Physicists at King's College London have invented an engine consisting of a single microparticle, smaller than a human cell. The microparticle floats in a vacuum at temperatures reaching 10 million degrees Celsius, hotter than the surface of the sun.
Even more surprising, the engine doesn't operate according to conventional laws of physics—its behavior is determined by randomness. The authors used a device in which the particle is confined by an oscillating electric field. "Noise" voltages were applied to electrodes. These random oscillations caused the particle to move erratically and heat up.
Unlike a steam engine, its behavior is unpredictable. In some experiments, the particle even cooled rather than heated. This contradicts classical thermodynamics but fits in with the new field of stochastic thermodynamics, in which laws apply only to averages, not specific cases.
The micromotor holds promise as a model for studying proteins, the molecules upon which life depends. Proteins act as tiny motors within cells, and malfunctions in their operation can lead to diseases such as Alzheimer's and Parkinson's. A new approach uses the microparticle as an analog computer, simulating the protein-folding process using controlled electrical "noise."
