Tat Wong, age 10, of Toronto, Ont., Can., for his question:

WHY DON'T WE FEEL THE EARTH MOVING?

Our earth, as we know, whizzes around in several different directions at fantastic speeds. It seems strange that we never feel this dizzy dancing. This is because the earth moves at the same steady speed all the time. For example, we feel the motion of a car when it is speeding up and slowing down. But we do not notice it when we travel along the highway at the same steady speed. We do not feel the earth moving because it never speeds up or slows down.