Question
What is the shape of the wavefront on earth for sunlight?
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Answer
The sun is at very large distance from the earth. Assuming sun as spherical, it can be considered as point source situated at infinity. We can treat it like a point object as seen from the surface of earth.
Because of large distance, the radius of wavefront can be considered as Large (infinity) and hence, wavefront is almost plane.
Because of large distance, the radius of wavefront can be considered as Large (infinity) and hence, wavefront is almost plane.
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