John Peck, age 12, of Tucson, AZ,, for his question:

How far away is the center of the earth?

Our round globe bulges a little at the waist   which means that the equator is somewhat farther from the exact center than are the two poles. There is evidence from orbiting satellites that our globe i s also a little bit egg shaped, but so far we have not exact figures on this. Until we do, we can use the global measurements.

If you stand at the equator, the exact center of the globe is about 3,963 1/4 miles under your feet. If you stand at either of the poles, the center of the globe is about 3,950 miles under your feet. These figures may be changed on trial basis of new evidence, but we can be pretty sure that the center of the earth is a little less than 4,000 miles below the surface.