Why are you asking me that? What curve, why are you asking me where's the curve, as if we were discussing "the curve".
The questions are
Why is there a massive conspiracy for something so inconsequential to everyday people?
Where are the dissenters from this massive conspiracy, so massive that it involves almost every individual directly or indirectly, from pilots to fishermen, from enthusiasts to professionals, where are the wistleblowers, where is the proof of this massive conspiracy?
Where is the science that is being held for us, where is the science that is not a massive conspiracy?
Where are the experiments proving rotation and curvature?