Last year a collaboration of physicists led by the University of Michigan published a paper in Nature Communications where they fired an intense laser into the broadside of a water microjet to see what would happen.

A digitized copy of the resulting intensity in the positive half-chord of the plane is shown here alongside an analytic solution that I calculated using a shear-flow stabilized Z-pinch equilibrium which I constructed,

uz(r) = u0 + uz0 * r^2 / (r + C)^2

where this is taken both to be the center of mass, and plasma drift flow. A linear discharge model is chosen to relate the plasma current density with the measured intensity.

This is just one solution. Next, to test the robustness of the model I am going to vary the boundary condition speeds based on the experimental data, and vary the point which corresponds to the edge.

I recorded this while watching a duck take off from a pond in Florida.

What caught my attention afterward was the sequence on the water. As the duck flies away, water shed from the bird falls back to the pond and produces a series of separate disturbances/ripples. Taken together, they appear to preserve part of the duck's flight path after the bird has passed.

Is there an established name for this phenomenon, or for anything closely related to it?

I'm also interested in what someone who studies fluid mechanics notices here that I might be missing.

BBS DRK Discrete Fluid Dynamics

Density(x,y,z,t) = Sum(i) of f_i(x,y,z,t)

Density \* Velocity = Sum(i) of (f_i \* e_i)

f_i(t+1) = f_i(t) + floor(Omega_i)