I Didn’t Know That . . .

Q: If the Earth were a ball three feet in diameter, how big would its mountains be?

A: Not very big. Although the Earth’s surface has mountains and valleys that appear very large to us, on a cosmic scale they are relatively insignificant. The diameter of the Earth is a little over 10,000 kilometers and Mt. Everest is just under 10 kilometers. The difference, then, is about one part in 1,000. If the Earth were a three-foot ball, the highest mountains would be about three-thousandths of a foot, or thirty-six-thousandths of an inch. The deepest oceans are only about 11 kilometers, so the surface would be very smooth. Taken one step further, if the Earth were shrunk to the size of a billiard ball, the Earth’s surface would be smoother than said ball.