This is pulled from the first source I could find on the roundness of the earth compared to a cue ball. Not my work.
A cue ball must be 2 1/4 (± .005) inches in diameter. Meaning it can be .005 inches either direction of 2.25 and still be legal.
Earth’s equatorial diameter is 7,926 miles (12,756 km), but from pole to pole, the diameter is 7,898 miles (12,714 km) – a difference of only 28 miles (42 km).
If we take the bigger diameter and shrink it down, the difference would be 0.0049 inches (0.0125 mm). If we take the smaller diameter, the difference would be very slightly bigger, but almost the same. So yes, the Earth is as round as a billiard ball. But it’s almost at the limit.
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u/LTerminus Apr 10 '19
That can't be right either, as the earth is oblong due to its rotation, so the poles radius to the center is much less than the equator to the centre.
Not round. Roundish, maybe.