Nancy Kierulf, age 15, of Los Angeles, Calif., for her question:

Is it true that radio travels as fast as light?

Light and radio are different forms of electromagnetic energy. These and other forms of electromagnetic energy have many features in common. All of them travel in straight lines in pulsing wave lengths, and all of them zoom through space at the same astounding speed. Radio beams and light rays whizz along at about 186,000 miles a second. If they could travel in circles, this speed could take them ripping around the Earth's Equator about seven times in a single second. So far as we know, nothing in the universe can travel faster than light. But several things can equal its astounding speed. Some of the subatomic particles that populate the plasma of space are thought to travel at the same speed as light, radio and other forms of electromagnetic energy.