Irrelevant to your point, but the earth is oval shaped
“The difference between the longest and shortest diameters is 44 kilometers (27 miles), and that means that the “oblateness” of the earth (its departure from true sphericity) is 44/12755, or 0.0034. This amounts to l/3 of 1 percent.
To put it another way, on a flat surface, curvature is 0 per mile everywhere. On the earth’s spherical surface, curvature is 0.000126 per mile everywhere (or 8 inches per mile). On the earth’s oblate spheroidal surface, the curvature varies from 7.973 inches to the mile to 8.027 inches to the mile.
...
Even the oblate-spheroidal notion of the earth is wrong, strictly speaking. In 1958, when the satellite Vanguard I was put into orbit about the earth, it was able to measure the local gravitational pull of the earth—and therefore its shape—with unprecedented precision. It turned out that the equatorial bulge south of the equator was slightly bulgier than the bulge north of the equator, and that the South Pole sea level was slightly nearer the center of the earth than the North Pole sea level was.”
Irrelevant to your point, but the earth is oval shaped
“The difference between the longest and shortest diameters is 44 kilometers (27 miles), and that means that the “oblateness” of the earth (its departure from true sphericity) is 44/12755, or 0.0034. This amounts to l/3 of 1 percent.
To put it another way, on a flat surface, curvature is 0 per mile everywhere. On the earth’s spherical surface, curvature is 0.000126 per mile everywhere (or 8 inches per mile). On the earth’s oblate spheroidal surface, the curvature varies from 7.973 inches to the mile to 8.027 inches to the mile.
...
Even the oblate-spheroidal notion of the earth is wrong, strictly speaking. In 1958, when the satellite Vanguard I was put into orbit about the earth, it was able to measure the local gravitational pull of the earth—and therefore its shape—with unprecedented precision. It turned out that the equatorial bulge south of the equator was slightly bulgier than the bulge north of the equator, and that the South Pole sea level was slightly nearer the center of the earth than the North Pole sea level was.”
Isaac Asimov
(ironic that this excellent article should have a secondary use as a reference for the example it discusses!)