flat and hollow earth

I am reading the book of Giannini about the continuous universum.
The Author tells us that "terrestrial sky" is only accessible from south and north pole. About south pole the solution seems to become ready  because the pole is not a geographic point but as a very long rim at the edge. But it is quite different with north pole because it is a point and one does not see how the terrestrial sky woud be connected with the earth without creating a kind of barrier cutting the middle of the Arctic Ocean; that is fully impossible.
The expeditions of Nansen, Admundsen, Peary in XIXth century and Wildkin and Byrd in XXth have unanimously related that curiously the ice-see increasely disappeared, the see became free, the temperature warmer, the sun light changed the colour and even an another sun reder was sought.
There was other continents and they met even mamouths. They still told that the observed flat horizon began to show a curvature and the 90° degree point of the pole more and pore impossible to reach.
These explorers have concluded that the ocean whitch appears like a funnel witch lead under the earth and probably communicated with Antarctic.
Woudn't be then a solution of a continuous Earth from north-Pole. The known earth on witch we live is flat but the under-earth and the "sky-earth" as says Giannini, witch begins from Antarctic  would have then a curvature?

It seems to me that the earth cannot be BOTH flat and hollow.   It might be flat with mines and caves below the surface, but this is different from hollow.  Hollow suggests another side (at least one other side) to the earth.  At most a flat earth with a sort of basement that goes down a limited way and then .... well, it was never quite decided what was underneath a flat earth, altho I heard some weird story about giant turtles.

You should take a look to Orlando Ferguson map. My scientific calculations correct a shape near to it is true. According to this model it is possible there is another worlds behind Antarctica.