Carol Burchaxdt, age 13, of Staten Island, R.Y., for her question:

Is gravity the same all over the earth?

Your weight comes from the pull of gravity at the earth's surface. If your weight at the equator is 95 pounds, a spring balance at the South Pole would record you as weighing only 94 pounds. About a third of this weight loss is caused by centrifugal force from the spinning earth. The rest is caused by a difference in gravity at the surface of the earth.

Gravitation is strongest at the center of the solid globe, and from this point it gets weaker with distance. Our globe is not a perfect sphere, and some parts of the surface are farther from the Center of gravity. The flattened poles are about 13 mils closer to the center than is the bulging equator. At the Poles., surface gravity is a trifle stronger than at the equator, and objects weigh a trifle more.