On average the Earth is about 7,917 miles in diameter. Mount Everest is about 29,029 feet tall (about 5.5 miles). If you shrank the earth down, maintaining all it’s proportions, so that it was 7.917 inches across, then Mount Everest would be a bump 0.0055 inches high. By comparison, a piece of 20 pound paper is about .0038 inches thick. The deepest part of the ocean would be 0.0067 inches deep. That would be a very smooth ball. If it was even smoother still it shouldn’t take too much water to cover the entire surface, right? About 70 percent of the surface is already under water.