Shape of the Earth
The radius of the earth (25,000 miles in circumference) is about 4,000 miles. The highest mountain is about 5 miles high. The deepest ocean trench is about 10 miles deep. This is not much compared to 4,000 miles to the center of the earth.
Except for the mountains and valleys, is the shape of the earth a perfect sphere? And if so, what does it have the spherical shape?