Introducing the World’s Most Precise Clock

An optical-lattice clock could lose just a second every 13.8 billion years

18 min read
Introducing the World’s Most Precise Clock
Illustration: Erik Vrielink

In 1967, time underwent a dramatic shift. That was the year the key increment of time—the second—went from being defined as a tiny fraction of a year to something much more stable and fundamental: the time it takes for radiation absorbed and emitted by a cesium atom to undergo a certain number of cycles.

This change, which was officially adopted in the International System of Units, was driven by a technological leap. From the 1910s until the mid-1950s, the most precise way of keeping time was to synchronize the best quartz clocks to Earth’s motion around the sun. This was done by using telescopes and other instruments to periodically measure the movement of stars across the sky. But in 1955, the accuracy of this method was easily bested by the first cesium atomic clock, which made its debut at the United Kingdom’s National Physical Laboratory, on the outskirts of London.

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Video Friday: Drone in a Cage

Your weekly selection of awesome robot videos

3 min read
A drone inside of a protective geometric cage flies through a dark rain

Video Friday is your weekly selection of awesome robotics videos, collected by your friends at IEEE Spectrum robotics. We also post a weekly calendar of upcoming robotics events for the next few months. Please send us your events for inclusion.

ICRA 2022: 23 May–27 May 2022, PHILADELPHIA
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Remembering 1982 IEEE President Robert Larson

He was a supporter of several IEEE programs including Smart Village

3 min read
A photo of two men in suits.  One behind the other.

Robert Larson [left] with IEEE Life Fellow Eric Herz, who served as IEEE general manager and executive director.

IEEE History Center

Robert E. Larson, 1982 IEEE president, died on 10 March at the age of 83.

An active volunteer who held many high-level positions throughout the organization, Larson was the 1975–1976 president of the IEEE Control Systems Society and also served as IEEE Foundation president.

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Take the Lead on Satellite Design Using Digital Engineering

Learn how to accelerate your satellite design process and reduce risk and costs with model-based engineering methods

1 min read
Keysight
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Win the race to design and deploy satellite technologies and systems. Learn how new digital engineering techniques can accelerate development and reduce your risk and costs. Download this free whitepaper now!

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