Daydreaming Townes.

In spring 1951 Charles H. Townes was in Washington, D.C., to attend a conference at the Office of Naval Research. He was trying to develop ways to produce extremely high frequency radio waves. The applicable technology of the day was vacuum tubes, and there was simply no way to make them so that they could produce waves high enough in frequency to satisfy Townes. While sitting on a park bench Townes realized how he could produce the radio waves he wanted using atoms and molecules instead of vacuum tubes.

Quantum Theory.

Townes's concept used Einstein's theory of "stimulated emission of radiation." Einstein suggested that forcing radiation (light or microwave, for example) past a group of atoms stimulates them to release energy. This energy will travel in the direction of the stimulating source and be of the same frequency as the source. Einstein...