In the Prologus of Snorri's Edda where Snorri Sturluson describes the world he says: "The world is in three halves; from south to west and into the Mediterranean sea, that part is called Africa. The southern part of that section is hot so there burns of sun. The second half is from west to north and into the ocean, called Europe or Enea, the northern part of that section is so cold that grass cannot grow there and you cannot live there. From north through the east-half all the way to south is called Asia, in that section of the world everything is beautiful and adorable and the land has fruits, gold and jewels. There is the middle of the world."
When you look quickly at this vision it reminds you a lot of the world according to Norse mythology. It's really not so long ago that the Icelanders were heathen. This "flat earth policy" was probably caused by ignorance and primitive equipments but it is also likley that in fact people didn't want to say completely goodbye to their ideas and previous religion. That is why no new ideas came up about a new world directly after Christianity.
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