Yeah, bi-polar map really doesn't work.

I’ve just realised this is the map which requires the famous ‘Pac man’ effect.

... In fact, every point on the circumference of the *map* represents the very same point as the one diametrically opposite. 4 o’clock=10 o’clock and so on.

It's not every point on the circumference represents it's counterpart on the opposite side.

ALL points on the circumference of this map are the very same point 00°N 180°W, the "anti vernal point".

This is a common problem with all flat map projections I've seen so far, there is at least one singularity [math.] on the chart.

On the unipolar flat earth map it's the south pole: All points on the circumference are the south pole.

On a Mercator projection you even have two singularities, the top and bottom end, the North and the South pole.

BTW. both models presented, the bipolar and unipolar map, are the same Azimuthal projection, only with different center points, the North pole 90°N 000°E and the vernal point 00°N 000°E