Untying the Knot: Experimental Topology in Fluid Flows

Untying the Knot: Experimental Topology in Fluid Flows

 

ABSTRACT: The idea that the knottedness of field lines represents a
conserved physical quantity has a long history, having been applied to
fluids, plasmas, and other physical fields.  Testing these ideas in
the laboratory, however, has proven difficult: it requires the ability
to generate and measure dynamically evolving knotted fields.  We have
developed methods for doing precisely this in a fluid, resulting in
the first observation of isolated linked and knotted vortices.
Measuring the subsequent evolution of these vortices leads to
surprising insights about the decay of...

Date

February 17, 2014 - 10:00am

Location

Pettit Bldg, Conference Room 102 A&B

 

ABSTRACT: The idea that the knottedness of field lines represents a
conserved physical quantity has a long history, having been applied to
fluids, plasmas, and other physical fields.  Testing these ideas in
the laboratory, however, has proven difficult: it requires the ability
to generate and measure dynamically evolving knotted fields.  We have
developed methods for doing precisely this in a fluid, resulting in
the first observation of isolated linked and knotted vortices.
Measuring the subsequent evolution of these vortices leads to
surprising insights about the decay of topology in the presence of
dissipation.  A comparison of these results to superfluid models
suggests that the observed behavior may represent a universal
mechanism, with parallels in many fields.