actually the proof is in the math. Celestial mechanics. The math is not trivial but it is conclusive. Once you've computed such things, there is no doubt. The derivations are based on the assumption the earth is a sphere traveling in an orbit. Observations (telescopic) provide the coefficients used in forecasting future positions and alignments. The results are so precise one can determine the magnitude of perturbations and expand knowledge (science). I've long asserted that flat-earthers are simply failing an IQ test on many fronts. Even if you show them they can't comprehend it.
actually the proof is in the math. Celestial mechanics. The math is not trivial but it is conclusive. Once you've computed such things, there is no doubt. The derivations are based on the assumption the earth is a sphere traveling in an orbit. Observations (telescopic) provide the coefficients used in forecasting future positions and alignments. The results are so precise one can determine the magnitude of perturbations and expand knowledge (science). I've long asserted that flat-earthers are simply failing an IQ test on many fronts. Even if you show them they can't comprehend it.