Of course Johannes Lang is a main concave earth beleaver as many nazi scientist (that went to NASA). But, of course, you are right about it doesn't matter much because the main topic is stiil the same: Flat Earth Challenge: Explain different directions of sky rotation. And still no explanation.
But in the concave earth theory the land don't move at all, just the field (eather) , the sun (it takes 24 hours to come the same place again) and the inside celestial sphere (it takes 23 hours, 56 minutes and 4 seconds to complete the circle), but that is another more complex explanation that I will be glad to explain you in detail (with seasons, milky way effect, light bending, eclipses of sun and moon in detail too, the Maurice Alllais effect of Foucault Pedulum, etc...etc...)
But, I am sorry, I just enter here to have an answer: Flat Earth Challenge: Explain different directions of sky rotation....And still no explanation.
After an explanation, maybe I can consider flat earth theory, not before.
In concave earth theory, the explanation is clear as cristal and precise as a swii clock for different observations of star rotations (23hours, 56 minutes and 4 seconds for complete circle any palce) north hemisphere and south hemisphere.
Put yourself aboeve a ball rotating and you see it rotating in one direction. But now put yourself below the same rotating ball (celestial inside earth sphere containing small stars and about 6000 km) and the direction of rotation is obviously observed as going the other side (because you are below the the celestial spere, not above).
As you can understand easily, concave earth (even convex) can explain diferent rotation of stars in our Bubble called earth (the land is older than our Bubble - motionless, not spinning but still expanding...) . And cavitation demonstrate that life can appear in a few years, All elements can appear with transmutation from cavitation too (no need of fusion in enormous stars (satrs are just a particular event of cavitation called sonoluminiscence caused by sound). But As I said, that is more complex, you just have to explain different directions observation of rotating sky above and below equator. Just that. Please. I cannot consider any flat earth theory without that completly missing explanation.