The confirmation of the Higgs boson and what it can tell us about the origins of mass is getting all of the attention but there are scientific mysteries about less-understood forces that may also be keys to figuring out natural laws.

Among these is quantum turbulence, the chaotic motion - at very high rates - of fluids that exist at temperatures close to zero. Observers as far back as Leonardo da Vinci have studied turbulence, a complex state of fluid motion. He observed that water falling into a pond creates eddies of motion, thus realizing that the motion of water shaped the landscape.

Today, scientists study much bigger ponds, the universe and beyond, but remain focused on this phenomenon's basic principles. This is because of its fundamental significance in daily occurrences -  the efficiency of jet engines depends on turbulence, for example, and turbulence impacts the generation of galactic magnetic fields.

A special issue of Proceedings of the National Academy of Sciences focuses on this quantum turbulence, which appears in quantum fluids. These fluids differ from ordinary fluids in fundamental ways beyond their vitality at near-zero temperatures. They can flow freely because they have no viscosity - resistance hindering flow - and their rotation is limited to vortex lines, in stark contrast to eddies in ordinary fluids, which vary in size, shape, and strength.  

"Our aim is to link together the articles of this special issue and to provide a perspective of the future development of a subject that contains aspects of fluid mechanics, atomic physics, condensed matter, and low-temperature physics," the authors write. "Further experimental studies of quantum turbulence, probing physical conditions not known to Nature at temperatures many orders of magnitude lower, may uncover phenomena not yet known to physics."

Citation: Carlo F. Barenghi, Ladislav Skrbek, and Katepalli R. Sreenivasan, 'Introduction to quantum turbulence', PNAS 2014 111:4647-4652; doi:10.1073/pnas.1400033111. Source: New York University