MISCONCEPTION: If you shrunk the earth down to the size of a Billiard ball, it would be smooth enough to use as an actual Billiard Ball
TRUTH: The Earth is a fairly round thing, in fact it is near excessively round. Imagine, say, that we shrunk down to the size of a Billiard ball. How smooth is the ball now? Is it smooth enough to play Billiards with?
The World Pool-Billiard Association classifies a billiard ball as having a no bumps or troughs greater than 0.002 the size of the diameter. Now I shall spare you the maths, but I can assure you that even when measuring the highest and lowest points on earth, it would still fall easily within the regulation, you are now residing on a bona fide billiard ball. Except, for the roundness.
You see the earth is not a perfect sphere, because the earth is constantly spinning, there is a greater outward force at the equator than at the poles the earth to be shaped like a slightly fat sphere, a shape known as an oblate spheroid. When measuring the difference in diameter between the two pole and two points along the equator, one sees that the limit is exceeded.
Unfortunate if you plan to play Galactic billiards. So now you know, the earth is smoother thn a billiard ball, it just isn’t round enough.
Most Odd - Facts of Interest 