  We perform experiments to investigate the relaxation of a highly deformed
elastic filament at a liquid-air interface. The dynamics for filaments of
differing length, diameter and elastic modulus collapse to a single curve when
the time-dependence is scaled by a time scale $\tau = 8 \pi \mu L_o^4/B$. The
relaxation, however, is completed in a very small fraction of the time $\tau$.
Even though the time scale $\tau$ can be obtained by balancing the linear
bending and viscous forces, it appears to control the highly nonlinear regime
of our experiments. Nonlinear numerical simulations show that the force due to
tension along the filament is comparable to the bending force, producing a net
elastic restoring force that is much smaller than either term. We perform
particle image velocimetry at the liquid-air interface to support the results
of the numerics. Finally, we find that when the filament is initialized in
asymmetric shapes, it rapidly goes to a shape with symmetric stresses. This
symmetrisation process is entirely non-linear; we show that the symmetric
curvature state minimizes energy at arbitrarily large deformation.
