The proof is so simple any half wit can run the experiment:

All you need is a camera with a sun filter.

1) Take a picture of the sun every hour from sunrise to sunset using the sun filter

2) compare the relative size of the sun on every picture.

You will notice to your amazement that the sun's relative size does not change throughout the day

Consequences:

The relative distance between your camera and the sun throughout the day is always the same.

This means:

->The sun does not move relative to the earth.
->The sun is very far away from the earth
->the earth cannot be a flat pancake
->Only possible shape the earth can be is a rotating globe.