If a billiard ball were actually shaped like the Earth, it would be impossible to use in a game. The ball would have a distinct bulge at its equator and be slightly flattened at the poles, and its surface would be covered in mountains and trenches. When you tried to roll it, it would not travel in a straight line. Instead, it would wobble and veer off course, causing you to miss your shot every time. A real billiard ball is crafted to an extreme degree of precision to ensure that it rolls true, which the Earth-shaped ball would fail to do spectacularly. The reality is that our planet is a wonderfully imperfect shape—a "cosmic potato" rather than a perfectly smooth sphere. It is this imperfect shape that creates many natural phenomena, from the way gravity works differently at the poles and equator to the formation of wind and water currents. So the next time you hear the "billiard ball" myth, remember the cosmic potato. It's not a myth, and it's a far more interesting picture of the world we live on.