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Superaccurate Atomic Clocks Could Be Linked

Scientists in Germany have created a link stable enough to sync next-generation atomic clocks

4 min read
Superaccurate Atomic Clocks Could Be Linked

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Image: Max-Planck-Institute of Quantum Optics
Speed of Light: A laser-generated frequency sent between Max Planck Institute of Quantum Optics (MPQ) and the Physikalisch-Technische Bundesanstalt (PTB) could sync two optical clocks. Click on image to enlarge.

30 April 2012—Scientists have taken a major step toward creating a worldwide network of the most accurate atomic clocks. In results published last week in Science, Katharina Predehl and her team in Germany demonstrated that it’s possible to connect two so-called optical atomic clocks over a distance of 600 kilometers using 920 kilometers of optical fiber.

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How Police Exploited the Capitol Riot’s Digital Records

Forensic technology is powerful, but is it worth the privacy trade-offs?

11 min read
 Illustration of the silhouette of a person with upraised arm holding a cellphone in front of the U.S. Capitol building. Superimposed on the head is a green matrix, which represents data points used for facial recognition
Gabriel Zimmer

The group of well-dressed young men who gathered on the outskirts of Baltimore on the night of 5 January 2021 hardly looked like extremists. But the next day, prosecutors allege, they would all breach the United States Capitol during the deadly insurrection. Several would loot and destroy media equipment, and one would assault a policeman.

No strangers to protest, the men, members of the America First movement, diligently donned masks to obscure their faces. None boasted of their exploits on social media, and none of their friends or family would come forward to denounce them. But on 5 January, they made one piping hot, family-size mistake: They shared a pizza.

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