Frankie Watson, age 9, of Winston Salem, North Carolina, for his question:

How far do radio waves go in a second?

A radio signal from the moon takes about one and a quarter seconds to reach the earth. The distance is 240,000 miles and the time it takes is ,just about long enough to make one blink. Radio waves must travel in straight lines all the way. But if they could go in circles, they could whizz around the earth seven and a half times in one second. However, they always travel in straight lines and always at the same speed. While the clock is ticking off one second, a beam of radio waves goes 186,000 miles. In one minute it goes more than 11 million miles. The sun is 93 million miles away and it is always sending out radio waves. They reach the earth in 8 1/2 minutes.

Radio waves are related to light waves (both being electromagnetic energy) and they both travel at the same speed. The sun's radio waves and light waves travel at 186,000 miles a second and both reach us in 8 1/2 minutes. The radio waves from a broadcasting station to your radio set also go 186,000 miles every second. So they reach you in a fraction of a second