Jamie Stringam, age 10, of Magrath, Alta., Can., for his question:

WHERE DOES GRAVITY COME FROM?

Gravity is a built in part of all the material in the universe. It comes in gases, liquids and in solid material—and nothing can take it away. Every speck of dust has a tiny amount of gravity. A pebble has a larger amount and a big boulder has still more. Massive objects with a lot of matter have even more built in gravity. The gravity in a speck of dust is too weak to notice. But the gravity built into our massive earth is strong  enough to hold us all on the surface of the globe.