Phillip Gutierrez age 16, of Galveston, Tex., for his question:

CAN YOU EXPLAIN THE MASER?

Maser is an electronic device that generates and amplifies radio and light waves. The word "maser" stands for Microwave Amplification by Stimulated Emission of Radiation.

Masers are used as atomic clocks. They are also used to amplify weak radio signals, such as those from distant stars. Lasers, or optical masers, produce an extremely narrow beam of light. Scientists hope that laser beams may be used to transmit radio and television signals.

The essential part of a maser is a substance that has been put into an excited or high energy state. In this state, the atoms of the substance are able to radiate energy of a particular frequency when stimulated or triggered by a radio or light wave of the same frequency. The energy released by the atoms is added to the stimulating wave, amplifying it.

The first ammonia maser was built in the United States in 1953. Several years later, American and Russian scientists developed the ruby maser. The first continuously operating laser was produced in the United States in 1961.