Hi guys,
glad I found this interesting forum. Living at a large lake in Europe I have known for quite some time that the round earth, earth being a ball claims are nonsense and have been sharing my observations (e.g. seeing storm warning lights positioned approximately 12 meters above sea level at a distance of more than 40 kilometers) with other people standing on the shore. Fortunately there are no earth curvature denial laws in Europe, at least not yet, so that topic can (still) be discussed freely

. Only problem is: most people don't want to know. Imagining that the earth might be flat after all is just too scary for most and, let's face it, most have lost touch with reality long ago anyway...
However, I have to disappoint the flat earth theorists here insofar as they still cling to that (primitive) disc theory. In reality it's simpler and at the same time more beautiful than that, albeit we humans can't visualize it at once: the earth's surface is a total plane. This total plane is flat, uncurved and yet closed within itself, it runs back on itself. All one needs for this to be possible is switch from Euclidian geometry to spherical or polar geometry. The surface of the earth then is a maximal sphere, which is flat...
This theory was first postulated by the Alsatian philosopher and mathematician Ernst Barthel in 1914 with strong (I would say forcing) geometrical and philosophical proofs. And he was never disproved, but simply declared crazy and his memory was made to go down the memory hole. Unfortunately for the Anglo-Saxon world -- the only place AFAIK where there still are flat earthers! -- his works, which were written in German, have, to my knowledge, not been translated into English.
Here is an online copy of the first edition of his work "Polargeometrie" for those who read German:
http://quod.lib.umich.edu/u/umhistmath/ABR1507.0001.001?view=tocHe wrote many more books on this topic, they can be found in a few university libraries, but as said all in German.
Now, I don't want to start a fight about the "correct" flat earth theory here, all I can say is I know most, if not all of them, and after studying the subject for a while I have come to the conclusion that Barthel got it right.
A belated Happy New Year to all!
Lactantius