Kenneth Miller, age 12, of Spencer, Neb., for his question:

What causes , gravity in things?

Gravity is a build‑in force, present in all matter, in all liquids, solids and gases. We do not know the howl and the whys of it yeti but it seems to be present in all atoms and atomic particles. When atoms are bulked together, they seem to pool their power of gravitation. A massive body, such as the sun, has more power of gravity than a less massive body, such as the; earth.

However, every stone, every piece of furniture has some degree of gravitational power. Even your body has gravitation ‑ a force which pulls at the earth and the earth pulls back. However, your pull is too small to notice and the earth’s pull is so strong that you cannot escape it and fall off.