Summary

Mathematica 11.0 code

c = 1;
tr[r_, t_] := t - Norm[r]/c;
n[r_, t_] := r/Norm[r];
Ef[r_, t_, \[Phi]_] := 
  E^(I 2 \[Pi] (t + \[Phi]))/Norm[r] E^(-t^2/(2 5^2));
Efr[r_, t_, \[Phi]_] := Ef[r, tr[r, t], \[Phi] ];
s = Sum[Efr[{x + j, y}, \[Tau], (j/11)^3], {j, -25, 25, 0.5}];
p1 = Table[
  DensityPlot[Norm[s]^2, {x, -20, 20}, {y, 0, 100}, 
   PlotPoints -> 100, ColorFunction -> "AvocadoColors", 
   Frame -> False, PlotRange -> {0, 1}, Exclusions -> None]
  , {\[Tau], 0, 100, 2}]
ListAnimate[p1]

Licensing

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This file, which was originally posted to https://twitter.com/j_bertolotti/status/1058773435290214401, was reviewed on 4 November 2018 by reviewer Ronhjones, who confirmed that it was available there under the stated license on that date.