""Can you give me an example where water curves and you can observe it and demonstrate this?"" Sure, but first let's see if we have the same understanding of light. A surface has 3 SAME LENGTH pins INLINE with each other inserted at 90 deg to surface. 1 is midline, other 2 are at 1/2 way from ends to middle. Light from a long distance is shone directly on same plane as center pin. Centre pin has no shadows, other 2 cast long shadows to outer ends. Does this happen if surface is FLAT, curved INWARDS or OUTWARDS ?
