The lake mirror is pretty obvious but also, the fact that and body of water will reflect the sun or moon in a direct line to your feet 100% proves there is no curvature.
Any curvature at all will distort the mirror image on the lake. It would also stop the sun or moon reflection from reaching your feet since the water would be angled away from you.
Nonanonanon 0 points 1.6 years ago
Yes, density makes them rise in the fluid of air. Now explain why they fall in the vacuum.