Atto Boy!

The world's most precise scale and stopwatch measure the world at the atto level.

By Alex Stone|Sunday, June 27, 2004

Scientists have built the world’s most sensitive scale and the fastest stopwatch. Both devices measure the world at the atto level—one part in a million trillion—allowing new ways to sniff out hazards and study chemical reactions.

Physicist Harold Craighead, along with graduate student Rob Ilic and colleagues at Cornell University, fashioned a scale from a vibrating silicon rod  just 1/50,000 of an inch wide. Tiny gold samples chemically bonded to the rod changed its vibrating frequency. “The rod was like a diving board going up and down,” says Craighead. “We bounced a laser beam off the rod and watched it move as the angle of reflection changed.” The result: He and Ilic can weigh masses as light as six attograms. The technique could be used to identify potentially dangerous viruses simply by detecting their mass.

Meanwhile, scientists at the Max Planck Institute for Quantum Optics and the Vienna University of Technology have created a strobe so fast it can illuminate rapidly moving atoms. Physicist Ferenc Krausz, who led the project, plans to go further: “We believe that we should get down to 100 attoseconds by the end of the year.”

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