Where is your evidence of A?

I meant the observation of the curve directly, across your field of view, when you look out at an open expanse of ocean. I know flat earthers today claim that’s an optical illusion, but that’s because they already decided the earth is flat and are working backwards.

As Chronos said above, I expect most peasants never thought about the shape of the earth. Those who did probably did so because of information filtered through from educated people. Who we established did know the earth was spherical. So those peasants who were exposed to the concept were probably exposed to the idea of a spherical world.

And yet the Norse colonized Greenland in North America five hundred years before Columbus ever thought about sailing west. With considerably less capable sea craft (though perhaps more applicable seafaring expertise).

Cherry-picked, probably, and perhaps a little wishful thinking. But none of it was unreasonable given the knowledge of the time. Columbus used one of the lowest estimates for the circumference of the planet, yes, but it was within the range accepted by experts of the time, as I recall. The main issue was that Europeans didn’t know how big Asia was.

The Toscanelli map Columbus probably used for planning is linked. It shows Japan (Cipangu) overlapping the west coast of Mexico. If he assumed there were more unknown islands to the east of Japan, then he would have expected to hit land in the Carribbean where he did. He just assumed they were off the coast of Asia, not a brand new pair of continents.

Just looking at the shape of Asia, Africa, and Europe it shows more or less fanciful all of geography was. You can also see how much better the charting was for long-explored well-traveled areas versus the sparsely visited “ends of the earth” from a European POV. Setting off towards the edge of that map was an exercise is looking mostly at guesswork. That took some seriously brass 'nads (or blind stubborn stupidity) in an era where brass 'nads were commonplace.

Also turns out CC was damned lucky there was something out there to bump into.

If by happenstance that map had been accurate he and his expedition would have disappeared without a trace in the great trackless vastness of Oceanus Occidentalis

Actually, no one has. I, along with several other posters, have asked you to provide cites for your assertion. If were it true, it would be easy enough for you to do. I’ll just assume at this point you have none and are just posting fallacies of distraction.

I will say that the traditional / illiterate peasant / etc. probably did have a cosmology which included earth, a heaven above that, and a hell below that. This is a layered system which makes spheres difficult. The thing is, just like today (where that system is still in place), it’s mythology, not geography, and there’s no reason to think your Average Uneducated Person™ was mistaking their mythological understanding of the universe for a literal one. That requires fundamentalism and a literal reading of mythology, which is also a 19th-century invention.

I’m willing to go with the idea that people, if they thought about it at all, might have come up with “flat,” but I’m unwilling to accept the assertation that any not-elite person of the past ever positively asserted a flat earth. We have plenty of records of superstitions and beliefs, mostly as decried by that same elite, and I don’t know of a single instance of “flat earth” being discussed.

I kind of agree with everything you say. What bothers me is that the textbook version (with exaggerated diagrams) would tend to give the impression that this effect, and the inference that the earth is curved, is immediately obvious to anyone who stands on the shore and looks out to sea. It is not at all, at least at these latitudes where the effect is usually either hidden by weather and sea conditions or counteracted by other optical effects. I don’t think it’s an exaggeration to say that it is more frequent to observe distant ships “flying” above the horizon than to observe a noticeable “sinking” below the horizon.

Just to be clear, do you mean that when you look out across an open ocean, you see the horizon curving around you to your left and right, as if to form a circle? This is indistinguishable from what the horizon would look like if the earth were flat, and does not evidence a curved earth.

Or do you mean that the horizon appears high in the centre of your field of view and curves downward to the left and right? There is no such visual effect - as far as we can tell by looking, the horizon is completely flat. The curvature of the earth is far too small to be visible at this scale.

Even if most peasants were uneducated, most of them would have known, at least superficially, someone who was educated (likely the local priest). And I expect that anyone who seriously pondered the question of the shape of the Earth any further than “Don’t worry about the shape and get back to tilling it, you lazy bum” would have asked that educated person. So you’d get basically two groups, not three: One small group who knew that it was spherical (the educated and anyone curious enough to ask them), and one much larger group who neither knew nor cared what shape it was. What there wasn’t, was a group who actively believed it was flat.

The Church didnt admit that the Earth went around the sun until 1822, 200 years after Galileo . Some part of the bible can be read as supporting a Flat earth. Now, do you still think a local parish priest would be holding classes on the earth is round?

Hold on a second… isn’t it your position that the fact we have evidence that educated elites believed the world was round, is also evidence that the uneducated masses at the same time believed it was flat?

By that logic, shouldn’t evidence that the educated elite believed the Sun revolved around the Earth, be evidence that the uneducated masses believed the Earth revolved around the Sun?

The educated elite believed no such thing.

So… the educated elite have always known and understood that the Earth revolved around the sun? They never believed in a geocentric model of the solar system?

Then what was Copernicus’ contribution to astronomy?

The Church admitted that the Earth went around the Sun before Galileo. Remember, Copernicus was a priest. Though I have no idea how that’s relevant, anyway. And there are also parts of the Bible that can be read as supporting a spherical Earth, and biblical literalism as a concept is only a couple hundred years old anyway.

Single priests do not speak for the Church as a whole. Besides, he was only one of many priests of that era. Virtually all the rest would likely have agreed with the standard Ptolemaic model where the Sun goes around the Earth.

I read his question wrong, sorry.