• DOI:10.1086/368707
• Corpus ID: 144033783

Inventing the Maser in Postwar America

@article{Forman1992InventingTM,
  title={Inventing the Maser in Postwar America},
  author={Paul Forman},
  journal={Osiris},
  year={1992},
  volume={7},
  pages={105 - 134}
}

• P. Forman
• Published 1 January 1992
• Physics
• Osiris

"A UNIQUE 'ATOMIC CLOCK' has just been perfected at Columbia Unit1versity" by Charles H. Townes and his coworkers. So read a press release that the Columbia University News Office distributed "to science writers, city editors, and photo editors" on Thursday, 20 January 1955. The release invited the press to meet Townes and photograph his apparatus the following Tuesday, 25 January. All previous types of atomic clocks, it explained, "employ more or less conventional oscillators and apply their output to a group of molecules." Those pursuing such conventional techniques have, "[u]nfortunately . . . not yet been able to produce oscillations ignificantly more accurate than the earth's rate of rotation clock, despite intelligent and persistent efforts." But now this new device, denominated a "maser" from the acronym for the novel principle it employs (microwave amplification by stimulated emission of radiation), "can measure time with greater accuracy than has ever been possible before." Indeed, "for the first ime it exceeds, by a considerable margin, the currently-accepted standard of the earth's rate of rotation."1 Townes and the Columbia News Office, well knowing what was newsworthy, stressed one particular superlative characteristic of the maser. Its very name pointed, however, to another characteristic of the device, namely that it was an amplifier of microwaves-an amplifier possessing exquisite selectivity and sensitivity. It was principally as an extraordinary amplifier and spectrometer that the maser had been announced to the scientific world eight months earlier, and it had so been employed in the interim, while a second such device was being constructed.2 For although one such device could suffice to demonstrate its superla-