Physics - Detecting Quantum Motion in a Gas

http://physics.aps.org/articles/v5/62

The quantum world hums with activity even at absolute zero temperature, thanks to the so-called zero-point motion. But this purely quantum effect is hard to see directly. In Physical Review Letters, a physicist analyzes pictures of a gas cloud a few billionths of a degree above absolute zero to reveal sound waves that result from this quantum motion.

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