I was reading about Portuguese starts of exploration, and one of the books mentioned that in Europe there were some myths about equator, Cape Bojador, Africa in general and if you could pass around it.
But the Portuguese were consulting all sorts of scientist, navigators, geographers, including Jew and Arab ones. And, basically, I am wondering what would they say about Africa?
An example: I know Herodotus mentions Phoenicians sailing around Africa and having sun in the north, but he himself doesn't believe it. Would the geographers of the time know about this episode (or Herodotus in general)? How would they feel about it at that moment? I am sure (as always) there would be a divide in opinion, but did they have any more information and evidence to deduce it could be possible to go around Africa?
I'll post this, I'm listening to the Yale lectures on early medieval history that covers this.
So these geographers were employed by the caliphs, for example, to figure out the circumference of the world, to figure out the relationship between land and water in the world. This is an interesting form of speculation. If you look at Christian maps of the world up to 1300 or so, they show almost no oceans, all huge amounts of land mass. This is partly, it's thought, an interpretation of something in one of the apocryphal books of the Bible that seems to suggest that seven-eighths of the world is land. Ptolemy, whom we spoke about last time, the Greek geographer, author of this book known as the Almagest or Geography, translated into Arabic as one of the first projects of this House of Wisdom in Baghdad. Ptolemy has a different picture. And Ptolemy is the first geographer received in the medieval period to suggest that there's an awful lot of water. And that you could get around much of the world by water. Although crucially, Ptolemy does not think that you can go around Africa. Ptolemy has a kind of Antarctic land mass that connects with Africa. And it was only the Portuguese at the end of the fifteenth century-- specifically in 1498, well really, 1489-- who demonstrated that you could go around Africa, and thus from the Atlantic Ocean into the Indian Ocean. Crucial, crucial discovery.
Source http://openmedia.yale.edu/projects/iphone/departments/hist/hist210/transcript17.html