Chuck Freeman, age 16, of Oregon City, Ore., for his question:

WHAT EXACTLY IS A SONIC BOOM?

A sonic boom is a loud noise caused by a plane traveling at supersonic speed. The noise is the result of a shock wave produced by the airplane. The shock wave is a pressure disturbance that builds up around the plane flying at a high speed. It results from a change in the air flow pattern around the plane’s leading edges.

A sonic boom sounds like a loud roar of thunder on earth. It cannot hurt people, but it has been known to break windows and even crack plaster.

A plane that reaches the speed of sound is said to be crossing the sonic or sound barrier. The first person to break this barrier was Capt. Charles E. Yeager of the U.S. Air Force who did it on Oct. 4, 1947, in a Bell X 1 rocket plane.