Image of Atomichron Atomic Clock Atomichron Atomic Clock
Atomichron, Cesium-Beam Atomic Clock, Jerrold Zacharias and National Company, 1953–1956

Most people don’t care if their watch is a few seconds or even minutes off. But for scientific experiments involving precise measures of position or time, more accurate timekeeping is necessary. Atomic clocks use the oscillations of atoms in a gas (cesium in this case) as an accurate frequency standard. Physicists at the MIT Radiation Lab (Rad Lab) had discussed the theoretical possibility of creating an atomic clock during World War II. After the war, some of the former Rad Lab scientists now in the newly formed Research Laboratory of Electronics began to experiment with the concept. One attempt was inspired by an undergraduate seminar Jerrold Zacharias taught on the action of gravity on individual atoms, while discussions with Jerome Wiesner suggested the application of new kinds of electronics. In cooperation with the National Company of Malden, MA, a recently reorganized local manufacturer of radio equipment, MIT scientists and engineers developed a self-contained commercial version of the clock to be sold to research and industrial institutions. The Atomichron was the first piece of quantum electronics equipment sold commercially but, more important, its introduction would greatly aid future work on missile guidance, navigation, and control systems.

On loan from the American Clock and Watch Museum, Bristol, CT.

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  • I find it unlikely that this image is correctly described.

    The header states that this clock was built some time between 1953 and 1956. However, the image shows an LED multi-segment display. These did not appear until at least a decade later.

    Clicking on the links at the bottom of the article I am taken to a page that shows a much larger device with no LED display that I suspect is the correct picture.

    Maury Markowirz
    28 Apr 12 at 10:08 pm