Cosmic test confirms quantum weirdness
Distant stars as source of randomness constrains loophole in entanglement experiments
COSMIC BELL Scientists used light from stars, including HIP 2876 (shown), to perform a cosmic Bell test, verifying the weird nature of quantum mechanics. The scientists used variations in the color of the light emitted from the star to randomly select measurement settings in the experiment.
Digitized Sky Survey/STScI/NASA, CDS
The spookiness of quantum mechanics has gone cosmic.
Physicists have used starlight to perform a “Bell test” to verify the strange nature of quantum mechanics. For decades, such tests have repeatedly confirmed quantum physics’s quirks, but the tests contained loopholes. While the major loopholes have already been closed (SN: 12/26/15, p. 24), a lingering caveat remained, regarding whether the measurement equipment’s settings were chosen randomly. To tackle that loophole, scientists used the starlight as a source of randomness. Quantum mechanics emerged unscathed, physicists from the United States and Austria reported online November 22 at arXiv.org.
“It’s a very elegant experiment and I think the results are quite beautiful,” says physicist Krister Shalm of the National Institute of
