Thursday, 29 November 2007

NIST on road to perpetual motion with 'superfluidity' demo

Perpetual motion is forbidden by the laws of classical physics, but in the quantum realm frictionless motion is possible. For instance, a closed loop of superconducting wire can exhibit perpetual motion, albeit only for electrons traveling around the frictionless loop of wire. If only such frictionless motion could be demonstrated for a fluid, then "superfluidity" could realize the frictionless motion of atoms around a torus, thereby enabling ultra-sensitive rotational sensors to be built.

Now the frictionless motion of superfluidity has been demonstrated at the National Institute of Standards and Technology and the Joint Quantum Institute at the University of Maryland. True perpetual motion is still years away, but the agency recently demonstrated a proof-of-concept--what it called "persistent" motion--using an ultra-cold form of matter called a Bose"Einstein condensate. NIST predicts that eventually it will harness the quantum effects of superfluidity for the frictionless motion of matter, much like the frictionless motion of electrons in superconductors. Such superfluids could enable NIST to build ultra-sensitive navigation sensors not possible using classical materials.

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