Ian Weisman, age 12, of Los Angeles CA for his question:

Radio is related to light, to X‑rays, to heat waves and ultra violet. All are forms of radiant energy. The radio waves are generated by electrical equipment in the broadcasting station, but they are not waves of electricity. Like other forms of radiant energy, radio fans out in straight lines from a central source.

All these forms of radiant energy travel at the same speed, which is about 186,000 miles a second. If radio traveled in a curve, it could whip around the equator seven and a half times in a second.