> since the Greeks that people knew the world was not flat
Actually, most Greek knowledge had fundamentally disappeared from Western Europe for centuries, even before the official dissolution of the Western Roman Empire. Some of it had just reappeared in the XV century, largely through translations of Arabic books; this is why the Renaissance produced so much stuff inspired by classic material - because it was all new and exciting to the people of the period, like they'd rediscovered an ancient civilization!
Also by "people" here we are literally talking about the 0.1% - educated people who could read and had access to books, which at the time were very rare and super expensive.
What the vikings did was not common knowledge, because basically they didn't come back regularly and so there was no real knowledge of their actions anywhere in Europe.
The consensus at the time, among the learned (i.e. Catholic Church and a few scientists with royal patronage here and there) was that the Earth was probably round, and probably small enough that you could maybe sail all the way to China and India from the edge of Europe - but they had no idea that there was land in between.
Thomas Aquinas (medieval Catholic philosopher) knew the Earth was round [1]. If your first point was to suggest that the roundness of the Earth disappeared with ancient Greece -- that didn't happen. Nor did the Renaissance rediscover that point, specifically.
> The consensus at the time, among the learned (i.e. Catholic Church and a few scientists with royal patronage here and there) was that the Earth was probably round, and probably small enough that you could maybe sail all the way to China and India from the edge of Europe - but they had no idea that there was land in between.
The first point is not probabilistic. The second, sure. It's only some Americans at this point who doubt the Earth is round.
[1] From Aquinas' Summa; search for "Earth": https://www.newadvent.org/summa/1001.htm (the also section has nothing to do with the Earth; he just drops that casually as an example in his reply to the objection in question.)
IIRC what Columbus didn't know was Eratosthones calculation of the circumference of the Earth that was <1% off, but believed Ptolemy's ~30% short estimation and figured there was no land in between Europe and the East Indies.
> Some of it had just reappeared in the XV century, largely through translations of Arabic books;
I thought it was mainly the Greek refugees fleeing from the Byzantine empire who “kickstarted” the Renaissance?
Of course all the pillaging the by the Venetians etc. as well. A lot of Greek texts that survived the Sack of Constantinople ended up in Western Europe.
Regardless, most “Greek knowledge” that we know of survived in the Greek half of the Roman Empire which remained a part of the “Christian Civilization”. In fact it was the undisputed center of it until the 800s and in many ways much later.
I’m not entirely downplaying the Arab influence which was very significant as well (especially considering that the Orthodox Church wasn’t really that supportive about the preservation of some philosophical texts).
Also it started much earlier than the 15th century, the translation of various Greek and Arab texts into Latin was well underway in the 1100s and 1200s, following the Reconquista which was effectively over by the 1300s, and the conquest Sicily.
Actually, most Greek knowledge had fundamentally disappeared from Western Europe for centuries, even before the official dissolution of the Western Roman Empire. Some of it had just reappeared in the XV century, largely through translations of Arabic books; this is why the Renaissance produced so much stuff inspired by classic material - because it was all new and exciting to the people of the period, like they'd rediscovered an ancient civilization!
Also by "people" here we are literally talking about the 0.1% - educated people who could read and had access to books, which at the time were very rare and super expensive.
What the vikings did was not common knowledge, because basically they didn't come back regularly and so there was no real knowledge of their actions anywhere in Europe.
The consensus at the time, among the learned (i.e. Catholic Church and a few scientists with royal patronage here and there) was that the Earth was probably round, and probably small enough that you could maybe sail all the way to China and India from the edge of Europe - but they had no idea that there was land in between.