What would a billiard ball's surface looks like if it was big as Earth?
The surface of the Earth is not as smooth as a billiard ball. [1][3]  The highest point on Earth is the top of Mount Everest, which is 8.85 km high.  [1] The deepest point on Earth is the Mariana Trench, which is 11 km deep. [1]  By comparison, the Earth's diameter is about 12,735 kilometers. [1]  Therefore, if the Earth was shrunk down to the size of a billiard ball, the height of Mount Everest would be only 0.04 millimeters. [1]  The depth of the Mariana Trench would be only 0.05 millimeters. [1]
As the Earth is not smooth, it is unlikely that it would be smooth if it were the size of a billiard ball [1, 2, 3, 4]. The highest point on Earth is Mount Everest, which is 8.85 km high, and the Mariana Trench is the deepest point at 11 km [1]. These two points represent small bumps on the Earth compared to its 12,735 km diameter [1]. If the Earth was the size of a billiard ball, these bumps would be only about 0.04 mm or 0.001 inches tall, well under the allowable tolerance of 0.127 mm or 0.005 inches [2, 3]. The Earth would also not be round since it is flattened at the poles. This means that if the Earth were the size of a billiard ball, it would not be smooth due to the variation in diameter. 