4,896 research outputs found
Generic transient memory formation in disordered systems with noise
Out-of-equilibrium disordered systems may form memories of external driving
in a remarkable fashion. The system "remembers" multiple values from a series
of training inputs yet "forgets" nearly all of them at long times despite the
inputs being continually repeated. Here, learning and forgetting are
inseparable aspects of a single process. The memory loss may be prevented by
the addition of noise. We identify a class of systems with this behavior,
giving as an example a model of non-brownian suspensions under cyclic shear.Comment: 4 pages, 3 figure
Ultrafast Interference Imaging of Air in Splashing Dynamics
A drop impacting a solid surface with sufficient velocity will emit many
small droplets creating a splash. However, splashing is completely suppressed
if the surrounding gas pressure is lowered. The mechanism by which the gas
affects splashing remains unknown. We use high-speed interference imaging to
measure the air beneath all regions of a spreading viscous drop as well as
optical absorption to measure the drop thickness. Although an initial air
bubble is created on impact, no significant air layer persists until the time a
splash is created. This suggests that splashing in our experimentally
accessible range of viscosities is initiated at the edge of the drop as it
encroaches into the surrounding gas
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